A lack of follow-up also prevents the use of formal ADR causality assessment methods because much of the data required by these methods, eg, information about dechallenge or rechallenge, are usually not available from health care utilization databases, especially when supplied in aggregate form as was done in this study. If the data had been obtained in such a way that events relating to individual patients were identified, it may have been possible to use an ADR causality assessment method, but more likely, further information from the original records that generated the computer data would be required. In Saskatchewan, hospital records are generally accessible and the validity of the information is good, but the process of obtaining such information is timeconsuming and the cost is high . Access to physicians’ records tends to be more difficult, due to the reluctance of doctors to provide such access and the limited duration for which most physicians retain old records, and the quality of the information is extremely variable. In an ideal system, follow-up information should be easily, quickly and cheaply accessible as well as reliable. Therefore, our method generates signals or hypotheses that should be evaluated prospectively by appropriate methods to identify whether they are real ADRs. buy asthma inhaler

The methodology presented here has been previously evaluated using two nonsteroidal anti-inflammatory drugs . The results of that analysis indicated that an acute adverse event signalling scheme based on good quality administrative health care utilization data is a feasible and practical proposition for a systematic approach to the identification of potential ADRs. However, it is important to assess whether the method also works with a different category of drugs. The present analysis suggested that potential reactions to benzodiazepines would also be signalled using this methodology with health care utilization databases. This leads us to the same conclusion that the method is feasible, although it would be much improved by more detailed coding of diagnoses in the physician services data and inexpensive, rapid, reliable access to the original records.