Prevalence of radiographic osteoarthritis in two elderly European populations.

Was compared the prevalence of radiographic osteoarthritis (ROA) in two elderly populations, one in Göteborg (Sweden) and one in Zoetermeer (The Netherlands). The comparison was preceded by an inter-observed analysis of 150 films, revealing lower percentage agreements and kappa values when analysing the films on a five-point scale compared to the analysis in a dichotomy of "abnormal" and "normal" films. An intra-observer analysis of 50 films revealed higher percentage agreement and kappa values of well over 0.75, suggesting that radiographs could be read by one observer when different populations are being compared. The prevalence of hand ROA was higher in the Göteborg population, while the prevalence of knee ROA showed no significant differences. No significant increase with age of the cohorts was found for hand ROA in either population and no increase with age for knee ROA was found in the Swedish population. In the Zoetermeer population, knee ROA increased with age in both sexes.