The Tasmanian Epilepsy Register--a community-based cohort. Background and methodology for patient recruitment from the Australian national prescription database.

BACKGROUND/AIMS: Centralized prescription databases may provide an efficient mechanism for recruitment of community-treated disease. METHODS: The Australian federal government agency, the Health Insurance Commission (HIC), invited patients to participate in the Tasmanian Epilepsy Register (TER). Eligible patients included those who received at least one anticonvulsant above a 'reportable' price threshold between July 1, 2001 and June 30, 2002. Patients were asked to disclose their medical indication for anticonvulsant treatment with additional demographic and prescription information obtained from the HIC. RESULTS: 7,541 were eligible for recruitment. After two mail invitations over 6 months, 3,375 (46.6%) had responded, but TER enrollment amongst those indicating treatment for epilepsy was 1,180 (78.3%). TER participants were more likely to obtain their prescriptions exclusively from their general practitioner (70.9%) or from combined sources (19.1%) rather than from pediatrician (4.2%), neurologist (1.4%) or general physician (1.0%) sources. Patients were more likely to respond with increasing age (linear trend p < 0.001), when from a higher socioeconomic area (linear trend p < 0.001), or if their prescription was obtained from a neurologist (p < 0.001). CONCLUSION: The national Australian prescription database represents community-treated epilepsy and provides an effective and efficient method for patient recruitment for clinical epidemiological research.