Lower prevalence of hip fractures in foreign-born individuals than in Swedish-born individuals during the period 1987-1999

BACKGROUND This is the first longitudinal study with a 22-year follow-up, based on a national and complete sample, to determine whether the prevalence of hip fracture and the age when it occurs are influenced by migration and by being foreign-born. Cultural background and environmental factors such as UV-radiation and lifestyle during childhood and adolescence may influence the risk of a hip fracture event later in life. Differences in prevalence might occur between the indigenous population and those who have migrated to a country. METHODS The study was based on national population data. The study population consisted of 321,407 Swedish-born and 307,174 foreign-born persons living in Sweden during the period 1987-1999. RESULTS Foreign-born individuals had a reduced risk of hip fracture, with odds ratios (ORs) of 0.47-0.77 for men and 0.42-0.88 for women. Foreign-born women had the hip fracture event at a higher age on average, but a longer time spent in Sweden was associated with a small but significant increase in risk. CONCLUSIONS We found that there was a reduced risk of hip fracture in all foreign-born individuals, and that the hip fracture event generally happened at a higher age in foreign-born women. Migration must therefore be considered in relation to the prevalence and risk of hip fracture. Migration can therefore have a positive effect on one aspect of the health of a population, and can influence and lower the total cost of healthcare due to reduced risk and prevalence of hip fracture.