https://orcid.org/0000-0002-9029-8925
Figures
Abstract
Antihypertensive medications are known to reduce the incidence of hypertension complications. While the benefits of these medications are recognized, the factors influencing the prescribing practices of primary care physicians in Qatar have not been assessed. This study investigated Qatar primary care physicians’ experiences, practices, and perceptions regarding hypertension management. The study further evaluated the factors that influence their prescribing behaviors and identified strategies for improving hypertension management in primary healthcare settings. A qualitative case study was conducted through one-to-one semi-structured interviews with physicians practicing at the 31 Primary Health Care Corporation (PHCC) centers in Qatar. Due to the small population size, there was no need for sample size calculation and whole population sampling was used (N=179). Physician leads at each PHCC center helped identify eligible participants. Study information were shared via email and interested candidates were contacted to arrange for interviews at their convenience. The interview guide questions were designed based on the 14 domains of the Theoretical Domains Framework (TDF) of behavior change. Interviews were conducted virtually and transcribed verbatim. Thematic analysis was undertaken using inductive and deductive approaches. Twelve themes emerged, including physicians’ knowledge, skills, goals and role in hypertension management, confidence about prescribing decisions, optimism that prescriptions yield positive results, methods to ensure the appropriateness of prescriptions, emotions, and experiences when prescribing antihypertensives, perceived barriers, and facilitators when prescribing and social influences. Strategies for improving hypertension management were also suggested. In conclusion, multiple factors were identified that affect participants’ antihypertensive prescribing. Further research is needed to evaluate the suggested strategies’ effectiveness and to explore other improvements.
Citation: Abdelkader N, Awaisu A, Elewa H, Al Abdulla SA, El Hajj MS (2025) Primary care physicians’ perceptions of hypertension management in Qatar: A qualitative study using the theoretical domains framework. PLoS ONE 20(4): e0318527. https://doi.org/10.1371/journal.pone.0318527
Editor: Ganesh Sritheran Paneerselvam, Taylor's University - Lakeside Campus: Taylor's University, MALAYSIA
Received: September 11, 2024; Accepted: January 16, 2025; Published: April 24, 2025
Copyright: © 2025 Abdelkader et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: Data sets available upon request. Only the research team, Qatar University IRB (reachable on IRB@qu.edu.qa or at 009744403 5307) and Qatar Ministry of Public Health (MoPH) can access the data (if needed). If you have any request regarding data access please contact QU IRB
Funding: The author(s) received no specific funding for this work.
Competing interests: NO authors have competing interests
Background
Around 1.28 billion persons worldwide were diagnosed with hypertension in 2023 according to the World Health Organization (WHO) [1]. Based on a 2015 survey, a global report on non-communicable diseases (NCDs) indicated that on average one in four men and one in five women experienced high blood pressure [2]. If not detected early and managed effectively, hypertension is one of the leading preventable causes for morbidity and death [3, 4].
A number of national and international clinical practice guidelines were developed to offer guidance for the treatment of hypertension [5–8]. The National Institute for Health and Care Excellence Hypertension in Adults Guideline (NICE), the American College of Cardiology/American Heart Association (ACC/AHA), the European Society of Cardiology/European Society of Hypertension Guideline (ESC/ESH), and the Eighth Joint National Committee Guideline (JNC8) are a few examples [5–8]. In addition to guidelines’ recommendations, several factors may affect physicians’ prescribing practices for hypertension management. These include their previous experiences, knowledge, and skills, patients’ socioeconomic status, medication adherence, medication profile and tolerability, as well as medication advertising, pricing, cost-effectiveness, and availability. In addition, the social and cultural context of the healthcare system and organizational factors play vital roles [9, 10].
A review of studies conducted in the State of Qatar and published between 1982 and 2019 found that 32% of people had hypertension [11]. According to estimates, 57% of deaths in Qatar in 2019 were attributed to cardiovascular diseases and high systolic blood pressure [12]. Qatar’s Ministry of Public Health (MOPH) has aligned its national strategy with the global target set by the WHO which is to reduce uncontrolled high blood pressure by 25% by 2025 [13]. In Qatar, the majority of hypertension patients are treated in government clinics run by the Primary Healthcare Corporation (PHCC) [14]. The JNC8 and NICE guidelines’ recommendations serve as the foundation for the PHCC’s hypertension management guidelines [14, 15]. However, there is a general lack of information regarding the practices and perspectives of primary care physicians in Qatar concerning hypertension management and the factors influencing their choice of antihypertensive medications. Therefore, the study aimed to: [1] investigate Qatar primary care physicians’ experiences, practices, and perceptions related to hypertension management, [2] evaluate the factors influencing their prescribing behaviors in this regard, and [3] potentially identify/propose strategies to improve hypertension management in primary care settings.
Methods
This study was reported as per the Consolidated Criteria for Reporting Qualitative Research (COREQ) [16].
Study setting
The study was conducted at primary health centers operated by PHCC in Qatar. This encompasses 31 centers throughout Qatar, covering the Central, Western, Southern and Northern regions [17]. The primary health centers in Qatar are responsible for managing the majority of outpatients suffering from such as hypertension in the country.
Study design
A qualitative case study was conducted using one-to-one semi-structured virtual interviews to explore physicians’ experiences, practices, and perceptions. Semi-structured interviews were chosen over focus groups (FGs) due to the varying schedules and availability of physicians at the health centers. The qualitative case study is the most common and deemed the most suitable method when exploring behavioral phenomena and perceptions [18]. The interview guide and the data analysis were designed based on a well-established theoretical framework, the Theoretical Domains Framework (TDF) [19].
Study population and participants’ recruitment
All primary care physicians from the 31 PHCC centers who were involved in hypertension management were eligible to participate. Physicians not engaged in managing hypertensive patients were excluded. There were 179 eligible physicians at the time of the study. Due to the small population size, there was no need for sample size calculation and whole population sampling was used. Physician leads at each PHCC center were approached to help identify eligible participants for the study. Emails including information about the study and its objectives were sent to potential participants. Interested candidates were subsequently contacted via email or phone to arrange for interviews at their convenience.
A day before the scheduled interviews, physicians were contacted again to confirm their attendance. Data collection continued until data saturation was achieved [20].
