Effect of different recruitment sources on the composition of a bipolar disorder case registry

Background: Conducting research on low-prevalence conditions presents an on going challenge for clinical and services researchers. Recruitment through health professionals versus other forms of self-referral may affect study g roup composition. Method's: We compared members of a voluntary case registr y for bipolar disorder who were recruited through a variety of sources incl uding health professionals, support groups, an Internet website, and mailin gs, brochures, and other general public relations activities. We also compa red the cost of recruitment methods. We hypothesized that self-referred reg istry members would be of higher socioeconomic status and less likely to be in treatment compared to members recruited through health professionals. R esults: Registrants referred through the Internet and patient support group s were better educated and more likely to be married than other registrants . However, Internet registrants were younger, had fewer lifetime hospitaliz ations and were more likely to be working. Nearly all registrants were in t reatment with a psychiatrist. Local registrants were predominantly recruite d through health professionals and public presentations. Registrants outsid e of the local region most often learned about the registry from patient su pport groups and the Internet. Local registrants were less likely to be usi ng non-lithium mood stabilizers. Recruitment through public relations effor ts tvas the most expensive method of recruitment, and the Internet website was the cheapest. Conclusions: Diverse recruitment methods can expand the p opulation available for clinical trials. For services research, the Interne t and patient support groups an less expensive ways to identify persons ser ved in diverse settings and health plans, but these recruitment methods yie ld a sample that is better educated than the remainder of the population. I t remains a difficult task to identify minorities and persons not in treatm ent.