Gaussian process emulation to improve efficiency of computationally intensive multidisease models: a practical tutorial with adaptable R code.

BACKGROUND: The rapidly growing burden of non-communicable diseases (NCDs) among people living with HIV in sub-Saharan Africa (SSA) has expanded the number of multidisease models predicting future care needs and health system priorities. Usefulness of these models depends on their ability to replicate real-life data and be readily understood and applied by public health decision-makers; yet existing simulation models of HIV comorbidities are computationally expensive and require large numbers of parameters and long run times, which hinders their utility in resource-constrained settings. METHODS: We present a novel, user-friendly emulator that can efficiently approximate complex simulators of long-term HIV and NCD outcomes in Africa. We describe how to implement the emulator via a tutorial based on publicly available data from Kenya. Emulator parameters relating to incidence and prevalence of HIV, hypertension and depression were derived from our own agent-based simulation model and other published literature. Gaussian processes were used to fit the emulator to simulator estimates, assuming presence of noise for design points. Bayesian posterior predictive checks and leave-one-out cross validation confirmed the emulator's descriptive accuracy. RESULTS: In this example, our emulator resulted in a 13-fold (95% Confidence Interval (CI): 8-22) improvement in computing time compared to that of more complex chronic disease simulation models. One emulator run took 3.00 seconds (95% CI: 1.65-5.28) on a 64-bit operating system laptop with 8.00 gigabytes (GB) of Random Access Memory (RAM), compared to > 11 hours for 1000 simulator runs on a high-performance computing cluster with 1500 GBs of RAM. Pareto k estimates were < 0.70 for all emulations, which demonstrates sufficient predictive accuracy of the emulator. CONCLUSIONS: The emulator presented in this tutorial offers a practical and flexible modelling tool that can help inform health policy-making in countries with a generalized HIV epidemic and growing NCD burden. Future emulator applications could be used to forecast the changing burden of HIV, hypertension and depression over an extended (> 10 year) period, estimate longer-term prevalence of other co-occurring conditions (e.g., postpartum depression among women living with HIV), and project the impact of nationally-prioritized interventions such as national health insurance schemes and differentiated care models.

Cost-effectiveness of differentiated care models that incorporate economic strengthening for HIV antiretroviral therapy adherence: a systematic review.

BACKGROUND: There is some evidence that differentiated service delivery (DSD) models, which use a client-centered approach to simplify and increase access to care, improve clinical outcomes among people living with HIV (PLHIV) in high HIV prevalence countries. Integrating economic strengthening tools (e.g., microcredit, cash transfers, food assistance) within DSD models can help address the poverty-related barriers to HIV antiretroviral therapy (ART). Yet there is minimal evidence of the cost-effectiveness of these types of multilevel care delivery models, which potentially prohibits their wider implementation. METHODS: Using a qualitative systematic review, this article synthesizes the literature surrounding the cost-effectiveness of differentiated service delivery models that employ economic strengthening initiatives to improve HIV treatment adherence in low- and middle-income countries. We searched three academic databases for randomized controlled trials and observational studies published from January 2000 through March 2024 in Sub-Saharan Africa. The quality of each study was scored using a validated appraisal system. RESULTS: Eighty-nine full texts were reviewed and 3 met all eligibility criteria. Two of the three included articles were specific to adolescents living with HIV. Economic strengthening opportunities varied by care model, and included developmental savings accounts, microenterprise workshops, and cash and non-cash conditional incentives. The main drivers of programmatic and per-patient costs were ART medications, CD4 cell count testing, and economic strengthening activities. CONCLUSION: All economic evaluations in this review found that including economic strengthening as part of comprehensive differentiated service delivery was cost-effective at a willingness to pay threshold of at least 2 times the national per capita gross domestic product. Two of the three studies in this review focused on adolescents, suggesting that these types of care models may be especially cost-effective for youth entering adulthood. All studies were from the provider perspective, indicating that additional evidence is needed to inform the potential cost-savings of DSD and economic strengthening interventions to patients and society. Randomized trials testing the effectiveness of DSD models that integrate economic strengthening should place greater emphasis on costing these types of programs to inform the potential for bringing these types of multilevel interventions to scale.

Phase-Based Gait Prediction after Botulinum Toxin Treatment Using Deep Learning.

