Table 1

Characteristics of participants and odds ratios in relation to symptomatic OAK in women from univariate analyses*

(R)=reference categoryCasesControls
(n=29)(n=82)Odds ratio95% CIp Value
Number (%)Number (%)
*Univariate analyses used conditional logistic regression, cases and controls matched for age and general practitioner. †Heberden’s nodes are bony swellings that develop around the distal interphalangeal joints. More common in women, they are regarded as a concomitant of osteoarthropathy and are age related.
Marital status: ever married27 (93.1)78 (95.1)0.920.16 to 5.260.93
Any qualification attained on ending full time education14 (48.3)50 (61.0)0.690.28 to 1.710.43
Total number of years lived in large town or city0–7(R)7 (24.1)30 (36.6)
>7–3411 (37.9)26 (31.7)1.640.53 to 5.100.39
>3411 (37.9)26 (31.7)1.640.47 to 7.200.38
Homeowner (total no of years)<20 (R)6 (20.7)9 (11.0)
20 to 4011 (38.0)23 (28.1)0.850.26 to 2.770.78
>4012 (41.4)50 (61.0)0.380.12 to 1.230.11
Central heating (total no of years without)<255 (17.2)22 (26.8)
25–4013 (44.8)43 (52.4)1.520.46 to 5.080.49
>4011 (38.0)17 (20.7)3.551.83 to 15.140.09
Age first drove a car regularlyNever(R)10 (34.5)19 (23.2)
<or = 259 (31.0)21 (25.6)0.990.29 to 3.350.99
>2510 (34.5)42 (51.2)0.450.14 to 1.460.09
Ever had treatment for a knee injury13 (44.8)17 (20.7)3.001.19 to 7.540.02
Arthritis affecting at least one joint (other than knee) n=10919 (70.4)48 (58.5)1.350.52 to 3.510.54
Has Heberden’s nodes†13 (44.8)33 (40.2)0.950.41 to 2.170.90
Arthritis affecting the feet13 (44.8)12 (14.6)3.851.45 to 10.300.007
Height n=110 ⩾1.6 metres17 (60.7)51 (62.2)1.010.40 to 2.530.99
BMI when left school: 25 or above5 (25.0)6 (8.6)5.541.03 to 29.760.05
BMI when age 36–40: 25 or above20 (69.0)13 (15.9)32.84.27 to 25.200.001
BMI when age 51–56: 25 or above22 (81.5)29 (37.7)12.052.68 to 54.310.001
Competitive sports (lifetime hours/tertiles)None (R)12 (41.4)34 (41.5)
1–4808 (27.6)21 (25.6)1.270.42 to 3.840.67
>4809 (31.0)27 (32.9)0.870.32 to 2.370.78
Number of full term pregnancies (tertiles)0–2(R)19 (65.5)54 (65.9)
35 (17.2)20 (24.4)0.720.22 to 2.360.59
>35 (17.2)8 (9.8)1.970.58–6.740.28
Oral contraception (ever) Yes12 (41.4)41 (50.0)0.870.35 to 2.150.76
HRT (ever) Yes7 (24.1)38 (46.3)0.460.17 to 1.270.13
Smoking (lifetime)None(R)11 (38.9)46 (56.1)
Low to moderate4 (13.8)15 (18.3)0.940.27 to 3.20.92
Heavy (>70,000)14 (48.3)21 (25.6)3.121.15 to 8.440.025
Number of years performing occupational activities regularly: (tertiles)
Lifting0 to <24(R)3 (10.3)36 (43.9)
>24–3316 (55.2)19 (23.2)7.312.01 to 26.70.003
>3310 (34.5)27 (32.9)3.580.89 to 14.40.072
Bending0–21(R)2 (6.9)35 (42.7)
>21–3416 (55.2)22 (26.8)12.362.40 to 63.70.003
>3411 (37.9)25 (30.5)6.981.45 to 33.60.015
Kneeling<15(R)5 (17.2)32 (39.0)
15 to <2610 (34.5)27 (32.9)2.700.76 to 9.580.13
26+14 (48.3)23 (28.1)4.181.26 to 13.80.02
Cleaning floors on knees0–6(R)8 (27.6)30 (36.6)
>6–135 (17.2)31 (37.8)0.630.17 to 2.370.49
>1316 (55.2)21 (25.6)5.281.48 to 8.840.01
Squatting0–15 (R)7 (24.1)33 (40.2)
>15 to <2713 (44.8)21 (25.6)2.540.88 to 7.340.08
27+9 (31.0)28 (34.2)1.530.51 to 4.560.45
Shoes
Ever worn 2 inch heels regularly26 (89.7)77 (93.9)0.720.13 to 4.020.70
Ever worn 3 inch heels regularly16 (55.2)55 (67.1)0.690.29 to 1.650.40
Age when first wore:
n=1112 in heels<16(R)9 (34.6)17 (22.1)
16–1710 (38.5)32 (41.6)0.760.26 to 2.200.61
18+7 (26.9)28 (36.4)0.640.20 to 2.060.46
n=713 in heels<17(R)3 (18.8)20 (36.4)
17–196 (37.5)18 (32.7)1.830.38 to 8.830.46
20+7 (43.8)17 (30.9)1.330.26 to 6.880.73
Total number of years between age 10 and 40 when regularly wore 3 inch heels for:
WorkNever(R)21 (72.4)51 (62.2)
1–204 (13.8)17 (20.7)0.590.17 to 2.020.40
>204 (13.8)14 (17.1)0.790.23 to 2.740.71
Going out sociallyNever(R)15 (51.7)27 (32.9)
1–206 (20.7)20 (24.4)0.560.18 to 1.750.32
>208 (27.6)35 (42.7)0.490.18 to 1.360.17
DancingNever(R)19 (65.5)32 (39.0)
1–204 (13.8)20 (24.4)0.340.10 to 1.130.078
>206 (20.7)30 (36.6)0.360.13 to 1.130.078