Patient and physician shared decision-making behaviors in oncology: evidence on adequate measurement properties of the iSHARE questionnaires

Bomhof-Roordink, H.; Stiggelbout, A.M.; Gartner, F.R.; Portielje, J.E.A.; Kroon, C.D. de; Peeters, K.C.M.J.; ... ; iSHARE Study Grp (2022)

Article / Letter to editor

Objectives: We have developed two Dutch questionnaires to assess the shared decision-making (SDM) process in oncology; the iSHAREpatient and iSHAREphysician. In this study, we aimed to determine: scores, construct validity, test-retest agreement (iSHAREpatient), and inter-rater (iSHAREpatient-iSHAREphysician) agreement. Methods: Physicians from seven Dutch hospitals recruited cancer patients, and completed the iSHAREphysician and SDM-Questionnaire-physician version. Their patients completed the: iSHAREpatient, nine-item SDM-Questionnaire, Decisional Conflict Scale, Combined Outcome Measure for Risk communication And treatment Decision-making Effectiveness, and five-item Perceived Efficacy in Patient-Physician Interactions. We formulated, respectively, one (iSHAREphysician) and 10 (iSHAREpatient) a priori hypotheses regarding correlations between the iSHARE questionnaires and questionnaires assessing related constructs. To assess test-retest agreement patients completed the iSHAREpatient again 1-2 weeks later. Results: In total, 151 treatment decision-making processes with unique patients were rated. Dimension and total iSHARE scores were high both in patients and physicians. The hypothesis on the iSHAREphysician and 9/10 hypotheses on the iSHAREpatient were confirmed. Test-retest and inter-rater agreement were >.60 for most items. Conclusions: The iSHARE questionnaires show high scores, have good construct validity, substantial test-retest agreement, and moderate inter-rater agreement. Practice implications: Results from the iSHARE questionnaires can inform both physician- and patient-directed efforts to improve SDM in clinical practice. 

• Shared decision-making
• Construct validity
• Hypotheses testing
• Inter-rater agreement
• Test-retest agreement
• Formative
• Oncology
• Questionnaire

• All authors: Bomhof-Roordink, H.; Stiggelbout, A.M.; Gartner, F.R.; Portielje, J.E.A.; Kroon, C.D. de; Peeters, K.C.M.J.; Neelis, K.J.; Dekker, J.W.T.; Weijden, T. van der; Pieterse, A.H.; Boer, S.M. de; Boersma, L.J.; Huinink, D.T.; Buijsen, J.; Cloos-van Balen, M.; Gelderblom, H.; Leeuwen-Snoeks, L. van; Lips, I.M.; Ramai, S.R.S.; Roshani, H.; Slingerland, M.; Vanneste, B.G.L.; Wiltink, L.M.; iSHARE Study Grp
• Date: 2022-05-01
• Journal: Patient Education and Counseling
• Volume: 105
• Issue: 5
• Pages: 1089 - 1100
• DOI: doi:10.1016/j.pec.2021.08.034