Context Retrospective drug utilization review is required of all state Medicaid
programs and is performed by most private-sector prescription programs. However,
it has not been shown to improve clinical outcomes or reduce the rate of potential
prescribing errors, known as "exceptions."
Objective To look for an effect of retrospective drug utilization review on the
rate of exceptions and of clinical outcomes in patients with an exception.
Design, Setting, and Participants Longitudinal ecologic study of the rate of exceptions, controlling for
preintervention trends and calendar time; and a cohort study of all-cause
and cause-specific hospitalizations in patients with an exception, controlling
for potential individual-level confounders in 6 Medicaid programs using the
same software in the mid-1990s.
Main Outcome Measures The rate of exceptions was examined as a function of retrospective drug
utilization review implementation. In addition, before-after comparisons were
made of the incidence of all-cause and cause-specific hospitalization in patients
Results We found no reduction in the rate of exceptions coincident with retrospective
drug utilization review implementation (rate increase, 0.064 exceptions per
1000 prescriptions per month; 95% confidence interval [CI], −0.006 to
0.133). We also found no effect of retrospective drug utilization review on
the incidence of all-cause hospitalization (odds ratio, 0.99; 95% CI, 0.98-1.00)
or cause-specific hospitalization. These results persisted in multiple subgroup
analyses. Study states intervened using physician alerts in between 1% and
25% of exceptions.
Conclusions We were unable to identify an effect of retrospective drug utilization
review on the rate of exceptions or on clinical outcomes. Given the lack of
evidence for effectiveness, and suggestions from previous research of possible
harm, policymakers should consider withdrawing the legislative mandate for
retrospective drug utilization review.