Characteristics of included children at the time of UHR
| Characteristics | Total study population (N=8601) | HDHP at the time of UHR (n=1858) | Other type of health plan at the time of UHR (n=6743) | P value |
| Age (years) | 5 (3–7) | 5 (3–7) | 5 (3–7) | 0.38 |
| Age <4 years | 2451 (28.5) | 514 (27.7) | 1937 (28.7) | 0.37 |
| Age >5 years | 3365 (39.1) | 739 (39.8) | 2626 (38.9) | 0.52 |
| Female | 4155 (48.31) | 933 (50.22) | 3222 (47.79) | 0.06 |
| Geographical region | <0.0001 | |||
| Northeast | 705 (8.20) | 100 (5.38) | 605 (8.97) | |
| North Central | 2170 (25.23) | 600 (32.29) | 1570 (23.28) | |
| South | 4442 (51.64) | 933 (50.22) | 3509 (52.04) | |
| West | 1284 (14.93) | 225 (12.11) | 1059 (15.71) | |
| Metro area size | <0.0001 | |||
| Large (≥1 million residents) | 6602 (76.76) | 1528 (82.24) | 5074 (75.25) | |
| Small/moderate (<1 million residents) | 1999 (23.24) | 330 (17.76) | 1669 (24.75) | |
| Year | <0.0001 | |||
| 2012 | 1700 (19.77) | 157 (8.50) | 1543 (22.88) | |
| 2013 | 1422 (16.53) | 232 (12.49) | 1190 (17.65) | |
| 2014 | 1390 (16.16) | 280 (15.07) | 1110 (16.46) | |
| 2015 | 946 (11.00) | 240 (12.92) | 706 (10.47) | |
| 2016 | 942 (10.95) | 236 (12.70) | 706 (10.47) | |
| 2017 | 769 (8.94) | 243 (13.08) | 526 (7.80) | |
| 2018 | 705 (8.20) | 225 (25.19) | 480 (7.12) | |
| 2019 | 727 (8.45) | 245 (13.19) | 482 (7.15) | |
| Any chronic condition | 1322 (15.4) | 294 (15.8) | 1028 (15.3) | 0.54 |
| Any concurrent surgical procedure | 2016 (23.44) | 439 (23.63) | 1577 (23.39) | 0.83 |
Data are shown as median (IQR) or number (column %).
HDHP, high deductible health plan; IQR, interquartile range; N, total sample; UHR, umbilical hernia repair.