Table 2.

Time to event analysis.

	Before PSM		After PSM
	Non-IC/BPS	IC/BPS	Control	IC/BPS
	n = 21 900	n = 1,095	n = 4,224	n = 1,056
Follow up person months	1,654,806	79,147	312,164	76,839
Event of ADs	1,373	105	287	102
Incidence rate* (95% CI)	8.30 (7.87–8.75)	13.27 (10.96–16.06)	9.19 (8.19–10.32)	13.27 (10.93–16.12)
Model 1: Crude hazard ratio (95% CI)	Reference	1.595 (1.308–1.945)	Reference	1.442 (1.151–1.808)

^*per 10,000 person-months.

IC/BPS, interstitial cystitis/bladder pain syndrome; ADs, autoimmune diseases; PSM, propensity score matching; CI, confidence interval.