Standardizing measurement of chronic obstructive pulmonary disease exacerbations. Reliability and validity of a patient-reported diary

Am J Respir Crit Care Med. 2011 Feb 1;183(3):323-9. doi: 10.1164/rccm.201005-0762OC. Epub 2010 Sep 2.

Abstract

Rationale: Although exacerbations are an important problem in chronic obstructive pulmonary disease (COPD) and a target of intervention, there is no valid, standardized tool for assessing their frequency, severity, and duration.

Objectives: This study tested the properties of the Exacerbations of Chronic Pulmonary Disease Tool (EXACT), a new patient-reported outcome diary.

Methods: A prospective, two-group, observational study was conducted in patients with COPD. The acute group (n = 222) was enrolled during a clinic visit for exacerbation with follow-up visits on Days 10, 29, and 60. The stable group (n = 188), recruited by telephone or during routine visits, was exacerbation free for at least 60 days.

Measurements and main results: Acute patients completed the diary on Days 1-29 and 60-67; stable patients for 7 days. All patients provided stable-state spirometry and completed the St. George Respiratory Questionnaire-COPD (SGRQ-C). Acute patient assessments included clinician and patient global ratings of exacerbation severity and recovery. Mean age of the sample (n = 410) was 65 (± 10) years; 48% were male; stable FEV₁ was 51% predicted (± 20). Internal consistency (Pearson separation index) for the EXACT was 0.92, 1-week reproducibility (stable patients; intraclass correlation) was 0.77. EXACT scores correlated with SGRQ-C (r = 0.64; P < 0.0001) and differentiated acute and stable patients (P < 0.0001). In acute patients, scores improved over time (P < 0.0001) and differentiated between degrees of clinician-rated exacerbation severity (P < 0.05). EXACT change scores differentiated responders and nonresponders on Day 10, as judged by clinicians or patients (P < 0.0001).

Conclusions: Results suggest the EXACT is reliable, valid, and sensitive to change with exacerbation recovery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Disease Progression
  • Female
  • Forced Expiratory Volume
  • Humans
  • Male
  • Medical Records* / standards
  • Pulmonary Disease, Chronic Obstructive / complications
  • Pulmonary Disease, Chronic Obstructive / diagnosis
  • Pulmonary Disease, Chronic Obstructive / physiopathology*
  • Reproducibility of Results
  • Severity of Illness Index
  • Surveys and Questionnaires