Table 4

Multinomial diagnostic regression function: 'moderate to severe OA'

N

688

Missing

57


NONE/MILD

ISO-PF

ISO-TF

COMB

n = 415

n = 91

n = 114

n = 68

aOR (95% CI)*

aOR (95% CI)*

aOR (95% CI)*


Age (per year)

0.91 (0.88, 0.95)

1

0.99 (0.95, 1.03)

1.00 (0.96, 1.05)

Female gender

1.20 (0.66, 2.18)

1

1.18 (0.58, 2.39)

1.09 (0.49, 2.44)

BMI (per kg/m2)

0.94 (0.87, 1.00)

1

1.02 (0.95, 1.09)

1.04 (0.97, 1.12)

Dramatic swelling ever

0.36 (0.19, 0.69)

1

0.35 (0.16, 0.76)

0.95 (0.44, 2.07)

Difficulty descending stairs

0.60 (0.35, 1.05)

1

1.36 (0.70, 2.66)

1.41 (0.65, 3.07)

Intercondylar gap > 0 cm

1.53 (0.67, 3.51)

1

4.50 (1.87, 10.84)

1.62 (0.56, 4.68)

PFJ compression test†

0.52 (0.29, 0.92)

1

0.40 (0.20, 0.79)

0.22 (0.10, 0.48)

Knee effusion‡

0.42 (0.25, 0.72)

1

1.21 (0.66, 2.25)

1.29 (0.63, 2.63)

Fixed flexion deformity

0.83 (0.31, 2.24)

1

2.68 (1.01, 7.08)

4.56 (1.67, 12.49)

Bony enlargement§

1.13 (0.66, 1.95)

1

1.75 (0.92, 3.32)

2.59 (1.21, 5.53)

Reduced knee extensor strength¶

0.38 (0.20, 0.69)

1

0.41 (0.20, 0.83)

0.68 (0.30, 1.56)

Coarse crepitus§

0.37 (0.22, 0.63)

1

0.75 (0.40, 1.38)

0.82 (0.40, 1.69)

Knee flexion ROM (per degree)

0.99 (0.96, 1.02)

1

0.96 (0.93, 0.99)

0.95 (0.92, 0.98)


Nagelkerke's Pseudo R2

0.47

Pearson goodness-of-fit

P = 1.00

Pre-test probability

0.60

0.14

0.16

0.10


Correctly classified on 'confident diagnosis' (probability ≥0.8)

222 (53%)

0

0

0

Correctly classified on 'balance of probabilities'

385 (93%)

23 (25%)

41 (36%)

18 (26%)


* odds ratio with 95% confidence interval, adjusted for all other covariates in model. aOR is interpreted as the odds relative to the ISO-PF group (for example, compared with those people with ISO-PF, those with ISO-TF have 4.5 times the odds of intercondylar gap > 0 cm (varus deformity); compared with ISO-PF participants with NONE/MILD, ISO-TF, and COMB were less likely to report pain on patellofemoral joint compression). †Compression or glide pain. ‡Mild/Moderate/Gross. §Possible/Definite. ¶< 141mmHg

Peat et al. Arthritis Research & Therapy 2012 14:R63   doi:10.1186/ar3779

Open Data