Does Continuity of Community Pharmacy Care Influence Adherence to Statins

Abstract

Background: Improving adherence to medication is a persistent challenge within the health system. Adherence is influenced by many factors at the patient, provider, treatment and health system levels. Adherence may also be affected by continuity of care; defined as the consistent professional relationship between a health provider or source of care and a patient. Objective: To estimate the strength of association between continuity of community pharmacy care and adherence to statin medication among persons initiating statin therapy in Nova Scotia between 1998 and 2008. Methods: This was a retrospective cohort study using administrative data from the Nova Scotia Seniors’ Pharmacare program. Subjects were included if they were dispensed at least one prescription for a statin medication between 1998 and 2008. Continuity of care was calculated via two methods: the Usual Provider of Care (UPC) index and the Continuity of Care Index (COCI), which measure the density and dispersion of relational continuity of care, respectively. Adherence was calculated using the medication possession ratio. The strength of association between continuity of care and adherence was analyzed using hierarchical regression. Results: During the study period, 31 592 individual subjects received a first statin dispensation. Adjusted hierarchical regression showed that for each 0.10 increase in continuity of care, the odds of adherence increase by 3% (95% CI: 1.01-1.05). Continuity of care measured by the UPC is highly correlated with continuity of care measured by the COCI (r=0.98). Conclusions: Continuity of community pharmacy care is positively associated with adherence to statins among Nova Scotian seniors who initiated statin therapy between 1998 and 2008.