Interview guide
The interview guide was structured based on the TDF, which was developed through consensus and validation by an expert panel to integrate multiple behavior change theories [19]. The TDF comprises 14 domains with 84 determinants grounded in psychological theory and has been widely utilized in healthcare to understand behaviors for designing complex interventions [21–24]. Moreover, the framework is derived from 33 psychological theories and 128 theoretical constructs developed into 14 overarching domains of behavioral determinants [25], offering a robust theoretical basis for implementation studies [21]. Therefore, the TDF was deemed a suitable framework to assess the physicians’ behavior and explore their perspectives on prescribing antihypertensives and managing hypertension. The behavior of interest for the current study was the prescribing practices of antihypertensive medications in PHCC centers in Qatar. Each question in the interview guide was carefully designed to be in line with each of the 14 TFD domains.
Validation of the interview guide
The interview guide was reviewed by a panel of experts consisting of two faculty members from the College of Pharmacy, Qatar University, with experience in qualitative research. The main purpose of this validation process was to ensure that the questions were appropriate and comprehensive. Subsequently, the interview guide was revised based on their feedback and suggestions.
Data collection
The semi-structured interviews were conducted between December 2021 to May 2022. Given that English is one of the primary languages of communication in Qatar, the interviews were conducted in English. Using the validated interview guide, one researcher (NA), who is a female Master of Pharmacy candidate and trained by the study's principal investigator in interview facilitation (MH), moderated all sessions of the interviews. MH took notes during the interviews.
The research team included MH: female faculty member and project leader, PharmD degree holder with experience in pharmacy practice research, AA and HE: male faculty members, and PhD degree holders. The researchers did not have any established relationships with the participants and had extensive experience in qualitative research.
Microsoft Teams™ software was utilized for virtual interviews, which were recorded and subsequently transcribed for analysis. The interview link was emailed to the participants who consented to participate at least three days prior to the interview. Before the interview, informed consent forms were sent to participants, who signed and scanned the forms and returned them to the research team. Data collection continued until saturation was achieved.
Transcribing of interviews
The interviews were audio-recorded and transcribed using Microsoft Teams™ software. The transcribed documents were carefully reviewed and compared with the original audio recordings and field notes to ensure accuracy by the lead principal investigator (MH) and the study researcher (NA). Then they were shared with participants for review.
Qualitative data analysis
Thematic analysis was conducted using both deductive and inductive methods manually Initially, a deductive approach was employed using the TDF, with its 14 domains to identify relevant themes [19]. Additionally, the transcripts underwent inductive analysis using the following six steps: familiarizing with the data; creating preliminary codes; looking for related themes; reviewing themes; defining themes; and writing the results [26]. The lead principal investigator (MH) and study researcher (NA) independently analyzed the data manually. Through an iterative process, the research team reviewed the findings, discussed and compared codes and themes, challenged individual assumptions, and refined the analyses as needed, until consensus was reached.
Quality measures
To ensure the trustworthiness of the research findings, four pillars of quality measures were used: credibility, transferability, dependability, and confirmability [27]. Lincoln and Guba define dependability as the stability of findings over time. While confirmability refers to the extent to which other researchers are able to confirm the study results and that the results are not based on the researcher’s bias rather than actual data [27]. Dependability and confirmability were addressed by having an audit trail, and a detailed description of the study methodology, and by building a database that contains all the records obtained as part of the project [28]. Credibility is defined as trust and confidence in the research findings, and it assesses whether participants’ contributions are correctly interpreted by the researchers [27]. To ensure credibility, interviews were both audio recorded and transcribed using Microsoft Teams™ and transcripts were double checked for accuracy by the research team.
Transferability is defined as the external validity and generalizability of study findings and the extent to which the results can be transferred to other settings and participants [27]. The transferability was ensured through providing detailed description of the study settings and participants’ characteristics and by inviting potential candidates from all 31 PHCC centers for participation [28]. Reflexivity is the researcher’s ability to criticize himself or herself and reflect on his or her own possible biases, preferences, or preconceptions or relationships with the participants and how this may affect the participants’ answers and responses [27]. Reflexivity was attained by researchers disclosing their previous relationships where applicable [28].
Results
Thirteen virtual semi-structured one-to-one interviews were conducted between December 2021 and May 2022 (Table 1). Out of 179 eligible participants contacted, 26 participants expressed interest in participating, and eventually, 13 physicians participated in the interviews. Each interview lasted between 45 and 60 minutes. Data saturation was achieved by the 13th interview, indicating no new information emerged thereafter. Twelve themes emerged from the data analysis. The identified themes and subthemes were shared with the study participants interested in the findings. These are illustrated in Fig 1 and summarized below. Relevant quotes are provided in Table 2 to provide context to the results with examples of quotes provided in text.
TDF domain: Knowledge and skills
Theme 1: Physicians’ knowledge and skills in hypertension management
Subtheme 1a: Training and clinical practice as sources of information
Several respondents considered their residency training and clinical experience as primary sources of knowledge.
“My clinical practice and experience are the major resources for my knowledge” P8
Subtheme 1b: Online resources other than guidelines as sources of information
Others, however, cited using literature searches or online resources other than guidelines such as search engines like Google © or others as sources of information.
“Through online resources accessible through Google© we get the latest updates on hypertension management.” P11
Subtheme 1c: Clinical practice guidelines as sources of information
Many respondents identified clinical practice guidelines as their primary information source for hypertension management, with the majority stating reliance on one or more guidelines. These included national guidelines like the PHCC guidelines, as well as international guidelines such as NICE guidelines, JNC 8, and American Heart Association (AHA) guidelines, among others. Furthermore, several interviewees emphasized the importance of staying current with guidelines and regularly checking for updates. Some physicians also reported receiving reminders about updates to the guidelines from the PHCC administration, which they found beneficial for staying informed.
“We have PHCC guidelines for the management of hypertension. Also, sometimes I’m using it.” P8
Subtheme 1d: Perceived needed skills
Nearly all physicians agreed that communication skills are essential when prescribing antihypertensives and managing patients with hypertension. It was also noted by some physicians that proper history-taking skills, the ability to convince the patient to attend follow-up appointments, effective time management skills, and self-confidence were all important skills in building patient trust.
