# Table 2 Simple regression analysis of candidate predictors in 1953 infants who had outcomes ascertained (DDH was defined as α < 55° at age > 42 days, or α < 50 at age < 42 days). All values are numbers (percentages) unless otherwise stated

Candidate Predictor All
infants
(N= 1953)
Infants with DDH
(N = 77)
Odds ratio
(95% confidence interval)
P
Female sex 1037 (53.1) 65 (77) 5.04 (2.70, 9.39) < 0.001
First degree family history of DDH 184 (9.4) 15 (9) 2.44 (1.36, 4.39) 0.003
Vaginal delivery 892 (45.7) 42(58) 1.59 (0.99, 2.55) 0.06
Birth weight in kg (mean ± SD) 3.22 ± 0.58 3.40 ± 0.52 1.81 (1.14, 2.87) 0.01
Foot deformity warranting followup c 51 (2.6) 5 (8) 2.76 (1.07, 7.16) 0.04
First born child 1108 (56.7) 46 (66) 1.35 (0.82, 2.23) 0.24
Multiple birth (twin pregnancy) 257 (13.2) 6 (9) 0.61 (0.26, 1.41) 0.25
Breech at presentation 586 (30.0) 20 (39) 0.81 (0.48, 1.36) 0.43
Oligohydramnios 39 (2.0) 0 (0) NAa NAa
Torticollis 10 (0.5) 1 (1) NAb NAb
Abnormal hip examination d 86 (4.4) 43 (56) 53.91 (31.35, 92.71) < 0.001
Ortolani positive 14 (0.7) 11 (14) NAb NAb
Barlow positive 20 (1.0) 14 (18) NAb NAb
Galeazzi positive (leg length discrepancy) 16 (0.8) 11 (14) NAb NAb
Hip instability 25 (1.3) 7 (9) NAb NAb
Asymmetry in hip abduction 36 (1.8) 21 (27) NAb NAb
1. SD standard deviation
2. aNot possible to estimate because no DDH cases had oligohydramnios
3. bNot applicable (NA) for risk model due to low prevalence
4. cFoot deformity receiving orthopedic or physiotherapy follow-up
5. dThis variable includes hips with at least one of the following criteria present: leg length discrepancy, asymmetry of hip abduction, Barlow positive, Ortolani positive, hip instability. The latter 3 were mutually exclusive. This variable thus indicates hips that showed an abnormal physical examination