A simplified score to quantify comorbidity in COPD.

TitleA simplified score to quantify comorbidity in COPD.
Publication TypePublication
AuthorsPutcha N, Puhan MA, M Drummond B, Han MK, Regan EA, Hanania NA, Martinez CH, Foreman M, Bhatt SP, Make B, Ramsdell J, DeMeo DL, R Barr G, Rennard SI, Martinez F, Silverman EK, Crapo J, Wise RA, Hansel NN
JournalPLoS One
Date Published2014
KeywordsArea Under Curve, Comorbidity, Cost of Illness, Health Status Indicators, Humans, Patient Outcome Assessment, Pulmonary Disease, Chronic Obstructive, quality of life, Surveys and Questionnaires

IMPORTANCE: Comorbidities are common in COPD, but quantifying their burden is difficult. Currently there is a COPD-specific comorbidity index to predict mortality and another to predict general quality of life. We sought to develop and validate a COPD-specific comorbidity score that reflects comorbidity burden on patient-centered outcomes.MATERIALS AND METHODS: Using the COPDGene study (GOLD II-IV COPD), we developed comorbidity scores to describe patient-centered outcomes employing three techniques: 1) simple count, 2) weighted score, and 3) weighted score based upon statistical selection procedure. We tested associations, area under the Curve (AUC) and calibration statistics to validate scores internally with outcomes of respiratory disease-specific quality of life (St. George's Respiratory Questionnaire, SGRQ), six minute walk distance (6MWD), modified Medical Research Council (mMRC) dyspnea score and exacerbation risk, ultimately choosing one score for external validation in SPIROMICS.RESULTS: Associations between comorbidities and all outcomes were comparable across the three scores. All scores added predictive ability to models including age, gender, race, current smoking status, pack-years smoked and FEV1 (p<0.001 for all comparisons). Area under the curve (AUC) was similar between all three scores across outcomes: SGRQ (range 0·7624-0·7676), MMRC (0·7590-0·7644), 6MWD (0·7531-0·7560) and exacerbation risk (0·6831-0·6919). Because of similar performance, the comorbidity count was used for external validation. In the SPIROMICS cohort, the comorbidity count performed well to predict SGRQ (AUC 0·7891), MMRC (AUC 0·7611), 6MWD (AUC 0·7086), and exacerbation risk (AUC 0·7341).CONCLUSIONS: Quantifying comorbidity provides a more thorough understanding of the risk for patient-centered outcomes in COPD. A comorbidity count performs well to quantify comorbidity in a diverse population with COPD.

Alternate JournalPLoS ONE
PubMed ID25514500
PubMed Central IDPMC4267736
Grant List2R01HL089897 / HL / NHLBI NIH HHS / United States
HHSN268200900017C / / PHS HHS / United States
R01 HL089897 / HL / NHLBI NIH HHS / United States
HHSN268200900015C / / PHS HHS / United States
HHSN268200900020C / / PHS HHS / United States
2R01HL089856 / HL / NHLBI NIH HHS / United States
U01 HL089897 / HL / NHLBI NIH HHS / United States
K23 HL103192 / HL / NHLBI NIH HHS / United States
T32HL007534 / HL / NHLBI NIH HHS / United States
R01 HL089856 / HL / NHLBI NIH HHS / United States
HHSN268200900018C / / PHS HHS / United States
U01 HL089856 / HL / NHLBI NIH HHS / United States
HHSN268200900014C / / PHS HHS / United States
S21 MD000101 / MD / NIMHD NIH HHS / United States
HHSN2682009000019C / / PHS HHS / United States
HHSN268200900013C / / PHS HHS / United States
HHSN268200900016C / / PHS HHS / United States
Manuscript Lead/Corresponding Author Affiliation: 
Clinical Center: Baltimore (Johns Hopkins University)
Manuscript Status: