Effect of Smoking on Motor Recovery After Cervical American Spinal Injury Association Grade D Traumatic Spinal Cord Injury

Article Figures & Data

Table 1

Demographic data for total study population and the smoking and nonsmoking groups.

Demographic Data	Total (N = 152)	Nonsmoker (n = 121)	Smoker (n = 31)	P Value
Age at injury, y				0.078^{^a}
15–29	17 (11.1%)	12 (9.9%)	5 (16.1%)
30–44	18 (11.8%)	11 (9.1%)	7 (22.6%)
45–59	67 (44.1%)	53 (43.8%)	14 (45.2%)
60–74	38 (25%)	35 (28.9%)	3 (9.7%)
>75	12 (7.9%)	10 (8.3%)	2 (6.5%)
Sex				0.173^{^a}
Men	113 (74.3%)	87 (71.9%)	26 (83.9%)
Women	39 (25.7%)	34 (28.1%)	5 (16.1%)
Race (N = 151)				0.435^{^a}
White	106 (70.2%)	86 (71.7%)	20 (64.5%)
Black	37 (24.5%)	27 (22.5%)	10 (32.3%)
Asian	5 (3.3%)	5 (4.2%)	0 (0.0%)
Other	3 (2.0%)	2 (1.7%)	1 (3.2%)
Body mass index	27.4 ± 5.7	27.6 ± 5.8	27.1 ± 5.5	0.730^{^b}
Diabetes (N = 134)				0.323^{^a}
No	110 (82.1%)	88 (72.7%)	22 (71.0%)
Yes	24 (17.9%)	17 (26.3%)	7 (29.0%)
Other injury				0.402^{^a}
No	121 (79.6%)	98 (70.3%)	23 (71.0%)
Yes	31 (20.4%)	23 (29.7%)	8 (29.0%)
Traumatic brain injury (N = 125)				0.229^{^a}
No	107 (85.6%)	85 (70.3%)	22 (71.0%)
Yes	18 (14.4%)	12 (29.7%)	6 (29.0%)
Rehabilitation length of stay, d	31.0 ± 20.1	31.8 ± 21.4	27.9 ± 13.9	0.350^{^b}
No. of rehospitalizations	0.3 ± 0.7	0.3 ± 0.6	0.5 ± 1.2	0.180^{^b}
Days of rehospitalization	2.3 ± 11.9	2.2 ± 12.5	2.7 ± 9.3	0.830^{^b}

Table 2

Total motor score at 3 separate timepoints, as well as change in total motor score from time of discharge from rehabilitation to 1-y follow-up visit.

Outcome Variable	Total (N = 152)	Nonsmoker (n = 121)	Smoker (n = 31)
Total motor score—rehabilitation admission	74.1 ± 15.4	74.5 ± 15.4	73.3 ± 14.3
Total motor score—rehabilitation discharge	85.6 ± 11.2	86.0 ± 10.4	85.4 ± 10.1
Total motor score—1-y follow-up	92.8 ± 9.7	94.0 ± 7.9	90.0 ± 9.0
Change in motor score—rehabilitation discharge to 1-y follow-up	7.3 ± 8.0	8.0 ± 7.6	4.6 ± 8.7

Table 3

Results of multiple linear regression with dependent variable of change in total motor score.

Change in Motor Score—Rehabilitation Discharge to 1-y Follow-Up	Effect Size	95% CI	Standardized β	P Value
Smoking	−3.80	(−6.98, −0.63)	−0.192	0.019
Age	−1.40	(−2.61, −0.19)	−0.186	0.024
Sex	−1.98	(−4.87, 0.90)	−0.109	0.117
Race	0.56	(−0.96, 2.07)	0.057	0.470
Rehabilitation length of stay	0.06	(0.00, 0.13)	0.159	0.048
No. of rehospitalizations	−0.62	(−2.60, 1.37)	−0.059	0.541
Days of rehospitalization	−0.06	(−0.18, 0.07)	−0.083	0.385

Table 4

Results of multiple linear regression with dependent variable of total motor score.

Total Motor Score—1-y Follow-Up	Effect Size	95% CI	Standardized β	P Value
Smoking	−4.53	(−8.27, −0.79)	−0.195	0.018
Age	−0.62	(−2.07, 0.84)	−0.067	0.404
Sex	−3.73	(−7.29, −1.68)	−0.166	0.040
Race	0.25	(−1.46, 1.97)	0.023	0.770
Traumatic brain injury	−2.13	(−6.52, 2.26)	−0.077	0.338
Rehabilitation length of stay	−0.19	(−0.27, −0.11)	−0.363	<0.01
No. of rehospitalizations	1.62	(−3.45, 6.67)	0.120	0.528
Days of rehospitalization	−0.62	(−1.33, 0.08)	−0.334	0.084