These drawbacks were overcome in Wilson’s scheme and, subsequently, in prescription-event monitoring by using the United Kingdom Prescription Pricing Authority to identify patients from the names and addresses on prescriptions in the normal course of its work. A possible alternative method of identifying patients without influencing prescribing patterns is to select them from health care utilization databases and to examine data after the initial prescription date for signals of potential adverse events. When tried in Saskatchewan, this method had some merit but also several limitations . Careful consideration must be given to how patients are identified and who registers them (Table 1). ventolin inhalers
The 1977 schemes were intended for drugs that were new active substances, although there was variation concerning whether all new products or only selected products should be monitored. The number of patients to be followed up varied from 5000 to 100,000, but would generally have been about 10,000 to allow the detection of a risk of one in 3000 with a good degree of confidence. In each scheme, patients would have been routinely followed up one year after registration and then annually for three to five years. Thus, there must be a decision about whether all new drugs should be monitored and for how long (Table 1).
Inman and the Committee on Safety of Medicines thought that all adverse events should be reported, whereas others were satisfied with the reporting of ‘serious’ events. In Dollery and Rawlins’ scheme , an additional and important part of the follow-up was a questionnaire to the patient, sent either directly or via the physician, asking about many different bodily systems and symptoms. Consequently, the last and possibly most important issue to be considered is what data would be reported and who would do the reporting (Table 1)?