Continuity and breaches in GP care and their associations with mortality for patients with chronic disease: an observational study using Norwegian registry data

Background Despite many benefits of continuity of care with a named regular GP (RGP), continuity is deteriorating in many countries. Aim To investigate the association between RGP continuity and mortality, in a personal list system, in addition to examining how breaches in continuity affect this association for patients with chronic diseases. Design and setting A registry-based observational study using Norwegian primary care consultation data for patients with asthma, chronic obstructive pulmonary disease (COPD), diabetes mellitus, or heart failure. Method The Usual Provider of Care (UPC, value 0-1) Index was used to measure both disease-related (UPCdisease) and overall (UPCall) continuity with the RGP at the time of consultation. In most analyses, patients who changed RGP during the study period were excluded. In the combined group of all four chronic conditions, the proportion of consultations with other GPs and out-of-hours services was calculated. Cox regression models calculated the associations between continuity during 2013-2016 and mortality in 2017-2018. Results Patients with COPD with UPCdisease<0.25 had 47% increased risk of dying within 2 years (hazard ratio 1.47, 95% confidence interval = 1.22 to 1.64) compared with those with UPCdisease >= 0.75. Mortality also increased with decreasing UPCdisease for patients with heart failure and decreasing UPCall for those with diabetes. In the combined group of chronic conditions, mortality increased with decreasing UPCall. This latter association was also found for patients who had changed RGP. Conclusion Higher disease-related and overall RGP UPC are both associated with lower mortality. However, changing RGP did not significantly affect mortality, indicating a compensatory benefit of informational and management continuity in a patient list system.