Quality‐of‐life‐adjusted survival for comparing cancer treatments. A commentary on twist and q‐twist

Abstract

In chronic disease situations where treatment comparisons favor no particular therapy, or where definitive outcome requires a considerable follow‐up period, it is useful to have additional and perhaps intermediate endpoints of relevant clinical significance to compare treatments. One such endpoint is Time Without Symptoms and Toxicity (TWiST) which, together with Q‐TWiST, attempts to address the quality of life of patients receiving the competing regimens. This paper provides a commentary on these techniques with an emphasis on the problems inherent in implementing Q‐TWiST, a measure that attempts to incorporate patient value preferences into TWiST. It is argued that while Q‐TWiST is intuitively appealing in the clinical setting, there are formidable design and psychometric hurdles that must be overcome to fully operationalize the concept. Copyright © 1991 American Cancer Society