2.3. Randomization and Distribution
Computer-based stratified randomization (1 : 1) was generated, with strata defined by age (40 to 55 years, 56 to 65 years, and 66 to 80 years) and sex. Assignments were concealed in opaque envelopes until the start of the intervention. After disclosure at the end of the study, we ensured that there were no allocation errors.