Table 2.

Multivariate Cox regression analysis of patient characteristics associated with infection of nontuberculous Mycobacterium

Variables	HR (95%CI)	P value	aHR* (95%CI)	P value
Diabetes mellitus
Without	Ref.	–	Ref.	–
With	1.44 (1.16–1.73)	< 0.01†	1.43 (1.17–1.74)	< 0.01†
Gender
Male	1.34 (1.10–1.63)	< 0.01†	1.36 (1.12–1.66)	< 0.01†
Female	Ref.	–	Ref.	–
Age group (y)
18–44	Ref.	–	Ref.	–
45–64	1.016 (0.57–1.75)	0.96	1.08 (0.56–1.73)	0.91
≥ 65	1.060 (0.62–1.81)	0.85	1.14 (0.66–1.95)	0.66
Insured premium (NT$)
< 8,000	Ref.	–	Ref.	–
18,000–34,999	1.18 (0.02–2.21)	0.07	1.09 (0.03–1.29)	0.09
≥ 35,000	1.23 (0.17–8.78)	0.83	1.22 (0.17–8.71)	0.84
CCI_R	1.18 (1.01–1.22)	< 0.01†	1.07 (1.02–1.11)	0.04†
Season
Spring	Ref.	–	Ref.	–
Summer	0.94 (0.72–1.24)	0.62	0.95 (0.72–1.24)	0.63
Autumn	0.82 (0.63–1.08)	0.14	0.82 (0.63–1.08)	0.14
Winter	0.86 (0.65–1.14)	0.26	0.87 (0.65–1.15)	0.29
Location
Northern Taiwan	Ref.	–	–	–
Middle Taiwan	0.83 (0.65–1.06)	0.12	–	–
Southern Taiwan	1.07 (0.85–1.35)	0.60	–	–
Eastern Taiwan	0.20 (0.09–1.47)	0.20	–	–
Outlying islands	0.53 (0.07–3.77)	0.52	–	–
Urbanization level
1 (the highest)	2.82 (1.83–4.35)	< 0.01†	2.79 (1.81–4.31)	< 0.01†
2	2.43 (1.70–3.47)	< 0.01†	1.77 (1.19–2.63)	< 0.01†
3	1.84 (1.29–2.61)	< 0.01†	1.51 (1.04–2.20)	0.03†
4 (the lowest)	Ref.	–	Ref.	–
Level of care
Hospital center	1.49 (1.15–1.93)	< 0.01†	1.46 (1.08–1.97)	0.02†
Regional hospital	1.22 (1.05–1.35)	0.02†	1.14 (1.05–1.27)	0.02†
Local hospital	Ref.	–	Ref.	–

aHR = adjusted hazard ratio; CCI_R = Charlson comorbidity index revised (CCI removed DM); HR = hazard ratio; NT$ = national Taiwanese dollars.

^*Adjusted variables listed in the table.

^†P < 0.05.