Treatments effect on the primary and secondary outcomes measured once per period (N=120 surgeries, 30 surgeons)
| Outcome | Cooling vest Mean±SE (N=60 surgeries) | No cooling vest Mean±SE (N=60 surgeries) | Difference in means (vest minus no vest) (95% CI) | P value |
| Primary outcome | ||||
| Thermal comfort range 0–10 | 4.5±0.19 | 6.6±0.19 | −2.1 (−2.7 to 1.6)* | <0.001 |
| Sensitivity analysis Median (Q1, Q3) | 4.0 (3.5, 5.0) | 7.0 (6.0, 7.0) | Proportional OR† 16 (6.7 to 39) | <0.001 |
| Secondary outcomes | ||||
| Average MST | 33.0±0.09 | 33.2±0.09 | −0.23 (−0.40 to 0.06) | 0.011 |
| Average CBT‡ | 36.1±0.12 | 36.2±0.12 | −0.13 (−0.33 to 0.07) | 0.194 |
| C3B PST Score | 69.4±0.83 | 69.4±0.83 | 0.03 (−2.44 to 2.51)* | 0.979 |
| C3B VMT Score range 0–70 | 58.4±1.43 | 57.5±1.42 | 0.88 (−2.25 to 4.01)* | 0.569 |
| Perception of sweat-soaked clothing range 0–10 | 1.4±0.39 | 4.3±0.38 | −2.91 (−3.75 to 2.07) | <0.001 |
| Fatigue range 0–10 | 2.3±0.26 | 3.3±0.25 | −0.95 (−1.63 to 0.28) | 0.007 |
| Median (Q1, Q3) | Median (Q1, Q3) | Proportional OR† | ||
| Borg perceived exertion range 6–20 | 13 (11, 13) | 13 (12, 15) | 2.3 (1.15 to 4.48) | 0.019 |
| Sensitivity analysis | Mean±SE | Mean±SE | Difference in means | |
| Borg perceived exertion | 12.4±0.27 | 13.2±0.27 | −0.78 (−1.46 to 0.09) | 0.028 |
Difference in means (95% CI) for the cooling vest versus no cooling vest was estimated from a repeated measures linear model with an AR (1) correlation structure adjusting for duration of the case.
*Adjusting for preoperative measurements.
†Proportional OR for the cooling vest versus no cooling vest was estimated from a generalised estimating equation proportional odds model with an independence correlation structure accounting for within-surgeon correlation.
‡n=1 surgery was not included as the thermometer was malfunctioning.
C3B, Cleveland Clinic Cognitive Battery; CBT, core body temperature; MST, mean skin temperature; PST, processing speed test; VMT, visual memory test.