Assessment of treatment expectations in people with suspected endometriosis: A psychometric analysis

Abstract

Background Treatment expectations influence clinical outcomes in various physical and psychological conditions; however, no studies have explored their role in endometriosis treatment. It is necessary to understand how these expectations can be measured to study treatment expectations and their effects in clinical practice. This study aimed to psychometrically analyze and compare different treatment expectation measurements and describe treatment expectations in women with suspected endometriosis. Method Analysis of cross-sectional baseline data of a mixed-method clinical observational study of N=699 patients undergoing laparoscopy in Germany. Descriptives, bivariate associations, convergent and discriminant validity of four expectation measurements (Treatment Expectation Questionnaire (TEX-Q); Generic rating scale for previous treatment experiences, treatment expectations, and treatment effects (GEEE); numerical rating scales (NRS) assessing improvement and worsening of endometriosis symptoms, expected Pain Disability Index (PDI); range: 0 to 10) were estimated. A cluster analysis was performed on the three GEEE items. Results Most participants expected high improvement (M=6.68 to 7.20, SD=1.90 to 2.09) and low worsening (M=1.09 to 2.52, SD=1.80 to 2.25) of disability from laparoscopy. Participants who expected greater worsening expected more side effects (r=.31 to .60, p<.001). Associations between the positive and negative expectation dimensions, including side effects, were small to non-significant (r =|.24| to .00, p<.001 to.978). Four distinct clusters, described as’positive’, ‘no pain, no gain’, ‘diminished’, and ‘uniform’ were found, with a total PVE of 62.2%. Conclusions Women with suspected endometriosis reported positive expectations concerning laparoscopy, but wide ranges indicated interindividual differences. Treatment expectations seem to be a multidimensional construct in this patient group. The investigated measurements did not correlate to the extent that they measured exactly the same construct. The selection of measurements should be carefully considered and adapted for the study purposes. Clusters provide initial indications for individualized interventions that target expectation manipulation. Trial Registration Number ID NCT05019612 (ClinicalTrials.gov)