Table 2 The cumulative incidence over 4 years of symptomatic knee OA by age, area, region, education, BMI group, activities and chronic disease (Values presented are the weighted incidence of symptomatic knee OA)
| Â | Incidence (%) (95%CI) | ||
|---|---|---|---|
Women | Men | Total | |
Total | 11.16 (10.15–12.26) | 5.58 (4.87–6.39) | 8.47 (7.74–9.26) |
Age, years | |||
  < 50 | 10.17 (7.55–13.57) | 4.08 (2.46–6.69) | 7.87 (5.95–10.35) |
 50–59 | 9.25 (7.79–10.94) | 4.77 (3.73–6.08) | 7.22 (6.19–8.42) |
 60–69 | 12.88 (11.12–14.88) | 6.10 (5.10–7.28) | 9.45 (8.36–10.65) |
  ≥ 70 | 11.77 (10.08–13.71) | 6.07 (4.93–7.45) | 8.84 (7.75–10.07) |
Area | |||
 Urban | 8.55 (7.25–10.07) | 3.51 (2.71–4.53) | 6.15 (5.26–7.17) |
 Rural | 13.36 (11.94–14.92) | 7.27 (6.27–8.42) | 10.40 (9.40–11.50) |
Region | |||
 East | 7.08 (5.66–8.82) | 3.21 (2.41–4.26) | 5.20 (4.27–6.33) |
 Central | 10.75 (9.32–12.38) | 5.30 (4.30–6.51) | 8.13 (7.19–9.19) |
 West | 17.01 (15.08–19.13) | 9.1 (7.57–10.9) | 13.22 (11.82–14.75) |
Education | |||
 No formal education | 12.42 (10.82–14.23) | 7.40 (6.29–8.68) | 9.73 (8.73–10.83) |
 Elementary school | 12.67 (11.09–14.43) | 8.23 (6.29–10.71) | 11.74 (10.39–13.25) |
 Middle school | 7.51 (5.91–9.49) | 3.83 (2.97–4.93) | 5.33 (4.46–6.36) |
 High school or Vocational school or higher | 6.82 (4.72–9.75) | 2.25 (1.46–3.45) | 3.84 (2.85–5.15) |
BMI group (kg/m2) | |||
  < 18.5 | 9.63 (6.75–13.55) | 9.43 (6.44–13.59) | 9.53 (7.29–12.38) |
 18.5–24.9 | 10.77 (9.52–12.16) | 6.54 (5.62–7.59) | 8.62 (7.77–9.56) |
  ≥ 25.0 | 12.35 (10.35–14.66) | 4.23 (3.20–5.57) | 9.02 (7.69–10.55) |
Done some activities (such as played a sport, social, or other kind of club dancing, doing physical exercise, doing Qigong,et al.) | |||
 Yes | 5.74 (3.59–9.05) | 0.95 (0.38–2.38) | 3.48 (2.27–5.31) |
 No | 11.58 (10.53–12.72) | 5.92 (5.19–6.76) | 8.85 (8.10–9.66) |
Hypertension | |||
 Yes | 13.72 (11.45–16.35) | 5.64 (4.41–7.19) | 9.85 (8.46–11.44) |
 No | 10.36 (9.3–11.51) | 5.48 (4.72–6.36) | 8.00 (7.25–8.83) |
Dyslipidemia | |||
 Yes | 14.79 (10.46–20.5) | 3.57 (2.37–5.35) | 9.28 (6.92–12.34) |
 No | 10.76 (9.72–11.9) | 5.62 (4.89–6.45) | 8.29 (7.54–9.10) |
Diabetes | |||
 Yes | 16.37 (10.16–25.31) | 4.37 (2.57–7.34) | 10.83 (7.33–15.73) |
 No | 10.87 (9.84–11.99) | 5.59 (4.87–6.42) | 8.31 (7.57–9.12) |
Chronic lung disease | |||
 Yes | 17.61 (14.13–21.74) | 9.00 (6.70–11.98) | 12.51 (10.40–14.98) |
 No | 10.69 (9.68–11.81) | 5.15 (4.47–5.94) | 8.08 (7.36–8.87) |
Liver disease | |||
 Yes | 15.31 (10.59–21.62) | 9.09 (6.06–13.43) | 11.78 (8.74–15.69) |
 No | 11.04 (10.01–12.16) | 5.36 (4.67–6.16) | 8.32 (7.59–9.12) |
Heart disease | |||
 Yes | 19.03 (16.12–22.32) | 6.94 (4.83–9.86) | 14.02 (12.00–16.32) |
 No | 10.14 (9.13–11.24) | 5.35 (4.63–6.17) | 7.79 (7.07–8.59) |
Stroke | |||
 Yes | 13.09 (7.54–21.76) | 11.19 (6.42–18.80) | 12.11 (8.16–17.61) |
 No | 11.14 (10.12–12.24) | 5.47 (4.76–6.29) | 8.41 (7.69–9.20) |
Kidney disease | |||
 Yes | 18.52 (13.48–24.9) | 10.82 (7.75–14.93) | 14.19 (11.33–17.64) |
 No | 10.81 (9.80–11.91) | 5.21 (4.51–6.00) | 8.13 (7.42–8.91) |
Digestive disease | |||
 Yes | 16.98 (14.85–19.34) | 8.2 (6.62–10.12) | 12.95 (11.44–14.63) |
 No | 9.63 (8.58–10.80) | 4.92 (4.18–5.77) | 7.33 (6.61–8.13) |
Psychiatric disease | |||
 Yes | 11.74 (5.9–22.00) | 1.71 (0.22–12.09) | 8.99 (4.93–15.82) |
 No | 11.16 (10.15–12.27) | 5.55 (4.85–6.34) | 8.44 (7.71–9.22) |
Asthma | |||
 Yes | 21.05 (14.56–29.43) | 9.29 (5.56–15.12) | 14.10 (10.54–18.61) |
 No | 10.93 (9.91–12.04) | 5.44 (4.73–6.25) | 8.30 (7.57–9.09) |