Attrition
From EvaluationWiki
(Redirected from Differential attrition)
This term refers to the loss of subjects from a group under study. In long-term studies looking for durable or eventual effects of an intervention or treatment-these being the effects of greatest interest-the attrition is often so serious that the study eventually lacks sufficient numbers to justify general conclusions. There is a related serious problem in studies involving two groups where the comparison is important, e.g., in control group studies; this is the problem of 'differential attrition' where a larger number of the group not receiving treatment drops out of the study, possibly because they are not receiving treatment. This may leave too few in that group to allow any conclusions about the effect of the treatment.
