The questionnaire has demonstrated good levels of validity as a measure of physical function in patients with CLBP [ 27].
The SMILI was tested for key features of validity and reliability using a number of approaches and was found to demonstrate good levels of validity and reliability.
This was not true for self-ratings, which showed good levels of validity for Dutch, but not for Korean participants in the present study, and were poor predictors of experimental lexical decision and word identification data from previous studies.
This adapted version demonstrated a good level of content validity.
The assessment of internal reliability, based on Cronbach α coefficients, revealed a good level of construct validity of both questionnaires.
A shortened version of the CQR increases the clinical utility by reducing the patient burden whilst maintaining a good level of reliability and validity for a short, self-administered, self-report questionnaire.
The SMILI was found to have good levels of construct validity through the identification of significant correlations between the care recorded and women's feelings expressed in the postnatal questionnaire (SCIB).
The comparison of our results with equivalent analyses run in independent studies [ 7, 24] showed a very good level of agreement, therefore confirming their validity (Additional file 8: Figure S15).
