title: Association of Continuity of Primary Care and Statin Adherence.
abstract: OBJECTIVE
  Deficiencies in medication adherence are a major barrier to effectiveness of chronic condition management. Continuity of primary care may promote adherence. We assessed the association of continuity of primary care with adherence to long-term medication as exemplified by statins.
  
  
  METHODS
  We linked data from a prospective study of 267,091 Australians aged 45 years and over to national data sets on prescription reimbursements, general practice claims, hospitalisations and deaths. For participants having a statin dispense within 90 days of study entry, we computed medication possession ratio (MPR) and usual provider continuity index (UPI) for the subsequent two years. We used multivariate Poisson regression to calculate the relative risk (RR) and 95% confidence interval (CI) for the association between tertiles of UPI and MPR adjusted for socio-demographic and health-related patient factors, including age, gender, remoteness of residence, smoking, alcohol intake, fruit and vegetable intake, physical activity, prior heart disease and speaking a language other than English at home. We performed a comparison approach using propensity score matching on a subset of the sample.
  
  
  RESULTS
  36,144 participants were eligible and included in the analysis among whom 58% had UPI greater than 75%. UPI was significantly associated with 5% increased MPR for statin adherence (95% CI 1.04-1.06) for highest versus lowest tertile. Dichotomised analysis using a cut-off of UPI at 75% showed a similar effect size. The association between UPI and statin adherence was independent of socio-demographic and health-related factors. Stratification analyses further showed a stronger association among those who were new to statins (RR 1.33, 95% CI 1.15-1.54).
  
  
  CONCLUSIONS
  Greater continuity of care has a positive association with medication adherence for statins which is independent of socio-demographic and health-related factors.
authors.affiliation: Department of Computer Science, University of Auckland, Auckland, New Zealand.
authors.forename: James R
authors.initials: JR
authors.lastname: Warren
authors.affiliation: Centre for Big Data Research in Health, University of New South Wales, Kensington, New South Wales, Australia.
authors.forename: Michael O
authors.initials: MO
authors.lastname: Falster
authors.affiliation: Centre for Big Data Research in Health, University of New South Wales, Kensington, New South Wales, Australia.
authors.forename: Bich
authors.initials: B
authors.lastname: Tran
authors.affiliation: Centre for Big Data Research in Health, University of New South Wales, Kensington, New South Wales, Australia.
authors.forename: Louisa
authors.initials: L
authors.lastname: Jorm
mesh_terms: D003266:Continuity of Patient Care; D050171:Dyslipidemias / Q000188:drug therapy*; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D011320:Primary Health Care; D011446:Prospective Studies; D012306:Risk; D016896:Treatment Outcome
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors