Simultaneous alleviation of verification and reference standard biases in a community-based tuberculosis screening study using Bayesian latent class analysis.

BACKGROUND: Estimation of prevalence and diagnostic test accuracy in tuberculosis (TB) prevalence surveys suffer from reference standard and verification biases. The former is attributed to the imperfect reference test used to bacteriologically confirm TB disease. The latter occurs when only the participants screening positive for any TB-compatible symptom or chest X-ray abnormality are selected for bacteriological testing (verification). Bayesian latent class analysis (LCA) alleviates the reference standard bias but suffers verification bias in TB prevalence surveys. This work aims to identify best-practice approaches to simultaneously alleviate the reference standard and verification biases in the estimates of pulmonary TB prevalence and diagnostic test performance in TB prevalence surveys. METHODS: We performed a secondary analysis of 9869 participants aged ≥15 years from a community-based multimorbidity screening study in a rural district of KwaZulu-Natal, South Africa (Vukuzazi study). Participants were eligible for bacteriological testing using Xpert Ultra and culture if they reported any cardinal TB symptom or had an abnormal chest X-ray finding. We conducted Bayesian LCA in five ways to handle the unverified individuals: (i) complete-case analysis, (ii) analysis assuming the unverified individuals would be negative if bacteriologically tested, (iii) analysis of multiply-imputed datasets with imputation of the missing bacteriological test results for the unverified individuals using multivariate imputation via chained equations (MICE), and simultaneous imputation of the missing bacteriological test results in the analysis model assuming the missing bacteriological test results were (iv) missing at random (MAR), and (v) missing not at random (MNAR). We compared the results of (i)-(iii) to the analysis based on a composite reference standard (CRS) of Xpert Ultra and culture. Through simulation with an overall true prevalence of 2.0%, we evaluated the ability of the models to alleviate both biases simultaneously. RESULTS: Based on simulation, Bayesian LCA with simultaneous imputation of the missing bacteriological test results under the assumption that the missing data are MAR and MNAR alleviate the reference standard and verification biases. CRS-based analysis and Bayesian LCA assuming the unverified are negative for TB alleviate the biases only when the true overall prevalence is <3.0%. Complete-case analysis produced biased estimates. In the Vukuzazi study, Bayesian LCA with simultaneous imputation of the missing bacteriological test results under the MAR and MNAR assumptions produced overall PTB prevalence of 0.9% (95% Credible Interval (CrI): 0.6-1.9) and 0.7% (95% CrI: 0.5-1.1) respectively alongside realistic estimates of overall diagnostic test sensitivity and specificity with substantially overlapping 95% CrI. The CRS-based analysis and Bayesian LCA assuming the unverified were negative for TB produced 0.7% (95% CrI: 0.5-0.9) and 0.7% (95% CrI: 0.5-1.2) overall PTB prevalence respectively with realistic estimates of overall diagnostic test sensitivity and specificity. Unlike CRS-based analysis, Bayesian LCA of multiply-imputed data using MICE mitigates both biases. CONCLUSION: The findings demonstrate the efficacy of these advanced techniques in alleviating the reference standard and verification biases, enhancing the robustness of community-based screening programs. Imputing missing values as negative for bacteriological tests is plausible under realistic assumptions.

The Tools for Integrated Management of Childhood Illness (TIMCI) study protocol: a multi-country mixed-method evaluation of pulse oximetry and clinical decision support algorithms.

Effective and sustainable strategies are needed to address the burden of preventable deaths among children under-five in resource-constrained settings. The Tools for Integrated Management of Childhood Illness (TIMCI) project aims to support healthcare providers to identify and manage severe illness, whilst promoting resource stewardship, by introducing pulse oximetry and clinical decision support algorithms (CDSAs) to primary care facilities in India, Kenya, Senegal and Tanzania. Health impact is assessed through: a pragmatic parallel group, superiority cluster randomised controlled trial (RCT), with primary care facilities randomly allocated (1:1) in India to pulse oximetry or control, and (1:1:1) in Tanzania to pulse oximetry plus CDSA, pulse oximetry, or control; and through a quasi-experimental pre-post study in Kenya and Senegal. Devices are implemented with guidance and training, mentorship, and community engagement. Sociodemographic and clinical data are collected from caregivers and records of enrolled sick children aged 0-59 months at study facilities, with phone follow-up on Day 7 (and Day 28 in the RCT). The primary outcomes assessed for the RCT are severe complications (mortality and secondary hospitalisations) by Day 7 and primary hospitalisations (within 24 hours and with referral); and, for the pre-post study, referrals and antibiotic. Secondary outcomes on other aspects of health status, hypoxaemia, referral, follow-up and antimicrobial prescription are also evaluated. In all countries, embedded mixed-method studies further evaluate the effects of the intervention on care and care processes, implementation, cost and cost-effectiveness. Pilot and baseline studies started mid-2021, RCT and post-intervention mid-2022, with anticipated completion mid-2023 and first results late-2023. Study approval has been granted by all relevant institutional review boards, national and WHO ethical review committees. Findings will be shared with communities, healthcare providers, Ministries of Health and other local, national and international stakeholders to facilitate evidence-based decision-making on scale-up.Study registration: NCT04910750 and NCT05065320.

