CAN PATIENTS WITH SCHIZOPHRENIA COMPLETE A CONJOINT ANALYSIS? EVIDENCE FROM GERMANY
Author(s)
John FP Bridges, PhD, Assistant Professor, Elizabeth Timberlake Kinter, MHS, PHD StudentJohns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, USA
BACKGROUND: Patient preferences are an important indicator of patients' underlying values and could enlighten literatures on both compliance and satisfaction with treatment. Patient preference methods, such as conjoint analysis, are increasingly used in clinical areas, but applications in mental health remain limited. OBJECTIVES: To determine the capability of patients with schizophrenia to complete a conjoint analysis questionnaire, document patients' reactions to conjoint tasks and assess the validity and reliability of their responses. METHODS: Attributes and levels relating to the medical management of schizophrenia were identified through patient focus groups and literature reviews to create simple conjoint analysis task of six attributes with two levels each. Respondents (n=25) were patients diagnosed with at least one episode of schizophrenia, presently stable and undergoing therapy with a neuroleptic medication and were recruited through clinics from four cities in Germany. The majority of respondents were presented with eight paired-comparisons; but a limited number of respondents were presented with sets of four scenarios to test satiation. Questionnaires were administered in person with limited explanation, were audio recorded and later analyzed. RESULTS: Respondents easily completed the conjoint tasks and results were consistent with underlying hypotheses. Specifically we identified four statistically significant factors: i) ability to think clearly (p>0.001); ii) tiredness (p>0.001); iii) having a supportive physician (p>0.001); and iv) the ability to participate in social activities (p>0.005). The reliability of responses based test-retest was high, 82.35% agreement between responses, Kappa 0.648 (p>0.0001). Patients could also complete more complicated tasks based on choice among four possible scenarios. CONCLUSIONS: Conjoint analysis can be used to assess the preferences of patients with schizophrenia, and such preferences appear valid and relatively consistent. Although further validation and refinement is needed, our results indicate that conjoint analysis is a feasible and beneficial method for measuring patient preferences among patients with schizophrenia.
Conference/Value in Health Info
2008-11, ISPOR Europe 2008, Athens, Greece
Value in Health, Vol. 11, No. 6 (November 2008)
Code
PMH38
Topic
Patient-Centered Research
Topic Subcategory
Adherence, Persistence, & Compliance, Health State Utilities, Stated Preference & Patient Satisfaction
Disease
Mental Health