Table 2. Incidence and adjusted hazard measures of pneumonia in association with acupuncture use by sex, age at first stroke and subtypes of stroke.

	No use			Acupuncture use			Pneumonia risk
	Events	PY	IR	Events	PY	IR	HR	(95% CI)*
Full model	3825	64904	58.9	2971	55596	53.4	0.86	(0.82–0.90)
Sex
Female	1473	28623	51.5	1009	24103	41.9	0.79	(0.70–0.82)
Male	2352	36281	64.8	1962	31493	62.3	0.92	(0.86–0.98)
Age, years
20–29	13	387	33.6	2	366	5.5	0.16	(0.04–0.69)
30–39	31	956	32.4	15	839	17.9	0.52	(0.28–0.98)
40–49	171	6839	25.0	112	5657	19.8	0.73	(0.58–0.93)
50–59	486	14836	32.8	362	12364	29.3	0.83	(0.72–0.95)
60–69	1254	23222	54.0	920	19532	47.1	0.82	(0.75–0.89)
70–79	1553	16896	91.9	1257	14952	84.1	0.88	(0.81–0.95)
≥80	317	1769	179.2	303	1885	160.7	0.86	(0.73–1.00)
Subtypes of stroke
Hemorrhagic	215	4310	49.9	147	4008	36.7	0.66	(0.53–0.81)
Ischemic	2324	36768	63.2	1862	32254	57.7	0.86	(0.81–0.92)
Others	1286	23826	54.0	962	19334	49.8	0.87	(0.80–0.95)
Medical conditions
0	471	4285	109.9	307	5115	60.0	0.49	(0.43–0.57)
1	971	14550	66.7	717	13006	55.1	0.77	(0.70–0.85)
2	1021	17711	57.6	816	14964	54.5	0.92	(0.84–1.01)
≥3	1362	28539	48.0	1131	22511	50.2	1.10	(1.01–1.19)
Length of stay, days
1–6	2420	44568	54.3	1820	36260	50.2	0.90	(0.84–0.95)
≥7	1405	20336	69.1	1151	19336	59.5	0.80	(0.74–0.87)

*Adjusted for all covariates listed in Table 1. The HR of pneumonia associated with acupuncture use is 0.86 (95% CI 0.82–0.91) in the additional full model adjusted all covariates listed in Table 1 plus suctioning, bacterial sensitivity test, general ward stay, nasogastric intubation, osmotherapy and urinary catheterization.

†In the sensitivity analysis, acupuncture was associated with reduced pneumonia risk after excluding pneumonia event in the 1 (OR 0.87, 95% CI 0.83–0.91), 3 (OR 0.88, 95% CI 0.84–0.93), 6 (OR 0.90, 95% CI 0.86–0.94), 9 (OR 0.91, 95% CI 0.86–0.95), 12 (OR 0.92, 95% CI 0.87–0.96) months during the follow-up period.