Pulse oximetry and clinical decision support algorithms show potential for supporting healthcare providers to identify and manage severe illness among children under-five attending primary care in resource-constrained settings, whilst promoting resource stewardship but scale-up has been hampered by evidence gaps.This study design article describes the largest scale evaluation of these interventions to date, the results of which will inform country- and global-level policy and planning .

Computer-aided detection thresholds for digital chest radiography interpretation in tuberculosis diagnostic algorithms.

Objectives: Use of computer-aided detection (CAD) software is recommended to improve tuberculosis screening and triage, but threshold determination is challenging if reference testing has not been performed in all individuals. We aimed to determine such thresholds through secondary analysis of the 2019 Lesotho national tuberculosis prevalence survey. Methods: Symptom screening and chest radiographs were performed in participants aged ≥15 years; those symptomatic or with abnormal chest radiographs provided samples for Xpert MTB/RIF and culture testing. Chest radiographs were processed using CAD4TB version 7. We used six methodological approaches to deal with participants who did not have bacteriological test results to estimate pulmonary tuberculosis prevalence and assess diagnostic accuracy. Results: Among 17 070 participants, 5214 (31%) had their tuberculosis status determined; 142 had tuberculosis. Prevalence estimates varied between methodological approaches (0.83-2.72%). Using multiple imputation to estimate tuberculosis status for those eligible but not tested, and assuming those not eligible for testing were negative, a CAD4TBv7 threshold of 13 had a sensitivity of 89.7% (95% CI 84.6-94.8) and a specificity of 74.2% (73.6-74.9), close to World Health Organization (WHO) target product profile criteria. Assuming all those not tested were negative produced similar results. Conclusions: This is the first study to evaluate CAD4TB in a community screening context employing a range of approaches to account for unknown tuberculosis status. The assumption that those not tested are negative - regardless of testing eligibility status - was robust. As threshold determination must be context specific, our analytically straightforward approach should be adopted to leverage prevalence surveys for CAD threshold determination in other settings with a comparable proportion of eligible but not tested participants.

COVID-19 screening in low resource settings using artificial intelligence for chest radiographs and point-of-care blood tests.

Artificial intelligence (AI) systems for detection of COVID-19 using chest X-Ray (CXR) imaging and point-of-care blood tests were applied to data from four low resource African settings. The performance of these systems to detect COVID-19 using various input data was analysed and compared with antigen-based rapid diagnostic tests. Participants were tested using the gold standard of RT-PCR test (nasopharyngeal swab) to determine whether they were infected with SARS-CoV-2. A total of 3737 (260 RT-PCR positive) participants were included. In our cohort, AI for CXR images was a poor predictor of COVID-19 (AUC = 0.60), since the majority of positive cases had mild symptoms and no visible pneumonia in the lungs. AI systems using differential white blood cell counts (WBC), or a combination of WBC and C-Reactive Protein (CRP) both achieved an AUC of 0.74 with a suggested optimal cut-off point at 83% sensitivity and 63% specificity. The antigen-RDT tests in this trial obtained 65% sensitivity at 98% specificity. This study is the first to validate AI tools for COVID-19 detection in an African setting. It demonstrates that screening for COVID-19 using AI with point-of-care blood tests is feasible and can operate at a higher sensitivity level than antigen testing.

Impact of a multi-disease integrated screening and diagnostic model for COVID-19, TB, and HIV in Lesotho.

