Table 2.

Outcome differences among groups

	Frequent users (N = 195)	Infrequent users (N = 55)	Control (N = 211)	p-value
6-month ΔBMI	11.7 ± 2.9 (N = 166)	10.6 ± 3.2 (N = 39)	10.7 ± 3.2 (N = 166)	0.046
1st year ΔBMI (mean ± SD)	14.8 ± 4.7 (N = 122)	13.1 ± 4.4 (N = 39)	13.2 ± 4.7 (N = 149)	0.017
2nd year ΔBMI (mean ± SD)	14.3 ± 5.0 (N = 47)	12.2 ± 6.0 (N = 26)	12.7 ± 5.7 (N = 128)	0.048
3rd year ΔBMI (mean ± SD)	12.3 ± 4.9 (N = 21)	10.0 ± 7.0 (N = 15)	11.0 ± 5.8 (N = 108)	0.226
Overall 3 year complications	17.7% (N = 144)	17.9% (N = 33)	18.1% (N = 140)	0.931

BMI body-mass-index, SD standard deviation, SD standard deviation, ΔBMI (follow-up BMI) – (preoperative BMI)