Regional distribution of rheumatic complaints in Sweden.

Regional differences regarding prevalence of rheumatic complaints were found in a nation-wide interview survey of the adult Swedish population. A higher prevalence was found in regions of low population density, the highest being in the North. Osteo-arthritis was more prevalent in Northern Sweden, particularly among men, while back disorders were more common in all regions of low population density. Physically strenuous working conditions were found more frequently in all regions of low population density. Among other possible factors contributing to the regional differences in rheumatic complaints, genetic differences in HLA B27 within the Swedish population and the occurrence of cryophilic arthritogenic microbial flora, are discussed.