Gait disorders in neurological diseases are frequently associated with spasticity. Intramuscular injection of Botulinum Toxin Type A (BTX-A) can be used to treat spasticity. Providing optimal treatment with the highest possible benefit-risk ratio is a crucial consideration. This paper presents a novel approach for predicting knee and ankle kinematics after BTX-A treatment based on pre-treatment kinematics and treatment information. The proposed method is based on a Bidirectional Long Short-Term Memory (Bi-LSTM) deep learning architecture. Our study's objective is to investigate this approach's effectiveness in accurately predicting the kinematics of each phase of the gait cycle separately after BTX-A treatment. Two deep learning models are designed to incorporate categorical medical treatment data corresponding to the injected muscles: (1) within the hidden layers of the Bi-LSTM network, (2) through a gating mechanism. Since several muscles can be injected during the same session, the proposed architectures aim to model the interactions between the different treatment combinations. In this study, we conduct a comparative analysis of our prediction results with the current state of the art. The best results are obtained with the incorporation of the gating mechanism. The average prediction root mean squared error is 2.99° (R2 = 0.85) and 2.21° (R2 = 0.84) for the knee and the ankle kinematics, respectively. Our findings indicate that our approach outperforms the existing methods, yielding a significantly improved prediction accuracy.

The Effects of Mobile Primary Health Teams: Evidence from the Médico del Barrio Strategy in Ecuador.

Starting in 2017, Ecuador gradually expanded its primary healthcare access program nationwide using mobile traveling healthcare teams through the Estrategia Médico del Barrio (EMB) [or Neighborhood Doctor Strategy]. EMB teams, composed of a primary care physician, a nurse, and a community health worker, made home visits in marginalized areas. We estimate the impact of the EMB on health and utilization outcomes using nationally representative household surveys for 2006 (N=55,666), 2012-13 (N=92,500) and 2018-19 (N=168,747). The treatment variable at the extensive margin is any exposure to EMB at the canton level. At the intensive margin, we use exposure in terms of weeks covered by EMB and the number and composition of EMB personnel per 1000 population. We identify outcomes of treated vs. non- or partially-treated cantons based on the random combination of the timing of the start of the program's implementation and the timing of the survey interview, which varied across cantons. We use difference-in-difference (DD) and difference-in-difference-in-difference (DDD) frameworks, the latter for cantons with high indigenous concentration. We find significant effects on the reported health problem and preventive care, but mixed results in terms of curative healthcare. The DDD specification shows that EMB improved health problem diagnoses and preventive healthcare utilization, including in highly indigenous cantons, yet it seemed to have had mixed results in terms of curative care use in Ecuador. Various alternative specifications and robustness tests do not qualitatively alter the main findings.

HIV Incidence and Death Among Orphaned and Nonorphaned Children and Adolescents Living in Family-Based Settings in Western Kenya: A Prospective Cohort Analysis.

OBJECTIVE: To compare the incidence of HIV, death, and abuse among orphaned children to nonorphaned children living in households caring for orphaned children in Western Kenya. STUDY DESIGN: A random sample was taken of 300 households caring for at least one orphaned child in Uasin Gishu County, Kenya. All orphaned and nonorphaned children in each selected household were enrolled in a prospective cohort study between 2010 and 2013. A total of 1488 children (487 double orphans, 743 single orphans, and 258 nonorphans) were followed up annually until 2019. Survival analysis was used to estimate hazard ratios and 95% confidence intervals (CIs) of the association between the number of parents the child had lost (none, 1, or 2), and HIV incidence, death, combined HIV incidence or death, and incident abuse. RESULTS: Among 1488 children enrolled, 52% of participants were females, 23 were HIV positive, and the median age was 10.4 years. Over the course of the study, 16 orphaned children died and 11 acquired HIV. No deaths or incident HIV infections were observed among the nonorphaned children. Among children who were HIV negative at enrollment, loss of a parent was strongly associated with incident HIV (adjusted hazard ratio: 2.21 per parent lost, 95% CI: 1.03-4.73) and HIV or death (adjusted hazard ratio: 2.46 per parent lost, 95% CI: 1.37-4.42). There were no significant associations between orphan level and abuse. CONCLUSIONS: In similar households, orphaned children experience a higher risk of HIV and death than nonorphaned children. Both orphaned children and the families caring for them need additional support to prevent adverse health outcomes.

