Table 4.

Comparison of hazard ratios of tuberculosis infection between metformin irregular users and regular users versus never users.

Tuberculosis Infection/Metformin Exposure	Irregular Metformin Users versus Never Users			Regular Metformin Users versus Never Users
	HR	95% CI	p Value	HR	95% CI	p Value
Any tuberculosis infection
Never users	1.000			1.000
Ever users	0.603	(0.538–0.677)	<0.0001	0.438	(0.382–0.501)	<0.0001
Tertiles of cumulative duration of metformin therapy (months)
Never users	1.000			1.000
<27.1	1.179	(1.040–1.336)	0.0103	0.889	(0.748–1.055)	0.1781
27.1–58.3	0.547	(0.478–0.627)	<0.0001	0.523	(0.435–0.628)	<0.0001
>58.3	0.214	(0.180–0.255)	<0.0001	0.190	(0.153–0.235)	<0.0001
Tertiles of cumulative dose of metformin therapy (mg)
Never users	1.000			1.000
<817,000	1.096	(0.965–1.245)	0.1570	0.847	(0.713–1.005)	0.0572
817,000–2,047,180	0.565	(0.494–0.647)	<0.0001	0.443	(0.366–0.535)	<0.0001
>2,047,180	0.268	(0.228–0.316)	<0.0001	0.230	(0.188–0.282)	<0.0001
Pulmonary tuberculosis infection
Never users	1.000			1.000
Ever users	0.605	(0.536–0.683)	<0.0001	0.431	(0.373–0.497)	<0.0001
Tertiles of cumulative duration of metformin therapy (months)
Never users	1.000			1.000
<27.1	1.185	(1.038–1.352)	0.0119	0.852	(0.710–1.023)	0.0853
27.1–58.3	0.551	(0.478–0.636)	<0.0001	0.517	(0.426–0.629)	<0.0001
>58.3	0.207	(0.171–0.249)	<0.0001	0.189	(0.151–0.237)	<0.0001
Tertiles of cumulative dose of metformin therapy (mg)
Never users	1.000			1.000
<817,000	1.101	(0.963–1.259)	0.1579	0.813	(0.678–0.976)	0.0262
817,000–2,047,180	0.566	(0.491–0.652)	<0.0001	0.440	(0.360–0.537)	<0.0001
>2,047,180	0.266	(0.224–0.316)	<0.0001	0.228	(0.184–0.283)	<0.0001

HR: hazard ratio (propensity score weighted), CI: confidence interval.