Higher mortality among ACS patients in Finland than in Norway: Do differences in acute services and scale effects in hospital treatment explain the variation?

Abstract

Mortality following hospital treatment in Finland and Norway is similar for major diseases, with acute coronary syndrome (ACS) as an important exception. For ACS, the mortality is significantly higher in Finland than in Norway. We study whether a decentralized structure with reduced emergency preparedness and smallscale production in Finland vs. a centralized structure with large percutaneous coronary intervention (PCI) departments performing acute services 24/7 in Norway explains the country differences in mortality. For patients discharged with acute myocardial infarction (International Classification of Diseases - ICD-10 I21 and I22) and unstable angina pectoris (ICD-10 I 20.0), data from the hospital discharge registers for 1 Jan. 2009–30 Nov. 2014 was linked with socio-demographic and regional variables, variables describing distances to hospitals, and with data from causes of death registers in Norway and Finland. Variables relating to hospital system and organization of care were included as independent variables in logistic regression analyses. Marginal mortality differences between the countries for different categories of the variables are presented separately for ST-segment elevation myocardial infarction (STEMI) and for other ACS patients. In Finland, 36% of STEMI patients and 25% of other ACS patients were admitted to hospitals having an emergency PCI service. The corresponding numbers for Norway were 77% and 66%. However, the percentage of patients receiving PCI within one day was similar (STEMI: Norway 54% vs. Finland 56%, p < 0.001), as was the distribution of PCIs performed during weekends (28% vs. 26%, p = 0.02). The short term mortality was a little lower in Norway for STEMI patients (30-day mortality: 10% vs. 12%, p < 0.001; 365-day mortality: 18% vs. 18%, p = 0.48), while markedly lower for other ACS (30-day mortality: 6% vs. 10%, p < 0.001; 365-day mortality: 14% vs. 20%, p < 0.001). After adjusting for individual and regional variables, the mortality was found to be 2–4% lower in Norway within most categories of the hospital system and organization of care variables in all analyses. As such, we were not able to explain the mortality differences by the hospital system and organization of care variables. Rather, the explanation seems to have other sources.