Accepted for Publication: December 9, 2013.
Published Online: February 17, 2014. doi:10.1001/jamainternmed.2013.14458.
Study concept and design: Hendriks, Wit, Akande, Kramer, Osagbemi, Gustafsson-Wright, Brewster, Lange, Schultsz.
Acquisition of data: Hendriks, Akande, Kramer, Osagbemi.
Analysis and interpretation of data: Hendriks, Wit, Tanović, Gustafsson-Wright, Brewster, Schultsz.
Drafting of the manuscript: Hendriks, Wit, Brewster, Schultsz.
Critical revision of the manuscript for important intellectual content: Akande, Kramer, Osagbemi, Tanović, Gustafsson-Wright, Brewster, Lange, Schultsz.
Statistical analysis: Hendriks, Wit, Tanović, Gustafsson-Wright.
Obtained funding: Lange.
Administrative, technical, or material support: Akande, Osagbemi.
Study supervision: Wit, Akande, Osagbemi, Gustafsson-Wright, Brewster, Schultsz.
Conflict of Interest Disclosures: None reported.
Funding/Support: The study was supported by the Health Insurance Fund (http://www.hifund.org/), PharmAccess Foundation, and Hygiea Nigeria Limited.
Role of the Sponsors: The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: We thank all members of the Household Survey Study Group for their contribution to the study. The following members of the study group contributed to data collection: Oladimeji Akeem Bolarinwa, MD, Sunday Adedeji Aderibigbe, MD, Hannah Olawumi, MD, Abiodun Oladipo, MD, and Kabir Durowade, MD, Department of Epidemiology and Community Health, University of Ilorin Teaching Hospital; Aina Olufemi Odusola, MD, Mark te Pas, MSc, Inge Brouwer, MD, and Alexander Boers, MSc, Amsterdam Institute for Global Health and Development; Marijke Roos, PhD, and Marissa Popma, MSc, PharmAccess Foundation; Jos Rooijakkers, BSc, Marijn van der List, MSc, Anne Duynhouwer, MSc, Judith Lammers, PhD, Daan Willebrands, MSc, Tobias Lechtenfeld, PhD, and David Pap, MSc, Amsterdam Institute for International Development; and all interviewers, data entrants, and other field workers from the University of Ilorin Teaching Hospital. Jacques van der Gaag, PhD, and Jeroen van Spijk, MSc, Amsterdam Institute for International Development; and Michiel Heidenrijk, BSc, Amsterdam Institute for Global Health and Development, contributed to the design of the study.