Continuity of care and mortality in patients with type 2 diabetes: a cohort study

Background How GP continuity of care (GP-CoC) affects mortality in patients with type 2 diabetes (T2D) is unclear.

Aim To examine the effect of having no continuity of care (CoC) and GP-CoC on mortality in primary health care (PHC) patients with T2D.

Design & setting A cohort study in patients aged ≥60 years with T2D, which was conducted within the public PHC of the city of Vantaa, Finland.

Method The inclusion period was between 2002 and 2011 and follow-up period between 2011 and 2018. Six groups were formed (no appointments, one appointment and Modified, Modified Continuity Index [MMCI] quartiles). Mortality was measured with standardised mortality ratio (SMR) and adjusted hazard ratio (aHR). GP-CoC was measured with MMCI. Comorbidity status was determined with Charlson Comorbidity Index (CCI).

Results In total, 11 020 patients were included. Mean follow-up time was 7.3 years. SMRs for the six groups (no appointments, one appointment, MMCI quartiles) were 2.46 (95% confidence interval [CI] = 2.24 to 2.71), 3.55 (95% CI = 3.05 to 4.14), 1.15 (95% CI = 1.06 to 1.25), 0.97 (95% CI = 0.89 to 1.06), 0.92 (95% CI = 0.84 to 1.01) and 1.21 (95% CI = 1.11 to 1.31), respectively. With continuous MMCI, mortality formed a U-curve. The inflection point was at a MMCI value of 0.65 with corresponding SMR of 0.86. Age and CCI aHR for death between men and women was 1.45 (95% CI = 1.35 to 1.58).

Conclusion Patients with no CoC had the highest mortality. In patients having care over time, the effect of GP-CoC on mortality was minor and mortality increased with high GP-CoC.