Enabling Adherence to Treatment (EAT): a pilot study of a combination intervention to improve HIV treatment outcomes among street-connected individuals in western Kenya.

BACKGROUND: Street-connected individuals (SCI) in Kenya experience barriers to accessing HIV care. This pilot study provides proof-of-concept for Enabling Adherence to Treatment (EAT), a combination intervention providing modified directly observed therapy (mDOT), daily meals, and peer navigation services to SCI living with HIV or requiring therapy for other conditions (e.g. tuberculosis). The goal of the EAT intervention was to improve engagement in HIV care and viral suppression among SCI living with HIV in an urban setting in Kenya. METHODS: This pilot study used a single group, pre/post-test design, and enrolled a convenience sample of self-identified SCI of any age. Participants were able to access free hot meals, peer navigation services, and mDOT 6 days per week. We carried out descriptive statistics to characterize participants' engagement in EAT and HIV treatment outcomes. We used McNemar's chi-square test to calculate unadjusted differences in HIV outcomes pre- and post-intervention among participants enrolled in HIV care prior to EAT. We compared unadjusted time to initiation of antiretroviral therapy (ART) and first episode of viral load (VL) suppression among participants enrolled in HIV care prior to EAT vs. concurrently with EAT using the Wilcoxon rank sum test. Statistical significance was defined as p < 0.05. We calculated total, fixed, and variable costs of the intervention. RESULTS: Between July 2018 and February 2020, EAT enrolled 87 participants: 46 (53%) female and 75 (86%) living with HIV. At baseline, 60 out of 75 participants living with HIV (80%) had previously enrolled in HIV care. Out of 60, 56 (93%) had initiated ART, 44 (73%) were active in care, and 25 (42%) were virally suppressed (VL < 1000 copies/mL) at their last VL measure in the 19 months before EAT. After 19 months of follow-up, all 75 participants living with HIV had enrolled in HIV care and initiated ART, 65 (87%) were active in care, and 44 (59%) were virally suppressed at their last VL measure. Among the participants who were enrolled in HIV care before EAT, there was a significant increase in the proportion who were active in HIV care and virally suppressed at their last VL measure during EAT enrollment compared to before EAT enrollment. Participants who enrolled in HIV care concurrently with EAT had a significantly shorter time to initiation of ART and first episode of viral suppression compared to participants who enrolled in HIV care prior to EAT. The total cost of the intervention over 19 months was USD $57,448.64. Fixed costs were USD $3623.04 and variable costs were USD $63.75/month/participant. CONCLUSIONS: This pilot study provided proof of concept that EAT, a combination intervention providing mDOT, food, and peer navigation services, was feasible to implement and may support engagement in HIV care and achievement of viral suppression among SCI living with HIV in an urban setting in Kenya. Future work should focus on controlled trials of EAT, assessments of feasibility in other contexts, and cost-effectiveness studies.

Clinical Gait Analysis: Characterizing Normal Gait and Pathological Deviations Due to Neurological Diseases.

This study addresses the characterization of normal gait and pathological deviations induced by neurological diseases, considering knee angular kinematics in the sagittal plane. We propose an unsupervised approach based on Dynamic Time Warping (DTW) to identify different normal gait profiles (NGPs) corresponding to real cycles representing the overall behavior of healthy subjects, instead of considering an average reference, as done in the literature. The obtained NGPs are then used to measure the deviations of pathological gait cycles from normal gait with DTW. Hierarchical Clustering is applied to stratify deviations into clusters. Results show that three NGPs are necessary to finely characterize the heterogeneity of normal gait and accurately quantify pathological deviations. In particular, we automatically identify which lower limb is affected for Hemiplegic patients and characterize the severity of motor impairment for Paraplegic patients. Concerning Tetraplegic patients, different profiles appear in terms of impairment severity. These promising results are obtained by considering the raw description of gait signals. Indeed, we have shown that normalizing signals removes the temporal properties of signals, inducing a loss of dynamic information that is crucial for accurately measuring pathological deviations. Our methodology could be exploited to quantify the impact of therapies on gait rehabilitation.

Continuity of Care is Associated with Higher Appointment Adherence Among HIV Patients in Low Clinician-to-Patient Ratio Facilities in Western Kenya.

