1. Introduction

Chronic Kidney Disease (CKD) is a progressive condition affecting approximately 850 million people worldwide [1]. It contributes significantly to morbidity and mortality, particularly among people living with HIV (PLHIV) on antiretroviral therapy (ART), who are at increased risk due to HIV related and treatment-related factors [2,3]. Tanzania carries a substantial burden of HIV, with an estimated prevalence of 4.6% among adults aged 15–49 years, and of these, 62% are aware of their status, and 90% of those are on ART [4].

Worldwide, approximately 39.9 million individuals are living with HIV, with a significant proportion facing an increased risk of developing CKD due to HIV-associated nephropathy, ART nephrotoxicity (particularly Tenofovir), and co-existing conditions such as hypertension and diabetes [5–7]. The prevalence of CKD among PLHIV varies widely across sub-Saharan Africa with a pooled estimates of 12%. In East African countries, reported prevalence ranges from approximately 8% to 22%, with most studies estimating rates between 10% and 18% in Kenya, Uganda, and Ethiopia [8]. In Tanzania, CKD prevalence in the general population ranges between 7% and 14%, with higher rates observed in people living with HIV (PLHIV) [9–11].

Screening for CKD among PLHIV on ART using recommended methods, such as serum creatinine-based estimation of glomerular filtration rate (eGFR) and the urine albumin-to-creatinine ratio (UACR) for detection of proteinuria or albuminuria, is crucial for early diagnosis and management, as untreated CKD can result in substantial morbidity and mortality [12,13]. International and national guidelines recommend routine screening for CKD at the initiation of ART, with periodic annual follow-up thereafter, due to the increased risk of kidney impairment associated with HIV infection and prolonged exposure to ART [2,14,15]. Early identification enables timely interventions and referral to nephrology services, thereby improving clinical outcomes and reducing healthcare costs [16].

Despite the availability of guidelines emphasizing the importance of CKD screening for PLHIV on ART, the uptake remains suboptimal in many resource-limited settings [17]. Several studies mentioned limited diagnostic tools, inconsistent follow-up mechanisms, workforce shortages, and insufficient public awareness as the causes of poor adherence to CKD screening among PLHIV [18,19]. The government of Tanzania has strengthened the CKD screening through integration into the National Non-Communicable Diseases (NCD) Strategic Plan, capacity building of healthcare providers, decentralization of services, and incorporation of CKD screening into HIV care services [11]. However, persistent resource constraints and knowledge gaps among healthcare providers continue to pose significant challenges to effective CKD screening and management [19]. Without effectively addressing these challenges, the burden of CKD-related complications among PLHIV is likely to increase, resulting in higher morbidity and mortality and placing additional strain on the healthcare system [18,19]. Generating evidence on the availability and trends of CKD screening is therefore essential to inform the formulation and implementation of effective screening policies. In Tanzania, there is a paucity of studies focusing on CKD screening among PLHIV. Accordingly, this study aimed to determine the prevalence of CKD screening and identify factors influencing its uptake, to improve early detection, patient outcomes, and informed allocation of healthcare resources.

2. Materials and methods

3. Results

Socio-demographic characteristics of the study participants

A total of 426 participants were enrolled in the study. The mean age of participants was 42.5 years (SD = 11.5), with more than half (61.0%) aged 40 years and above. Females constituted 66.7% of the study population. More than half of participants (58.0%) had a partner (married or cohabiting), and almost half (49.5%) had attained secondary-level or higher education. Approximately four-fifths (81.5%) of participants were employed or self-employed, and the majority (87.1%) resided in urban areas (Table 1).

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Table 1. Socio-demographic characteristics of the study participants (N = 426).

https://doi.org/10.1371/journal.pone.0352024.t001

Prevalence of CKD screening and clinical characteristics of participants (N=426)

Table 2 summarizes participants’ clinical characteristics and health information. The majority (n = 402, 94.1%) of participants had been screened for CKD in the past 12 months prior to enrollment in the study. Approximately half of the participants had been on ART for up to 36 months (n = 215, 50.5%). Nearly half attended ART clinics on a monthly basis (n = 196, 46.0%), and almost all were receiving tenofovir-based ART regimens (n = 414, 97.2%). Viral load (VL) suppression was high, with 407 participants (95.5%) having suppressed VL results. More than half of participants (n = 246, 57.7%) had a CD4 count of less than 350 cells/µL. Most participants reported no comorbid hypertension or diabetes (n = 353, 82.9%). The majority had no kidney disease-related symptoms (n = 409, 96.0%) and no prior diagnosis of kidney disease (n = 416, 97.7%). Information on chronic CKD provided by healthcare providers was perceived as adequate by 393 participants (92.3%). More than half reported having received recommendations for CKD screening during ART follow-up visits (n = 240, 56.3%). In terms of access to services, 264 participants (62.0%) resided within 5 km of a CKD screening facility, and most reported no costs associated with CKD screening (n = 408, 95.8%).

