3.3. Effect of the HHS Intervention on Perceived Stress
The mean PSS-10 score increased from 13.8 (SD = 6.5) at the baseline to 16.7 (SD = 6.8) at the follow-up among students at the intervention schools, and from 14.2 (SD = 6.4) to 16.7 (SD = 6.7) among students at the control schools. In the primary intention-to-treat analysis with an adjustment for the baseline covariates, we found no significant between group difference on perceived stress at the follow-up [b = 0.42, 95% CI: −0.16;1.00]. Similarly, the sensitivity analyses of complete cases did not show any evidence of an effect on perceived stress either [b = 0.59, 95% CI: −0.15;1.33] (