The Value of Patient-Centred Registries in Phase IV Drug Surveillance

In the past, postmarketing surveillance of drugs relied mainly on the spontaneous reporting of adverse drug reactions. There are now several other approaches used, including databases with individual prescription data (or prescription event monitoring systems), electronic health records and record linkage between health databases. The recent drug withdrawals have continued to highlight the inadequacies of current postmarketing surveillance and the need for better strategies to monitor the safety of new drugs. One such strategy is the use of drug registries.Drug registries facilitate a special form of prospective observational cohort study of patients exposed to a particular drug. They are particularly useful in establishing the safety of orphan drugs and ascertaining the safety of drugs in specific populations. To minimize bias, patient eligibility is defined and data capture is standardized. All patients are followed up systematically over a pre-defined time period, either manually or using electronic record linkage to other health databases. To establish the incidence of any adverse events using a drug registry, there should be complete follow-up of all patients.Drug registries may play an important role in postmarketing surveillance of new drugs. Unlike spontaneous reporting systems they have the benefit of being able to determine the incidence of one or more outcomes in the patient population. Drug registries do, however, have some limitations, including a potential for bias and confounding, long periods of follow-up and high cost.