Prevalence 1 assuming none of the non-attenders with pain (n=75 of 279) had OA, prevalence 2 assuming that the prevalence of OA was the same in those with pain not attending (75 of 279) as in the group examined (n=204)
| Diagnostic group |
Number of people with radiographic tibiofemoral OA | Prevalence 1 (%) | Prevalence 2 (%) | Sex (female/male) | Age median (range) | BMI median (range) |
| Ahlbäck ≥ grade 1 | 20 | 1.1 (0.63–1.57) | 1.4 (0.87–1.93) | 10/10 | 50.0 (38–54) | 26.0 (20.3–32.7) |
| KL ≥ grade 2 | 28 | 1.5 (0.95–2.05) | 2.1 (1.45–2.75) | 13/15 | 49.5 (35–54) | 26.0 (20.3–37.5) |
| KL ≥ grade 3 | 16 | 0.9 (0.44–1.28) | 1.2 (0.71–1.69) | 6/10 | 45.5 (35–54) | 25.7 (18.3–28.9) |
The figures in parentheses in the prevalence columns denote the 95% CI. KL= Kellgren & Lawrence. The age was significantly higher in the groups with radiographic OA (without any differences beween the different groups) according to Ahlbäck and Kellgren & Lawrence grade 3 or more (p<0.05) compared with those without radiographic OA. The BMI values did not differ significantly between any of the groups.