We sought to determine the relationship between continuity of care and adherence to clinic appointments among patients receiving HIV care in high vs. low clinician-to-patient (C:P) ratios facilities in western Kenya. This retrospective analysis included 12,751 patients receiving HIV care from the Academic Model Providing Access to Healthcare (AMPATH) program, between February 2016-2019. We used logistic regression analysis with generalized estimating equations to estimate the relationship between continuity of care (two consecutive visits with the same provider) and adherence to clinic appointments (within 7 days of a scheduled appointment) over time. Adjusting for covariates, patients in low C:P ratio facilities who had continuity of care, were more likely to be adherent to their appointments compared to those without continuity (adjusted odds ratio = 1.50; 95% confidence interval, 1.33-1.69). Continuity in HIV care may be a factor in clinical adherence among patients in low C:P ratio facilities and should therefore be promoted.

"The Money, It's OK but It's not OK": Patients' and Providers' Perceptions of the Acceptability of Cash Incentives for HIV Treatment Initiation in Cape Town, South Africa.

Incentive-based interventions are used to encourage HIV testing, linkage to HIV care, and antiretroviral therapy (ART) adherence. Studies assessing efficacy of cash incentives have raised questions about the perceived ethicality of and attitudes towards incentives. Here we explore patients' and health providers' perspectives of the acceptability of a conditional cash transfer for ART initiation after receiving a positive HIV test through community-based services in resource-poor communities in Cape Town, South Africa. Drawing on in-depth interviews with patients and health care workers (HCWs), we find that, despite the perception that cash incentives are effective in promoting ART initiation, significant ambivalence surrounds the acceptability of such incentives. The receipt of a financial incentive was highly moralized, and fraught with challenges. Increasing the acceptability of cash incentives through careful design and delivery of interventions is central to the potential of this type of intervention for improving outcomes along the HIV care continuum.

Preferences for Conditional Economic Incentives to Improve Pre-exposure Prophylaxis Adherence: A Discrete Choice Experiment Among Male Sex Workers in Mexico.

Pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV but requires sustained adherence. Conditional economic incentives (CEIs) can improve medication-taking behaviors, yet preferences for programs that employ CEIs to increase PrEP use among male sex workers (MSWs) have not been investigated. We conducted a discrete choice experiment in Mexico City to elicit stated preferences for a CEI-based PrEP adherence program among MSWs. Respondents expressed their preferences for different program characteristics: incentive amount; incentive format; incentive type; and adherence-verification method. We used a random utility logit model to estimate the relative importance of each attribute and estimated willingness-to-pay. MSWs preferred a higher, fixed incentive, with PrEP adherence measured via hair sampling. MSWs were willing to forego up to 21% of their potential maximum CEI amount to ensure receipt of a fixed payment. MSWs are highly willing to accept a CEI-based intervention for PrEP adherence, if offered along with fixed payments.

RESUMEN: La profilaxis previa a la exposición (PrEP) es muy eficaz para prevenir el VIH, pero requiere una adherencia sostenida. Los incentivos económicos condicionales (IEC) pueden mejorar los comportamientos de toma de medicamentos, sin embargo, no se han investigado las preferencias por los programas que emplean IEC para aumentar el uso de PrEP entre los trabajadores sexuales masculinos (TSM). Realizamos un experimento de elección discreta con TSM en la Ciudad de México para obtener preferencias declaradas para un programa de adherencia a la PrEP basado en IEC. Los participantes expresaron sus preferencias en cuanto a diferentes características: monto del incentivo; formato del incentivo; tipo de incentivo; y método de verificación de la adherencia. Utilizamos un modelo logit de utilidad aleatoria para estimar la importancia relativa de cada atributo y la disposición a pagar estimada (DAP). Los TSM prefirieron un incentivo fijo más alto, con la adherencia a la PrEP medida a través de muestras de cabello. Los TSM estaban dispuestos a renunciar hasta el 21% de su monto máximo potencial de IEC para garantizar la recepción de un pago fijo. Los TSM están muy dispuestos a aceptar una intervención basada en IEC para la adherencia a la PrEP, si se ofrece junto con pagos fijos.

Effect of care environment on educational attainment among orphaned and separated children and adolescents in Western Kenya.

