. 2022 Feb 28;12:3270. doi: 10.1038/s41598-022-07294-1

Table 2.

Hazard ratios and 95% confidence intervals for outcomes in patients with metformin use versus nonuse.

Outcome	T2D without metformin			T2D with metformin			cHR	(95% CI)	P value	aHR^a	(95% CI)	P value
Outcome	n	PY	IR	n	PY	IR	cHR	(95% CI)	P value	aHR^a	(95% CI)	P value
All-cause pneumonia	2950	252,412	11.69	3203	268,320	11.94	1.02	(0.97, 1.07)	0.497	1.01	(0.96, 1.06)	0.793
Bacterial pneumonia	2220	254,691	8.72	2133	271,465	7.86	0.9	(0.84, 0.95)	< 0.001	0.89	(0.84, 0.94)	< 0.001
NIPPV	1211	256,617	4.72	1250	274,214	4.56	0.96	(0.89, 1.04)	0.332	0.93	(0.86, 1.01)	0.083
IMV	2382	256,847	9.27	1979	274,261	7.22	0.77	(0.73, 0.82)	< 0.001	0.77	(0.73, 0.82)	< 0.001
Respiratory causes of death	461	259,066	1.78	319	277,433	1.15	0.65	(0.56, 0.75)	< 0.001	0.64	(0.56, 0.74)	< 0.001

NIPPV noninvasive positive pressure ventilation, IMV invasive mechanical ventilation, PY person-years, IR incidence rate, per 1000 person-years, cHR crude hazard ratio, aHR adjusted hazard ratio.

aHR^a, multivariable analysis adjusted for sex, age, comorbidities, CCI, DCSI scores, insulin, statin, aspirin, item and number of oral antidiabetic drugs.