Improving rational use of ACTs through diagnosis-dependent subsidies: Evidence from a cluster-randomized controlled trial in western Kenya.

Abstract

BACKGROUND:More than half of artemisinin combination therapies (ACTs) consumed globally are dispensed in the retail sector, where diagnostic testing is uncommon, leading to overconsumption and poor targeting. In many malaria-endemic countries, ACTs sold over the counter are available at heavily subsidized prices, further contributing to their misuse. Inappropriate use of ACTs can have serious implications for the spread of drug resistance and leads to poor outcomes for nonmalaria patients treated with incorrect drugs. We evaluated the public health impact of an innovative strategy that targets ACT subsidies to confirmed malaria cases by coupling free diagnostic testing with a diagnosis-dependent ACT subsidy. METHODS AND FINDINGS:We conducted a cluster-randomized controlled trial in 32 community clusters in western Kenya (population approximately 160,000). Eligible clusters had retail outlets selling ACTs and existing community health worker (CHW) programs and were randomly assigned 1:1 to control and intervention arms. In intervention areas, CHWs were available in their villages to perform malaria rapid diagnostic tests (RDTs) on demand for any individual >1 year of age experiencing a malaria-like illness. Malaria RDT-positive individuals received a voucher for a discount on a quality-assured ACT, redeemable at a participating retail medicine outlet. In control areas, CHWs offered a standard package of health education, prevention, and referral services. We conducted 4 population-based surveys-at baseline, 6 months, 12 months, and 18 months-of a random sample of households with fever in the last 4 weeks to evaluate predefined, individual-level outcomes. The primary outcome was uptake of malaria diagnostic testing at 12 months. The main secondary outcome was rational ACT use, defined as the proportion of ACTs used by test-positive individuals. Analyses followed the intention-to-treat principle using generalized estimating equations (GEEs) to account for clustering with prespecified adjustment for gender, age, education, and wealth. All descriptive statistics and regressions were weighted to account for sampling design. Between July 2015 and May 2017, 32,404 participants were tested for malaria, and 10,870 vouchers were issued. A total of 7,416 randomly selected participants with recent fever from all 32 clusters were surveyed. The majority of recent fevers were in children under 18 years (62.9%, n = 4,653). The gender of enrolled participants was balanced in children (49.8%, n = 2,318 boys versus 50.2%, n = 2,335 girls), but more adult women were enrolled than men (78.0%, n = 2,139 versus 22.0%, n = 604). At baseline, 67.6% (n = 1,362) of participants took an ACT for their illness, and 40.3% (n = 810) of all participants took an ACT purchased from a retail outlet. At 12 months, 50.5% (n = 454) in the intervention arm and 43.4% (n = 389) in the control arm had a malaria diagnostic test for their recent fever (adjusted risk difference [RD] = 9 percentage points [pp]; 95% CI 2-15 pp; p = 0.015; adjusted risk ratio [RR] = 1.20; 95% CI 1.05-1.38; p = 0.015). By 18 months, the ARR had increased to 1.25 (95% CI 1.09-1.44; p = 0.005). Rational use of ACTs in the intervention area increased from 41.7% (n = 279) at baseline to 59.6% (n = 403) and was 40% higher in the intervention arm at 18 months (ARR 1.40; 95% CI 1.19-1.64; p < 0.001). While intervention effects increased between 12 and 18 months, we were not able to estimate longer-term impact of the intervention and could not independently evaluate the effects of the free testing and the voucher on uptake of testing. CONCLUSIONS:Diagnosis-dependent ACT subsidies and community-based interventions that include the private sector can have an important impact on diagnostic testing and population-wide rational use of ACTs. Targeting of the ACT subsidy itself to those with a positive malaria diagnostic test may also improve sustainability and reduce the cost of retail-sector ACT subsidies. TRIAL REGISTRATION:ClinicalTrials.gov NCT02461628.

