Hospitalisation in adults with intellectual disabilities compared with the general population in Norway

Background Previous studies have found that adults with intellectual disabilities (ID) are hospitalised more often than the general population (GP). This study investigates hospital discharge rates and main diagnostic causes for hospitalisation among administratively defined people with ID compared with the GP in Norway. Method Data from the Norwegian Labour and Welfare Service was combined with data from the Norwegian Patient Register (Ntotal = 1 764 072 and NID = 7573) for the period 2008–2011. Data from a Norwegian patient report generator and Statistics Norway are also analysed. Results During the study period, 11% of people with ID and 11.5% of the GP were admitted to hospitals. The length of the average hospital stay was just over 4 days for both groups. Among those who were hospitalised, the majority were only admitted to hospital once during the study period: ID 66% and GP 70%. People with ID were admitted somewhat more often than people in the GP. Contrary to the GP, adults with ID were more frequently hospitalised at a younger age and less frequently at old age. The most common International Classification of Diseases diagnostic group for hospitalisation among people with ID is injury, poisoning and certain other consequences of external causes, whereas for the GP, it is diseases of the circulatory system. Conclusion This study finds that the proportion of people being hospitalised per year is statistically, but only slightly, different among adult people with ID and the GP. The results must be interpreted in light of the organisation of the health care system in Norway.