[omarhaneef]

Can anyone find the effect size in this study? When it is missing, I suspect that it is small, and that in turn leads me to suspect p-hacking.

[nialse]

Mean and standard deviation for PSQI at the end of the study.

Vitamin D group: 6.75 (2.97) Placebo group: 9.73 (3.04)

Cohen's D: 0.99 (>0.8 is regarded a large effect size)

Side note: The translation "Petersburg’s Sleep Index" instead of "Pittsburgh Sleep Quality Index" just cracks me up though! =)

[omarhaneef]

Thanks. That's pretty compelling.