Table 2.

Crude incidence of herpes zoster per 1000 person-years for each treatment.

Variable	No. of person-quarter	Net person-year on treatment	No. of herpes zoster	Incidence (95% CI)*	P value versus control period
Control period	2,375,268	576,853.3	4628	8.0 (7.8–8.3)	–
Methotrexate with any biological agents	1781	440.7	3	6.8 (− 0.9 to 14.5)	0.042
Etanercept without Methotrexate	1063	262.9	3	11.4 (− 1.5 to 24.3)	0.008
Adalimumab without Methotrexate	926	229.2	3	13.1 (− 1.7 to 27.9)	0.001
Ustekinumab without Methotrexate	249	61.7	0	NA	NA
Methotrexate with PUVA or UVB	7093	1729.4	3	1.7 (− 0.2 to 3.7)	0.027
Methotrexate with Acitretin	2233	545.5	2	3.7 (− 1.4 to 8.7)	0.368
Methotrexate with Azathioprine	1095	267.9	5	18.7 (2.3–35.0)	0.001
Methotrexate only	48,839	11,799.0	79	6.7 (5.2–8.2)	0.522
Acitretin only	17,484	4173.4	16	3.8 (2.0–5.7)	< 0.001
Acitretin with PUVA or UVB	4591	1113.4	4	3.6 (0.1–7.1)	0.092
PUVA or UVB only	41,144	9824.7	71	7.2 (5.5–8.9)	0.055
Azathioprine only	2262	550.7	7	12.7 (3.3–22.1)	0.060
Other combinations	4521	1101.2	10	9.1 (3.5–14.7)	0.056
Total	2,508,549	608,964.3	4834	7.9 (7.7–8.2)	–

NA not applicable, PUVA photochemotherapy, UVB ultraviolet B.

*Per 1000 person-years.