Introduction

Inducible laryngeal obstruction (ILO) is a laryngeal disorder characterized by the unwanted adduction of the vocal folds, temporarily restricting the laryngeal airway, resulting in difficulty breathing and related symptoms of discomfort [1]. Considered a diagnosis of elimination, patient report of symptoms in the absence of other etiologies is common in supporting a diagnosis of ILO. Other clinical findings like truncated inspiratory flow loops during pulmonary function tests have been suggested by some to indicate the presence of ILO [2,3] but an indirect laryngeal exam when symptoms are present is the current gold standard in diagnosis [4]. Dyspnea, the chief symptom of ILO, has long been inversely associated with quality of life (QOL) in patients with COPD, and congestive heart failure [5,6]. While dyspnea can result in patient morbidity and distress irrespective of etiology, studies relating spirometry and laryngeal exams to the severity of ILO have not been pursued, likely because these measures are not thought to be consistently sensitive to the episodic presentation of the disorder [7], and they do not delineate an objective level of breathing impairment in the same way that pulmonary function may provide benchmarks for staging chronic conditions such as COPD. More recently, work has focused on the cost associated with care of dyspnea prior to and following diagnosis of ILO [8]. Additionally, questionnaires focused on upper airway disorders [9] and/or ILO-specific items [10] have been developed to quantify patient perception of impairment which may prove beneficial in future outcomes-related research on this disorder. Yet, the specific impact of ILO on quality of life has not been closely examined and reported via direct patient report. It is important to systematically study and document patient perspectives regarding personal experiences, as the collective input from patients with this diagnosis could improve understanding and treatment of the disorder and help to refine the measurement of treatment outcomes.

The purpose of the present investigation was to document patient perspectives on ILO, providing a qualitative analysis detailing experiences that appear to be the most consistent and meaningful to patients with this disorder as it impacts their quality of life. Assessing patients’ experience in this manner is important in reducing the bias that may occur when clinicians identify, and target treatment outcomes based mostly on their professional experience. Characterizing the salient experiences of patients with ILO will thus improve our ability to refine assessment and treatment in a way that may better support the specific needs of patients.

Materials and methods

Individuals diagnosed with ILO in an outpatient clinic were recruited to participate in this qualitative study. Utilizing qualitative methods detailed in the literature on grounded theory and phenomenological research [15], participants underwent semi-structured interviews about their experiences; responses were transcribed and analyzed. Participants were recruited from a large tertiary care academic outpatient clinic from a variety of different specialties including primary care, pulmonology, and asthma/allergy. Assessment of laryngeal appearance and function was completed using videostroboscopy as standard of care at all evaluations. Given that ILO can be described as a disorder of laryngeal behavior or function, patients were routinely evaluated and treated in our clinic by Speech-Language Pathologists (SLP). Occasionally, they were scheduled in multi-disciplinary visits with Otolaryngology (ENT).

Semi-structured interviews

Interviews were conducted by speech language-pathologists who specialized in managing ILO. Interview questions were pre-scripted and could be modified/expanded when necessary to promote clarity of responses. Interview questions are listed in Table 1. All interviews were recorded in a quiet, private room. Full transcripts were typed by research assistants and provided to the initial rater, KM.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 1. Interview questions to assess patient experiences related to paradoxical vocal fold motion disorder.

https://doi.org/10.1371/journal.pone.0307002.t001

Data analysis

Burnard’s 14 step method for transcript analysis [15] was employed as the basis for content analysis. This method involved 5 stages during which KM read the transcripts multiple times and then devised categories for all meaningful statements from the interviews conducted. Next, two additional raters with six to ten years of professional experience in research and/or clinical management of ILO were asked to categorize meaningful statements extracted from the interviews. A total of 8 overarching themes were agreed upon to address all content derived across participants. Categories were identified and the frequency with which these emerged in interviews is summarized in Table 2. A random sample of statements was pulled in increments of 10–20% of the total interview content until good rater consensus was reached. Agreement was initially acceptable but lower than desired at (71%). To improve consensus in the coding system, discrepancies between category systems were discussed and resolved after each sample of the data was co-rated. In discussion, differences were mainly attributed to some overlapping themes in statements. Examples of this included statements that discussed both physical limitations and lifestyle changes such as “I used to enter in small races, and I’ve stopped doing that because I can’t maintain the speed … I’ve gotten a lot slower.” In total, raters were provided a sampling of 70% of all the meaningful content from the interviews and ultimately achieved 80% interrater reliability in coding the statements.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 2. Categorized responses and their frequency across participants.

