For clinical trials, instruments need to be based on a clear conceptual framework, have evidence supporting content validity and acceptable psychometric qualities.
In clinical trials, PRO instruments can be used to measure the effect of a medical intervention on one or more concepts – such as symptoms, functioning, severity of disease, or HRQL.
To be a viable measure of treatment outcome in clinical trials, PRO instruments need to be extensively documented to meet scientific standards [ 27, 28] and to satisfy regulatory criteria, particularly with regard to claims for labelling and promotion [ 28, 29].
In this randomised controlled clinical trial comparing rotary instruments with a piezoelectric device during maxillary sinus floor elevation, no significant difference was observed between the two groups.
In the clinical trial setting, Bayesian instruments based on the INLA approach can be applied as decision support to pre-specify a suitable final model for sensitivity analyses.
We have advocated that dichotomizing the results of a PRO measure facilitates interpretation of the clinical trial utilizing HRQL instruments [ 53, 54].
Because this was a post-hoc analysis of clinical trial data, the instruments selected for use in assessing construct validity may not have been optimal, in that they did not assess nursing strain per se.
Concept selection and confirmation were guided by expert opinion (one US and one Australian gastroenterologist) and a review of published GERD studies, including observational studies, clinical trials, and instrument development and validation studies.
Two merged randomised clinical trials compared instrumented transpedicular fusion with cognitive intervention and exercises in 124 patients with disc degeneration and at least 1 year of symptoms after or without previous surgery for disc herniation.
