Open Access Study protocol

Outcomes associated with matching patients' treatment preferences to physicians' recommendations: study methodology

Nasir Umar1*, David Litaker12, Marthe-Lisa Schaarschmidt3, Wiebke K Peitsch3, Astrid Schmieder3 and Darcey D Terris14

Author Affiliations

1 Mannheim Institute of Public Health, Social and Preventive Medicine and the Competence Center for Social Medicine and Occupational Health Promotion, Medical Faculty Mannheim, University of Heidelberg, Ludolf-Krehl-Str. 7-11, 68167 Mannheim, Germany

2 Departments of Medicine, Epidemiology and Biostatistics, Case Western Reserve University, Cleveland Ohio, USA

3 Department of Dermatology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68135 Mannheim, Germany

4 Department of Health Policy and Management, College of Public Health, University of Georgia, Athens, Georgia, USA

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BMC Health Services Research 2012, 12:1  doi:10.1186/1472-6963-12-1

Published: 3 January 2012



Patients often express strong preferences for the forms of treatment available for their disease. Incorporating these preferences into the process of treatment decision-making might improve patients' adherence to treatment, contributing to better outcomes. We describe the methodology used in a study aiming to assess treatment outcomes when patients' preferences for treatment are closely matched to recommended treatments.


Participants included patients with moderate and severe psoriasis attending outpatient dermatology clinics at the University Medical Centre Mannheim, University of Heidelberg, Germany. A self-administered online survey used conjoint analysis to measure participants' preferences for psoriasis treatment options at the initial study visit. Physicians' treatment recommendations were abstracted from each participant's medical records. The Preference Matching Index (PMI), a measure of concordance between the participant's preferences for treatment and the physician's recommended treatment, was determined for each participant at t1 (initial study visit). A clinical outcome measure, the Psoriasis Area and Severity Index, and two participant-derived outcomes assessing treatment satisfaction and health related quality of life were employed at t1, t2 (twelve weeks post-t1) and t3 (twelve weeks post-t2). Change in outcomes was assessed using repeated measures analysis of variance. The association between participants' PMI scores at t1 and outcomes at t2 and t3 was evaluated using multivariate regressions analysis.


We describe methods for capturing concordance between patients' treatment preferences and recommended treatment and for assessing its association with specific treatment outcomes. The methods are intended to promote the incorporation of patients' preferences in treatment decision-making, enhance treatment satisfaction, and improve treatment effectiveness through greater adherence.

Patients' preferences; Patients' satisfaction; Psoriasis; Psoriasis treatment