“It is your time management and communication skills which make the difference. You need to possess the necessary skills to ensure that your patients return for follow-up appointments, thus establishing a safety net in the event you initiate therapy, allowing you to monitor their response effectively.” P5
Subtheme 1e: Feedback and assessments on prescribing antihypertensives and managing hypertension
The participants provided varied responses regarding the feedback they received about their prescribing practices. Some physicians stated they had not received any specific feedback or assessments concerning their antihypertensives prescribing. On the other hand, others mentioned receiving general feedback that was not specifically focused on their antihypertensives prescribing. A few physicians noted that that their health centers’ administration conducts quality checks specifically on their antihypertensives prescribing practices.
“We don’t get individual feedback on our antihypertensive prescriptions. No, it’s an overall appraisal. We get annual appraisals on how we treat patients in general. We don’t get individual clinical appraisals.” P3
TDF domain: Professional role and identity
Theme 2: Physician’s role in hypertension management
Subtheme 2a: The influence of doctors’ social and professional roles on antihypertensives prescribing
Many participants stated that their prescribing decisions for antihypertensive medications are not influenced by their social or professional roles. They emphasized that their clinical roles take precedence over any social considerations.
“Alright, well I don’t think it affects a lot. I just use my own experience and whatever is the prescribing protocol, but I don’t think it affects me. I do my job” P13
Subtheme 2b: The significance of family physicians’ roles
Several physicians highlighted the crucial importance of the family physician’s role in diagnosing and managing hypertension Furthermore, many physicians emphasized that they believe family physicians play several crucial roles in the treatment of hypertensive patients, including educating patients, providing counseling, and offering advice.
“So, for us primary care physicians, we are the basic block in identifying hypertensive patients, diagnosing them, and initiating treatment.” P3
Subtheme 2c: Patient engagement in hypertension management
Several respondents noted that patients tend to adhere more to their treatment plans when they are actively engaged in their own treatment plans. They stressed the importance for physicians to collaborate with patients in reaching agreements on their pharmacotherapy regimen.
“However, we must always come to an agreement, otherwise the patient will not take any prescribed medication. In order to provide the best care for the patient, we have to find out what’s best for him/her. Afterward, we’ll come to an agreement between us after I explain it to him or her.” P4
TDF domain: Beliefs about capabilities
Theme 3: Physicians’ confidence about prescribing decisions
Subtheme 3a: Level of physicians’ confidence in prescribing decisions
When physicians were asked about their confidence in prescribing antihypertensive medications, the majority answered that they were highly confident in their prescribing decisions.
“I think I’m confident 100%, I practice it and I read about it.” P11
Subtheme 3b: Factors affecting physicians’ confidence in prescribing decisions
Many physicians stated that various factors influence their confidence in prescribing decisions such as knowledge, experience, adherence to guidelines, and patient follow-up. Other physicians mentioned additional factors such as educating patients about medication side effects, listening to their concerns, and reviewing their medical profiles.
“Experience of 15 years is a long time, so I think that’s probably the main source of confidence.” P4
Subtheme 3c: Physicians’ actions when uncertain about antihypertensives prescribing
The majority of the participants indicated that when they encounter uncertainties in prescribing antihypertensives, they typically look for information in medical resources or seek advice from a senior colleague. Other participants mentioned strategies such as scheduling more frequent follow-ups with the patient, consulting available pharmacists, and prescribing standard antihypertensive agents while ensuring the patient has no contraindications.
“The clinical pharmacists we have in the health center can sometimes guide us and support us with medication-related information” P8
Subtheme 3d: Ease of managing hypertension in a primary care setting
The majority of respondents considered hypertension management as straightforward, especially handling simple uncomplicated cases within a primary care setting. However, some participants emphasized that patients with complicated hypertension may require referral to specialists and cannot be effectively managed solely in a primary care setting. Moreover, when physicians were asked about what makes hypertension management easy, some cited experience and familiarity with guidelines as the main factors for making hypertension management easy.
“OK, it is much harder to manage patients who have multiple comorbidities and are taking medications for these comorbidities than somebody who has only been hypertensive. It’s straightforward for patients with simple hypertension” P3
TDF domain: Optimism
Theme 4: Physicians’ optimism that their antihypertensive prescriptions yield positive results
All of the participating physicians expressed optimism that their prescribing of antihypertensive medications would yield positive outcomes such as improved blood pressure control, and the prevention of complications like stroke and myocardial infarction.
“I am confident that my prescribing of antihypertensives will yield positive outcomes eight out of 10.” P10
TDF domain: Beliefs about consequences
Theme 5: Factors influencing the prescribing behavior of physicians
Subtheme 5a: Patient-related factors
Many respondents highlighted that patients’ medical and medication history including comorbidities and chronic medications, as well as age, and ethnicity, are the main factors that significantly influence their decisions when prescribing antihypertensive medications. Some physicians also mentioned patients’ gender, the stage of hypertension, lifestyle factors, medication adherence, and financial status as additional factors affecting their prescribing behavior.
“Prescribing of antihypertensives depends on the patient’s age.” P12
Subtheme 5b: Medication-related factors
Respondents generally agreed that the potential benefits and risks of medications influence their prescribing decisions when treating hypertension.
“OK, I can change my decision depending upon the medication side effects” P9
Subtheme 5c: Organization-related factors
Participants stated that the availability of medications in the drug formulary at PHCC also plays a role in their decisions regarding prescribing antihypertensive medications.
“Another factor that impacts my decision is the availability of the medicine in our formulary at the clinic” P7
Subtheme 5d: Clinical practice guidelines and evidence-based medicine-related factors
The interviewees indicated that their prescribing decisions are primarily based on clinical practice guidelines and evidence-based medicine. However, a few respondents noted that while medications may be strongly supported by evidence and recommended by guidelines, they may not always be optimal for every patient.
“I follow NICE guidelines, that are evidence-based.” P5
Subtheme 5e: Potential risk to physician-patient relationships
Most physicians believed that their prescribing decisions do not harm their relationships with patients, especially when they provide explanations about the benefits and possible side effects of the medications and offer follow-up care.
“It is my responsibility to make a decision based on the patient’s signs and if it is the right choice, not based on my relationship with that patient.” P5
Subtheme 5f: Relationship with professional colleagues or managers
According to most participants, their professional relationships with colleagues or managers have affected how they select antihypertensive medications or make prescribing decisions. Yet, some participants suggested that medical representatives could influence physicians’ prescribing behaviors, potentially affecting their relationships with colleagues who oppose such practices.
