Does nonparticipation in studies of advanced cancer lead to biased quality-of-life scores?
We did not find indications that using observed responses only resulted in clinically important underestimation of palliative care patients' symptomatology. Either nonparticipants' scores did not differ significantly from participants' or the variables used to describe the non-participants were insufficient predictors of the patients' scores. In any case, the study indicated that imputation of scores of nonparticipants in palliative care may not be worthwhile unless very good predictors are available.
The emergence of this possible pattern of secondary malignancy emphasizes the importance of randomized controlled trials in defining safety and efficacy of new approaches for patients in the adjuvant setting.