1           !  " # Nyasha Tirivayi* and Wim Groot § *$ : Maastricht Graduate School of Governance, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands. E-mail: nyasha.tirivayi@maastrichtuniversity.nl . Tel: +31-0433884695. Fax: 31 43 3884864 § Department of Health Organization, Policy and Economics, Maastricht University. P.O. Box 616, 6200 MD, Maastricht, the Netherlands. E-mail: wim.groot@beoz.unimas.nl 1 Nyasha Tirivayi is a PhD Fellow at the Maastricht Graduate School of Governance, Maastricht University, in the Netherlands. Wim Groot is professor of health economics in the department of Health Organization, Policy and Economics, Maastricht University. This study was financed by UNAIDS, World Health Organization, Ford Foundation and Poverty Reduction, Equity and Growth Network. The funding bodies were not involved in the study design, data collection, analysis, interpretation, or manuscript preparation. The study was carried out with logistical and operational assistance from the World Food Program (WFP Zambia), the Zambia Ministry of Health and the Centre for Infectious Disease Research in Zambia. Ethical approval was obtained from the University of Zambia Research Ethics Committee and the Ministry of Health of the Republic of Zambia. We are deeply indebted to Calum McGregor (WFP Zambia) for all the preparations and the arrangements he made for this study to be successful. We especially acknowledge the support received from Pablo Recalde (WFP Zambia), Purnima Kashyap (WFP Zambia), Bruce Mulenga (PUSH), Godfrey Phiri (PUSH), and Joseph Mudenda (Zambia Ministry of Health). We are also grateful for the support and assistance provided by the Central Statistical Office of the Republic of Zambia and the efforts of the Enumerators, Community Liaison Officers, Food Committee Members, Adherence Support Workers, Support Group Leaders and Home Based Caregivers.