The surge of the COVID-19 pandemic challenged health services globally, and in Lesotho, the HIV and tuberculosis (TB) services were similarly affected. Integrated, multi-disease diagnostic services were proposed solutions to mitigate these disruptions. We describe and evaluate the effect of an integrated, hospital-based COVID-19, TB and HIV screening and diagnostic model in two rural districts in Lesotho, during the period between December 2020 and August 2022. Adults, hospital staff, and children above 5 years attending two hospitals were pre-screened for COVID-19 and TB symptoms. After a positive pre-screening, participants were offered to enroll in a service model that included clinical evaluation, chest radiography, SARS-CoV-2, TB, and HIV testing. Participants diagnosed with COVID-19, TB, or HIV were contacted after 28 days to evaluate their health status and linkage to HIV and/or TB care services. Of the 179160 participants pre-screened, 6623(3.7%) pre-screened positive, and 4371(66%) were enrolled in this service model. Of the total 458 diagnoses, only 17 happened in children. One positive rapid antigen test for SARS-CoV-2 was found per 11 participants enrolled, one Xpert-positive TB case was diagnosed per 85 people enrolled, and 1 new HIV diagnosis was done per 182 people enrolled. Of the 321(82.9%) participants contacted after 28 days of diagnosis, 304(94.7%) reported to be healthy. Of the individuals that were newly diagnosed with HIV or TB, 18/24(75.0%) and 46/51(90.1%) started treatment within 28 days of the diagnosis. This screening and diagnostic model successfully maintained same-day, integrated COVID-19, TB, and HIV testing services, despite frequent disruptions caused by the surge of COVID-19 waves, healthcare seeking patterns, and the volatile context (social measures, travel restrictions, population lockdowns). There were positive effects in avoiding diagnostic delays and ensuring linkage to services, however, diagnostic yields for adults and children were low. To inform future preparedness plans, research will need to identify essential health interventions and how to optimize them along each phase of the emergency response.

Body mass index trends and its impact of under and overweight on outcome among PLHIV on antiretroviral treatment in rural Tanzania: A prospective cohort study.

INTRODUCTION: Increased body weight is an important risk factor for cardiovascular disease and is increasingly reported as a health problem in people living with HIV (PLHIV). There is limited data from rural sub-Saharan Africa, where malnutrition usually presents with both over- and undernutrition. We aimed to determine the prevalence and risk factors of underweight and overweight/obesity in PLHIV enrolled in a cohort in rural Tanzania before the introduction of integrase inhibitors. METHODS: This nested study of the prospective Kilombero and Ulanga Antiretroviral Cohort included adults aged ≥19 years initiated on antiretroviral therapy between 01/2013 and 12/2018 with follow-up through 06/2019. Body Mass Index (BMI) was classified as underweight (<18.5 kg/m2), normal (18.5-24.9 kg/m2), or overweight/obese (≥25.0 kg/m2). Stratified piecewise linear mixed models were used to assess the association between baseline characteristics and follow-up BMI. Cox proportional hazard models were used to assess the association between time-updated BMI and death/loss to follow-up (LTFU). RESULTS: Among 2,129 patients, 22,027 BMI measurements (median 9 measurements: interquartile range 5-15) were analysed. At baseline, 398 (19%) patients were underweight and 356 (17%) were overweight/obese. The majority of patients were female (n = 1249; 59%), and aged 35-44 years (779; 37%). During the first 9 months, for every three additional months on antiretroviral therapy, BMI increased by 2% (95% confidence interval 1-2%, p<0.0001) among patients underweight at baseline and by 0.7% (0.5-0.6%, p<0.0001) among participants with normal BMI. Over a median of 20 months of follow-up, 107 (5%) patients died and 592 (28%) were LTFU. Being underweight was associated with >2 times the hazard of death/LTFU compared to participants with normal BMI. CONCLUSION: We found a double burden of malnutrition, with underweight being an independent predictor of mortality. Monitoring and measures to address both states of malnutrition among PLHIV should be integrated into routine HIV care.

Beyond Undetectable: Modeling the Clinical Benefit of Improved Antiretroviral Adherence in Persons With Human Immunodeficiency Virus With Virologic Suppression.

Background: Incomplete antiretroviral therapy (ART) adherence has been linked to deleterious immunologic, inflammatory, and clinical consequences, even among virally suppressed (<50 copies/mL) persons with human immunodeficiency virus (PWH). The impact of improving adherence in the risk of severe non-AIDS events (SNAEs) and death in this population is unknown. Methods: We estimated the reduction in the risk of SNAEs or death resulting from an increase in ART adherence by (1) applying existing data on the association between adherence with high residual inflammation/coagulopathy in virally suppressed PWH, and (2) using a Cox proportional hazards model derived from changes in plasma interleukin 6 (IL-6) and D-dimer from 3 randomized clinical trials. Comparatively, assuming 100% ART adherence in a PWH who achieves viral suppression, we estimated the number of persons in whom a decrease in adherence to <100% would need to be observed for an additional SNAE or death event to occur during 3- and 5-year follow-up. Results: Increasing ART adherence to 100% in PWH who are suppressed on ART despite imperfect adherence translated into a 6%-37% reduction in the risk of SNAEs or death. Comparatively, based on an anticipated 12% increase in IL-6, 254 and 165 PWH would need to decrease their adherence from 100% to <100% for an additional event to occur over 3- and 5-year follow-up, respectively. Conclusions: Modest gains in ART adherence could have clinical benefits beyond virologic suppression. Increasing ART adherence (eg, via an intervention or switch to long-acting ART) in PWH who remain virally suppressed despite incomplete adherence should be evaluated.

