Table 3: Characteristics of patients who underwent surgery compared with those who did not have surgery*

Characteristic	Surgery	No surgery	p value
Sex			< 0.001§
Male	139	287
Female	585	653
Substance use			< 0.001§
Yes	9	33
No	715	907
BMI, kg/m²; mean ± SD	48.87 ± 8.19	47.67 ± 7.92	0.003§
Age, yr; mean ± SD	46.78 ± 10.54	48.42 ± 11.86	0.003§
Distance from the hospital, km; mean ± SD	119.73 ± 179.49	113.64 ± 177.57	0.5
Operational period (referral)†			0.047§
1	478	575
2	246	347
Operational period (orientation)‡			< 0.001§
1	233	155
2	490	507

Note: BMI = body mass index. *The Pearson χ² test and Student t test were used as appropriate. †Binary variable indicating if a patient was referred in Period 1 or Period 2. ‡Binary variable indicating if a patient attended orientation in Period 1 or Period 2. §p < 0.05 was considered statistically significant.