Table 3. Incidence rates and the number of late diagnoses per region for the 2011–13 birth cohorts.
| Region | Incidence rate (per 10,000 births) | Late diagnosis | |||
| 2011 | 2012 | 2013 | total | N (%) | |
|
| |||||
| 1.Hokkaido and Tohoku | 9.20 | 10.54 | 7.95 | 9.23* | 31 (10.7) |
| 2.Kanto | 7.50 | 6.63 | 6.42 | 6.85 | 82 (11.6) |
| 3.Chubu | 6.97 | 7.62 | 6.52 | 7.04 | 47 (12.4) |
| 4.Kinki | 7.54 | 7.92 | 7.23 | 7.57 | 47 (11.2) |
| 5.Chugoku | 10.81 | 11.72 | 10.17 | 10.90** | 31 (11.5)*** |
| 6.Shikoku | 6.49 | 7.92 | 7.07 | 7.16 | |
| 7.Kyushu and Okinawa | 7.09 | 8.16 | 7.35 | 7.53 | 35 (11.7) |
|
| |||||
| Total | 7.71 | 7.96 | 7.10 | 7.59 | 273 (11.5) |
Post-hoc chi-square test (P-values for the standardized residuals of patients with developmental dysplasia of the hip-dislocation): Region 1*: P = 0.006, Region 5**: P < 0.001.
***Data for Regions 5 and 6 were combined to protect patient identity.