title: Evaluation of a measurement strategy for Parkinson's disease: assessing patient health-related quality of life.
abstract: This study evaluated the feasibility and psychometric properties of self-completed and telephone interview versions of a patient health-related quality-of-life (HQL) questionnaire for Parkinson's disease that included the SF-36 Health Survey (SF-36), the Parkinson's Disease Questionnaire (PDQ-39), and the Medical Outcomes Study Sexual Function Survey. Parkinson's disease patients (n = 150) completed the questionnaire twice: once at the study site and once over the telephone in a randomized order. Ninety-four percent of enrolled patients completed the first HQL assessment and 88% completed both assessments. Cronbach's alpha exceeded 0.70 for all scales except for the self-completed PDQ-39 Social Support subscale (0.57) and the telephone interview PDQ-39 Social Support (0.60) and Cognitions (0.67) subscales and the SF-36 General Health (0.60) and Social Function (0.61) subscales. There were no statistically significant differences in mean HQL scale scores across the two modes of administration. Mean scores for 3 of the PDQ-39 subscales and the Summary Index were significantly poorer (p < 0.05) for patients at later clinical stages. Similarly, patients with dyskinesias reported significantly poorer scores for 4 of the PDQ-39 subscales and the Summary Index and patients with self-reported comorbidities reported poorer SF-36 Physical Function and General Health subscale scores than patients without dyskinesias and comorbidities, respectively. This study suggests that the self-completed and telephone interview versions of the patient HQL questionnaire are feasible and valid for future clinical trial applications.
authors.affiliation: Covance Health Economics and Outcomes Services Inc., Washington, DC, USA. anne.damiano@covance.com
authors.forename: A M
authors.initials: AM
authors.lastname: Damiano
authors.forename: M M
authors.initials: MM
authors.lastname: McGrath
authors.forename: M K
authors.initials: MK
authors.lastname: Willian
authors.forename: C F
authors.initials: CF
authors.lastname: Snyder
authors.forename: P A
authors.initials: PA
authors.lastname: LeWitt
authors.forename: P F
authors.initials: PF
authors.lastname: Reyes
authors.forename: R R
authors.initials: RR
authors.lastname: Richter
authors.forename: E D
authors.initials: ED
authors.lastname: Means
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D005240:Feasibility Studies; D005260:Female; D006304:Health Status; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D010300:Parkinson Disease / Q000523:psychology*; D011594:Psychometrics / Q000379:methods*; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013689:Telephone; D014481:United States