Hi,
What is meant by "Cointerventions" as listed in question 1a and 1b part iii? Are you referring to interventions that may be introduced to patients who screen positive for disease (but are thus not offered to their unscreened/undiagnosed counterparts)?
Thanks for any clarification.
Elan
One of the reasons for blinding patients and their clinical care providers to treatment group is to prevent differential co-interventions. If the clinical care provider knows the patient is getting placebo, she might intervene more aggressively with other treatments than she would if she knew the patient was getting active drug. In a trial to of AAA screening, there is not blinding. Subjects know that they were screened. The screening clinician knows too. But in this case, the opportunity for differential co-interventions is just that the screening might turn up another treatable problem that is not an AAA. Obviously, this isn't going to happen in the unscreened group.