Table 2.

Risk of basal cell carcinoma, cutaneous squamous cell carcinoma and cutaneous malignant melanoma according to the cumulative dose of methotrexate.

Subgroup	Cases, n	Controls, n	Crude ORa (95% CI)	Adjusted ORb (95% CI)
BCC
Non-use	128,631	1,292,298	1.0 (ref.)	1.0 (ref.)
Ever-use	2816	22,146	1.28 (1.23–1.33)	1.16 (1.11–1.22)
Accumulated dose ≥2.5 g	1214	8389	1.45 (1.37–1.54)	1.29 (1.20–1.38)
Cumulative dose (g)
0–1.25	1080	9707	1.12 (1.05–1.19)	1.03 (0.96–1.10)
1.25–2.5	522	4050	1.30 (1.18–1.42)	1.20 (1.09–1.31)
2.5–5.0	583	4348	1.35 (1.24–1.47)	1.24 (1.13–1.36)
5.0–7.5	322	2138	1.52 (1.35–1.70)	1.39 (1.24–1.58)
≥7.5	309	1903	1.63 (1.45–1.84)	1.48 (1.31–1.68)
cSCC
Non-use	18,164	183,374	1.0 (ref.)	1.0 (ref.)
Ever-use	497	3224	1.56 (1.42–1.72)	1.22 (1.09–1.37)
Accumulated dose ≥2.5 g	233	1296	1.82 (1.58–2.10)	1.61 (1.37–1.89)
Cumulative dose (g)
0–1.25	182	1366	1.35 (1.15–1.58)	0.99 (0.84–1.17)
1.25–2.5	82	562	1.47 (1.17–1.86)	1.15 (0.90–1.46)
2.5–5.0	106	623	1.72 (1.40–2.11)	1.47 (1.18–1.83)
5.0–7.5	62	311	2.02 (1.54–2.66)	1.81 (1.36–2.41)
≥7.5	65	362	1.82 (1.40–2.37)	1.57 (1.18–2.08)
CMM
Non-use	25,617	256,736	1.0 (ref.)	1.0 (ref.)
Ever-use	451	3944	1.15 (1.04–1.27)	1.19 (1.06–1.33)
Accumulated dose ≥2.5 g	183	1465	1.25 (1.07–1.46)	1.35 (1.13–1.61)
Cumulative dose (g)
0–1.25	193	1776	1.09 (0.94–1.27)	1.13 (0.97–1.32)
1.25–2.5	75	703	1.07 (0.84–1.36)	1.10 (0.86–1.41)
2.5–5.0	97	747	1.30 (1.05–1.61)	1.37 (1.10–1.72)
5.0–7.5	47	378	1.25 (0.92–1.69)	1.31 (0.96–1.79)
≥7.5	39	340	1.15 (0.83–1.60)	1.21 (0.85–1.71)

BCC basal cell carcinoma, CI confidence interval, CMM cutaneous malignant melanoma, cSCC cutaneous squamous cell carcinoma, OR odds ratio.

^aAdjusted for age, sex and calendar time (by design).

^bAdjusted for age, sex, calendar time and other covariates (see 'Covariates').