Table 3 Predictors of change over follow-up in Short Form 36 Health Survey (SF-36) physical function score of patients
Characteristics at baselineSubjects, nMean change (95% CI) in SF-36 physical function score relative to reference level of risk factor*
Baseline SF-36 physical function score (change per 10 units of score at baseline)259−4.6 (−6.3 to −2.9)
Sex:
Male93Reference
Female166−7.5 (−14.9 to 0.0)
Age (years):
<70123Reference
70–7567−1.3 (−8.8 to 6.2)
>7569−9.1 (−16.9 to −1.2)
BMI (kg/m2):
<2537Reference
25 to <30134−1.2 (−10.2 to 7.8)
⩾3088−4.6 (−14.5 to 5.3)
Smoking habits:
Never smoked121Reference
Ex-smoker118−5.7 (−12.4 to 0.9)
Current smoker20−5.1 (−17.1 to 6.9)
Hypertension:
Absent150Reference
Present109−3.4 (−9.6 to 2.7)
Diabetes:
Absent243Reference
Present163.8 (−8.5 to 16.2)
Thyroid disease:
Absent235Reference
Present241.9 (−8.6 to 12.5)
Kellgren and Lawrence grade of knee listed for surgery:
0–254Reference
31267.6 (−0.2 to 15.3)
4795.6 (−2.8 to 14.1)
Previous injury to knee listed for surgery:
No178Reference
Yes812.8 (−3.8 to 9.4)
Heberden nodes:
Absent34Reference
Present225−1.1 (−10.7 to 8.5)
No. of painful joint sites in hands, shoulders and knees:
0106Reference
151−4.3 (−12.5 to 3.9)
245−7.3 (−15.7 to 1.2)
329−6.3 (−16.5 to 3.8)
4+28−10.3 (−20.9 to 0.3)
  • *All estimates were derived from a single model and thus are mutually adjusted.

  • BMI, body mass index.