Table 4. Nine-year changes in body weight (BW), body mass index (BMI) and waist circumference (WC): adjusted estimates (mean, Δ, RR).
Outcomes | Analysis on dataset | Intervention group | Control group | Intention-to-treat analysis: intervention versus control | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Continuous | N | Mean | 95% CI | p | N | Mean | 95% CI | p | N | Δ | 95% CI | p | |
BW (kg) | available | 125 | +3.1 | +1.3 to +4.8 | 0.001 | 134 | +5.1 | +3.5 to +6.8 | <0.001 | 259 | -2.1 | -4.1 to -0.1 | 0.043 |
BW (kg) | imputed | - | +3.1 | +1.5 to +4.7 | <0.001 | - | +5.3 | +3.6 to +7.0 | <0.001 | - | -2.2 | -4.6 to +0.2 | 0.073 |
BMI (kg/m²) | available | 125 | +1.11 | +0.44 to +1.77 | 0.002 | 132 | +1.90 | +1.26 to +2.54 | <0.001 | 257 | -0.79 | -1.57 to -0.01 | 0.046 |
BMI (kg/m²) | imputed | - | +1.19 | +0.59 to +1.79 | <0.001 | - | +2.00 | +1.37 to +2.63 | <0.001 | - | -0.81 | -1.69 to +0.08 | 0.074 |
WC (cm) | available | 124 | +1.9 | +0.1 to +3.7 | 0.043 | 134 | +4.8 | +3.0 to +6.5 | <0.001 | 258 | -2.9 | -5.0 to -0.8 | 0.008 |
WC (cm) | imputed | - | +2.1 | +0.3 to +3.9 | 0.022 | - | +4.5 | +2.8 to +6.1 | <0.001 | - | -2.4 | -4.7 to -0.0 | 0.046 |
Binary | Dataset | n/N | Pr | 95% CI | p | n/N | Pr | 95% CI | p | N | RR | 95% CI | p |
BW loss | available | 40/125 | 0.32 | 0.24 to 0.41 | <0.001 | 28/134 | 0.21 | 0.14 to 0.29 | <0.001 | 259 | 1.60 | 1.04 to 2.46 | 0.032 |
BW loss | imputed | - | 0.35 | 0.27 to 0.43 | <0.001 | - | 0.25 | 0.17 to 0.32 | <0.001 | - | 1.50 | 1.02 to 2.22 | 0.040 |
BW loss ≥ 5% | available | 21/125 | 0.17 | 0.11 to 0.25 | <0.001 | 12/134 | 0.09 | 0.05 to 0.15 | <0.001 | 259 | 1.83 | 0.90 to 3.71 | 0.096 |
BW loss ≥ 5% | imputed | - | 0.19 | 0.13 to 0.26 | <0.001 | - | 0.12 | 0.06 to 0.18 | <0.001 | - | 1.66 | 0.91 to 3.02 | 0.100 |
BMI reduction | available | 40/125 | 0.32 | 0.24 to 0.41 | <0.001 | 27/132 | 0.20 | 0.14 to 0.28 | <0.001 | 257 | 1.61 | 1.04 to 2.50 | 0.032 |
BMI reduction | imputed | - | 0.35 | 0.27 to 0.43 | <0.001 | - | 0.24 | 0.17 to 0.32 | <0.001 | - | 1.49 | 1.01 to 2.20 | 0.046 |
WC reduction | available | 55/124 | 0.44 | 0.35 to 0.54 | <0.001 | 36/134 | 0.27 | 0.20 to 0.35 | <0.001 | 258 | 1.60 | 1.13 to 2.25 | 0.007 |
WC reduction | imputed | - | 0.44 | 0.36 to 0.52 | <0.001 | - | 0.30 | 0.22 to 0.37 | <0.001 | - | 1.46 | 1.06 to 2.00 | 0.019 |
95% CI = 95% confidence interval. Pr = univariate proportion (= n/N). RR = adjusted relative risk (intervention group as exposure category versus control group as reference category). BW loss ≥ 5% of the inclusion measurement. Continuous outcome within group = follow-up measurement minus inclusion measurement. Δ = intergroup difference in mean change (intervention minus control). p for test with (H0: mean = 0) or (H0: Δ = 0) or (H0: Pr = 0) or (H0: RR = 1) according to outcome and comparison. All results, except Pr, were adjusted on baseline characteristics (gender, age, BW or BMI or WC, HbA1c, occupation, stress). Missing data were imputed under MAR assumption with MICE method implemented in Stata 10 (ice and Micombine packages). Variables included in the imputation models: baseline characteristics, exposure-group, participation in the medical visit at trial completion (yes/no), and the shifted log transformation of BW and WC at follow-up, respectively. Forty imputed datasets were generated from an original dataset of 432 observations.