Do practice guidelines augment drug utilisation review?

Drug utilisation review (DUR) or drug use evaluation (DUE) studies or programmes are intended to detect and/or correct inappropriate drug use. Appropriateness can be assessed at 3 levels: (i) whether any medication is warranted, or whether either no therapy or nondrug therapy is preferred (level 1); (ii) assuming drug therapy is indicated, which of several alternative drugs is the preferred choice? (level 2); and (iii) appropriateness of the drug regimen, including dosage, duration, type and frequency of monitoring, and drug interactions (level 3). The traditional approach to DUR/DUE has been to begin the appropriateness evaluation after a drug is prescribed. However, changes in healthcare organisation provide the basis for a disease-management or health-maintenance approach to DUR/DUE, and practice guidelines afford a possible source for guiding such studies. We hypothesised that the latter approach to DUR/DUE would be more likely to result in evaluation of level 1 drug-therapy issues than the traditional DUR/DUE approach. We tested this hypothesis by reviewing 56 practice guidelines involving drug therapy and also reviewed research studies published from 1992 to 1996. We found that studies that used the traditional DUR/DUE approach were most likely to examine level 3 drug-therapy issues, never addressed level 1 issues, and typically evaluated adherence to provider- or study team-developed guidelines rather than published guidelines. In contrast, the disease- or health-management approach nearly always examined level 1 issues, seldom addressed level 3 issues, and almost always evaluated adherence to a published practice guideline. Regardless of the DUR/DUE approach, about 40% of studies evaluated level 2 issues. The guidelines themselves were much more likely to include recommendations about level 1 and level 2 issues than about level 3 issues; however, even when a guideline included level 2 or level 3 issues, studies of adherence to the guideline rarely assessed anything beyond level 1 issues. This suggests that guideline recommendations about level 2 and level 3 issues may be too imprecise for use in evaluative studies. The drug-information compendia, on the other hand, provide detailed recommendations about level 3 issues. Revision of drug compendia may be warranted to include recommendations about all levels of drug-therapy issues. The results of intervention studies to improve drug-therapy compliance with guidelines suggest that information provided at the time of prescribing, information presented by local health professionals and information provided with a large amount of provider contact may be more likely to demonstrate significant improvements in drug therapy. We conclude that practice guidelines are a useful resource for augmenting DUR/DUE but that challenges to optimising their use include whether they can be kept current, acceptable and accessible to providers.