Head-to-head comparison of nasal and nasopharyngeal sampling using SARS-CoV-2 rapid antigen testing in Lesotho.

OBJECTIVES: To assess the real-world diagnostic performance of nasal and nasopharyngeal swabs for SD Biosensor STANDARD Q COVID-19 Antigen Rapid Diagnostic Test (Ag-RDT). METHODS: Individuals ≥5 years with COVID-19 compatible symptoms or history of exposure to SARS-CoV-2 presenting at hospitals in Lesotho received two nasopharyngeal and one nasal swab. Ag-RDT from nasal and nasopharyngeal swabs were performed as point-of-care on site, the second nasopharyngeal swab used for polymerase chain reaction (PCR) as the reference standard. RESULTS: Out of 2198 participants enrolled, 2131 had a valid PCR result (61% female, median age 41 years, 8% children), 84.5% were symptomatic. Overall PCR positivity rate was 5.8%. The sensitivity for nasopharyngeal, nasal, and combined nasal and nasopharyngeal Ag-RDT result was 70.2% (95%CI: 61.3-78.0), 67.3% (57.3-76.3) and 74.4% (65.5-82.0), respectively. The respective specificity was 97.9% (97.1-98.4), 97.9% (97.2-98.5) and 97.5% (96.7-98.2). For both sampling modalities, sensitivity was higher in participants with symptom duration ≤ 3days versus ≤ 7days. Agreement between nasal and nasopharyngeal Ag-RDT was 99.4%. CONCLUSIONS: The STANDARD Q Ag-RDT showed high specificity. Sensitivity was, however, below the WHO recommended minimum requirement of ≥ 80%. The high agreement between nasal and nasopharyngeal sampling suggests that for Ag-RDT nasal sampling is a good alternative to nasopharyngeal sampling.

Dolutegravir in real life: Self-reported mental and physical health outcomes after transitioning from efavirenz- to dolutegravir-based antiretroviral therapy in a prospective cohort study in Lesotho.

INTRODUCTION: HIV programmes across many countries in Africa have recently transitioned people living with HIV from efavirenz (EFV)- to dolutegravir (DTG)-containing antiretroviral therapy (ART). As both drugs are associated with neuropsychiatric adverse effects, this study assessed the mental health and HIV/ART-associated symptoms of people living with HIV before and after transition to DTG. METHODS: The prospective DO-REAL cohort enrolled people starting DTG-based ART in Lesotho from February to December 2020. For this analysis within DO-REAL, we included adults changing from tenofovir disoproxil fumarate (TDF)/lamivudine (3TC)/EFV to TDF/3TC/DTG within first-line therapy. At transition and 16 weeks thereafter, participants completed the Patient Health Questionnaire-9 (PHQ-9; depression screening), the 12-item Short-Form Health Survey (SF-12; mental and physical health), and a modified HIV Symptom Index (mHSI; HIV/ART-related symptoms). We also assessed weight change. We used McNemar tests with Bonferroni corrections to assess binary outcomes. CLINICALTRIALS: gov: NCT04238767. RESULTS: Among 1228 participants, 1131 completed follow-up. Of these, 60.0% were female, the median age was 46 years (interquartile range [IQR] 38-55), and the median time taking ART was 5.7 years (IQR 3.5-8.9). No change was observed for weight or overall PHQ-9 or SF-12 outcomes. However, three mHSI items decreased at follow-up: 'feeling sad/down/depressed' (bothered 6.0% vs. 3.3% of participants at least 'a little' before vs. after transition; adjusted p = 0.048); 'feeling nervous/anxious' (7.4% vs. 3.4%; adjusted p = 0.0009); and 'nightmares, strange/vivid dreams' (6.3% vs. 3.5%; adjusted p = 0.027). Individual PHQ-9 or SF-12 items also improved. Being symptom free across all measures increased from 5.1% to 11.4% (p < 0.0001). CONCLUSIONS: We observed no negative impacts and potential moderate improvements with DTG, providing further support for the rollout of DTG.

Diagnosis of SARS-CoV-2 infection from breath - a proof-of-concept study.