“Not much, I don’t think anyone from my managers or colleagues interfere with my prescribing.” P8
TDF domain: Goals
Theme 6: Physicians’ goals in managing hypertension
Most interviewees emphasized that their main goals in managing hypertension include achieving BP targets and reducing and preventing hypertension-related complications. While others declared their goals include ensuring medication compliance with minimal side effects and prescribing the lowest effective medication dose. Moreover, a few physicians highlighted patient engagement as an important goal in hypertension management, as patients need to understand well their condition.
“Achieving blood pressure control is my goal.” P1
TDF domain: Behavioral regulation
Theme 7: Approaches physicians use to ensure appropriate prescribing of antihypertensives
When participants were asked about how they ensure the appropriateness of their antihypertensive medications prescribing, the majority indicated that regular follow-ups with patients are key. They also noted that improving patients’ outcomes, along with achieving target blood pressure levels are indicators of optimal use of antihypertensives.
“In order to ensure that my antihypertensive choice was appropriate I follow-up with the patient and monitor his or her blood pressure.” P8
TDF domain: Emotions
Theme 8: Physicians’ emotions and experiences when prescribing antihypertensives
Subtheme 8a: Physicians’ positive emotions and experiences when prescribing antihypertensives
For some physicians, prescribing antihypertensives to patients was a positive experience, especially when the patient’s BP was controlled. In addition, a few physicians felt positive when patients returned for their follow-up appointments.
“Positive, always positive. So, whenever a doctor prescribes a medication to help his or her patient this is considered a positive experience and I will always feel positive about it.” P2
Subtheme 8b: Physicians’ negative emotions and experiences when prescribing antihypertensives
Most interviewed physicians considered prescribing medications that proved ineffective or caused side effects for their patients as a negative experience. As an example, some physicians found prescribing ACEIs to be a negative encounter when patients developed coughs as a side effect. Conversely, others considered it an unfavorable experience when the patient did not adhere to their prescribed medications. Additionally, some physicians reported feeling stressed and concerned when their patients’ blood pressure is not controlled.
“There are times when I am stressed when I see the blood pressure log is not controlled or when hypertensive patients come in with high blood pressure. Medications’ side effects also can make it a negative experience when prescribing antihypertensives” P3
TDF domain: Environmental context and resources
Theme 9: Physicians perceived barriers when prescribing antihypertensive medications and managing hypertension
Subtheme 9a: Organization-related barriers
Several organizational barriers were perceived by interviewees, such as medication shortages, limited medications in the PHCC formulary, and inappropriate BP measurement conditions. Additionally, some physicians perceived that there was insufficient patient-physician interaction outside of clinic settings, that patients did not always return for follow-up appointments with the same physician, and that there was a lack of communication between primary and secondary care in the country. Moreover, some physicians reported occasional technical errors in the Cerner© electronic medical record system and delays in referring patients to secondary care.
“OK, the first barrier, and this is very common when you do not have the medication in the pharmacy of the health center” P10
Subtheme 9b: Patient-related barriers
Physicians interviewed identified several patient-related barriers to prescribing antihypertensive medications. These barriers included concerns about medication costs and side effects, language barriers, as well as issues related to patients’ noncompliance.
“Language is another probably important barrier because sometimes patients don’t understand what you’re talking about.” P4
Subtheme 9c: Physician-related barriers
Interviewees noted that they had limited time for consultations with patients, and therefore referred patients to NCD (Non-Communicable Diseases) clinics to overcome this limitation. Moreover, some physicians indicated a lack of time to attend continuing education webinars.
“Time is very limited in our consultations this can be a barrier. But we try to figure that out.” P11
Theme 10: Physicians perceived facilitators when prescribing antihypertensive medications and managing hypertension
Subtheme 10a: Organization-related facilitators
Most interviewed physicians viewed available resources as facilitators, including online drug information resources, and PHCC educational webinars. A number of physicians also pointed out that Cerner’s® medical record system played a critical role in ensuring safe medication prescribing practices.
“The availability of the most important medications is a facilitator.” P11
Subtheme 10b: Pharmacist-related facilitators
Most physicians acknowledged that pharmacists’ availability is a major facilitator for antihypertensive prescribing and hypertension management at PHCCs.
“There’s a safety net when communicating with the pharmacist.” P5
TDF domain: Social influences
Theme 11: Social impact on physicians’ prescribing behaviors
Subtheme 11a: Social influences on physicians’ prescribing behaviors
In general, respondents reported that they do not let patients, caregivers, or families influence their decisions when prescribing antihypertensives. They emphasized that they would not prescribe medications that are not clinically indicated or could potentially harm their patients. For them, patient safety comes first when managing hypertension. However, several physicians admitted feeling pressured sometimes to prescribe specific antihypertensive medications when patients are resistant to their advice and are difficult to convince. According to these physicians, this problem stems partly from the prescribing practices of certain private sector physicians in Qatar or from patients obtaining these medications from abroad.
“There is no pressure from patients or families.” P2
Subtheme 11b: Physicians’ perceptions of their colleagues’ antihypertensive prescribing behavior
Overall, the interviewed physicians believed that their colleagues prescribe antihypertensive medications similarly due to shared training background and adherence to guidelines. Moreover, PHCC fosters an open discussion culture where physicians discuss patients’ cases with their colleagues.
“Generally, we practice along the same lines because we are all trained in the same way.” P5
Strategies (not related to TDF)
Theme 12: Physicians proposed strategies to improve hypertension management and prescribing of antihypertensive medications in PHCC in Qatar
Subtheme 12a: Education-focused strategies
The interviewed physicians proposed several approaches to improve the prescribing of antihypertensive medications and the management of hypertension within the PHCC setting in Qatar. The suggestions included educating nurses and physicians, organizing conferences and workshops, reminding physicians to regularly consult guidelines when prescribing, and precepting students to stay updated. Moreover, the physicians suggested allocating protected time for updating their knowledge and reviewing guidelines and literature.
“More education, more training will help a lot.” P2
Subtheme 12b: Other strategies
The interviewees further proposed other strategies to improve the management of hypertension and prescribing of antihypertensive medications in primary care settings. These include improving home BP monitoring, optimizing the use and functions of Cerner®, adding more medications to the formulary, re-establishing the NCD clinics, emphasizing the role of primary care physicians to reduce secondary care burden, increasing consultation times, and standardizing antihypertensives prescribing practices among physicians. Other proposed strategies included establishing support groups for patients with hypertension to improve adherence and educating patients on proper etiquette when entering physicians’ rooms.
