Choosing Profile Double-Sampling Designs for Survival Estimation with Application to PEPFAR Evaluation

• Activity Number: 8
• Type: Invited
• Date/Time: Sunday, August 3, 2014 : 2:00 PM to 3:50 PM
• Sponsor: ENAR
• Author(s): Ming-Wen An and Constantine E. Frangakis and Constantin T. Yiannoutsos*+
• Companies: Vassar College and Johns Hopkins University and Indiana University School of Public Health
• Keywords: double sampling ; design ; missing data ; PEPFAR

Abstract

Most studies that follow subjects over time are challenged by having some subjects who dropout. Double-sampling is a design that selects, and devotes resources to intensively pursue and find a subset of these dropouts; then uses data obtained from these to adjust naive estimates, which are potentially biased by the dropout. In limited-resource settings, generating accurate estimates using a minimum of resources is important. We propose using double-sampling designs that oversample certain profiles of dropouts as more efficient alternatives to random designs. First, we develop a framework to estimate the survival function under these profile double-sampling designs. We then derive the precision of these designs as a function of the rule for selecting different profiles, in order to identify more efficient designs. We illustrate using data from the United States President's Emergency Plan for AIDS Relief (PEPFAR)-funded HIV care and treatment program in western Kenya.