Table 1. Characteristics of the cohort in study.

Variables (n=229,617)		Medium (range)
Age (yr)		41.07 (2.24–96.41)
Time to ovarian cancer (day)		2,438 (0–5,113)
Post-endometriosis ovarian cancer (%)		0.64
Hospital stratification (%)
	Medical centers	49.28
	Regional hospitals	37.32
	District hospitals	12.58
	Local hospitals	0.82
Urbanization (%)
	Highly urbanized	35.71
	Moderately urbanized	32.03
	Newly urbanized	15.40
	Rural areas	11.02
	Others*	5.84
Premium range (monthly income, NTD)
	>15,840 and ≤25,000	15.56
	≤15,840	47.73
	>25,000	36.71
Comorbidity
	Myocardial infarction	0.14
	Congestive heart failure	0.42
	Peripheral vascular disease	0.11
	Cerebrovascular diseases	1.18
	Dementia	0.05
	Chronic pulmonary disease	1.08
	Rheumatologic disease	0.45
	Peptic ulcer disease	2.02
	Mild liver disease	0.40
	Diabetes	2.76
	Diabetes with chronic complications	0.38
	Hemiplegia/paraplegia	0.17
	Renal disease	0.41
	Moderate/severe liver disease	0.15
	AIDS	0.00
	Parkinson's disease	0.09
	Stroke	1.18
	Coronary heart disease	1.21
	Immune rheumatism	0.45
	Depression	1.36
	Hypertension	5.22
	Hyperlipidaemia	1.53
	Pelvic inflammation	6.36
Childbearing post endometriosis		9.65

AIDS, acquired immune deficiency syndrome; NTD, New Taiwan Dollar.

^*Others includes areas with aged population, agrarian towns and cities, and remote areas.