Study Retention as Bias Reduction in a Hard-to-Reach Population

Very poor and otherwise disadvantaged populations pose a challenge for research. The circumstances of extreme disadvantage—homelessness, acute economic insecurity, untreated addiction or mental illness, for example—are urgent problems but also make research subjects elusive or unwilling. We examine study retention in a deeply disadvantaged sample of newly released prisoners, achieving a 94% response rate over five survey waves over 1 y of follow-up. The high response rate indicates strategies for study retention and points to biases associated with nonresponse. Small-scale data collections can illuminate very harsh conditions of contemporary poverty by observing repeated and co-occurring episodes of homelessness, institutionalization, mental illness, and physical disability that are largely unobserved with conventional methods.