This article shows how to compute statistical power for testing the main effect of treatment in three-arm cluster randomized trials. Using orthogonal coding, we derive the exact test statistic of the treatment effect and its non-central distribution. The non-centrality parameter in the omnibus test is found to be related to the non-centrality parameters in the contrast tests. A study of physician and pharmacist comanagement of patients' blood pressure is used as an example to show the power computation in a three-arm cluster randomized trial.
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http://dx.doi.org/10.1177/0163278713498392 | DOI Listing |
BMC Public Health
January 2025
Nutrition and Health Department, Action Against Hunger, Madrid, Spain.
Background: Acute malnutrition treatment coverage remains low worldwide, causing significant morbidity and mortality. Decentralisation of treatment to Community Health Worker (CHW) sites has shown to be an effective strategy to improve access and increase coverage, but evidence on the cost and cost-effectiveness of this approach as well the use of simplified treatment protocols in conflict settings is lacking. The objective of this study was to determine cost per child treated as well as the cost-effectiveness of the hybrid model of treatment delivery (where treatment is provided at both health facilities and CHW sites) using either a standard protocol (Intervention 1) or simplified protocol (Intervention 2) compared to standard treatment at health facilities only (Control) in the conflict affected region of Gao in Northern Mali.
View Article and Find Full Text PDFLancet Infect Dis
January 2025
Ministry of Health, Kampala, Uganda.
Background: Seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine combined with amodiaquine (SPAQ) effectively protects eligible children from malaria in areas of high and seasonal transmission. However, concerns about parasite resistance to sulfadoxine-pyrimethamine in East and Southern Africa necessitate evaluating alternative drug regimens. This study assessed the effectiveness of SPAQ and dihydroartemisinin-piperaquine for SMC in Uganda.
View Article and Find Full Text PDFBackground: In settings with low pneumococcal conjugate vaccine (PCV) coverage, multi-age cohort mass campaigns could increase population immunity, and fractional dosing could increase affordability. We aimed to evaluate the effect of mass campaigns on nasopharyngeal pneumococcal carriage of Pneumosil (PCV10) in children aged 1-9 years in Niger.
Methods: In this three-arm, open-label, cluster-randomised trial, 63 clusters of one to four villages in Niger were randomly assigned (3:3:1) using block randomisation to receive campaigns consisting of a single full dose of a 10-valent PCV (Pneumosil), a single one-fifth dose of Pneumosil, or no campaign.
Health Technol Assess
December 2024
Centre for Research in Public Health and Community Care, University of Hertfordshire, Hatfield, UK.
Lancet Glob Health
January 2025
Institute for Global Health and Development, Aga Khan University, Karachi, Pakistan; Centre for Global Child Health, The Hospital for Sick Children, Toronto, ON, Canada.
Background: Infectious diseases remain the leading cause of death among children younger than 5 years due to disparities in access and acceptance of essential interventions. The Community Mobilisation and Community Incentivisation (CoMIC) trial was designed to evaluate a customised community mobilisation and incentivisation strategy for improving coverage of evidence-based interventions for child health in Pakistan.
Methods: CoMIC was a three-arm cluster-randomised, controlled trial in rural areas of Pakistan.
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