BACKGROUND: There are approximately 140 million orphaned and separated children (OSCA) around the world. In Kenya, many of these children live with extended family while others live in institutions. Despite evidence that orphans are less likely to be enrolled in school than non-orphans, there is little evidence regarding the role of care environment. This evidence is vital for designing programs and policies that promote access to education for orphans, which is not only their human right but also an important social determinant of health. The purpose of this study was to compare educational attainment among OSCA living in Charitable Children's Institutions and family-based settings in Uasin Gishu County, Kenya. METHODS: This study analyses follow up data from a cohort of OSCA living in 300 randomly selected households and 17 institutions. We used Poisson regression to estimate the effect of care environment on primary school completion among participants age ≥ 14 as well as full and partial secondary school completion among participants age ≥ 18. Risk ratios and 95% confidence intervals were estimated using a bootstrap method with 1000 replications. RESULTS: The analysis included 1406 participants (495 from institutions, 911 from family-based settings). At baseline, 50% were female, the average age was 9.5 years, 54% were double orphans, and 3% were HIV-positive. At follow-up, 76% of participants age ≥ 14 had completed primary school and 32% of participants age ≥ 18 had completed secondary school. Children living in institutions were significantly more likely to complete primary school (aRR: 1.18, 95% CI: 1.10-1.28) and at least 1 year of secondary school (aRR: 1.28, 95% CI: 1.18-1.39) than children in family-based settings. Children living in institutions were less likely to have completed all 4 years secondary school (aRR: 0.79, 95% CI: 0.43-1.18) than children in family-based settings. CONCLUSION: Children living in institutional environments were more likely to complete primary school and some secondary school than children living in family-based care. Further support is needed for all orphans to improve primary and secondary school completion. Policies that require orphans to leave institution environments upon their eighteenth birthday may be preventing these youth from completing secondary school.

Treatment Outcome Prediction Using Multi-Task Learning: Application to Botulinum Toxin in Gait Rehabilitation.

We propose a framework for optimizing personalized treatment outcomes for patients with neurological diseases. A typical consequence of such diseases is gait disorders, partially explained by command and muscle tone problems associated with spasticity. Intramuscular injection of botulinum toxin type A is a common treatment for spasticity. According to the patient's profile, offering the optimal treatment combined with the highest possible benefit-risk ratio is important. For the prediction of knee and ankle kinematics after botulinum toxin type A (BTX-A) treatment, we propose: (1) a regression strategy based on a multi-task architecture composed of LSTM models; (2) to introduce medical treatment data (MTD) for context modeling; and (3) a gating mechanism to model treatment interaction more efficiently. The proposed models were compared with and without metadata describing treatments and with serial models. Multi-task learning (MTL) achieved the lowest root-mean-squared error (RMSE) (5.60°) for traumatic brain injury (TBI) patients on knee trajectories and the lowest RMSE (3.77°) for cerebral palsy (CP) patients on ankle trajectories, with only a difference of 5.60° between actual and predicted. Overall, the best RMSE ranged from 5.24° to 6.24° for the MTL models. To the best of our knowledge, this is the first time that MTL has been used for post-treatment gait trajectory prediction. The MTL models outperformed the serial models, particularly when introducing treatment metadata. The gating mechanism is efficient in modeling treatment interaction and improving trajectory prediction.

Barriers and facilitators to pre-exposure prophylaxis uptake among male sex workers in Mexico: an application of the RE-AIM framework.

