Results of univariate analysis of misdiagnosis at the first visit
| Characteristic | Diagnosis group (n=256) | Misdiagnosis group (n=95) | OR (95% CI) | P value |
| Sex, n (%) | ||||
| Male | 43 (16.8) | 12 (12.6) | Reference | |
| Female | 213 (83.2) | 83 (87.4) | 0.72 (0.36 to 1.43) | 0.342 |
| Age (months), medians (25th percentile, 75th percentile) | 16 (8.25–22.75) | 15 (12–19) | 0.99 (0.98 to 1.01) | 0.299 |
| Birthplace, n (%) | ||||
| Rural | 139 (54.3) | 53 (55.8) | Reference | |
| Urban | 117 (45.7) | 42 (44.2) | 1.06 (0.66 to 1.71) | 0.803 |
| Main symptom, n (%) | ||||
| Lower limbs were asymmetrical | 45 (17.6) | 13 (13.7) | Reference | |
| Buttock lines are asymmetrical | 47 (18.4) | 14 (14.7) | 0.97 (0.41 to 2.29) | 0.944 |
| Abnormal gait* | 149 (58.2) | 59 (62.1) | 0.73 (0.37 to 1.45) | 0.368 |
| Abnormal hip* | 15 (5.9) | 9 (9.5) | 0.48 (0.17 to 1.35) | 0.165 |
| Year, n (%) | ||||
| 2010–2015 | 128 (50) | 46 (36.8) | Reference | |
| 2016–2020 | 128 (50) | 49 (51.6) | 0.94 (0.59 to 1.50) | 0.793 |
| Hospital level, n (%) | ||||
| Tertiary | 186 (72.7) | 49 (51.6) | Reference | |
| Secondary | 56 (21.9) | 35 (36.8) | 0.42 (0.25 to 0.71) | 0.001 |
| Primary | 14 (5.5) | 11 (11.6) | 0.34 (0.14 to 0.79) | 0.012 |
| Department, n (%) | ||||
| Paediatric orthopaedics | 145 (56.6) | 25 (26.3) | Reference | |
| Surgery | 8 (3.1) | 8 (8.4) | 0.17 (0.06 to 0.50) | 0.001 |
| Paediatrics | 18 (7.0) | 16 (16.8) | 0.19 (0.09 to 0.43) | <0.001 |
| General orthopaedics | 85 (33.2) | 46 (48.4) | 0.32 (0.18 to 0.56) | <0.001 |
| Title of the physician, n (%) | ||||
| Junior | 41 (16.0) | 32 (33.7) | Reference | |
| Intermediate | 70 (27.3) | 28 (29.5) | 1.95 (1.03 to 3.69) | 0.040 |
| Senior | 145 (56.6) | 35 (36.8) | 3.23 (1.79 to 5.84) | <0.001 |
| Affected hip, n (%) | ||||
| Left | 99 (38.7) | 41 (43.2) | Reference | |
| Right | 73 (28.5) | 26 (27.4) | 1.16 (0.65 to 2.07) | 0.608 |
| Bilateral | 84 (32.8) | 28 (29.5) | 1.24 (0.71 to 2.18) | 0.449 |
| Infant physical examination, n (%) | ||||
| Yes | 67 (26.2) | 23 (24.2) | Reference | |
| No | 189 (73.8) | 72 (75.8) | 0.90 (0.52 to 1.56) | 0.709 |
| Parity, n (%) | ||||
| Firstborn | 179 (69.9) | 71 (74.7) | Reference | |
| Second child or more | 77 (30.1) | 24 (25.3) | 1.27 (0.75 to 2.17) | 0.377 |
| Fetal presentation, n (%) | ||||
| Cephalic presentation | 227 (88.7) | 84 (88.4) | Reference | |
| Breech presentation | 29 (11.3) | 11 (11.6) | 0.98 (0.47 to 2.04) | 0.948 |
| Family history, n (%) | ||||
| Yes | 21 (8.2) | 6 (6.3) | Reference | |
| No | 235 (91.8) | 89 (93.7) | 0.75 (0.30 to 1.93) | 0.557 |
| Severity of DDH, n (%) | ||||
| Mild (Graf: Ⅱb–Ⅱc/Tönnis: 1–2) | 133 (52.0) | 47 (49.5) | Reference | |
| Severe (Graf: Ⅲ–Ⅳ/Tönnis: 3–4) | 123 (48.0) | 48 (50.5) | 0.91 (0.57 to 1.45) | 0.680 |
*Abnormal gait (lameness, duck gait, delay in learning to walk, unstable gait). Abnormal hip (pain, limited joint movement, abnormal joint movement).
DDH, developmental dysplasia of the hip.