The Norwegian Sports Membership Database: coverage, biases and research potential

AimsTo describe the Norwegian Sports Membership Database (NSMD), assess its coverage and develop definitions of active sports memberships. MethodsWe validated the coverage of NSMD, a database capturing individual-level sports memberships among persons 10 to 70 years of age between 2015 and 2024. We compared yearly membership counts in NSMD with figures from official reports from The Norwegian Olympic and Paralympic Committee and Confederation of Sports (NIF). We defined all memberships as memberships lasting one day or longer, and active memberships as memberships lasting at least one season or with a paid licence. ResultBetween 2015 and 2024, NSMD contained 3 148 213 memberships in which 2 180 621 (60%) was considered active. In total, there were 1 606 048 unique individuals across 55 sports federations and 279 disciplines. Football accounted for 24% of all memberships, handball for 11%, and gymnastics for 9%. Database coverage was low in 2015, capturing 11-16% of expected memberships, but improved substantially over time and exceeded 85% of all memberships and 92% of active memberships in 2023 for ages 13-19. ConclusionThe coverage of the NSMD is high in recent years, representing a level of completeness that allows meaningful population-level analyses from 2019, although with large variations between sports. Linking sports data with health and socio-demographic outcomes provides a potentially large opportunity for population-based research on sports participation and health across the lifespan.