Measurement equivalence using a mixed-mode approach to administer health-related quality of life instruments
ABSTRACT To evaluate the effects of mode, order of administration, and the interaction of mode and order on health-related quality of life scales when self-administered by mixed mode (paper-mode and web-mode) for measurement equivalence.
Health-related quality of life data was analyzed from the Cancer of the Prostate Strategic Urologic Research Endeavor using the Medical Outcomes Study (MOS) Short Form-36 (SF-36) and the University of California Los Angeles Prostate Cancer Index (UCLA-PCI). A randomized crossover design assigned participants to two groups with a preferred 2-5-day washout period. Cognitive debriefing evaluated participants' mode preference.
Of the 245 men enrolled, 85 % completed both modes. The majority were White (97 %), college educated (66 %), reported an annual income >$75,000 (46 %), and a median age of 69 years. Intraclass correlation coefficients were high for each item on both instruments (r = .54-.97). Exact percentage agreement for yes/no items was high (≥.88). For the SF-36, significant differences were observed for order of administration (physical component and physical function scores) and for the interaction between mode and order (mental component, role emotional, social function, vitality, and mental health scores). For the UCLA-PCI, the largest difference was 12.8 points lower for sexual bother for order of administration by web-mode first (p = .03). Seventy percent preferred the web-mode, 21 % had no preference, and 9 % preferred the paper-mode.
Web-mode and paper-mode administrations of the SF-36 and UCLA-PCI are equivalent in men with prostate cancer, implying that mixed-mode survey administration is warranted.
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ABSTRACT: The objective was to obtain a standardized evaluation of available prostate cancer-specific quality of life instruments used in patients with early-stage disease. We carried out systematic literature reviews in the PubMed database to identify manuscripts which contained information regarding either the development process or metric properties of prostate cancer-specific quality of life instruments. Each instrument was evaluated by two experts, independently, using the Evaluating Measures of Patient-Reported Outcomes (EMPRO) tool. An overall and seven attribute-specific EMPRO scores were calculated (range 0-100, worst to best): measurement model, reliability, validity, responsiveness, interpretability, burden and alternative forms. Eight instruments and 57 manuscripts (2-15 per instrument) were identified. The Expanded Prostate Cancer Index Composite (EPIC) was the best rated (overall EMPRO score 83.1 points). Good results were also obtained by University of California Los Angeles-Prostate Cancer Index (UCLA-PCI), Patient-Oriented Prostate Utility Scale (PORPUS) and Prostate Cancer Quality of Life Instrument (PC-QoL) with 77.3, 70.5 and 64.8 points, respectively. These four instruments passed with distinction the validity and responsiveness evaluation. Insufficient reliability results were observed for UCLA-PCI and PORPUS. Current evidence supports the choice of EPIC, PORPUS or PC-QoL. Attribute-specific EMPRO results facilitate selecting the adequate instrument for every purpose. For longitudinal studies or clinical trials, where responsiveness is the priority, EPIC or PC-QoL should be considered. We recommend the PORPUS for economic evaluations because it allows cost-utility analysis, and EPIC short versions to minimize administration burden.Quality of Life Research 04/2014; 23(8). DOI:10.1007/s11136-014-0678-8 · 2.86 Impact Factor