2.7. Statistical Analysis
prediabetes
REGRESSION, SECONDARY, PREDIABETES
A superiority trial approach utilizing a one-way analysis of variance method was applied for estimating the sample size. The baseline mean and standard deviation (SD) of FPG in the prediabetes cohort were 105 and 9 mg/dL, respectively [Mean (SD) or median (interquartile range, IQR) and frequency and percentages were used to describe continuous data and categorical data, respectively. Means of primary and secondary outcomes among the three groups were compared using a mixed-effect linear regression model by regressing an outcome of intervention and time, considering patients as a random effect (i.e., repeated measure at 4, 8, and 12 weeks after randomization) and the intervention arms (TRE plus BE and TRE alone versus usual care) as a fixed effect. Marginal means and differences between any pair of the three interventions were estimated accordingly. If baseline characteristics differed between the 3 groups, these were adjusted using multivariate regression analysis.All analyses were performed using three approaches. First, an intention-to-treat analysis (ITT) was applied by considering interventions that were initially assigned regardless of compliance. Second, a per-protocol analysis (PPA) excluded patients who did not comply with TRE (i.e., complied < 5 days per week) in the TRE plus BE and TRE alone and patients in the usual care group who took TRE 5 days or more per week from the analysis. Third, an “as-treated” analysis kept participants in either TRE plus BE or TRE alone if they complied with TRE ≥ 5 days/week; otherwise, they were considered in the usual care group. Likewise, participants in a usual care group were moved to the TRE group if they adhered to TRE ≥ 5 days/week. If a participant missed an appointment in week 4, 8 or 12, the previous outcome measure was carried forward to impute the missing outcome to minimize the lost to follow-up.All analyses were performed using STATA 18.0. A 