Primary nonadherence occurs when new prescriptions are not dispensed. Little is known about how to reduce primary nonadherence. We performed a randomized controlled trial to evaluate an automated system to decrease primary nonadherence to statins for lowering cholesterol.
Adult members of Kaiser Permanente Southern California with no history of statin use within the past year who did not fill a statin prescription after 1 to 2 weeks were passively enrolled. The intervention group received automated telephone calls followed 1 week later by letters for continued nonadherence; the control group received no outreach. The primary outcome was a statin dispensed up to 2 weeks after delivery of the letter. Secondary outcomes included refills at intervals up to 1 year. Intervention effectiveness was determined by intent-to-treat analysis and Fisher exact test. Subgroups were examined using logistic regression.
There were 2606 participants in the intervention group and 2610 in the control group. Statins were dispensed to 42.3% of intervention participants and 26.0% of control participants (absolute difference, 16.3%; P < .001). The relative risk for the intervention vs control group was 1.63 (95% CI, 1.50-1.76). Intervention effectiveness varied slightly by age (P = .045) but was effective across all age strata. Differences in the frequency of statin dispensations persisted up to 1 year (P < .001).
The intervention was effective in reducing primary nonadherence to statin medications. Because of low marginal costs for outreach, this strategy appears feasible for reducing primary nonadherence. This approach may generalize well to other medications and chronic conditions.