The spectrum captured: a methodological approach to studying incidence and outcomes of traumatic brain injury on a population level.

OBJECTIVE Drawing on the experience of conducting the Brain Injury Incidence and Outcomes New Zealand in the Community study, this article aims to identify the issues arising from the implementation of proposed guidelines for population-based studies of incidence and outcomes in traumatic brain injury (TBI). STUDY DESIGN AND SETTING All new cases of TBI (all ages and severities) were ascertained over a 1-year period, using overlapping prospective and retrospective sources of case ascertainment in New Zealand. All eligible TBI cases were invited to participate in a comprehensive assessment at baseline and at 1-month follow-up. RESULTS Our experience to date has revealed the feasibility of case ascertainment methods. Consultation with community health services and professionals resulted in feasible referral pathways to support the identification of TBI cases. 'Hot pursuit' methods of recruitment were essential to ensure complete case ascertainment for this population with few additional cases of TBI identified through cross-checks. CONCLUSION This review of proposed guidelines in relation to practical study methodology provides a framework for future comparable population-based epidemiological studies of TBI incidence and outcomes in developed countries.