Appendix A1.

The odds ratios (OR) and 95% confidence intervals (CI) calculated, using conditional logistic regression modeling, as the ratio of the proportion of children exposed to maternal autoimmune disease and its medication in offspring with childhood cancer (cases) and the proportion of exposure to maternal autoimmune disease and its medication in healthy offspring (controls), 1996–2014. Both crude and adjusted ORs are presented. Stratified, unmatched analysis by sex and birth year.

	N cases (%)	N controls (%)	Crude OR	95% CI	Adj. OR	95% CI
No autoimmune disease			1.00	---	1.00	---
Any autoimmune disease	19 (0.9)	134 (1.3)	0.68	0.42–1.12	0.70	0.43–1.15
IBD	12 (0.6)	61 (0.6)	1.01	0.54–1.89	1.07	0.57–2.00
Rheumatic disease	7(0.3)	74 (0.7)	0.41	0.18–0.94	0.41	0.18–0.94
No AI medication purchases			1.00	---	1.00	---
Any AI medication purchase	169 (8.3)	888 (8.8)	0.95	0.80–1.13	0.96	0.80–1.14
IBD medication	13 (0.6)	65 (0.6)	1.01	0.56–1.84	1.07	0.59–1.95
Systemic corticosteroids	21(1.0)	107 (1.1)	0.91	0.56–1.49	0.93	0.57–1.52
Immunosuppressants	3 (0.1)	13 (0.1)	0.83	0.19–3.72	0.90	0.20–4.06
Anti-inflammatory and -rheumatic products	141 (6.9)	761 (7.5)	0.93	0.77–1.13	0.93	0.77–1.13

^*Stratified, unadjusted analysis

^**Stratified analysis adjusted for maternal age (categorized), parity and smoking status.