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

Abstract

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 (UPC^disease) and overall (UPC^all) 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 UPC^disease <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 UPC^disease ≥0.75. Mortality also increased with decreasing UPC^disease for patients with heart failure and decreasing UPC^all for those with diabetes. In the combined group of chronic conditions, mortality increased with decreasing UPC^all. 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.

Keywords: chronic disease; continuity of care; general practice; mortality; observational study; primary health care.

Figure 1.

Flow chart showing the inclusion and exclusion process for the five study populations: asthma, chronic obstructive pulmonary disease, diabetes mellitus, heart failure, and the group of chronic conditions. Patients were identified in 2012 and have ≥2 disease-related consultations in the four diagnosis populations and ≥2 all-cause consultations in the group of chronic conditions. COPD = chronic obstructive pulmonary disease. OOH = out of hours. PSPC = private specialist with public contracts. RGP = regular GP. SSB = Statistics Norway.

Figure 2.

Mortality associated with overall UPC (UPC^all) and disease-related UPC (UPC^disease) for patients a) with asthma; b) chronic obstructive pulmonary disease; c) diabetes mellitus; and d) heart failure, adjusted for age (continuous), sex, Centrality Index, and comorbidity groups^a (based on ICPC Morbidity Index^b). The horizontal lines on x-axis present the 95% confidence interval and the hazard ratio. Reference category is the group with patients with the highest UPC (0.75–1.00). ^aThe analyses for UPC^all are not adjusted for comorbidity. ^b Number of comorbidity groups based on ICPC Morbidity Index. ICPC = International Classification of Primary Care. UPC = Usual Provider of Care Index (where 1 = all consultations by the RGP).

Figure 3.

Mortality associated with UPC^all for patients in the group of chronic conditions, both with the same and different RGPs, adjusted for age (continuous), sex, and Centrality Index. The reference category is the group with patients with the highest UPC (0.75–1). RGP = regular GP. UPC = Usual Provider of Care Index (where 1 = all consultations by the RGP).