Determining the optimal measurement for general practitioner encounters following stroke using linked data from the Australian Stroke Clinical Registry.

Background: General practitioners (GPs) provide ongoing support after a stroke, but little is known about these encounters and the metrics to measure them. Objective(s): To compare methods for measuring patterns of GP encounters following stroke in survival models. Method(s): We performed a landmark analysis using data from the Australian Stroke Clinical Registry (2010-2014) linked with Australian Medicare claims (2009-2016) to determine GP encounters within 18 months following stroke. Continuity of GP encounters (consistency) and regularity (distribution) were each calculated using 3 indices. Indices were compared based on 1-year survival using multivariable Cox regression models. The best performing measures of regularity and continuity, based on model fit, were combined into a composite 'optimal care' variable. Result(s): Among 10,728 registrants (43% female, 69% aged >=65 years), the median number of encounters was 17 (Q1: 10, Q3: 26) within 18 months. The measures most strongly associated with survival (hazard ratio [95% confidence interval], Akaike information criterion [AIC], Bayesian information criterion [BIC]) were the Continuity of Care Index (COCI, as a measure of continuity; 0.88 [0.76-1.02], p=0.099, AIC=13746, BIC=13855) and our persistence measure of regularity (encounter at least every 6 months; 0.80 [0.67-0.95], p=0.011, AIC=13742, BIC=13852). Our composite measure, persistence plus COCI >=80% (0.80 [0.68-0.94], p=0.008, AIC=13742, BIC=13851), performed marginally better than our persistence measure alone. Conclusion(s): GP continuity and regularity of care are important indicators of ongoing support after stroke. Our persistence measure of regularity or composite indice may be useful measures of patient outcome with respect to general practitioner encounters following stroke.