Online Program

Costs of Failing to Reach the Hard to Reach among a High Needs Population and Tips for Sampling and Cohort Retention

*Angela A Aidala, Columbia University 
Peter Messeri, Columbia University 

Keywords: Hard to reach, services research, HIV/AIDS

Most studies examining costs of increased effort to reach the harder to reach have examined the issue among study populations where distributions of variables of interest are not greatly different among interviewed and not interviewed, or imbalance can be statistically adjusted by use of demographic or other controls. This is not the case when substantial proportions of the study population live their lives at the margins of society, and study goals are to better understand and respond to their challenges and needs. The NYC Community Health study has enrolled several probability samples of persons living with HIV/AIDS and followed them successfully (85-90% cohort retention)over multiple years –investing considerable effort to reach the hardest to reach. This presentation will: 1) examine differences among cohort members by length of time required to locate and complete follow-up interviews; 2) examine characteristics of the hardest to reach with regard to potential for using alternative modes of contact including internet, TTS, or RDS techniques; 3) sharing lessons learned in maintaining a hard to reach/ harder to follow cohort. The HTR more likely to have unstable housing, to be actively using drugs and have low mental health functioning – however less likely to be receiving services to address these needs. They have equal access to HIV medical care and medications but much more likely to miss scheduled appointments. Marginal connection to the HIV care system limits the use of medical clinics as recruitment venues. The HTR have smaller social networks with substantial proportion of non-associative members (other heterosexual, non-drug using, non-HIV positive women or men) challenging RDS methods. More than half have no internet access. Sampling, tracking and tracing lessons learned will be shared.