Prevalence of Doctor-Diagnosed Thumb Carpometacarpal Joint Osteoarthritis: An Analysis of Swedish Health Care

Objective. While the prevalence of radiographic thumb carpometacarpal (CMC1) osteoarthritis (OA) is well-described, little is known about clinically symptomatic disease presenting to physicians for care. We sought to determine the prevalence of doctor-diagnosed CMC1 OA. Methods. Using health care data from Skane in southern Sweden (population 1.24 million), we identified all adults ages >= 20 years who consulted a physician at least once and received a diagnosis for CMC1 OA (International Classification of Diseases, Tenth Revision, code M18). Data from the 15-year period 1998-2012 were analyzed. Using cross-referencing with the Swedish population register to exclude subjects who were deceased or had relocated, we obtained point estimates of the proportion of the population consulting for CMC1 OA. Results. The prevalence of doctor-diagnosed CMC1 OA in adults was estimated at 1.4% (2.2% in women and 0.62% in men). The mean +/- SD age in the prevalent CMC1 cohort (n = 11,111) was 67.7 +/- 11.4 years; 78.5% of diagnoses were in women. Prevalence peaked in women ages 70-74 years with an estimate of 5.3% and in men ages 80-84 years with an estimate of 1.7%. Age at initial diagnosis also differed, with women presenting between ages 60-69 years and men presenting between ages 70-79 years. Conclusion. The clinically important prevalence of CMC1 OA is 3 to 4 times higher in women than men. By the end of 2012, more than 1 in 20 elderly women had consulted a physician for CMC1 OA over the last 15 years. The high prevalence of this subset of hand OA is a concern in an aging population