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Table 2. Clinical characteristics and health information among study participants (N = 426).

https://doi.org/10.1371/journal.pone.0352024.t002

Factors associated with CKD screening

Bivariate and multivariate logistic regression analyses of factors associated with CKD screening among the 426 study participants are displayed in Table 3. In bivariate analysis, frequency of ART clinic attendance, CD4 count, and recommendation of CKD screening during ART follow-up were significantly associated with CKD screening. Participants attending ART clinics every six months had significantly lower odds of CKD screening compared with those attending monthly clinics (COR: 0.13, 95% CI: 0.04, 0.39; p < 0.001). Participants with a CD4 count greater than 350 cells/µL had higher odds of CKD screening compared with those with lower CD4 counts (COR; 19.35, 95% CI: 2.59, 144.43; p = 0.004). In addition, participants who reported receiving a recommendation for CKD screening during ART follow-up visits had significantly lower odds of CKD screening compared with those who did not receive such recommendations (COR: 0.10, 95% CI: 0.02, 0.44; p = 0.002).

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Table 3. Bivariate and multivariate logistic regression analysis of the factors associated with CKD screening (N = 426).

https://doi.org/10.1371/journal.pone.0352024.t003

In multivariate analysis, the three variables remained significantly associated with CKD screening. Attending ART clinics every six months was independently associated with lower odds of CKD screening (AOR: 0.16, 95% CI: 0.05, 0.48; p = 0.001). Higher CD4 count (>350 cells/µL) was independently associated with increased odds of CKD screening (AOR: 9.73, 95% CI: 1.21, 78.16; p = 0.032). Participants who reported receiving a recommendation for CKD screening during ART follow-up visits had significantly lower odds of CKD screening compared with those who did not receive such recommendations (AOR = 0.17, 95% CI: 0.04–0.79; p = 0.024). The Hosmer-Lemeshow goodness-of-fit test yielded a chi-square value of 1.411 with a p-value of 0.994, indicating that the model demonstrated a good fit to the data.

Sociodemographic characteristics, including age, sex, marital status, education level, employment status, and place of residence, as well as viral load status, comorbidity status, perceived adequacy of CKD information, and distance to CKD screening facilities, were not significantly associated with CKD screening in either bivariate or multivariate analyses. Several variables including time on ART, ART regimen used, experience of kidney disease-related symptoms, prior kidney disease diagnosis, and costs associated with CKD screening, were not included in the regression models due to sparse data and zero-cell counts, which resulted in unstable or non-estimable odds ratios.

4. Discussion

This study found a high CKD screening prevalence of 94.1% among PLHIV. This finding likely to reflect the routine integration of renal function assessment into HIV care services rather than a formal, guideline-structured CKD screening program. Current HIV kidney care guidelines recommend regular monitoring of serum creatinine and urinalysis among PLHIV receiving ART, particularly during treatment initiation and follow-up [23,25]. Therefore, the observed high prevalence may represent cumulative exposure to routine renal testing among clinic attending patients rather than systematic CKD screening as defined in clinical guidelines. This indicates strong integration of basic renal monitoring within routine HIV care, but suggests variability in how screening is operationalized in routine practice [26]. This uptake is substantially higher than that reported in many low-middle-income (LMI) settings, where CKD screening among PLHIV remains limited due to resource constraints, competing priorities, and inconsistent guideline implementation [27,28]. The observed high coverage may reflect strengthened HIV program infrastructure, increased provider awareness, policy emphasis on routine laboratory monitoring, and effective implementation of differentiated service delivery models that integrate chronic comorbidity screening into HIV care [29]. However, high screening coverage alone is insufficient to ensure optimal outcomes, as the quality of screening, follow-up of abnormal results, and linkage to specialized care remain critical for effective CKD prevention and management among PLHIV [30,31]. In addition to that, this study was conducted in the three urban regional referral hospitals in Dar es Salaam region, Tanzania which are more likely to have better staff, laboratory infrastructure and diagnostic capacity compared with rural and primary health facilities in Tanzania, as evidenced from previous studies conducted in Tanzania shown that staff gap, laboratory service availability and access of diagnostic tests are typically more limited in rural and primary healthcare settings, which could restrict the generalizability of the observed screening prevalence applied to these groups [32,33].

The frequency of ART clinic attendance emerged as a key determinant of CKD screening. Participants attending ART clinics every six months had significantly lower odds of being screened for CKD compared with those attending monthly visits, even after adjustment for potential confounders. This suggests that extended appointment intervals, while beneficial for decongesting clinics and improving convenience for stable patients, may inadvertently reduce opportunities for routine screening of comorbid conditions. Similar observations have been reported in differentiated service delivery models, where reduced clinical contact may limit preventive service uptake if not deliberately integrated into care protocols [34–36]. These findings underscore the need to ensure that CKD screening is systematically incorporated into less frequent ART follow-up schedules.

