Table 3.
—Model-Based Comparisons of Clinical Outcomes Between Normal and High BMI Groups
| Outcome | Normal Weight, BMI 18.5-24.9 (n = 3,490) | Overweight, BMI 25-29.9 (n = 2,604) | Obese, BMI 30-39.9 (n = 1,772) | Extreme Obesity, BMI ≥ 40 (n = 524) | Extreme Obesity, BMI 40-49.9 (n = 348) | Extreme Obesity, BMI 50-59.9 (n = 118) | Extreme Obesity, BMI ≥ 60 (n = 58) |
| Death at 60 d, OR (95% CI) | Reference | 0.84 (0.74-0.94)a | 0.76 (0.67-0.86)b | 0.77 (0.62-0.94)a | 0.81 (0.64-1.04)c | 0.74 (0.51-1.08) | 0.51 (0.27-0.96)a |
| 0.81 (0.71-0.91)b | 0.74 (0.64-0.84)b | 0.87 (0.69-1.09) | 0.86 (0.66-1.12) | 0.86 (0.58-1.26) | 0.73 (0.38-1.38) | ||
| 0.80 (0.71-0.90)b | 0.73 (0.64-0.84)b | 0.87 (0.69-1.09) | 0.86 (0.66-1.12) | 0.87 (0.59-1.29) | 0.73 (0.38-1.40) | ||
| No. survivors | 2,475 | 1,953 | 1,363 | 402 | 263 | 91 | 48 |
| Time to extubation, HR (95% CI) | Reference | 1.04 (0.97-1.11) | 0.94 (0.88-1.02) | 0.88 (0.78-0.99)a | 0.97 (0.85-1.10) | 0.77 (0.62-0.97)a | 0.66 (0.46-0.94)a |
| 1.02 (0.95-1.10) | 0.91 (0.84-0.99)a | 0.85 (0.75-0.97)a | 0.92 (0.83-1.05) | 0.74 (0.59-0.94)a | 0.54 (0.36-0.80)a | ||
| 0.97 (0.90-1.05) | 0.85 (0.78-0.93)b | 0.80 (0.70-0.92)a | 0.89 (0.76-1.04) | 0.70 (0.56-0.89)a | 0.44 (0.28-0.71)b | ||
| Time to ICU discharge, HR (95% CI) | Reference | 1.03 (0.96-1.10) | 0.98 (0.91-1.05) | 0.96 (0.86-1.07) | 1.02 (0.91-1.15) | 0.88 (0.71-1.10) | 0.79 (0.58-1.07) |
| 1.00 (0.93-1.08) | 0.92 (0.85-0.99)a | 0.86 (0.77-0.97)a | 0.92 (0.81-1.04) | 0.79 (0.63-1.00)a | 0.60 (0.42-0.84)a | ||
| 0.95 (0.88-1.03) | 0.86 (0.79-0.94)b | 0.82(0.72-0.93)a | 0.89 (0.77-1.02)c | 0.75 (0.60-0.92)a | 0.54 (0.37-0.77)b | ||
| Time to hospital discharge, HR (95% CI) | Reference | 1.04 (0.97-1.12) | 1.11 (1.03-1.20)a | 1.14 (1.01-1.29)c | 1.21 (1.05-1.39)a | 1.05 (0.81-1.36) | 0.99 (0.70-1.41) |
| 1.02 (0.95-1.10) | 1.00 (0.93-1.08) | 0.92 (0.80-1.05) | 0.97 (0.83-1.12) | 0.84 (0.63-1.11) | 0.63 (0.44-0.89)a | ||
| 0.98 (0.91-1.05) | 0.96 (0.89-1.04) | 0.91 (0.80-1.04) | 0.96 (0.83-1.12) | 0.84 (0.65-1.09) | 0.64 (0.46-0.88)a |
BMI in kg/m according to NHLBI classification of overweight and obesity by BMI. In each cell, the first estimate is unadjusted for covariates. The second estimate is adjusted for the following covariates: year, age, gender, APACHE II score, initial diagnosis by admission category (medical, elective surgical, emergency surgical), geographic region, hospital type (teaching vs nonteaching), ICU type (closed vs open), and the product of age by APACHE II score. The third estimate adjusted the percent of nutritional prescription received in addition to the other covariates. Because of missing covariates, the second and third models exclude 55 (0.7%) and 138 (1.6%) patients. OR < 1 indicates reduced mortality compared with reference group. HR < 1 indicates reduced rate of event, which implies longer durations (worse outcome). Boldface type indicates statistical significance. HR = hazard ratio. See Figure 1 legend for expansion of other abbreviations.
P ≤ .05
P ≤ .001
.05 < P ≤ .10