Improved access to and continuity of primary care after attachment to a family physician: longitudinal cohort study on centralized waiting lists for unattached patients in Quebec, Canada

BACKGROUND: Having a regular family physician is associated with many benefits. Formal attachment – an administrative patient-family physician agreement – is a popular feature in primary care, intended to improve access to and continuity of care with a family physician. However, little evidence exists about its effectiveness. In Quebec, Canada, where over 20% of the population is unattached, centralized waiting lists help attach patients. This provides a unique opportunity to observe the influence of attachment in previously unattached patients. The aim was to evaluate changes in access to and continuity of primary care associated with attachment to a family physician through Quebec’s centralized waiting lists for unattached patients. METHODS: We conducted an observational longitudinal population cohort study, using medical services billing data from public health insurance in the province of Québec, Canada. We included patients attached through centralized waiting lists for unattached patients between 2012 and 2014 (n = 410,140). Our study was informed by Aday and Andersen’s framework for the study of access to health services. We compared outcomes during four 12-month periods: two periods before and two periods after attachment, with T0–2 years as the reference period. Outcome measures were number of primary care visits and Bice-Boxerman Concentration of Care Index at the physician and practice level (for patients with ≥2 visits in a given period). We included age, sex, region remoteness, medical vulnerability, and Charlson Comorbidity Index as covariates in regression models fitted with generalized estimating equations. RESULTS: The number of primary care visits increased by 103% in the first post attachment year and 29% in the second year (p < 0.001). The odds of having all primary care visits concentrated with a single physician increased by 53% in the first year and 22% (p < 0.001) in the second year after attachment. At the practice level, the odds of perfect concentration of care increased by 19% (p < 0.001) and 15% (p < 0.001) respectively, in first and second year after attachment. CONCLUSION: Our results show an increase in patients’ number of primary care visits and concentration of care at the family physician and practice level after attachment to a family physician. This suggests that attachment may help improve access to and continuity of primary care. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12875-022-01850-4.