The New Zealand intensive medicines monitoring programme in pro-active safety surveillance.

Purpose-The purpose of this paper is to demonstrate the pro-active nature of the New Zealand Intensive Medicines Monitoring Programme (IMMP) and make an assessment of its effectiveness in postmarketing drug safety evaluation.Methods-The IMMP undertakes prospective observational cohort studies of selected new drugs. Patient cohorts are established from prescription data received from dispensing pharmacists nationwide. Adverse events are reported by doctors on prescription follow-up questionnaires or as spontaneous reports. The method of signal generation is reviewed with particular emphasis on the review of individual event reports and their relationship to the medicine. Signals reported over the last 10 years are assessed for timeliness in advising the regulatory authority.Results-Mean cohort size is 10,964 patients and the mean study period for each drug was 58 months. A total of 153 signals were recorded from 11 drugs with 132 (86%) being notified to the regulatory authority prior to any publication in the literature. The use of 'incidents' in controlling for reporting bias is illustrated and examples are given of data on safety in pregnancy and lactation, the assessment of deaths, reassurance with drug scares, risk comparison and signal validation studies.Conclusion-PEM type methodology is effective and cost-efficient in pro-active safety surveillance even with limited resources. Copyright (c) 2000 John Wiley & Sons, Ltd.