BACKGROUND: The ImPrEP México demonstration project is the first to distribute free HIV pre-exposure prophylaxis (PrEP) to men who have sex with men (MSM) and transgender women living in Mexico. In Mexico City, MSM who are also male sex workers (MSWs) face a disproportionately high risk of HIV infection. PrEP is highly effective for HIV prevention, yet "real-life" implementation among MSWs is a challenge due to the unique adherence barriers faced by this population. METHODS: This study uses the RE-AIM implementation science framework to characterize the unique barriers to and facilitators of PrEP uptake among MSWs in Mexico City. We conducted 9 in-depth key informant interviews and 2 focus group discussions with MSWs across 5 clinic and community sites. Qualitative data were analyzed using inductive, open coding approaches from grounded theory. We supplemented findings from the primary qualitative analysis with quantitative indicators derived from ImPrEP program records to describe the current Reach of the ImPrEP program among MSWs in Mexico City and the potential for wider PrEP Adoption among other high-risk populations in Mexico. RESULTS: The Reach of the ImPrEP program was 10% of known HIV-negative MSWs in Mexico City. Program Reach was lowest among MSWs who were street-based sex workers, of lower socioeconomic status, migrants from other states and self-identified as heterosexual. Barriers to program Reach included limited PrEP knowledge, HIV-related stigma, and structural barriers; facilitators included in-person program recruitment, patient-centered care, and spread of information through word of mouth among MSWs. Two out of the four eligible institutions had adopted the ImPrEP protocol. Barriers to wider program Adoption included HIV- and sexual identity- related stigma, protocol limitations, and lack of a national policy for PrEP distribution; facilitators of Adoption included existing healthcare infrastructure, sensitized providers, and community support from non-governmental organizations. CONCLUSIONS: Increasing the ImPrEP program's Reach among MSWs will depend on improving PrEP education and addressing HIV-related stigma and access barriers. Future Adoption of the ImPrEP program should build on existing clinical infrastructure and community support. Creation of a national policy for PrEP distribution may improve the Reach and Adoption of PrEP among highest-risk populations in Mexico.

Implementing enhanced patient care to promote patient engagement in HIV care in a rural setting in Kenya.

BACKGROUND: Patient engagement is effective in promoting adherence to HIV care. In an effort to promote patient-centered care, we implemented an enhanced patient care (EPC) intervention that addresses a combination of system-level barriers including provider training, continuity of clinician-patient relationship, enhanced treatment dialogue and better clinic scheduling. We describe the initial implementation of the EPC intervention in a rural HIV clinic in Kenya, and the factors that facilitated its implementation. METHODS: The intervention occurred in one of the rural Academic Model Providing Healthcare (AMPATHplus) health facilities in Busia County in the western region of Kenya. Both qualitative and quantitative data were collected through training and meeting proceedings/minutes, a patient tracking tool, treatment dialogue and a peer confirmation tool. Qualitative data were coded and emerging themes on the implementation and adaptation of the intervention were developed. Descriptive analysis including percentages and means were performed on the quantitative data. RESULTS: Our analysis identified four key factors that facilitated the implementation of this intervention. (1) The smooth integration of the intervention as part of care that was facilitated by provider training, biweekly meetings between the research and clinical team and having an intervention that promotes the health facility agenda. (2) Commitment of stakeholders including providers and patients to the intervention. (3) The adaptability of the intervention to the existing context while still maintaining fidelity to the intervention. (4) Embedding the intervention in a facility with adequate infrastructure to support its implementation. CONCLUSIONS: This analysis demonstrates the value of using mixed methods approaches to study the implementation of an intervention. Our findings emphasize how critical local support, local infrastructure, and effective communication are to adapting a new intervention in a clinical care program.

Cost-Effectiveness of Care Environments for Improving the Mental Health of Orphaned and Separated Children and Adolescents in Kenya

