Development of the EXAcerbations of Chronic Obstructive Pulmonary Disease Tool (EXACT): a patient-reported outcome (PRO) measure.

BACKGROUND

This article describes the qualitative methods used to develop the EXAcerbation of Chronic Pulmonary Disease Tool (EXACT), a new patient-reported outcome (PRO) instrument for evaluating frequency, severity, and duration of exacerbations of chronic obstructive pulmonary disease (COPD).

METHODS

Focus groups and interviews were conducted in the United States with COPD patients treated for exacerbations during the past 6 months. Participants were asked to describe exacerbation attributes, care-seeking cues, and indications of progression and recovery. An iterative process was used to identify themes in the data to inform instrument content and structure. Cognitive debriefing interviews were performed to evaluate and revise the draft item pool. Experts in COPD, instrument development, and clinical research participated in the process.

RESULTS

Eighty-three subjects participated in elicitation focus groups or interviews (n=48); elicitation interviews with cognitive debriefing (n=23), or cognitive interviews alone (n=12). Mean age of the sample was 65 years (SD=10); 45% were male; mean FEV-1% predicted was 44% (SD=16). Participants characterized exacerbations as a persistent increase in the severity of respiratory symptoms and other systemic manifestations accompanied by a dramatic reduction in activity. Specific attributes included shortness of breath, chest congestion, cough, sputum, chest discomfort, feeling weak or tired, sleep disturbances, and concern or worry. The diary card of 23 candidate items was debriefed in booklet and electronic format.

CONCLUSIONS

Qualitative data from patients and input from experts formed the basis of the EXACT's structure and item pool, ready for empirically based item reduction and reliability and validity testing.