BACKGROUND: Ambulatory blood pressure monitoring (ABPM) has proven to be a superior predictor of morbid events when compared to clinic or office blood pressure measurement (CBPM). The purpose of this study was to evaluate the predictive value of ABPM in a sample of 14 414 people referred for management of cardiovascular risk. METHODS: In this paper we describe the methodology required to examine mortality outcome in the absence of a national unique identifier. RESULTS: Using a computerized database of deaths we were able to establish that 1348 people had died by the end of the follow-up period (30 September 2002). Sixty-four percent of deaths were cardiovascular and in 207 subjects who had post-mortem examinations, 78% were cardiovascular. CONCLUSIONS: The accurate identification of the cause of death in a large population will allow comparison of the relative predictive power of APBM and CBPM in an Irish population.