Table 3

Risks of dementia associated with acupuncture treatment in patients with stroke stratified by age, sex, type of stroke, medical conditions and length of stay*

	Acupuncture treatment
	No						Yes
Stratification	N	Events	PYs	Incidence†	HR	(95% CI)	N	Events	PYs	Incidence*	HR	(95% CI)‡
Sex
Female	2426	467	13 132	35.6	1.00	(reference)	2426	305	12 015	25.4	0.70	(0.60 to 0.80)
Male	3189	558	16 471	33.9	1.00	(reference)	3189	415	15 193	27.3	0.75	(0.66 to 0.85)
Age, years
50–59	1368	116	8137	14.3	1.00	(reference)	1368	69	7195	9.6	0.64	(0.47 to 0.86)
60–69	2242	355	12 634	28.1	1.00	(reference)	2242	250	11 235	22.3	0.75	(0.64 to 0.88)
70–79	1770	474	8112	58.4	1.00	(reference)	1770	348	7989	43.6	0.72	(0.63 to 0.83)
≥80	230	80	712	112.4	1.00	(reference)	230	53	788	67.3	0.54	(0.38 to 0.76)
Subtypes of stroke
Haemorrhagic	464	64	2504	25.6	1.00	(reference)	464	49	2322	21.1	0.77	(0.53 to 1.12)
Ischaemic	3386	664	17 380	38.2	1.00	(reference)	3386	479	16 214	29.5	0.74	(0.66 to 0.84)
Others	1760	297	9710	30.6	1.00	(reference)	1760	192	8671	22.1	0.69	(0.57 to 0.82)
Medical conditions
0	428	84	1480	56.8	1.00	(reference)	428	60	1821	32.9	0.55	(0.39 to 0.77)
1	1298	210	6263	33.5	1.00	(reference)	1298	140	6073	23.1	0.64	(0.52 to 0.80)
2	1554	265	8175	32.4	1.00	(reference)	1554	196	7398	26.5	0.81	(0.68 to 0.98)
≥3	2330	466	13 677	34.1	1.00	(reference)	2330	324	11 915	27.2	0.82	(0.71 to 0.95)
Length of stay, days
1–6	3449	609	19 024	32.0	1.00	(reference)	3405	441	16 712	26.4	0.81	(0.71 to 0.91)
≥7	2161	416	10 570	39.4	1.00	(reference)	2205	279	10 495	26.6	0.64	(0.55 to 0.74)

*For all patients with haemorrhagic stroke (n=19 761) without any matching procedures, acupuncture was associated with reduced risk of dementia (adjusted HR 0.69, 95% CI 0.61 to 0.79).
†Per 1000 PYs.
‡Adjusted for all covariates listed in table 1.
PY, person-years.