Novel Respiratory Disability Score Predicts COPD Exacerbations and Mortality in the SPIROMICS Cohort.

TitleNovel Respiratory Disability Score Predicts COPD Exacerbations and Mortality in the SPIROMICS Cohort.
Publication TypePublication
AuthorsCooper CB, Paine R, Curtis JL, Kanner RE, Martinez CH, Meldrum CA, Bowler R, O'Neal W, Hoffman EA, Couper D, Quibrera M, Criner G, Dransfield MT, Han MK, Hansel NN, Krishnan JA, Lazarus SC, Peters SP, R Barr G, Martinez FJ, Woodruff PG
Corporate AuthorsSPIROMICS Investigators
JournalInt J Chron Obstruct Pulmon Dis
Date Published2020
KeywordsCohort Studies, DYSPNEA, Female, Humans, Lung, Male, Pulmonary Disease, Chronic Obstructive, Surveys and Questionnaires

RATIONALE: Some COPD patients develop extreme breathlessness, decreased exercise capacity and poor health status yet respiratory disability is poorly characterized as a distinct phenotype.OBJECTIVE: To define respiratory disability in COPD based on available functional measures and to determine associations with risk for exacerbations and death.METHODS: We analyzed baseline data from a multi-center observational study (SPIROMICS). This analysis includes 2332 participants (472 with severe COPD, 991 with mild/moderate COPD, 726 smokers without airflow obstruction and 143 non-smoking controls).MEASUREMENTS: We defined respiratory disability by ≥4 of 7 criteria: mMRC dyspnea scale ≥3; Veterans Specific Activity Questionnaire <5; 6-minute walking distance <250 m; St George's Respiratory Questionnaire activity domain >60; COPD Assessment Test >20; fatigue (FACIT-F Trial Outcome Index) <50; SF-12 <20.RESULTS: Using these criteria, respiratory disability was identified in 315 (13.5%) participants (52.1% female). Frequencies were severe COPD 34.5%; mild-moderate COPD 11.2%; smokers without obstruction 5.2% and never-smokers 2.1%. Compared with others, participants with disability had more emphysema (13.2 vs. 6.6%) and air-trapping (37.0 vs. 21.6%) on HRCT (P<0.0001). Using principal components analysis to derive a disability score, two factors explained 71% of variance, and a cut point -1.0 reliably identified disability. This disability score independently predicted future exacerbations (ß=0.34; CI 0.12, 0.64; P=0.003) and death (HR 2.97; CI 1.54, 5.75; P=0.001). Thus, participants with disability by this criterion had almost three times greater mortality compared to those without disability.CONCLUSION: Our novel SPIROMICS respiratory disability score in COPD was associated with worse airflow obstruction as well as airway wall thickening, lung parenchymal destruction and certain inflammatory biomarkers. The disability score also proved to be an independent predictor of future exacerbations and death. These findings validate disability as an important phenotype in the spectrum of COPD.

Alternate JournalInt J Chron Obstruct Pulmon Dis
PubMed ID32821092
PubMed Central IDPMC7417644
Grant ListU01 HL137880 / HL / NHLBI NIH HHS / United States
Manuscript Full Title: 
Novel Respiratory Disability Score Predicts COPD Exacerbations and Mortality in the SPIROMICS Cohort.
Manuscript Lead/Corresponding Author Affiliation: 
Clinical Center: Los Angeles (University of California at Los Angeles)
Manuscript Status: 
Published and Public