“If they brought back noncommunicable disease (NCD) clinics it would be more beneficial for patients. Believe me back when noncommunicable disease (NCD) clinics were available our patients’ BP and blood sugar were more controlled. The percentage of controlled patients was about more than 60% or 65%, however, now after they closed these clinics the percentage became less than 50% you know why because now most patients come, and find the physicians very busy” P1
Discussion
This study investigated the perceptions and experiences of primary care physicians in Qatar regarding hypertension management. It also explored their prescribing behavior as well as their perceived factors for the effective management of hypertension in primary care settings. These participants identified several resources that contributed to their hypertension-related knowledge such as experience, and clinical practice guidelines. These resources also function as a source of information for managing various diseases besides hypertension. A 2018 review of 33 studies revealed that clinical practice guidelines serve as a significant source of knowledge for physicians and influence their medication prescribing decisions [29]. Furthermore, a systematic review of 19 studies found that pocket-based antibiotic guidelines were judged to be the most helpful source of information for prescribing antibiotics [30].
The study results showed that the physicians’ self-confidence in managing hypertension was generally high. These results are in line with a 2023 study that evaluated the practices, attitudes, and expertise of primary care physicians in Qatar. According to this study, primary care physicians in Qatar were highly confident in their ability to treat hypertension, with the majority adhering to both local and international clinical practice guidelines [31]. Furthermore, a strong association was observed between physicians’ confidence level and the frequency of treating hypertensive patients; physicians who managed hypertensive patients daily exhibited greater confidence compared to those who treated patients less frequently, highlighting the impact of experience in nurturing self-confidence in hypertension management [31]. The high self-esteem observed among interviewed primary care physicians in Qatar is reassuring as it can improve their therapeutic decision making and strengthen patient trust ultimately leading to better clinical and humanistic outcomes for patients with hypertension [32]. Moreover, physicians’ self-confidence can enhance their ability to manage stress and to elevate their mood which is essential given the relatively high percentage of burnout among healthcare professionals in Qatar [33, 34].The interviewees also emphasized their role as family physicians which extends beyond prescribing medications. It includes educating and advising patients to ensure their engagement in hypertension management. Similarly, in a qualitative study conducted in the United Kingdom (UK) using the TDF, general practitioners (GPs) perceived their professional role and identity as facilitators in achieving BP targets [35].
The physicians who were interviewed highlighted several factors that affect their prescribing behavior such as those related to patients, organizations, medications, and evidence-based medicine. As recommended by hypertension management guidelines patient-related factors should be taken into account when prescribing antihypertensive medications [6–8].
Moreover, most interviewed physicians mentioned medications’ side effect profiles among the factors that influenced their prescribing of certain antihypertensives and these findings are also supported by the published literature [36]. Researchers in Greece and Cyprus found similar results, with 90% of physicians changing their prescribing patterns because of medications’ side effects [37]. Furthermore, physicians reported following hypertension management guidelines and evidence-based medicine which aligns well with published studies elsewhere [38].
Physicians’ adherence to guidelines was assessed in several published studies in the literature with one study assessing physicians’ role in hypertension management and their compliance to JNC7, World Health Organization/International Society of Hypertension (WHO/ISH), and European Society of Hypertension (ESH) guidelines in Nigeria [39]. The study revealed that physicians followed the recommendations for hypertension management [39]. Conversely, a Malaysian study discovered that physicians did not follow clinical practice standards, and that when physicians followed recommendations for managing hypertension, hypertension control improved [40]. The adherence of primary care physicians in Qatar to clinical practice guidelines as compared to other regions reflects the exceptional quality control measures implemented within the Qatari healthcare system specifically in the primary care system. These measures are mandated by the government and driven by Qatar Healthcare Strategy as well as recommended by the accreditation and certification bodies of the PHCC in Qatar [41, 42].
Physicians’ patient-oriented goals were an important finding throughout the interviews. This finding is very encouraging as embracing patient-oriented goals has the potential to improve patient outcomes especially in achieving optimal BP control and ensuring better translation of clinical trial findings into real-life clinical practice. For instance, BP control was assessed in 437 patients who underwent follow-up for at least one year at a specialist clinic implementing “goal-oriented management” in 2002 in the United States. According to the study, goal-oriented management significantly improved control rates over standard practice, demonstrating its usefulness in applying clinical trial outcomes to outpatient care [43].
Interviewed physicians identified certain resources within the PHCC organization as barriers. These obstacles are similar to those reported in previous studies about physicians’ challenges in managing chronic conditions [44, 45]. Furthermore, interviewed physicians reported some perceived patient-related barriers that included medications’ price, side effects, language barriers, and patients’ noncompliance. In comparison, a systematic review conducted in 2021 to assess the factors related to inappropriate prescribing and barriers for medication optimization among elderly patients in the primary care settings published similar results regarding patients’ related barriers including patient response to side effects [46–49]. Qatar’s primary healthcare centers currently subsidize medications’ prices, making them more affordable for patients. However, it would be beneficial to assess further lowering of medication prices for patients with relatively low salaries. Proposed strategies to enhance medication adherence include following up with patients through the reestablishment of NCD clinics and recruiting multilingual staff to explain the importance of adhering to prescribed medication regimens to patients facing communication barriers.
Conversely, the interviewees highlighted some facilitators for prescribing antihypertensives including organization-related facilitators such as availability of information resources and supporting software. In line with the results of numerous studies conducted elsewhere, several interviewees also considered the presence of pharmacists as a facilitator in their prescribing of antihypertensives.[49, 50]. Physicians’ recognition of pharmacist’s role in hypertension management is promising given the vital contribution of pharmacists to Qatar’s governmental healthcare sector. Pharmacy practice in Qatar has greatly advanced in the past decade transitioning from traditional medication dispensing to offer holistic patient centered care [51].
