I don’t understand the math here. The average per calendar day didn’t go down, so the total drinking is the same. That total is distributed among the drinking days, which are also the same. So how can the drinks per drinking day have changed?
I don’t understand the math here. The average per calendar day didn’t go down, so the total drinking is the same. That total is distributed among the drinking days, which are also the same. So how can the drinks per drinking day have changed?
Strange, right? Take a look at figure 4 here: https://jamanetwork.com/journals/jamapsychiatry/fullarticle/...
This is as in the abstract:
1. drinks/day declined in both groups and somewhat more in the treatment group but wasn't statistically significant 2. number of drinks/day basically wasn't different at all 3. drinks/drinking day didn't change in the placebo group but did decline in the treatment group
(These are all actually regression coefficients computed on non-random samples but nevermind.) Somehow it seems like what's happening is that 3 rises to statistical significance even though 1 doesn't.