BACKGROUND: Institutionalization has shown contradictory effects on the mental health of orphaned and separated children and adolescents (OSCA) in sub-Saharan Africa. There is a paucity of data surrounding the cost-effectiveness of different care environments for improving OSCA's mental health. AIMS OF THE STUDY: The goal of this analysis was to evaluate the cost-effectiveness of Charitable Children's Institutions (orphanages) compared to family-based settings serving OSCA in East Africa in terms of USD/unit reduction in mental health diagnoses (depression, anxiety, post-traumatic stress disorder, suicidality) and quality-adjusted life-year (QALY) gained. METHODS: This economic analysis was conducted from a societal perspective as part of the Orphaned and Separated Children's Assessments Related to their (OSCAR's) Health and Well-Being Project, a 10-year longitudinal cohort study evaluating the effects of different care environments on OSCA's physical and psychological health in western Kenya. Cost data were ascertained from 9 institutions and 225 family-based settings in the OSCAR cohort via survey assessments, budget reports, and expert interviews. Monthly per-child costs were calculated as the sum of recurrent and capital costs divided by the environment's maximum residential capacity, and cost differences between care environments were estimated using two-part models. Mental health effectiveness outcomes were derived from prior survival regression analyses conducted among the OSCAR cohort. We used Child Depression Inventory Short-Form scores at baseline and follow-up to calculate the number of depression-free days (DFDs) over the follow-up period, and translated DFDs into QALYs using established utility weights. Incremental cost-effectiveness ratios (ICERs) were calculated as the difference in monthly per-child cost divided by the difference in each mental health outcome, comparing institutions to family-based settings. Sampling uncertainty in the ICERs was handled using nonparametric bootstrapping with 1,000 replications. We assumed a willingness-to-pay threshold of three times Kenya's per capita gross domestic product. RESULTS: Charitable Children's Institutions cost USD 123 more on average than family-based settings in terms of monthly per-child expenditures (p<0.001). Compared to family-based care, institutional care resulted in an ICER of USD 236, USD 280, USD 397, and USD 456 per unit reduction in depression, anxiety, PTSD, and suicidal diagnosis among OSCA, respectively. The incremental cost per additional QALY was USD 4,929 (95% CI: USD 3096 -- USD 6740). The probability of Charitable Children's Institutions being more cost-effective than family-based settings was greater than 90% for willingness-to-pay thresholds above USD 7,000/QALY. DISCUSSION: Only a subset of institutions in the cohort were willing to provide budgetary information for this assessment, which potentially biased our cost estimates. However, institutions who did not provide budget data likely had lower expenditures than those for whom cost data were collected, leading to more conservative cost estimates. Furthermore, our QALY estimates were based solely on depression-free days such that OSCA in institutions may experience added mental health benefits for no additional costs. IMPLICATIONS FOR HEALTH POLICY: Compared to family-based settings, institutions may be more cost-effective for improving mental health outcomes among orphaned and separated children and adolescents. Our findings suggest that policy-makers should prioritize resources to strengthen family-based care but that formal institutions can offer cost-effective, mental health support as a last resort.

Cash Transfers and Contraceptive Use: A Regression Discontinuity Analysis.

Conditional cash transfers (CCTs) have become important components of social protection policies in Latin America. By establishing coresponsibilities tied to health and education, CCTs may reduce poverty and encourage human capital investment. While CCT programs can have unintended effects on sexual and reproductive health outcomes, such effects have been mixed and poorly documented in South America. This study examines the impact of Ecuador's CCT program, Bono de Desarrollo Humano, on contraceptive behavior among women of childbearing age who are sexually active and do not wish to become pregnant. We analyze nationally representative data in a regression-discontinuity quasi-experimental design. Using an instrumental variable approach and a set of robustness checks, our study finds no significant effects of the CCT program on contraceptive use. Our results offer important considerations for the ongoing policy debate in South America regarding the effects of cash transfer programs on beneficiaries.

"I Do Try To Use Condoms, But ": Knowledge and Interest in PrEP Among Male Sex Workers in Mexico City.

In Mexico City, male sex workers (MSWs) are up to 126 times more likely to be living with HIV than the general public. We conducted interviews with 23 MSWs in Mexico City to examine their subjective understandings about their sexual risk behaviors and explore opportunities about HIV pre-exposure prophylaxis (PrEP) as a prevention approach in this group. Despite knowledge about sexual HIV risks, most participants reported condomless anal sex with clients. There was very little prior knowledge about PrEP, but very high interest in using a daily pill for prevention. Several participants expected an increase in condomless anal sex if taking PrEP, because of monetary incentives from clients or a perceived increase in pleasure. Additionally, seasonal sex workers expressed interest in using PrEP only during months when they were performing sex work. PrEP implementation efforts through Mexico's healthcare system should recognize the varying needs and sexual risk behaviors of MSWs.

Effects of social health insurance on access and utilization of obstetric health services: results from HIV+ pregnant women in Kenya.

