. 2020 Mar 11;156(5):1–9. doi: 10.1001/jamadermatol.2020.0218

Table 4. Association of Risk of Skin Cancer With Extremely Long-term NBUVB Phototherapy in Patients With Vitiligo.

Group	Incidence Rate (95% CI)^a	Events, No.	Population, No.	No. of Person-Years	Univariable Analysis		Multivariable Analysis
Group	Incidence Rate (95% CI)^a	Events, No.	Population, No.	No. of Person-Years	Crude HR (95% CI)	P Value	Adjusted HR (95% CI)^b	P Value
Actinic keratosis
No NBUVB^c	6.1 (4.7-7.7)	65	20 105	106 910	1 [Reference]		1 [Reference]
NBUVB ≥500^d	12.6 (5.1-25.9)	7	717	5565	2.104 (0.963-4.595)	.06	1.739 (0.796-3.799)	.17
Bowen disease
No NBUVB^c	0.7 (0.3-1.3)	7	20 105	107 110	1 [Reference]		1 [Reference]
NBUVB ≥500^d	1.8 (0-10.0)	1	717	5587	2.961 (0.362-24.217)	.31	2.520 (0.308-20.592)	.39
Nonmelanoma skin cancer
No NBUVB^c	2.6 (1.7-3.8)	28	20 105	107 025	1 [Reference]		1 [Reference]
NBUVB ≥500^d	1.8 (0-10.0)	1	717	5585	0.668 (0.091-4.921)	.69	0.563 (0.076-4.142)	.57
Melanoma
No NBUVB^c	1.3 (0.7-2.2)	14	20 105	107 090	1 [Reference]		1 [Reference]
NBUVB ≥500^d	0.0 (0-3.7)	0	717	5588	0 (NA)	.99	0 (NA)	.99

Abbreviations: HR, hazard ratio; NA, not applicable; NBUVB, narrowband UV-B.

^{^a}

Incidence rate per 10 000 person-years.

^{^b}

Adjusted by age and sex.

^{^c}

Patients who had not received phototherapy.

^{^d}

Patients who had received 500 or more sessions.