Table 2. Incidence, adjusted hazard ratios and confidence intervals of new-onset stroke for TBI patients with and without acupuncture treatment in the stratification of sex and age.

	Non-acupuncture				Acupuncture treatment
	n	Events	Person-years	Incidence*	n	Events	Person-years	Incidence*	IRR (95% CI)	HR (95% CI)
Overall†	29636	1250	173682	7.5	7409	163	33071	4.9	0.68 (0.58–0.81)	0.59 (0.50–0.69)
Sex‡
Female	14056	550	84939	6.5	3514	73	15890	4.6	0.71 (0.55–0.91)	0.62 (0.48–0.79)
Male	15580	700	88743	7.9	3895	90	17181	5.2	0.66 (0.53–0.83)	0.57 (0.46–0.71)
Age§
20–44	17781	235	109647	2.1	4420	24	20054	1.2	0.56 (0.35–0.85)	0.46 (0.30–0.71)
45–64	7854	480	45206	10.6	1997	66	8953	7.4	0.69 (0.53–0.90)	0.64 (0.50–0.83)
≥65	4001	535	18829	28.4	992	73	4064	18.0	0.63 (0.49–0.81)	0.60 (0.47–0.76)

*Per 1000 person-years with calculated by correcting immortal time.

^†Adjusted for age, gender, low income, density of TCM physicians, types of TBI, diabetes mellitus, hypertension, hyperlipidemia, mental disorders, ischemic heart disease, migraine, epilepsy, anticoagulants, antiplatelet agents, and lipid-lowering agents.

^‡Adjusted for all covariates in the full model except gender.

^§Adjusted for all covariates in the full model except age.

CI, confidence interval; HR, hazard ratio; IRR, incidence rate ratio; TBI, traumatic brain injury; TCM traditional Chinese medicine.