BACKGROUND: Reducing maternal morbidity and mortality remains a top global health agenda especially in high HIV/AIDS endemic locations where there is increased likelihood of mother to child transmission (MTCT) of HIV. Social health insurance (SHI) has emerged as a viable option to improve population access to health services, while improving outcomes for disenfranchised populations, particularly HIV+ women. However, the effect of SHI on healthcare access for HIV+ persons in limited resource settings is yet to undergo rigorous empirical evaluation. This study analyzes the effect of health insurance on obstetric healthcare access including institutional delivery and skilled birth attendants for HIV+ pregnant women in Kenya. METHODS: We analyzed cross-sectional data from HIV+ pregnant women (ages 15-49 years) who had a delivery (full term, preterm, miscarriage) between 2008 and 2013 with their insurance enrollment status available in the electronic medical records database of a HIV healthcare system in Kenya. We estimated linear and logistic regression models and implemented matching and inverse probability weighting (IPW) to improve balance on observable individual characteristics. Additionally, we estimated heterogeneous effects stratified by HIV disease severity (CD4 < 350 as "Severe HIV disease", and CD4 > 350 otherwise). FINDINGS: Health Insurance enrollment is associated with improved obstetric health services utilization among HIV+ pregnant women in Kenya. Specifically, HIV+ pregnant women covered by NHIF have greater access to institutional delivery (12.5-percentage points difference) and skilled birth attendants (19-percentage points difference) compared to uninsured. Notably, the effect of NHIF on obstetric health service use is much greater for those who are sicker (CD4 < 350) - 20 percentage points difference. CONCLUSION: This study confirms conceptual and practical considerations around health insurance and healthcare access for HIV+ persons. Further, it helps to inform relevant policy development for health insurance and HIV financing and delivery in Kenya and in similar countries in sub-Saharan Africa in the universal health coverage (UHC) era.

The Impact of Rhode Island's Multipayer Patient-centered Medical Home Program on Utilization and Cost of Care.

OBJECTIVE: To estimate the effect of patient-centered medical home (PCMH) participation on cost and utilization of care for patients in Rhode Island's statewide, multipayer PCMH program, which serves over one-third of the state population. DATA SOURCES/STUDY SETTING: 2009-2014 claims data from all payers in Rhode Island, representing >743,000 unique patients. STUDY DESIGN: A propensity score-matched difference-in-differences framework was used to separately estimate the effect of the PCMH on 3 patient cohorts, which were defined by their intervention start dates and amounts of implementation time. Outcomes included patient costs (total, inpatient, outpatient, professional, pharmacy) and utilization [emergency department (ED) visits, preventable ED visits, inpatient admissions, preventable inpatient admissions, all-cause 30-day readmissions]. Interaction effects were estimated to assess heterogeneity among clinical risk groups and payers. PRINCIPAL FINDINGS: There was no evidence of a PCMH effect on total costs, though we observed evidence of an increase in the odds of PCMH patients having outpatient and professional costs, and in one cohort, a decrease in inpatient costs for those with an inpatient visit. We also observed evidence of reduced ED visits, preventable ED visits, and inpatient admissions for PCMH patients. While subgroup effects varied by cohort and measure, high-risk patients often experienced the largest reductions in ED visits. CONCLUSIONS: All PCMH cohorts experienced statistically significant reductions in some types of utilization in as little as 1.25 years. Reductions were greatest for measures included in the PCMH contractual agreement. While PCMH programs may not expect cost savings in the short-term, costs could potentially be reduced in the longer-term through avoided ED and inpatient expenses.

Risk Factors for Early Disenrollment From Colorado's Affordable Care Act Marketplace.

BACKGROUND: Midyear disenrollment from Marketplace coverage may have detrimental effects on continuity of care and risk pool stability of individual health insurance markets. OBJECTIVE: The main objective of this study was to assess associations between insurance plan characteristics, individual and area-level demographics, and disenrollment from Marketplace coverage. DATA: All payer claims data from individual market enrollees, 2014-2016. STUDY DESIGN: We estimated Cox proportional hazards models to assess the relationship between plan actuarial value and Marketplace enrollment. The primary outcome was disenrollment from Marketplace coverage before the end of the year. We also calculated the proportion of enrollees who transitioned to other coverage after leaving the Marketplace, and identified demographic and area-level factors associated with early disenrollment. Finally, we compared monthly utilization rates between those who disenrolled early and those who maintained coverage. RESULTS: Nearly 1 in 4 Marketplace beneficiaries disenrolled midyear. The hazard rate of disenrollment was 30% lower for individuals in plans receiving cost-sharing reductions and 21% lower for those enrolled in gold plans, compared with silver plans without cost-sharing subsidies. Young adults had a 70% increased hazard of disenrollment compared with older adults. Those who disenrolled midyear had greater hospital and emergency department utilization before disenrollment compared with those who maintained continuous coverage. CONCLUSIONS: Plan generosity is significantly associated with lower disenrollment rates from Marketplace coverage. Reducing churning in Affordable Care Act Marketplaces may improve continuity of care and insurers' ability to accurately forecast the health care costs of their enrollees.