Author Contributions: Dr Qato had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Schumm, Lindau.
Acquisition of data: Johnson, Schumm, Lindau.
Analysis and interpretation of data: Qato, Alexander, Conti, Schumm, Lindau.
Drafting of the manuscript: Qato, Alexander, Conti, Schumm, Lindau.
Critical revision of the manuscript for important intellectual content: Qato, Alexander, Conti, Johnson, Schumm, Lindau.
Statistical analysis: Qato, Schumm.
Obtained funding: Schumm, Lindau.
Administrative, technical, or material support: Johnson, Schumm, Lindau.
Study supervision: Alexander, Conti, Lindau.
Financial Disclosures: Dr Qato reported serving as a consultant for IMS Health. Dr Alexander reported serving as a consultant to AstraZeneca and receiving grant support from Pfizer and the Merck Foundation. No other authors reported disclosures.
Funding/Support: The National Social Life, Health and Aging Project (NSHAP) is supported by the National Institutes of Health, including the National Institute on Aging, the Office of Research on Women's Health, the Office of AIDS Research, and the Office of Behavioral and Social Sciences Research (5R01AG021487). NSHAP is also supported by NORC, whose staff was responsible for the data collection. The National Institutes of Health, National Institute on Aging University of Chicago—NORC Center on Demography and Economics of Aging Core on Biomarkers in Population-Based Health and Aging Research (5 P30 AG 012857) and the University of Chicago Program in Pharmaceutical Policy (David Meltzer, principal investigator) also supported the effort of Dr Qato and Mssrs Schumm and Johnson on this article with a pilot grant (Dr Lindau, principal investigator). The University of Chicago Program in Pharmaceutical Policy is supported by the Merck Foundation. Dr Alexander has career development awards from the Agency for Healthcare Research and Quality (K08 HS15699-01A1) and the Robert Wood Johnson Physician Faculty Scholars Program. Supplies were donated to the NSHAP study by OraSure, Sunbeam, A & D Medical/LifeSource, Wilmer Eye Institute at the Johns Hopkins Bloomberg School of Public Health, Schleicher & Schuell Bioscience, BioMerieux, Roche Diagnostics, Digene, and Richard Williams.
Role of the Sponsors: The funding sources had no role in the design and conduct of the study; the analysis or interpretation of the data; or the preparation or final approval of the manuscript.
Additional Contributions: We gratefully acknowledge the research assistance of Andreea Mihai, who is a paid research assistant for Dr Lindau at the University of Chicago.