Also, the current study revealed that a higher CD4 count (>350 cells/µL) was independently associated with increased odds of CKD screening, likely reflecting better health-seeking behavior and stronger engagement with HIV care among immunologically stable individuals. PLHIV with higher CD4 counts generally have well-controlled HIV, consistent ART adherence, and regular clinic attendance, which increases opportunities for comprehensive care, including routine CKD screening [37,38]. Similar findings have been reported in sub-Saharan Africa, where clinically stable PLHIV (CD4 > 500 cells/µL) were more likely to receive preventive services, including renal function testing, due to sustained engagement with care [39]. Provider-related factors may also contribute, as clinicians may prioritize preventive services for patients perceived to be clinically stable and more likely to benefit from early intervention [40]. In contrast, PLHIV with lower CD4 counts may present with competing acute clinical needs, resulting in reduced attention to routine screening. This pattern has been observed in Nigeria, where individuals with advanced immunosuppression (CD4 < 200 cells/µL) were less likely to undergo CKD screening despite elevated risk, as clinical focus shifted toward managing opportunistic infections [31]. These findings underscore the importance of integrating NCD screening into HIV care across all levels of immunological recovery and highlight the need for targeted strategies to ensure that immunocompromised patients are not overlooked in routine CKD screening.

There was an inverse association between healthcare provider recommendations for CKD screening and actual screening uptake among PLHIV, which was discovered in the present study. Although this finding appears counterintuitive, it may reflect reverse causality [41,42], in which healthcare providers are likely to recommend screening to patients perceived to be at higher risk or with advanced disease, groups that may already have lower screening uptake due to competing clinical priorities [31]. Furthermore, residual confounding, namely disease severity, comorbid conditions, or access-related barriers that impact both the likelihood of receiving a healthcare provider recommendation and actual screening uptake, may influence this association [42,43]. Additionally, contextual barriers within the study setting may have reduced the effectiveness of provider recommendations. The clinics in which this study was conducted had a high patient-to-staff ratio, limited private space for counselling, and insufficient time for individualized health education and advice [21]. These structural restrictions may hinder effective provider-to-patient communication, patient understanding, and timely access to screening services, thereby contributing to lower screening uptake regardless of the recommendations. Related studies from HIV clinics in sub-Saharan Africa have shown that prolonged waiting times, staffing shortages, and privacy-related challenges adversely affect service delivery and uptake of recommended care services [44–48]. Therefore, this finding, which underscores that provider recommendation alone is insufficient and highlights the need for integrated, system-level approaches to ensure effective CKD screening within routine HIV care, should be considered hypothesis-generating and warrant further investigation in longitudinal studies.

The sociodemographic characteristics were not significantly associated with the uptake of CKD screening. Similarly, viral load status, comorbidity with hypertension or diabetes, perceived adequacy of CKD information, and distance to CKD screening facilities showed no significant associations. These findings suggest relatively equitable access to CKD screening within the study population and may reflect the strengths of Tanzania’s ART program in minimizing social and structural barriers to care. Comparable findings were reported in Dar es Salaam, where age, sex, education level, and comorbidity were not significantly associated with screening for NCDs among PLHIV on ART [49]. However, evidence from other settings differs; studies in Uganda reported higher education levels to be associated with missed NCD screening opportunities [50], while research in Kilimanjaro demonstrated a negative association between distance to health facilities and cervical cancer screening, another NCD-related service [51]. These variations highlight the context-specific nature of NCD screening behaviors and underscore the influence of health system organization and service integration on CKD screening uptake.

Several limitations should be considered when interpreting the findings of this study. First, the cross-sectional design precludes causal inference, and observed associations should be interpreted as correlational. Second, reliance on routine clinic records and self-reported information may have introduced information bias, including misclassification or recall bias. In addition, CKD screening was operationally defined as documentation of at least one renal assessment test since ART initiation, which may reflect cumulative routine renal monitoring rather than a formal, guideline-structured CKD screening program, potentially contributing to the high observed screening prevalence. Third, the presence of sparse data and zero-cell counts for several clinically relevant variables limited their inclusion in regression analyses, potentially underestimating their true association with CKD screening. Finally, the study was conducted within ART clinics in the urban referral hospitals, which may limit the generalizability of findings to populations with limited engagement in HIV care or to non-HIV settings, and to rural and primary healthcare facilities, where staffing, diagnostic capacity, and access to routine renal monitoring may be more constrained.

5. Conclusion

CKD screening uptake among adults receiving ART was high; however, important differences were observed based on frequency of ART clinic attendance, CD4 count, and provider recommendation. Patients with less frequent ART visits were significantly less likely to undergo CKD screening, highlighting a potential gap in preventive service delivery within differentiated ART models. Strengthening provider-initiated screening recommendations and integrating CKD screening into all ART follow-up schedules, regardless of visit frequency or immunological status, may enhance early detection and management of kidney disease among people living with HIV. These findings support the need for deliberate, effective integration of NCD screening into HIV care to sustain long-term health outcomes.

Supporting information

Acknowledgments

We thank the authors for their invaluable assistance in making the study a success. We also thank the institutions and ethical boards for allowing us to carry out the study. Finally, I would like to thank the study participants for their time and important information, without which this study would not have been possible.