. Author manuscript; available in PMC: 2019 Mar 15.

Published in final edited form as: Int J Cancer. 2017 Nov 20;142(6):1174–1181. doi: 10.1002/ijc.31143

Table 2.

Risk of skin cancers, overall and by histological subtype in patients with DM1.

Outcome	All Patients (N=16,180)			Excluding individuals with skin cancer event occurred within 6 months of start of follow-up (N=16,171)

	N event (crude incident rate¹)	HR² (95% CI)	P	N event (crude incident rate¹)	HR² (95% CI)	p
1^st skin cancer³
DM1-free subjects⁴	108 (131.07)	1.00 (reference)		100(121.36)	1.00 (reference)
DM1 patients	35 (434.55)	5.44 (3.33–8.89)	<.0001	34 (422.14)	5.81 (3.52–9.59)	<.0001
Melanoma
DM1-free subjects	20 (24.27)	1.00 (reference)		20 (24.27)	1.00 (reference)
DM1 patients	<5 (37.25)	2.40 (0.56–10.31)	0.24	<5 (37.25)	2.40 (0.56–10.31)	0.24
Basal cell carcinoma
DM1-free subjects	80 (97.09)	1.00 (reference)		73 (88.59)	1.00 (reference)
DM1 patients	30 (372.47)	5.78 (3.36–9.92)	<.0001	29 (360.06)	6.48 (3.71–11.34)	<.0001

per 100,000 person-years.

Models were stratified on matched set, and adjusted for average number of clinic visit/year after the start date until 1 year prior to the end of follow-up.

In addition to the melanoma and BCC cases in the table, there were 6 SCC (all in DM1-free subjects), and <5 skin cancer, not otherwise specified in all patients; person-year of follow-up=82400 for DM1-free subjects, and 8054 for DM1 patients in analysis of all patients, and 82399 and 8054, respectively in analysis excluding cases within first 6 months of follow-up

⁴

DM1-free individuals were matched to DM1 patients on gender, birth year (±2 years), attending practice, and registration year (±1 year).