Effective Rx choices depend on careful literature review

June 15, 2011

An accurate understanding of the effectiveness of medications, which guides decisions about their optimal use, depends on a critical appraisal of published literature, according to Alvin Goo, PharmD. Goo is a clinical pharmacist with Harborview Medical Center and clinical associate professor, University of Washington School of Pharmacy and Family Medicine, Seattle.

Key Points

An accurate understanding of the effectiveness of medications, which guides decisions about their optimal use, depends on critical appraisal of published literature, according to Alvin Goo, PharmD. Goo is a clinical pharmacist with Harborview Medical Center and clinical associate professor, University of Washington School of Pharmacy and Family Medicine, Seattle.

"Knowledge of which agent benefits which patients and the relative benefit of a new medication is the basis for safe and rational prescribing. Acquiring this knowledge requires careful evaluation of clinical trial reports and clinical practice treatment guidelines," said Goo, speaking at PPSI's Distinguished Person of the Year breakfast during the recent American Pharmacists Association conference in Seattle, Wash.

Possible pitfalls

"Efficacy demonstrated based on composite end points, relative risk reduction, or measures that are not patient-oriented may create an overstated perception of benefits that promotes drug overutilization. Analysis of number needed to treat (NNT) rather than relative risk may provide a more useful understanding of a medication's benefit, and it is important to pay attention to the characteristics of the patients enrolled to appropriately extrapolate the findings to clinical practice," he said.

When readers review the literature, they also need to be aware of publication bias, i.e., the greater likelihood for publication of studies with positive rather than negative results. In addition, when enthusiasm for a drug is based on positive results from a truncated study, such enthusiasm may need to be restrained. There have been instances in which more mature data show that interim results overestimated the treatment benefit.