Association between continuity of primary care and both prescribing and adherence of common cardiovascular medications: a cohort study among patients in England.

objectivesTo investigate whether better continuity of care is associated with increased prescribing of clinically relevant medication and improved medication adherence.

settingRandom sample of 300 000 patients aged 30+ in 2017 within 83 English general practitioner (GP) practices from the Clinical Practice Research Datalink.

designPatients were assigned to a randomly selected index date in 2017 on which medication use and continuity of care were determined. Adjusted associations between continuity of care and the prescribing and adherence of five cardiovascular medication groups were examined using logistic regression.

participantsContinuity of Care Index was calculated for 173 993 patients with 4+ GP consultations 2 years prior to their index date and divided into five categories: absence of continuity, below-average continuity, average, above-average continuity and perfect continuity.

main outcome measures(A) Prescription for statins (primary or secondary prevention separately), anticoagulants, antiplatelet agents and antihypertensives covering the patient's index date. (B) Adherence (>80%) estimated using medication possession ratio.

resultsThere was strong evidence (p<0.01) that prescription of all five cardiovascular medication groups increased with greater continuity of care. Patients with absence of continuity were less likely to be prescribed cardiovascular medications than patients with above-average continuity (statins primary prevention OR 0.73, 95% CI 0.59 to 0.85; statins secondary prevention 0.77, 95% CI 0.57 to 1.03; antiplatelets 0.55, 95% CI 0.33 to 0.92; antihypertensives 0.51, 95% CI 0.39 to 0.65). Furthermore, patients with perfect continuity were more likely to be prescribed cardiovascular medications than those with above-average continuity (statins primary prevention OR 1.23, 95% CI 1.01 to 1.49; statins secondary prevention 1.37, 95% CI 1.10 to 1.71; antiplatelets 1.37, 95% CI 1.08 to 1.74; antihypertensives 1.10, 95% CI 0.99 to 1.23). Continuity was generally not associated with medication adherence, except for adherence to statins for secondary prevention (OR 0.75, 95% CI 0.60 to 0.94 for average compared with above-average continuity).

conclusionBetter continuity of care is associated with improved prescribing of medication to patients at higher risk of cardiovascular disease but does not appear to be related to patient's medication adherence.