Bioaerosol capture and analysis is emerging as a non-invasive diagnostic method for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this proof-of-concept study conducted in Lesotho, we evaluated the novel and simple AL2 bioaerosol detection device in comparison to conventional nasopharyngeal sampling methods. We demonstrated for the first time that SARS-CoV-2 can be detected using the AL2 bioaerosol capture device. However, studies with a larger sample size are needed to further evaluate this bioaerosol capture device for the detection of SARS-CoV-2.

Causes of death and associated factors over a decade of follow-up in a cohort of people living with HIV in rural Tanzania.

BACKGROUND: Nearly half of HIV-related deaths occur in East and Southern Africa, yet data on causes of death (COD) are scarce. We determined COD and associated factors among people living with HIV (PLHIV) in rural Tanzania. METHODS: PLHIV attending the Chronic Diseases Clinic of Ifakara, Morogoro are invited to enrol in the Kilombero and Ulanga Antiretroviral Cohort (KIULARCO). Among adults (≥ 15 years) enrolled in 2005-2018, with follow-up through April 2019, we classified COD in comprehensive classes and as HIV- or non-HIV-related. In the subset of participants enrolled in 2013-2018 (when data were more complete), we assessed cause-specific mortality using cumulative incidences, and associated factors using proportional hazards models. RESULTS: Among 9871 adults (65% female, 26% CD4 count < 100 cells/mm3), 926 (9%) died, among whom COD were available for 474 (51%), with missing COD mainly in earlier years. The most common COD were tuberculosis (N = 127, 27%), non-AIDS-related infections (N = 72, 15%), and other AIDS-related infections (N = 59, 12%). Cardiovascular and renal deaths emerged as important COD in later calendar years, with 27% of deaths in 2018 attributable to cardiovascular causes. Most deaths (51%) occurred within the first six months following enrolment. Among 3956 participants enrolled in 2013-2018 (N = 203 deaths, 200 with COD ascertained), tuberculosis persisted as the most common COD (25%), but substantial proportions of deaths from six months after enrolment onwards were attributable to renal (14%), non-AIDS-related infections (13%), other AIDS-related infections (10%) and cardiovascular (10%) causes. Factors associated with higher HIV-related mortality were sex, younger age, living in Ifakara town, HIV status disclosure, hospitalisation, not being underweight, lower CD4 count, advanced WHO stage, and gaps in care. Factors associated with higher non-HIV-related mortality included not having an HIV-positive partner, lower CD4 count, advanced WHO stage, and gaps in care. CONCLUSION: Incidence of HIV-related mortality was higher than that of non-HIV-related mortality, even in more recent years, likely due to late presentation. Tuberculosis was the leading specific COD identified, particularly soon after enrolment, while in later calendar years cardiovascular and renal causes emerged as important, emphasising the need for improved screening and management.

Incidence, Treatment and Outcome of Patients with Retroperitoneal Soft-Tissue Sarcoma in Switzerland 2005-2015: A Population-Based Analysis.

BACKGROUND: Reports on the epidemiology and mortality of retroperitoneal soft tissue sarcoma (RSTS) in Switzerland are scarce. This study investigates the incidence and outcomes of surgically treated RSTS inpatients in Switzerland depending on the hospital type and size. METHODS: Data from the Swiss Federal Statistical Office were used to conduct a retrospective analysis of all RSTS inpatients and hospitalizations in Switzerland between 2005 and 2015. RSTS was identified by the code C48.x of the International Classification of Diseases (ICD-10). Sarcoma centers were identified by the annual total number of sarcoma patients (> 50 patients/year). The analysis of yearly incidence, age distribution as well as in-hospital complication and mortality was performed for non- and surgical-treated patients. A centralization of treating sarcoma patients was analyzed by the trend of hospitalizations in sarcoma centers and high-volume hospitals. RESULTS: During 2005-2015, 2.801 hospitalizations (1651 patients) were admitted to Swiss hospitals with the primary diagnosis of a RSTS. The yearly number of RSTS patients and the incidence (1.91/100.000) stayed constant within these 11 years. There were five sarcoma centers. We saw a clear trend of RSTS patients being treated (especially surgically) in centers over the 11 years. The complication rate of surgical-treated patients was higher in sarcoma centers (55% vs. 40%), though the overall mortality rate was lower (3.2% vs. 9.1%). CONCLUSION: Centralization of RSTS treatment to certified sarcoma centers leads to a lower overall mortality rate and thus is highly recommended.

The Suboptimal Pediatric HIV Viral Load Cascade: Multidistrict Cohort Study Among Children Taking Antiretroviral Therapy in Lesotho, Southern Africa.

