The validity and utility of the MD Anderson Symptom Inventory in patients with prostate cancer: evidence from the Symptom Outcomes and Practice Patterns (SOAPP) data from the Eastern Cooperative Oncology Group

Background: The MD Anderson Symptom Inventory (MDASI) is a psychometrically validated patient-reported outcome measure that assesses the severity and impact of multiple symptoms related to cancer and its treatment and has the potential to guide treatment specific to patients with prostate cancer. Although the original MDASI validation study encompassed various cancer types, the instrument's psychometric properties have not been examined in a large homogeneous sample of patients with prostate cancer.

Patients and methods: This study involved secondary analysis of data from the nationwide multicenter Eastern Cooperative Oncology Group (ECOG) SOAPP (Symptom Outcomes and Practice Patterns) study, which enrolled patients from 38 ECOG-affiliated institutions, including 6 academic centers and 32 community clinics. Data were used to establish the psychometric properties of the MDASI in a subsample of 320 patients with prostate cancer. The instrument was administered twice, approximately 1 month apart.

Results: The MDASI demonstrated good internal consistency and test-retest reliability (with Cronbach alphas of ≥ .84 and intraclass correlations of ≥ 0.76 for all subscales), strong ability to discriminate between clinically different patient groups (by performance status, tumor response, and disease stage), and high sensitivity in detecting symptom change (with respect to patient-reported quality of life [QOL] between the baseline and 1-month follow-up visits).

Conclusion: The MDASI is a valid, reliable, and sensitive symptom-assessment instrument that can be used with confidence in descriptive and clinical studies of symptom status in patients with prostate cancer.