TY - JOUR
T1 - Variability in objective and subjective measures affects baseline values in studies of patients with COPD
AU - SPIROMICS Research Group
AU - Anderson, Wayne H.
AU - Ha, Jae Wook
AU - Couper, David J.
AU - O’Neal, Wanda K.
AU - Barr, R. Graham
AU - Bleecker, Eugene R.
AU - Carretta, Elizabeth E.
AU - Cooper, Christopher B.
AU - Doerschuk, Claire M.
AU - Drummond, M. Bradley
AU - Han, Mei Lan K.
AU - Hansel, Nadia N.
AU - Kim, Victor
AU - Kleerup, Eric C.
AU - Martinez, Fernando J.
AU - Rennard, Stephen I.
AU - Tashkin, Donald
AU - Woodruff, Prescott G.
AU - Paine, Robert
AU - Curtis, Jeffrey L.
AU - Kanner, Richard E.
N1 - Publisher Copyright:
© 2017 Anderson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2017/9
Y1 - 2017/9
N2 - Rationale: Understanding the reliability and repeatability of clinical measurements used in the diagnosis, treatment and monitoring of disease progression is of critical importance across all disciplines of clinical practice and in clinical trials to assess therapeutic efficacy and safety. Objectives: Our goal is to understand normal variability for assessing true changes in health status and to more accurately utilize this data to differentiate disease characteristics and outcomes. Methods: Our study is the first study designed entirely to establish the repeatability of a large number of instruments utilized for the clinical assessment of COPD in the same subjects over the same period. We utilized SPIROMICS participants (n = 98) that returned to their clinical center within 6 weeks of their baseline visit to repeat complete baseline assessments. Demographics, spirometry, questionnaires, complete blood cell counts (CBC), medical history, and emphysema status by computerized tomography (CT) imaging were obtained. Results: Pulmonary function tests (PFTs) were highly repeatable (ICC’s >0.9) but the 6 minute walk (6MW) was less so (ICC = 0.79). Among questionnaires, the Saint George’s Respiratory Questionnaire (SGRQ) was most repeatable. Self-reported clinical features, such as exacerbation history, and features of chronic bronchitis, often produced kappa values <0.6. Reported age at starting smoking and average number of cigarettes smoked were modestly repeatable (kappa = 0.76 and 0.79). Complete blood counts (CBC) variables produced intraclass correlation coefficients (ICC) values between 0.6 and 0.8. Conclusions: PFTs were highly repeatable, while subjective measures and subject recall were more variable. Analyses using features with poor repeatability could lead to misclassification and outcome errors. Hence, care should be taken when interpreting change in clinical features based on measures with low repeatability. Efforts to improve repeatability of key clinical features such as exacerbation history and chronic bronchitis are warranted.
AB - Rationale: Understanding the reliability and repeatability of clinical measurements used in the diagnosis, treatment and monitoring of disease progression is of critical importance across all disciplines of clinical practice and in clinical trials to assess therapeutic efficacy and safety. Objectives: Our goal is to understand normal variability for assessing true changes in health status and to more accurately utilize this data to differentiate disease characteristics and outcomes. Methods: Our study is the first study designed entirely to establish the repeatability of a large number of instruments utilized for the clinical assessment of COPD in the same subjects over the same period. We utilized SPIROMICS participants (n = 98) that returned to their clinical center within 6 weeks of their baseline visit to repeat complete baseline assessments. Demographics, spirometry, questionnaires, complete blood cell counts (CBC), medical history, and emphysema status by computerized tomography (CT) imaging were obtained. Results: Pulmonary function tests (PFTs) were highly repeatable (ICC’s >0.9) but the 6 minute walk (6MW) was less so (ICC = 0.79). Among questionnaires, the Saint George’s Respiratory Questionnaire (SGRQ) was most repeatable. Self-reported clinical features, such as exacerbation history, and features of chronic bronchitis, often produced kappa values <0.6. Reported age at starting smoking and average number of cigarettes smoked were modestly repeatable (kappa = 0.76 and 0.79). Complete blood counts (CBC) variables produced intraclass correlation coefficients (ICC) values between 0.6 and 0.8. Conclusions: PFTs were highly repeatable, while subjective measures and subject recall were more variable. Analyses using features with poor repeatability could lead to misclassification and outcome errors. Hence, care should be taken when interpreting change in clinical features based on measures with low repeatability. Efforts to improve repeatability of key clinical features such as exacerbation history and chronic bronchitis are warranted.
UR - http://www.scopus.com/inward/record.url?scp=85029686679&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85029686679&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0184606
DO - 10.1371/journal.pone.0184606
M3 - Article
C2 - 28934249
AN - SCOPUS:85029686679
SN - 1932-6203
VL - 12
JO - PLoS One
JF - PLoS One
IS - 9
M1 - e0184606
ER -