BACKGROUND: Children living with HIV and taking antiretroviral therapy (ART) are a priority group for routine viral load (VL) monitoring. As per Lesotho guidelines, a VL ≥1000 copies/mL ("unsuppressed") should trigger adherence counseling and a follow-up VL; 2 consecutive unsuppressed VLs ("virologic failure") qualify for switching to second-line ART, with some exceptions. Here, we describe the pediatric VL cascade in Lesotho. METHODS: In a prospective open cohort study comprising routine VL results from 22 clinics in Lesotho, we assessed outcomes along the VL cascade for children who had at least 1 VL test from January 2016 through June 2020. Data were censored on February 10, 2021. RESULTS: In total, 1215 children received 5443 VL tests. The median age was 10 years (interquartile range 7-13) and 627/1215 (52%) were female; 362/1215 (30%) had at least 1 unsuppressed VL. A follow-up VL was available for 325/362 (90%), although only for 159/362 (44%) within 6 months of the first unsuppressed VL. Of those with a follow-up VL, 172/329 (53%) had virologic failure and 123/329 (37%) qualified for switching to second-line ART. Of these, 55/123 (45%) were ever switched, although only 9/123 (7%) were switched within 12 weeks of the follow-up VL. Delays were more pronounced in rural facilities. Overall, 100/362 (28%) children with an unsuppressed VL received a timely follow-up VL and, if required, a timely regimen switch. CONCLUSIONS: Despite access to VL monitoring, clinical management was suboptimal. HIV programs should prioritize timely clinical action to maximize the benefits of VL monitoring.

Failure to return pillbox is a predictor of being lost to follow-up among people living with HIV on antiretroviral therapy in rural Tanzania.

OBJECTIVES: Pill count is used to assess drug adherence in people living with HIV (PLHIV). Carrying a pillbox is associated with fear of concealment and stigma and might indicate poor adherence and predict someone who will be lost to follow-up (LTFU). We therefore assessed the association between pillbox return and being LTFU in rural Tanzania. METHODS: This is a nested study of the Kilombero and Ulanga Antiretroviral Cohort (KIULARCO). We included PLHIV aged ≥ 18 years enrolled in KIULARCO between January 2013 and March 2019 with follow-up through January 2020, who were on antiretroviral treatment (ART) for ≥ 6 months. Baseline was defined as the latest ART initiation or KIULARCO enrolment. We determined the association between time-dependent failed pillbox return updated at every visit and LTFU using Kaplan-Meier estimation and Cox models. RESULTS: Among 2552 PLHIV included in the study, 1735 (68.0%) were female, 959 (40.3%) had a WHO stage III/IV and 1487 (66.4%) had a CD4 cell count < 350 cells/µL. The median age was 38.4 years [interquartile range (IQR): 31.7-46.2]. During a median follow-up of 33.1 months (IQR: 17.5-52.4), 909 (35.6%) participants were LTFU, 43 (1.7%) died and 194 (7.6%) had transferred to another clinic. The probability of being LTFU was higher among PLHIV with failed pillbox return than among those who returned their pillbox [30.0%, 95% confidence interval (CI): 26.8-33.2% vs. 19.4%, 95% CI: 17.4-21.6%, respectively, at 24 months (hazard ratio = 1.67, 95% CI: 1.46-1.90; p < 0.001)]. CONCLUSIONS: Failed pillbox return was associated with a higher risk of being LTFU and could be used as a simple tool to identify PLHIV for appropriate interventions to reduce their chance of being LTFU.

Estimating intervention effectiveness in trials of malaria interventions with contamination.

BACKGROUND: In cluster randomized trials (CRTs) or stepped wedge cluster randomized trials (SWCRTs) of malaria interventions, mosquito movement leads to contamination between trial arms unless buffer zones separate the clusters. Contamination can be accounted for in the analysis, yielding an estimate of the contamination range, the distance over which contamination measurably biases the effectiveness. METHODS: A previously described analysis for CRTs is extended to SWCRTs and estimates of effectiveness are provided as a function of intervention coverage. The methods are applied to two SWCRTs of malaria interventions, the SolarMal trial on the impact of mass trapping of mosquitoes with odor-baited traps and the AvecNet trial on the effect of adding pyriproxyfen to long-lasting insecticidal nets. RESULTS: For the SolarMal trial, the contamination range was estimated to be 146 m ([Formula: see text] credible interval [Formula: see text] km), together with a [Formula: see text] ([Formula: see text] credible interval [Formula: see text]) reduction of Plasmodium infection, compared to the [Formula: see text] reduction estimated without accounting for contamination. The estimated effectiveness had an approximately linear relationship with coverage. For the AvecNet trial, estimated contamination effects were minimal, with insufficient data from the cluster boundary regions to estimate the effectiveness as a function of coverage. CONCLUSIONS: The contamination range in these trials of malaria interventions is much less than the distances Anopheles mosquitoes can fly. An appropriate analysis makes buffer zones unnecessary, enabling the design of more cost-efficient trials. Estimation of the contamination range requires information from the cluster boundary regions and trials should be designed to collect this.

