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


OBJECTIVE
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.


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.
Leidy
Nancy K
NK
Center for Health Outcomes Research, Bethesda, MD 20814, USA. Nancy.Leidy@unitedbiosource.com
Wilcox
Teresa K
TK
Jones
Paul W
PW
Roberts
Laurie
L
Powers
John H
JH
Sethi
Sanjay
S
D000368:Aged; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008499:Medical Records / Q000592:standards; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires