The aim of this study was to estimate the prevalence of frequent knee pain in radiographic, symptomatic and clinically defined knee OA in middle-aged and elderly patients and the proportion that seeks medical care.
In 2007 a random sample of 10 000 56- to 84-year-old residents of Malmö, Sweden, were questioned about knee pain. We classified subjects reporting knee pain with a duration of at least 4 weeks as having frequent knee pain. A random sample of 1300 individuals with frequent knee pain and 650 without were invited for assessment by the ACR clinical knee OA criteria and for bilateral weight-bearing knee radiography. We considered a Kellgren-Lawrence grade =2 as radiographic knee OA and that in combination with frequent knee pain as symptomatic knee OA. By linkage with the Skåne Healthcare Register, we determined the proportion of subjects that had consulted for knee OA or pain.
The 10 000 subjects had a mean age of 70 years (s.d. 7.6), a mean BMI of 27.1 kg/m(2) and 62% were women. The prevalence of frequent knee pain was 25.1% (95% CI 24.1, 26.1), higher in women and similar across age groups. The prevalence of radiographic knee OA was 25.4% while 15.4% had either symptomatic or clinically defined knee OA. Of these, 68.9% consulted a physician for knee OA or pain during 2004-11.
Fifteen per cent of middle-aged or elderly individuals have knee OA and symptoms. About one in three of those do not consult a physician. Inefficient care of OA and self-coping may be an explanation.