On the other hand, social influences were not identified as major influencing factors for physicians’ prescribing behavior. Most physicians indicated that their decisions were not affected by patients ‘requests and that they prescribed what was appropriate for their patients. They suggested that proper patient education improves compliance with prescribed therapy. In comparison, the social influences of patients were deemed as important behavioral determinants in the literature. For instance, in 2018, Van Middeaar et al. published a study evaluating prescribing and deprescribing of antihypertensives in elderly patients in the Netherlands using semi-structured interviews and found that patients’ requests influenced both their prescribing and deprescribing behaviors [52]. Several published studies also revealed that patients’ preferences played a significant role in physicians’ prescribing decisions [30,53–59]. In this study, interviewed physicians reported feeling uncomfortable whenever patients insisted on using specific medications similar to the findings in a 2011 study conducted in the UK [60]. Several factors can explain the results of the Qatari study. Primary care physicians in Qatar largely rely on clinical practice guidelines for their prescribing decisions with the goal of selecting the most appropriate treatment for patients. Another potential factor is the time constraint as it may prevent physicians to have the needed time to consider patients’ preferences. In fact, in a previous survey 75% of primary care physicians identified lack of time for consultation as barrier for hypertension management [31]. Moreover, the availability of medications in the PHCC formulary may hinder physicians from accommodating patients’ requests.
Notably, a theme related to the feedback and assessments that physicians received regarding their prescribing of antihypertensives emerged throughout the interviews. Based on these results, PHCC clinics should implement a standardized system utilizing active strategies with audit and continuous feedback to physicians about their prescribing decisions for managing chronic diseases, including hypertension [61].
Several strategies were recommended by participants to improve hypertension management in Qatar, including patients monitoring their blood pressure at home, this has been proven to be a highly effective strategy for blood pressure control in hypertensive patients [62, 63]. Other recommended strategies included Cerner® system optimization, adding more medications to the PHCC formulary, and re-establishing NCD clinics. NCD clinics are effective in hypertension management as demonstrated in a study conducted in Rwanda in 2022 [64]. This study revealed that patients treated for either diabetes or hypertension or both in NCD clinics have a higher level of hypertension control than patients managed in family practice clinics [64]. Previously PHCC had NCD clinics and further investigation is needed to assess the logistical and financial feasibility of reintroducing them.
Strengths and limitations
This study has several strengths. This is the first study in Qatar to assess primary care physicians’ perceptions and experiences regarding hypertension management qualitatively. The TDF served as a conceptual framework to inform the design of the study. The use of TDF enhanced the robustness, methodological rigor, and applicative relevance of findings [65]. On the other hand, this study had some limitations. Firstly, the interviews were conducted in English only; however, none of the physicians interviewed reported any linguistic difficulties in reading or understanding English, and English is considered one of the core languages for communication in Qatar. In addition, not all participants who were contacted responded, and some responded but refused to participate, subsequently there is a possibility of nonresponse bias. Yet, based on the demographics of respondents, it is clear that they are representative of the population of primary care physicians in Qatar, confirming the external validity of the study.
Conclusions
In conclusion, the interviews revealed that physicians’ knowledge, skills, goals, and beliefs about capabilities and consequences based on patient, medication, and organization factors, along with behavioral regulation, resources, and perceived sociopolitical and organizational context were the main factors that affect their prescribing of antihypertensives. Among their perceived barriers for hypertension management, they considered lack of consultation time and insufficient availability of certain antihypertensives in primary care. On the other hand, several facilitators were identified, and many strategies for improving hypertension management were suggested. These include the re-establishment of NCD clinics and offering education workshops for physicians and nurses on the management of hypertension. Further research is warranted within the primary care healthcare sector in Qatar to investigate the efficacy of NCD clinics on the management of chronic diseases. This should be accompanied by assessments of Continuous Professional Development (CPD) workshops focused on hypertension management and their impact on physicians’ competencies. Moreover, there is a need for additional investigation into the availability of antihypertensive medications in primary care centers across Qatar to determine potential formulary adjustments. Furthermore, research aimed at exploring the feasibility of extending consultation durations for physicians to enhance the management of chronic conditions is recommended.
References
- 1. Hypertension World Health Organization (WHO) 2023 [Available from: https://www.who.int/news-room/fact-sheets/detail/hypertension.
- 2. Noncommunicable Diseases Country Profiles World Health Organization (WHO) 2018 [Available from: https://www.who.int/docs/default-source/ncds/9789241514620-eng.pdf?sfvrsn=48f7a45c_2.
- 3.
DiPiro JT, Yee GC, Posey LM, Haines ST, Nolin TD, Ellingrod V. Pharmacotherapy: A Pathophysiologic Approach, 11e. New York, NY: McGraw-Hill Education; 2020.
- 4. Hypertension World Heart Federation [Available from: https://world-heart-federation.org/what-we-do/hypertension/.
- 5. Cuspidi C, Tadic M, Grassi G, Mancia G. Treatment of hypertension: The ESH/ESC guidelines recommendations. Pharmacological Research. 2018 (1096-1186 (Electronic)).
- 6. James PA, Oparil S, Carter BL, Cushman WC, Dennison-Himmelfarb C, Handler J, et al. Evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the Eighth Joint National Committee (JNC 8). Journal of the American Medical Association (JAMA). 2014;311(5):507–20.
- 7. Whelton P, Carey RM, Aronow WS, Casey DE Jr, Collins KJ, Dennison Himmelfarb C, et al. ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018;71(6):1269–324.
- 8. National Institute for Health and Care Excellence Hypertension in adults: diagnosis and management NG136. 2019 [Available from: https://www.nice.org.uk/guidance/ng136/chapter/Recommendations.
- 9. Stafford RS, Monti V, Furberg CD, Ma J. Long-term and short-term changes in antihypertensive prescribing by office-based physicians in the United States. Hypertension. 2006;48(2):213–8. pmid:16785334
- 10. Abdelkader NN, Awaisu A, Elewa H, El Hajj MS. Prescribing patterns of antihypertensive medications: A systematic review of literature between 2010 and 2020. Explor Res Clin Soc Pharm. 2023;11:100315. pmid:37635839
- 11. Rashid R, Hameed R, Hamid T. Prevalence of hypertension among the adult population in Qatar: A literature review. Scholars Journal of Applied Medical Sciences. 2021;9:1805–12.
- 12. Hypertension Profiles World Health Organization (WHO) 2023 [Available from: https://www.who.int/docs/default-source/ncds/ncd-surveillance/hypertension-profiles-2023.pdf.
- 13. Global action plan for the prevention and control of noncommunicable diseases 2013-2020 World Health Organization (WHO) 2013 [Available from: https://www.who.int/publications/i/item/9789241506236.