https://doi.org/10.1371/journal.pone.0307002.t002

Results

Twenty-seven adult patients diagnosed with ILO provided informed consent to participate in the study (2 males and 25 females) and 26 participants completed an interview (2 males and 24 females). The mean age in the interviewed population was 45 (range 18–72, SD 16.74). The mean age for male participants was 39 (range 37–41, SD 2.83) and for female participants, 45 (range 18–72< SD 17.48). Although there were a disproportionate number of women in the study, the literature describes a predominance of women with diagnosis of ILO [16]. In addition to ILO, just over half (53.8%) of the participants endorsed a diagnosis of asthma, 7.7% were diagnosed with COPD, and 11.5% had obstructive sleep apnea. Fifty percent were currently using inhalers. Mental and/or behavioral health diagnoses were noted 42.3% of participants. Included, was report of depression in 30.8% of participants and anxiety in 26.9%.

The interview content was analyzed according to qualitative research methods based on grounded theory [17]. Eight themes in total were identified. Participant’s descriptions of the symptoms they experienced and the triggers for their symptoms dominated the interviews. In addition to discussion of symptoms and their triggers (theme 1), seven additional themes were judged to encapsulate the interview material and included: 2) diagnosis and treatment, 3) emotional impact of ILO, 4) perception of health and prognosis, 5) ameliorating factors, 6) influence of ILO on lifestyle, 7) the physical impact of ILO, and 8, social consequences of ILO.

Discussion

The aim of this study was to qualitatively describe patient experiences and perspectives related to ILO so that future treatments and outcome measures can be more specific to the needs of this patient population. Patients who present clinically with ILO report a range of symptoms that can vary based on pattern of triggers and what responses are most helpful [18]. They still generally share a well-established constellation of symptoms that include dyspnea, change in voice, and discomfort (often localized to the throat and/or upper chest) that are triggered by activity or environmental stimuli [19,20]. The qualitative method of the interviews in this study was selected to promote discussion of patient experience rather than focus on the aspects of ILO that are most salient to clinical care providers. In this setting, a rather robust discussion of the emotional impact of the disorder that had not been widely reported before occurred. This is similar to themes that have emerged recently in the literature on patient perspectives surrounding chronic cough, where the emotional toll of the disorder appeared to be a meaningful aspect of patient experience [21]. For the present investigation, a theme underscoring the importance of appropriate diagnosis and treatment was also common. Although it is well known that patients with ILO often require multiple visits to healthcare professionals [2] and incur meaningful medical costs [2,8] before being accurately diagnosed with ILO, the emotional toll of this as described by participants in this study has not been emphasized in the literature. Further research is necessary to examine these themes specifically and determine how they could impact a patient’s self-efficacy and treatment readiness or outcomes.

As clinical care providers, it is important to remain cognizant not only of the physical symptoms of ILO and the strategies used to eliminate them, but of patient experience as a whole. This includes the frustration, stigma, and burnout many patients with ILO experience and the potential for these factors to shape a patient’s perceived severity and outcomes. In both the broader medical/surgical literature, and literature specific to voice and ILO, there is evidence to suggest that common objective measures and clinician impression of treatment success and QOL may fail to account for important aspects of the patient perception of outcomes [22–24]. This work underscores the need for clinical care providers to engage in dialogue with patients that addresses significant elements of their perception of the disorder and how it impacts their lives. For example, the validation many patients associate with accurate diagnosis itself draws attention to an important aspect of their experience with the disorder and may highlight an important topic of discussion and education in clinical care visits.

The recruitment of participants from a single tertiary care center is a limitation of the study. Patients seen in these settings have typically had extensive prior medical work-up and may also represent a specific cultural and socioeconomic group. Thus, for many reasons, our participants may have shared experiences that do not reflect a larger population.

It is also possible that allowing participants’ treating clinician to serve as the first contact for discussing recruitment may represent a source of bias. Provider-patient relationships are complex in a way that may influence a participant’s willingness to consent. In a busy clinical setting, without a dedicated team of assistants and research personnel consistently present on site, deferring all recruitment inquiries to other staff would have likely disrupted clinic flow and been infeasible. While power imbalances between patient and care provider must be considered, the consent process is intended to communicate as compellingly as possible that participation is voluntary and declining to participate does not influence care choices. Additionally, excluding the treating clinician from the interview itself was intended to minimize bias that may be influenced by the patient-client relationship.

Although the qualitative nature of this study is typically considered a limitation, qualitative methods are preferable when attempting to identify specific experiences. Themes captured in this study may provide directions and questions for future work with more quantitative methods.

Conclusions

Patient perceptions of ILO have not been adequately described in the literature. The present study demonstrates that patients place particular emphasis on the emotional and psychosocial consequences of the disorder. As such, future efforts to treat ILO and to collect outcomes measures may be inaccurate if they do not address these experiences specifically and proportionally.