The effect of enrolment policies on patient affiliation to a family physician: A quasi-experimental evaluation in Canada

Affiliation, defined as having a usual source of care, revealed by patterns of repeated interactions between the patient and a clinician over time, can influence patients' care experience, continuity of care and health outcomes. Many jurisdictions implement primary care enrolment policies, with the motivation to increase affiliation and thereby improve downstream patient outcomes. However, there is little evidence on the impacts of these policies on patient-physician affiliation. Using health administrative data, we evaluated the population-level effects of two policies that encourage primary care enrolment on affiliation in Quebec, Canada. We used quasi-experimental study designs (difference-in-difference and interrupted-time-series) to estimate changes in affiliation that could be attributed to the introduction of these policies. The 2003 policy targeted the enrolment of elderly and/or chronically ill patients, whereas the 2009 policy targeted the general population. We used three measures of patient-physician affiliation: dichotomous and continuous usual provider continuity, and the Reporting a Regular Medical Doctor (RRMD) index. Our analyses for both policies did not yield substantively important changes in our outcomes at the population level. Our effect estimates for both policies were stable under several robustness checks specific to each method. Our results suggest that policies that encourage enrolment do not, on their own, have an impact on patient-physician affiliation. If enrolment policies are not sufficient to increase patient-physician affiliation, further research is needed to understand the factors that influence both affiliation and other downstream outcomes.