- 14. Clinical Guidelines for the State of Qatar. 2019 [Available from: https://www.moph.gov.qa/Admin/Lists/ClinicalGuidelinesAttachments/Attachments/23/The%20diagnosis%20and%20management%20of%20hypertension%20in%20adults.pdf.
- 15. National Institute for Health and Care Excellence Hypertension in adults: diagnosis and management NG136. 2019 [Available from: https://www.niceorg.uk/guidance/ng136.
- 16. Tong A, Sainsbury P, Craig J. Consolidated criteria for reporting qualitative research (COREQ): a 32-item checklist for interviews and focus groups. Int J Qual Health Care. 2007;19(6):349–57. pmid:17872937
- 17. Primary health care centers [Available from: https://www.phcc.gov.qa/Health-Centers/All-Health-Centers).
- 18.
Schwandt T. Constructivist, interpretivist approaches to human inquiry. Handbook of qualitative research/Sage. 1994.
- 19. Atkins L, Francis J, Islam R, O’Connor D, Patey A, Ivers N, et al. A guide to using the Theoretical Domains Framework of behaviour change to investigate implementation problems. Implement Sci. 2017;12(1):77. pmid:28637486
- 20. Francis JJ, Johnston M, Robertson C, Glidewell L, Entwistle V, Eccles MP, et al. What is an adequate sample size? Operationalising data saturation for theory-based interview studies. Psychol Health. 2010;25(10):1229–45. pmid:20204937
- 21. Cane J, O’Connor D, Michie S. Validation of the theoretical domains framework for use in behaviour change and implementation research. Implement Sci. 2012;7:37. pmid:22530986
- 22. Murphy K, O’Connor DA, Browning CJ, French SD, Michie S, Francis JJ, et al. Understanding diagnosis and management of dementia and guideline implementation in general practice: a qualitative study using the theoretical domains framework. Implement Sci. 2014;9:31. pmid:24581339
- 23. Lawton R, Heyhoe J, Louch G, Ingleson E, Glidewell L, Willis TA, et al. Using the Theoretical Domains Framework (TDF) to understand adherence to multiple evidence-based indicators in primary care: a qualitative study. Implement Sci. 2016;11:113. pmid:27502590
- 24. Debono D, Taylor N, Lipworth W, Greenfield D, Travaglia J, Black D, et al. Applying the Theoretical Domains Framework to identify barriers and targeted interventions to enhance nurses’ use of electronic medication management systems in two Australian hospitals. Implement Sci. 2017;12(1):42. pmid:28347319
- 25. Francis JJ, O’Connor D, Curran J. Theories of behaviour change synthesised into a set of theoretical groupings: introducing a thematic series on the theoretical domains framework. Implement Sci. 2012;7:35. pmid:22531601
- 26. Clarke V, Braun V. Teaching thematic analysis: Overcoming challenges and developing strategies for effective learning. The Psychologist. 2013;26:120–3.
- 27.
Lincoln Y, Guba E. Naturalistic inquiry: sage; 1985.
- 28. Korstjens I, Moser A. Series: Practical guidance to qualitative research. Part 4: Trustworthiness and publishing. Eur J Gen Pract. 2018;24(1):120–4. pmid:29202616
- 29. Davari M, Khorasani E, Tigabu BM. Factors Influencing Prescribing Decisions of Physicians: A Review. Ethiop J Health Sci. 2018;28(6):795–804. pmid:30607097
- 30. Md Rezal RS, Hassali MA, Alrasheedy AA, Saleem F, Md Yusof FA, Godman B. Physicians’ knowledge, perceptions and behaviour towards antibiotic prescribing: a systematic review of the literature. Expert Rev Anti Infect Ther. 2015;13(5):665–80. pmid:25813839
- 31. Joudeh AI, Elderawy NM, Alhitmi MA, Alnuaimi AS, Aabdien M, Alotaibi M, et al. Assessment of knowledge, attitude, and practice of primary healthcare physicians in Qatar towards hypertension management: An online cross-sectional study. Medicine (Baltimore). 2023;102(38):e34751. pmid:37746967
- 32. Peters-Klimm F, Laux G, Campbell S, Müller-Tasch T, Lossnitzer N, Schultz J-H, et al. Physician and patient predictors of evidence-based prescribing in heart failure: a multilevel study. PLoS One. 2012;7(2):e31082. pmid:22363553
- 33. Molero Jurado MdM, Pérez-Fuentes MdC, Martos Martínez Á, Gázquez Linares JJ. Emotional intelligence and self-esteem: Personal competencies necessary for physicians. Frontiers in Medicine. 2022;9.
- 34. Albazoon F, Khogali F, Burjaq R, Chandra P, Alabdulla M, Abdulaziz M, et al. Burnout among healthcare professionals in Qatar: A systematic review. Asian J Psychiatr. 2023;85:103601. pmid:37156048
- 35. Lugtenberg M, Burgers JS, Besters CF, Han D, Westert GP. Perceived barriers to guideline adherence: a survey among general practitioners. BMC Fam Pract. 2011;12:98. pmid:21939542
- 36. Chen X, Zhang T, Wang H, Feng Z, Jin G, Shao S, et al. Factors influencing the prescription pattern of essential medicines from the perspectives of general practitioners and patients: a qualitative study in China. BMJ Open. 2022;12(5):e055091. pmid:35545386
- 37. Theodorou M, Tsiantou V, Pavlakis A, Maniadakis N, Fragoulakis V, Pavi E, et al. Factors influencing prescribing behaviour of physicians in Greece and Cyprus: results from a questionnaire based survey. BMC Health Serv Res. 2009;9:150. pmid:19695079
- 38. Abulhaj E, Abu Elsamen A, Assistant E, Alabbadi I. Investigating the Factors Affecting Doctor’s Prescribing Behavior in Jordan: Anti-Hypertensive Drugs as an Example. European Journal of Social Sciences. 2013;38:1450–2267380.
- 39. Odili V, Oghagbon E, Ugwa NA, Ochei U, Aghomo O. Adherence to International Guidelines in the Management of Hypertension in a Tertiary Hospital in Nigeria. Trop J Pharm Res. 2008;7(2).
- 40. Ahmad N, Hassan Y, Tangiisuran B, Meng O, Aziz N, Khan A. Guidelines Adherence and Hypertension Control in an Outpatient Cardiology Clinic in Malaysia. Trop J Pharm Res. 2012;11(4).
