Table 2

Principal strata according to potential behavior in each source of noncompliance (alternative version of Table1)
Strata Behavior pattern in noncompliance sources 1, 2 and 3a Treatment assigned and received for subject R in corresponding stratum
Compliers Yes, no, no Ri(Ti) = Ti
Yes, yes, no
Yes, yes, yes
Yes, no, yes
Always takers No, yes, no Ri(Ti) = 1
No, yes, yes
No, no, yes
Never-takers No, no, no Ri(Ti) = 0

*As the trial is blinded, there are no defiers, as subjects cannot systematically take the opposite treatment; **Ri = treatment received, Ti = treatment assigned (0 = placebo, 1 = calcium); asources of (non)compliance: 1, taking >80% of pills assigned; 2, collateral treatment involving substantial calcium indicated by physician; 3, self-indicated collateral treatment involving substantial calcium.

Seuc et al.

Seuc et al. Trials 2013 14:78   doi:10.1186/1745-6215-14-78

Open Data