Association between trajectories of statin adherence and subsequent cardiovascular events

作者：Franklin Jessica M^*; Krumme Alexis A; Tong Angela Y; Shrank William H; Matlin Olga S; Brennan Troyen A; Choudhry Niteesh K

来源：Pharmacoepidemiology and Drug Safety, 2015, 24(10): 1105-1113.

DOI：10.1002/pds.3787

• adherence
• comparative effectiveness
• epidemiologic methods
• prediction
• trajectories

PurposeTrajectory models have been shown to (1) identify groups of patients with similar patterns of medication filling behavior and (2) summarize the trajectory, the average adherence in each group over time. However, the association between adherence trajectories and clinical outcomes remains unclear. This study investigated the association between 12-month statin trajectories and subsequent cardiovascular events.
MethodsWe identified patients with insurance coverage from a large national insurer who initiated a statin during January 1, 2007 to December 31, 2010. We assessed medication adherence during the 360days following initiation and grouped patients based on the proportion of days covered (PDC) and trajectory models. We then measured cardiovascular events during the year after adherence assessment. Cox proportional hazards models were used to evaluate the association between adherence measures and cardiovascular outcomes; strength of association was quantified by the hazard ratio, the increase in model C-statistic, and the net reclassification index (NRI).
ResultsAmong 519842 statin initiators, 8777 (1.7%) had a cardiovascular event during follow-up. More consistent medication use was associated with a lower likelihood of clinical events, whether adherence was measured through trajectory groups or PDC. When evaluating the prediction of future cardiovascular events by including a measure of adherence in the model, the best model reclassification was observed when adherence was measured using three or four trajectory groups (NRI=0.189; 95% confidence interval: [0.171, 0.210]).
ConclusionsStatin adherence trajectory predicted future cardiovascular events better than measures categorizing PDC. Thus, adherence trajectories may be useful for targeting adherence interventions.

• 出版日期2015-10