Analysis of contamination in cluster randomized trials of malaria interventions.

BACKGROUND: In cluster randomized trials (CRTs) of interventions against malaria, mosquito movement between households ultimately leads to contamination between intervention and control arms, unless they are separated by wide buffer zones. METHODS: This paper proposes a method for adjusting estimates of intervention effectiveness for contamination and for estimating a contamination range between intervention arms, the distance over which contamination measurably biases the estimate of effectiveness. A sigmoid function is fitted to malaria prevalence or incidence data as a function of the distance of households to the intervention boundary, stratified by intervention status and including a random effect for the clustering. The method is evaluated in a simulation study, corresponding to a range of rural settings with varying intervention effectiveness and contamination range, and applied to a CRT of insecticide treated nets in Ghana. RESULTS: The simulations indicate that the method leads to approximately unbiased estimates of effectiveness. Precision decreases with increasing mosquito movement, but the contamination range is much smaller than the maximum distance traveled by mosquitoes. For the method to provide precise and approximately unbiased estimates, at least 50% of the households should be at distances greater than the estimated contamination range from the discordant intervention arm. CONCLUSIONS: A sigmoid approach provides an appropriate analysis for a CRT in the presence of contamination. Outcome data from boundary zones should not be discarded but used to provide estimates of the contamination range. This gives an alternative to "fried egg" designs, which use large clusters (increasing costs) and exclude buffer zones to avoid bias.

Recognition and management of clinically significant drug-drug interactions between antiretrovirals and co-medications in a cohort of people living with HIV in rural Tanzania: a prospective questionnaire-based study.

BACKGROUND: The extent to which drug-drug interactions (DDIs) between antiretrovirals (ARVs) and co-medications are recognized and managed has not been thoroughly evaluated in limited-resource settings. OBJECTIVES: This prospective questionnaire-based study aimed to determine the prevalence and risk factors for unrecognized/incorrectly managed DDIs in people living with HIV followed-up at the Chronic Diseases Clinic of Ifakara (CDCI) and enrolled in the Kilombero and Ulanga Antiretroviral Cohort (KIULARCO). METHODS: We prospectively included ARV-treated adults receiving ≥1 co-medication coming for a follow-up visit at the CDCI between March and July 2017. Using a structured questionnaire, physicians were requested to identify potentially clinically significant DDIs in the prescribed treatment, to provide recommendations for their management and to indicate any hurdles to implement the recommendations. Prescriptions were subsequently screened for DDIs using the Liverpool DDIs database. Identified clinically significant DDIs and their recommended management according to the DDIs database were compared with the information provided in the questionnaires. RESULTS: Among 334 participants, the median age was 47 years (IQR = 40-56 years), 69% were female and 82% had ≥1 non-communicable disease (NCD). Overall, 129 participants had ≥1 clinically relevant DDI, which was not recognized and/or incorrectly managed in 56 participants (43%). Of those, 6 (11%) were due to limited monitoring options or medication affordability issues. In the multivariable logistic regression, the presence of ≥1 NCD was associated with an increased risk for unrecognized/incorrect DDI management (OR = 15.8; 95% CI = 1.8-139.6). CONCLUSIONS: Recognition/appropriate management of DDIs is suboptimal, highlighting the need for educational programmes, pharmacovigilance activities and increased access to medications and monitoring options. This should become a focus of HIV programmes given the increasing burden of NCDs in sub-Saharan Africa.

Association of Incomplete Adherence to Antiretroviral Therapy With Cardiovascular Events and Mortality in Virologically Suppressed Persons With HIV: The Swiss HIV Cohort Study.

