A higher correlation between one of the two utility measures and the NDI cannot interpreted as evidence of superiority in psychometric terms over the other utility measure (the NDI cannot be regarded as a gold standard and generic, preference based measures are not intended to measure the same constructs as condition specific measures [ 22]).
In some early phase trials, preference based measures are not usually collected, but condition specific measures such as the QLQ-C30 are collected to provide early indications of symptom control for future phase II/III trial planning, particularly for re-imbursement.
Another limitation was that the main outcome measures were self-reported and performance-based measures were not included.
The SEER-based and claims-based measures were not consistent in terms of the relationship between physician visits (i.e., medical oncologists, radiation oncologists) and BM.
The results showed that, although there were often parallel improvements in these 2 outcomes, there were cases in which improvements in symptom-based measures were not accompanied by corresponding changes in PRO measures.
In an attempt to reduce patient burden 'preference based' measures are often not used [ 8].
On this matter our view is more radical: the scale produced by HRQOL preference based measures is an interval scale, not a ratio scale; this means that the numerical values assigned by the scale are totally arbitrary, and 0 does not imply an 'absolute lack' of HRQOL.
Social factors based on occupational measures were not a risk factor for testicular cancer in this study.
The effects of previous adiposity, based on the 4 measures, were not confounded by changes in adiposity across (concurrent with) the PWV assessments or by changes in available risk factors (triglyceride, high-density lipoprotein, fasting glucose, hemoglobin A1c, and heart rate; Table S6).