Department

Description

Provenance

Subjects

Humans, Malaria, Artemisinins, Drug Combinations, Antimalarials, Treatment Outcome, Predictive Value of Tests, Time Factors, Private Sector, Adolescent, Adult, Child, Child, Preschool, Infant, Drug Costs, Kenya, Female, Male, Nonprescription Drugs, Medication Adherence, Public-Private Sector Partnerships, Community Health Workers, Healthcare Financing, Point-of-Care Testing

Citation

Published Version (Please cite this version)

10.1371/journal.pmed.1002607

Publication Info

Prudhomme O'Meara, Wendy, Diana Menya, Jeremiah Laktabai, Alyssa Platt, Indrani Saran, Elisa Maffioli, Joseph Kipkoech, Manoj Mohanan, et al. (2018). Improving rational use of ACTs through diagnosis-dependent subsidies: Evidence from a cluster-randomized controlled trial in western Kenya. PLoS medicine, 15(7). p. e1002607. 10.1371/journal.pmed.1002607 Retrieved from https://hdl.handle.net/10161/18523.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.

Scholars@Duke

Platt

Alyssa Platt

Biostatistician III

Education: Masters Degree, Applied Economics.  Duke University. 2007
Bachelors Degree, Economics and Mathematics.  University of North Carolina at Greensboro

Overview: Alyssa has ongoing collaborations with faculty from Duke Global Health Institute, Hospital Medicine, and Center for Aging. She has experience spanning the entire research cycle from grant development and research design, to primary data (or secondary data analysis), and publication of research findings. Alyssa has an MA in applied economics from Duke University and has a range of experience in the fields of health economics, health behaviors and health outcomes, including physician behavior, obesity and physical activity, infectious diseases, and childhood hearing loss. Special areas of expertise are in pilot/feasibility studies, cluster-randomized trials, electronic health records, and health economics.

Mohanan

Manoj Mohanan

Interim Dean of the Sanford School of Public Policy

Manoj Mohanan is an applied microeconomist, focusing on health and development economics, with a background in medicine and public health. His research focuses on topics related to health and health care in developing countries including: performance-based contracts, measurement of provider quality and performance, social franchising, and social accountability / monitoring.  He also studies the role of subjective expectations and beliefs in health care behavior.

Several of his projects feature field experiments, policy interventions and evaluations. Many of his current projects are based in India. 

Turner

Elizabeth Louise Turner

Associate Professor of Biostatistics & Bioinformatics

Dr. Turner is Associate Professor of Biostatistics and Global Health and serves as Director of the Research Design and Analysis Core of the Duke Global Health Institute. Her primary methodological focus is on the design and analysis of randomized controlled trials, particularly those that involve clustering such as cluster randomized trials (CRTs), stepped wedge CRTs and individually-randomized group treatment trials. She is expert in the implementation of trials in low resource settings, with a substantive focus on malaria, mental health and cardiovascular disease.

Dr. Turner joined the Department of Biostatistics & Bioinformatics and Duke Global Health Institute in March 2012 following four years as Research Fellow in the Department of Medical Statistics at the London School of Hygiene and Tropical Medicine (LSHTM). Since then, she has continued to hold a joint position with Duke's Global Health Institute (DGHI) where she serves as faculty statistician and collaborates with faculty and affiliates. Dr. Turner earned her undergraduate honors degree in Mathematics from the University of Warwick, UK, during which she spent an intercalated year at the Universite of Pierre et Marie Curie, Paris, France. She then earned her MSc and PhD in Statistics from McGill University, Canada, with her doctoral studies funded by the prestigious Commonwealth Scholarship.

Thanks to her participation in multi-disciplinary projects, Dr. turner has a great appreciation for the importance of good study design and data collection and is well aware that no fancy statistical analyses can save researchers from the scourge of bad data. Through those experiences and her teaching in different settings, including the UK, Canada, France and Tanzania, she is aware that statisticians and their collaborators sometimes “speak a different language”. As a result, her approach is very much one of translation, pragmatism and collaboration.

Further information about the Global Health Research Design and Analysis Core service can be found at:
https://globalhealth.duke.edu/dghi-research-design-analysis-core


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