BACKGROUND: Incomplete antiretroviral therapy (ART) adherence, even if sufficient to maintain viral suppression, is associated with enhanced inflammation in persons with HIV (PWH). However, its clinical implications remain unknown. METHODS: PWH enrolled in the Swiss HIV Cohort Study without a history of cardiovascular disease (CVD) who initiated ART between 2003 and 2018 and had viral suppression (<50 copies/mL) for ≥6 months were evaluated. The association between incomplete self-reported ART adherence (≥1 or ≥2 missed doses in the last month) and (1) any CVD event (myocardial infarction, revascularization, cerebral hemorrhage, stroke, and/or death due to CVD event) or (2) non-CVD-related death was evaluated using adjusted Cox proportional hazards models. RESULTS: A total of 6971 PWH (74% male) were included in the analysis (median age [interquartile range {IQR}], 39 [32-47] years). The median (IQR) follow-up was 8 (4-11) years, with 14 (8-23) adherence questionnaires collected per participant. In total, 205 (3%) participants experienced a CVD event, and 186 (3%) died a non-CVD-related death. In an adjusted competing risk model where missing data were imputed, missing ≥1 ART dose showed an increased, but not statistically significant, risk for CVD events (hazard ratio [HR], 1.23; 95% CI, 0.85-1.79; P = .28). Non-CVD-related mortality showed a statistically significantly increased risk with missing ≥1 ART dose (HR, 1.44; 95% CI, 1.00-2.07; P = .05) and missing ≥2 ART doses (HR, 2.21; 95% CI, 1.37-3.57; P = .001). CONCLUSIONS: Incomplete ART adherence was significantly associated with an increased risk for non-CVD-related mortality in PWH with virologic suppression. This highlights the potential role of nonadherence to ART as a driver of non-AIDS clinical outcomes.

Abdominal Decompression after Cardiac Surgery: Outcome of 42 Patients with Abdominal Compartment Syndrome.

BACKGROUND: Up to 50% of patients in intensive care units develop intraabdominal hypertension (IAH) in the course of medical treatment. If not detected on time and treated adequately, IAH may develop into an abdominal compartment syndrome (ACS) which is associated with a high mortality rate. Patients undergoing cardiac surgery are especially prone to develop ACS due to several risk factors including intraoperative hypothermia, fluid resuscitation and acidosis. We investigated patients who developed ACS after cardiac surgery and analyzed potential risk factors, treatment and outcome. METHODS: From 2011 to 2016, patients with ACS after cardiac surgery requiring decompressive laparotomy were prospectively recorded. Patient characteristics, details on the cardiac surgery, mortality rate and type of treatment of the open abdomen were analyzed. RESULTS: Incidence of ACS in cardiac surgery patients was 1.0% (n = 42/4128), with a mortality rate of 57%. Ejection fraction, Euroscore2 as well as the perfusion time are independent risk factors for the development of ACS. The outcome of patients with ACS was independent of elective versus emergency surgery, gender, age, BMI or ASA score. In the 18 surviving patients, fascial closure was achieved in 72% after a median of 9 days. CONCLUSION: Abdominal compartment syndrome is a rare but serious complication after cardiac surgery with a high mortality rate. Independent risk factors for ACS were identified. Negative pressure wound therapy seems to promote and allow early fascia closure of the abdomen and represents therefore a likely benefit for the patient.

The Role of Human Immunodeficiency Virus (HIV) Asymptomatic Status When Starting Antiretroviral Therapy on Adherence and Treatment Outcomes and Implications for Test and Treat: The Swiss HIV Cohort Study.

BACKGROUND: Since the advent of universal test-and-treat , more people living with human immunodeficiency virus (PLHIV) initiating antiretroviral therapy (ART) are asymptomatic with a preserved immune system. We explored the impact of asymptomatic status on adherence and clinical outcomes. METHODS: PLHIV registered in the Swiss HIV Cohort Study (SHCS) between 2003 and 2018 were included. We defined asymptomatic as Centers for Disease Control and Prevention stage A within 30 days of starting ART, non-adherence as any self-reported missed doses and viral failure as two consecutive viral load>50 copies/mL after >24 weeks on ART. Using logistic regression models, we measured variables associated with asymptomatic status and adherence and Cox proportional hazard models to assess association between symptom status and viral failure. RESULTS: Of 7131 PLHIV, 76% started ART when asymptomatic and 1478 (22%) experienced viral failure after a median of 1.9 years (interquartile range, 1.1-4.2). In multivariable models, asymptomatic PLHIV were more likely to be younger, men who have sex with men, better educated, have unprotected sex, have a HIV-positive partner, have a lower viral load, and have started ART more recently. Asymptomatic status was not associated with nonadherence (odds ratio, 1.03 [95% confidence interval {CI}, .93-1.15]). Asymptomatic PLHIV were at a decreased risk of viral failure (adjusted hazard ratio, 0.87 [95% CI, .76-1.00]) and less likely to develop resistance (14% vs 27%, P < .001) than symptomatic PLHIV. CONCLUSIONS: Despite concerns regarding lack of readiness, our study found no evidence of adherence issues or worse clinical outcomes in asymptomatic PLHIV starting ART.