The reliability and validity of patient-reported chronic obstructive pulmonary disease exacerbations

Despite the increasing awareness of their pathogenesis and clinical consequences, research on and clinical management of acute exacerbations of chronic obstructive lung disease (AECOPDs) have been hindered by the lack of a consistent and reliable definition. Symptom-based definitions of exacerbations are sensitive to events and account for unreported exacerbations. Event (healthcare utilization)-based definitions are somewhat more definitive but miss unreported events. Objective quantification of symptoms in AECOPD is now possible with the development of the Exacerbations of Chronic Obstructive Pulmonary Disease Tool (EXACT-PRO), a patient-reported outcome (PRO) measure.

Several studies have revealed that unreported AECOPDs are more frequent than reported events and are associated with long-term adverse consequences. New antibiotic development for AECOPD has been hampered by the lack of validated measures for resolution of exacerbations. As a result of these observations, a unique collaborative effort between academia, industry and regulatory agencies resulted in the development of the EXACT-PRO. It consists of 14 questions that generate a score between 0 and 100, and it has been shown to have excellent reliability and validity.

In the absence of a reliable biomarker, the definition and measurement of exacerbations has been subjective and imprecise. PRO measures such as EXACT can provide much needed objectivity in assessing symptom-defined exacerbations, which may translate into a uniform outcome measure in clinical trials. With further development and validation, it may have a role in clinical practice in the earlier detection of exacerbations, stratification of an exacerbation severity and the assessment of clinical response to treatment.