Regional variation in hospitalizations and outpatient appointments for diverticular disease in Norway: a nationwide cross-sectional study

Abstract

Objective: To investigate the use of specialized health care services for diverticular disease in different hospital referral regions in Norway.Materials and methods: Nationwide cross-sectional study with data from the Norwegian Patient Registry and Statistics Norway. All Norwegian inhabitants aged 40 years and older in the years 2012–16 (2,517,938) were included. We obtained the rates (n/100,000 population) for hospitalizations, outpatient appointments, and surgery for diverticular disease for the population in each hospital referral region. We also quantified the use of lower gastrointestinal (LGI) endoscopy in hospitalizations and outpatient appointments for diverticular disease and the use of LGI endoscopy performed on any indication.Results: There were 131 hospitalizations and 381 outpatient appointments for diverticular disease per 100,000 population annually. Hospitalization rates varied 1.9-fold across regions from 94 to 175. Outpatient appointment rates varied 2.5-fold across regions from 258 to 655. Outpatient appointments were strongly correlated to hospitalizations (rs=0.75, p < .001) and outpatient LGI endoscopy for any indication (rs=0.67, p < .001). Hospitalization and surgery rates remained stable over the study period, while outpatient appointment rates increased by 37%. Concurrently, rates of outpatient LGI endoscopy performed on any indication increased by 35%.Conclusion: There was considerable regional variation in both hospitalizations and outpatient appointments for diverticular disease. The extent of variation and the correlation with diagnostic intensity of LGI endoscopy indicate that the regional variation in health care utilization for diverticular disease to a large extent can be explained by regional differences in clinical practice rather than disease burden.