Table 5.
Logistic regression by predictor variable
| Predictor | Treatment period weight loss | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≥5% | ≥10% | ≥15% | |||||||||||
| OR | P value | 95% CI | R2 | OR | P value | 95% CI | R2 | OR | P value | 95% CI | R2 | ||
| Surgery type | |||||||||||||
| Gastrectomy (reference) | |||||||||||||
| RYGB | 2.96 | .0001 | (.44, 1.97) | .0323 | 3.47 | .002 | (1.58, 7.62) | .0307 | 4.23 | .019 | (1.27, 14.1) | .0291 | |
| RYGB* | 2.97 | .0001 | (1.64, 5.37) | .0404 | 3.4 | .002 | (1.55, 7.54) | .0307 | 4.18 | .02 | (1.25, 13.9) | .0323 | |
| RYGB† | 2.92 | .001 | (1.54, 5.51) | .0324 | 3.5 | .003 | (1.53, 8.0) | .0307 | 4.6 | .016 | (1.33, 15.9) | .0301 | |
| Gender‡ | |||||||||||||
| Male (reference) | |||||||||||||
| Female | 1.79 | .031 | (1.05, 3.05) | .0108 | 1.7 | .093 | (.92, 3.14) | .0077 | 1.37 | .431 | (.63, 2.97) | .0024 | |
| Female* | 1.75 | .04 | (1.03, 2.98) | .0427 | 1.8 | .034 | (1.05, 3.1) | .0427 | 1.35 | .457 | (.61, 2.9) | .0312 | |
| Age | |||||||||||||
| 20–30 (reference) | |||||||||||||
| 31–50 | 1.28 | .28 | (.82, 1.99) | .0027 | .97 | .894 | (.6, 1.56) | .0000 | 1.08 | .817 | (.55, 2.12) | .0023 | |
| 51 + | .82 | .406 | (.52, 1.3) | .0016 | .94 | .793 | (.57, 1.54) | .0002 | .92 | .817 | (.47, 1.81) | .0023 | |
| Weight when medications prescribed | |||||||||||||
| At plateau (reference) | |||||||||||||
| At regain | 1.44 | .18 | (.84, 2.5) | .0041 | 1.15 | .635 | (.64, 2.09 | .0006 | 1.08 | .847 | (.51, 2.29) | .0001 | |
| At regain*,§ | .98 | .948 | (.54, 1.78) | .0527 | .76 | .412 | (.39, 1.46) | .0463 | .71 | .409 | (.32, 1.6) | .0372 | |
| Race/ethnicity | |||||||||||||
| Caucasian (reference) | |||||||||||||
| All other | 1.59 | .069 | (.96, 2.64) | .0077 | .95 | .859 | (.56, 1.63) | .0001 | 1.18 | .628 | (.61, 2.29) | .0008 | |
| BMI class - at baseline preoperatively | |||||||||||||
| For 1 unit increase | 1.02 | .1 | (1.0, 1.05) | .0063 | 1.03 | .052 | (1.0, 1.05) | .0096 | 1.03 | .097 | (1.0, 1.06) | .0097 | |
| Class I (reference) | |||||||||||||
| Class II | .54 | .043 | (.30, .98) | .0095 | .55 | .102 | (.27, 1.12) | .0075 | .52 | .19 | (.19, 1.38) | .0072 | |
| Class III | 1.53 | .15 | (.86, 2.72) | .0048 | 1.79 | .097 | (.9, 3.56) | .0076 | 1.68 | .26 | (.68, 4.17) | .0051 | |
| Co-morbities - number present at preop§ | |||||||||||||
| 0 (reference) | |||||||||||||
| 1 | 1.03 | .929 | (.55, 1.91) | .0428 | .9 | .761 | (.46, 1.77) | .0383 | .29 | .045 | (.08, .97) | .0510 | |
| 2 | 1.14 | .66 | (.65, 2.0) | .0432 | 1.19 | .566 | (.66, 2.14) | .0388 | 1.38 | .38 | (.67, 2.81) | .0339 | |
| 3 | .70 | .19 | (.41, 1.19) | .0467 | .62 | .116 | (.34, 1.13) | .0447 | .87 | .721 | (.42, 1.82) | .0317 | |
| 4 | .88 | .65 | (.51, 1.52) | .0432 | .79 | .453 | (.44, 1.45) | .0395 | .9 | .785 | (.43, 1.91) | .0315 | |
| 5 | 2.01 | .208 | (.68, 5.99) | .0466 | 2.06 | .159 | (.75, 5.6) | .043 | 1.61 | .431 | (.49, 5.23) | .0333 | |
| Type of co-morbidity§ | |||||||||||||
| HTN | .86 | .526 | (.54, 1.37) | .0437 | .79 | .347 | (.48, 1.3) | .0403 | .8 | .494 | (.42, 1.5) | .0329 | |
| Diabetes | 1.36 | .212 | (.84, 2.2) | .0463 | .9 | .692 | (.54, 1.51) | .0384 | 1.02 | .944 | (.54, 1.95) | .0312 | |
| OSA | .77 | .302 | (.47, 1.26) | .0452 | .47 | .01 | (.27, .84) | .0559 | .81 | .541 | (.40, 1.6) | .0326 | |
| Dyslipidemia | .83 | .434 | (.52, 1.32) | .0441 | 1.16 | .56 | (.7, 1.9) | .0389 | 1.22 | .543 | (.64, 2.3) | .0326 | |
| NAFLD | .98 | .946 | (.58, 1.67) | .0428 | 1.21 | .53 | (.67, 2.17) | .039 | 1.25 | .573 | (.58, 2.7) | .0324 | |
| Mental illness | 1.04 | .878 | (.65, 1.64) | .0428 | 1.41 | .177 | (.86, 2.32) | .0427 | 1.3 | .019 | (1.05, 1.62) | .0526 | |
| Time to achieve nadir weight postop before meds§,¶ | |||||||||||||
| ≤12 mo (reference) | |||||||||||||
| 13–36 mo | .97 | .91 | (.61, 1.56) | .0428 | 1.31 | .29 | (.80, 2.15) | .0409 | 1.93 | .041 | (1.03, 3.61) | .0467 | |
| >36 mo | .84 | .756 | (.29, 2.45) | .0430 | .73 | .601 | (.22, 2.39) | .0387 | .33 | .292 | (.04, 2.59) | .0467 | |
| BMI at start of medications (every 1 unit increase) | 1.03 | .052 | (1.0, 1.07) | .0089 | 1.02 | .111 | (.99, 1.06) | .0065 | 1.02 | .291 | (.98, 1.06) | .0040 | |
BMI = body mass index; CI = confidence interval; HTN = hypertension; NAFLD = nonalcoholic fatty liver disease; OR = odds ratio; obstructive OSA = obstructive sleep apnea; RYGB = Roux-en-Y gastric bypass.
*
Adjusted for BMI at start of medications.
†
Adjusted time elapse between surgery date and start of medications.
‡
Adjusted for type of surgery by including as covariate.
§
Adjusted for type of surgery and gender.
¶
n = 306, missing this data for 13 patients.