Baseline and demographic characteristics for cases and controls on first visit
| Cases n=270 | Controls n=270 | P value | |
| Gender | 1.00* | ||
| Male | 139 (51.5) | 139 (51.5) | |
| Female | 131 (48.5) | 131 (48.5) | |
| Age (years), mean (±SD) | 48.5±19.6 | 48.6±19.2 | 0.98* |
| Marital status | 0.28 | ||
| Not married | 90 (33.1) | 102 (37.8) | |
| Married | 180 (66.7) | 168 (62.2) | |
| Guarantor† | 0.06 | ||
| Insured | 213 (78.9) | 230 (85.2) | |
| Self-paying | 57 (21.1) | 40 (14.8) | |
| Hospitalisation (past 30 days) | 45 (16.7) | 7 (2.6) | <0.0001 |
| No of ED visits (past year) | 0.08 | ||
| Mean (±SD) | 0.93±1.80 | 0.64±2.06 | |
| Median (IQR) | 0.0 (1.0) | 0.0 (1.0) | |
| 0 | 158 (58.5) | 202 (74.8) | 0.001 |
| 1 | 53 (19.6) | 34 (12.6) | |
| 2 | 34 (12.6) | 18 (6.7) | |
| 3+ | 25 (9.3) | 16 (5.9) | |
| Major diagnostic category | <0.0001 | ||
| Digestive system | 67 (24.8) | 42 (15.6) | |
| Musculoskeletal system and connective tissues | 25 (9.3) | 75 (27.8) | |
| Infectious and parasitic diseases | 22 (8.1) | 6 (2.2) | |
| Kidney and urinary tract | 37 (13.7) | 20 (7.4) | |
| Others‡ | 119 (44.1) | 127 (47.0) |
*Matching characteristics.
†Guarantor group: includes university insurance, private insurance, social assistance and diplomatic coverage.
‡Others include: the circulatory system, the skin, subcutaneous tissue and breast, the ears, nose, mouth and throat, the respiratory system, the eye, the blood and blood forming organs and immunological disorders, the female reproductive system, the hepatobiliary system and pancreas, the male reproductive system, the nervous system, endocrine, nutritional and metabolic diseases, factors influencing health status and other contacts with health services, injuries, Poisonings and toxic effects of drugs, mental diseases and disorders, pregnancy, childbirth, and puerperium, alcohol/drug use, burns and vaginal bleeding.
ED, emergency department.