Measuring the symptom burden of lung cancer: the validity and utility of the lung cancer module of the M. D. Anderson Symptom Inventory

We conducted a study to establish the psychometric properties of a module of the M. D. Anderson Symptom Inventory (MDASI) developed specifically for patients with lung cancer (MDASI-LC). The MDASI measures 13 common "core" symptoms of cancer and its treatment. The MDASI-LC includes the 13 core MDASI symptom items and three lung cancer-specific items: coughing, constipation, and sore throat. MDASI-LC items were administered to three cohorts of patients with lung cancer undergoing either chemotherapy or chemoradiotherapy. Known-group validity and criterion (concurrent) validity of the MDASI-LC were evaluated using the Eastern Cooperative Oncology Group performance status and the 12-item Short-Form Health Survey. The internal consistency and test-retest reliability of the module were adequate, with Cronbach coefficient α-values of 0.83 or higher for all module items and subscales. The sensitivity of the MDASI-LC to changes in patient performance status (disease progression) and to continuing cancer treatment (effects of treatment) was established. Cognitive debriefing of a subset of participants provided evidence for content validity and indicated that the MDASI core items and three additional lung cancer-specific items were clear, relevant to patients, and easy to understand; only two patients suggested additional symptom items. As expected, the item "sore throat" was sensitive only for patients receiving chemoradiotherapy. The MDASI-LC is a valid, reliable, and sensitive symptom-assessment instrument whose use can enhance clinical studies of symptom status in patients with lung cancer and epidemiological and prevalence studies of symptom severity across various cancer types.