Validation of a Patient Satisfaction Questionnaire for Anemia Treatment (PSQ-An).

Despite the high prevalence of anemia in patients with cancer, there has previously been no assessment tool for evaluating anemia treatment satisfaction. This study aimed to test the validity, reliability, and responsiveness of a newly developed patient satisfaction instrument, the PSQ-An. This questionnaire was designed specifically to measure two domains: treatment burden (including items pertaining to convenience, pain and discomfort, and financial aspects of treatment) and overall satisfaction. A total of 312 patients were enrolled in one of 3 concurrent, randomized, open label, identically designed trials of breast (n = 141), gynecologic (n = 69) or non-small cell lung cancer (n = 102). Patients were randomized 1:1 to receive either darbepoetin alfa 200 mcg once every two weeks (Q2W) (n = 157) or epoetin alfa 40,000 U once weekly (QW) (n = 155) for up to 16 weeks for the treatment of chemotherapy-induced anemia. In general, the treatment groups (darbepoetin alfa and epoetin alfa) had similar baseline characteristics. No differences were observed for transfusion rates (16% and 17%), hemoglobin change (1.4 g/dL and 1.5 g/dL), hematopoietic response rates (69% and 72%) or the ability to achieve (82% and 86%) and maintain (81% and 75%) a hemoglobin target range of 11–13 g/dL. Patients were asked to complete the PSQ-An at weeks 5, 9, 13 and 17; data from week 5 were analyzed, (with the exception of the test-retest reliability assessment that used data from weeks 5 and 9) as this provided the largest sample size. Patients also completed the Medical Outcomes Study Short Form-36 (MOS SF-36) questionnaire. Factor analyses were first conducted to extract interpretable factors. Convergent and divergent validity were examined by calculating both Pearson’s and Spearman rank-ordered correlation coefficients between subscales of the PSQ-An and the MOS SF-36 global health question, hemoglobin (Hb) level, and measures of time devoted to treatment. Discriminant validity was assessed using analyses of variance (ANOVA) by relating PSQ-An subscale scores to three parameters measuring different aspects of patient health: MOS SF-36 global health, Hb level and Eastern Cooperative Oncology Group (ECOG) Performance Status Rating. Test-retest reliability was examined in a subset of patients with stable health status (ie, those whose Global Health responses did not change between weeks 5 and 9) using intraclass correlation coefficients (ICC). Responsiveness was evaluated by week 5 to 9 effect sizes and ANOVA on week 5 to 9 variations in each PSQ-An subscale and changes in MOS SF-36 Global Health responses. Internal consistency was tested using Cronbach’s alpha coefficient. Two factors were identified and exhibited reasonable convergent and divergent validity with independent measures of health. ANOVA results indicated that the Satisfaction subscale discriminated between levels of Global Health (p = 0.006). Test-retest reliability was demonstrated in the instrument’s subscale scores (ICC: 0.45–0.67). The week 5 to 9 effect size for the Satisfaction domain was 0.44. Both domains were found to be internally consistent (α= 0.83, P < 0.001). The PSQ-An instrument has validity, reliability, and responsiveness in measuring cancer patients’ satisfaction with their anemia treatment. The two domains of the PSQ-An reflect the burden of injection anemia treatment on cancer patients and their assessment of the overall value of that treatment.