Table 3.

Subgroup analysis of clinical variables for the associations of piracetam with NIHSS score improvement and the adjusted ratio difference in each clinical category in Taiwan ischemic stroke patients.

Variables	NIHSS Improved (n = 131)	NIHSS NotImproved (n = 1220)	Rate (Proportion)	95% CI Lower-Upper Rate	SE	p Value *	Adjusted Ratio Difference of NIHSS Improvement (95% CI) †
Age (years)
<75	56	713	0.073	0.054–0.091	0.009	0.061	-
≥75	75	507	0.129	0.102–0.156	0.014	0.025
Gender
male	46	433	0.096	0.070–0.122	0.013	0.273	-
female	85	787	0.097	0.078–0.117	0.010	0.007
BMI
normal weight	59	596	0.090	0.068–0.112	0.011	0.016	reference
underweight	14	42	0.250	0.137–0.363	0.058	0.425	20.3% (4.7%–52.2%)
overweight	45	443	0.092	0.067–0.118	0.013	0.688	-
obese	9	117	0.071	0.026–0.116	0.023	0.035	-
Smoking
non-smoker	70	761	0.084	0.065–0.103	0.010	0.123	reference
current smoker	40	327	0.109	0.077–0.141	0.016	0.074	7.5% (0.6%–18.9%)
ex-smoker	21	132	0.137	0.083–0.192	0.028	0.033	11.9% (2.0%–30.2%)
Piracetam
negative	72	822	0.081	0.063–0.098	0.009	-	reference
positive	59	398	0.129	0.098–0.160	0.016		6.4% (2.2%–13.6%)
Hypertension
negative	29	249	0.104	0.070–0.140	0.018	0.866	-
positive	102	971	0.095	0.078–0.113	0.009	0.004
Diabetes mellitus
negative	76	625	0.108	0.085–0.131	0.012	0.018	-
positive	55	595	0.085	0.063–0.106	0.011	0.124
Dyslipidemia
negative	43	374	0.103	0.074–0.132	0.015	0.280	-
positive	88	846	0.094	0.075–0.113	0.010	0.013
Atrial fibrillation
negative	82	1025	0.074	0.059–0.090	0.008	0.020	reference
positive	49	195	0.201	0.151–0.251	0.026	0.131	23.4% (2.5%–57.9%)
TOAST
Small-vessel occlusion	21	411	0.049	0.028–0.069	0.010	0.106	reference
large-artery atherosclerosis	51	355	0.126	0.093–0.158	0.016	0.145	8.6% (2.9%–18.4%)
cardioembolism	34	159	0.176	0.122–0.230	0.027	0.106	-
others	25	295	0.078	0.049–0.108	0.015	0.453	-

Statistical analysis: logistic regression model. * p value, to define the statistical significance for the associations of piracetam with NIHSS score improvement in each subgroup of each clinical category in subgroup analysis using logistic regression model. ^† The adjusted ratio difference in favor of improvement in NIHSS that was calculated as I₀ × (AOR-1), for which AOR is the adjusted odds ratio in case subgroup and I₀ the unadjusted odds for patients in control subgroup. The adjusted ratio difference was only calculated in the item with statistically significant comparison with its reference of each clinical category using multivariate analysis in Table 2, otherwise it was not showed. Abbreviations: NIHSS, National Institute of Health Stroke Scale; BMI, body mass index; TOAST, Trial of Organization 10,172 in Acute Stroke Treatment classification; SE, standard error; 95% CI, 95% confidence interval.