- 41. National Health Strategy 2024-2030 “Health For All” [Available from: https://www.moph.gov.qa/english/NHS/Documents/NHS_2024_2030_EN.pdf.
- 42. Accreditation & Certifications [Available from: https://www.phcc.gov.qa/about-us/accreditation-certifications.
- 43. Singer GM, Izhar M, Black HR. Goal-oriented hypertension management: translating clinical trials to practice. Hypertension. 2002;40(4):464–9. pmid:12364348
- 44. Ronksley PE, Sanmartin C, Campbell DJT, Weaver RG, Allan GM, McBrien KA, et al. Perceived barriers to primary care among western Canadians with chronic conditions. Health Rep. 2014;25(4):3–10. pmid:24744042
- 45. Baig M, Sayedalamin Z, Almouteri O, Algarni M, Allam H. Perceptions, Perceived Barriers, and Practices of Physicians’ towards Evidence-Based Medicine. Pak J Med Sci. 2016;32(1):49–54. pmid:27022344
- 46. Xu Z, Liang X, Zhu Y, Lu Y, Ye Y, Fang L. Factors associated with potentially inappropriate prescriptions and barriers to medicines optimisation among older adults in primary care settings: a systematic review. Fam Med Community Health. 2021;9(4):e00167.
- 47. Tang KL, Ghali WA, Manns BJ. Addressing cost-related barriers to prescription drug use in Canada. CMAJ. 2014;186(4):276–80. pmid:24043654
- 48. Khera R, Valero-Elizondo J, Das SR, Virani SS, Kash BA, de Lemos JA, et al. Cost-Related Medication Nonadherence in Adults With Atherosclerotic Cardiovascular Disease in the United States, 2013 to 2017. Circulation. 2019;140(25):2067–75. pmid:31760784
- 49. Yuan J, Yin G, Gu M, Lu KZ, Jiang B, Li M. Physicians’ Knowledge, Altitudes, and Perceived Barriers of Inappropriate Prescribing for Older Patients in Shanghai, China. Front Pharmacol. 2022;13:821847. pmid:36071836
- 50. Magzoub M, Neyaz Y, Khoja T, Qureshi N, Haycox A, Walley T. Determinants of physicians’ medication prescribing behaviour in primary care in Riyadh City, Saudi Arabia. East Mediterr Health J. 2011;17(2):160–6.
- 51.
Wilbur K, El Hajj MS, Kheir N. Pharmacy practice in the gulf states. Elsevier; 2019.
- 52. van Middelaar T, Ivens SD, van Peet PG, Poortvliet RKE, Richard E, Pols AJ, et al. Prescribing and deprescribing antihypertensive medication in older people by Dutch general practitioners: a qualitative study. BMJ Open. 2018;8(4):e020871. pmid:29678989
- 53. Yamada J, Potestio ML, Cave AJ, Sharpe H, Johnson DW, Patey AM, et al. Using the theoretical domains framework to identify barriers and enablers to pediatric asthma management in primary care settings. J Asthma. 2018;55(11):1223–36. pmid:29261346
- 54. Rajendran S, Sajbel TA, Hartman TJ. Factors involved in making decisions to prescribe medications for psychiatric disorders by psychiatrists: a survey study. Psychiatr Q. 2012;83(3):271–80. pmid:22038271
- 55. Lagerløv P, Loeb M, Andrew M, Hjortdahl P. Improving doctors’ prescribing behaviour through reflection on guidelines and prescription feedback: a randomised controlled study. Qual Health Care. 2000;9(3):159–65. pmid:10980076
- 56. Britten N, Stevenson FA, Barry CA, Barber N, Bradley CP. Misunderstandings in prescribing decisions in general practice: qualitative study. BMJ. 2000;320(7233):484–8. pmid:10678863
- 57. Ljungberg C, Lindblad AK, Tully MP. Hospital doctors’ views of factors influencing their prescribing. J Eval Clin Pract. 2007;13(5):765–71. pmid:17824870
- 58. Choi K-H, Park S-M, Lee J-H, Kwon S. Factors affecting the prescribing patterns of antibiotics and injections. J Korean Med Sci. 2012;27(2):120–7. pmid:22323857
- 59. van Buul LW, van der Steen JT, Doncker SMMM, Achterberg WP, Schellevis FG, Veenhuizen RB, et al. Factors influencing antibiotic prescribing in long-term care facilities: a qualitative in-depth study. BMC Geriatr. 2014;14:136. pmid:25514874
- 60. Lewis PJ, Tully MP. The discomfort caused by patient pressure on the prescribing decisions of hospital prescribers. Res Social Adm Pharm. 2011;7(1):4–15. pmid:21397877
- 61. Lim WY, Hss AS, Ng LM, John Jasudass SR, Sararaks S, Vengadasalam P, et al. The impact of a prescription review and prescriber feedback system on prescribing practices in primary care clinics: a cluster randomised trial. BMC Fam Pract. 2018;19(1):120. pmid:30025534
- 62. McManus RJ, Mant J, Franssen M, Nickless A, Schwartz C, Hodgkinson J, et al. Efficacy of self-monitored blood pressure, with or without telemonitoring, for titration of antihypertensive medication (TASMINH4): an unmasked randomised controlled trial. Lancet. 2018;391(10124):949–59. pmid:29499873
- 63. Margolis KL, Asche SE, Dehmer SP, Bergdall AR, Green BB, Sperl-Hillen JM, et al. Long-term Outcomes of the Effects of Home Blood Pressure Telemonitoring and Pharmacist Management on Blood Pressure Among Adults With Uncontrolled Hypertension: Follow-up of a Cluster Randomized Clinical Trial. JAMA Netw Open. 2018;1(5):e181617. pmid:30646139
- 64. Kabakambira JD, Shumbusho P, Mujawamariya G, Rutagengwa W, Twagirumukiza M. The Role of the Integrated District Hospital Based Non Communicable Diseases’ Clinics in Cardiovascular Disease Control: Preliminary Data from Rwanda. Diabetes Metab Syndr Obes. 2022;15:2107–15. pmid:35898444
- 65. Stewart D, Klein S. The use of theory in research. Int J Clin Pharm. 2016;38(3):615–9. pmid:26511946