Assessing health status in COPD. A head-to-head comparison between the COPD assessment test (CAT) and the clinical COPD questionnaire (CCQ).

Ioanna G Tsiligianni,Konstantinos Karagiannis,Janwillem W H Kocks,Thys Van Der Molen,Ilaine Lopez,Nikolaos Siafakas,Nikolaos Tzanakis,Despoina Moraitaki

doi:10.1186/1471-2466-12-20

Ioanna G Tsiligianni, Konstantinos Karagiannis + Show 6 more

Open Access

https://doi.org/10.1186/1471-2466-12-20

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Abstract

BackgroundHealth status provides valuable information, complementary to spirometry and improvement of health status has become an important treatment goal in COPD management. We compared the usefulness and validity of the COPD Assessment Test (CAT) and the Clinical COPD Questionnaire (CCQ), two simple questionnaires, in comparison with the St. George Respiratory Questionnaire (SGRQ).MethodsWe administered the CAT, CCQ and SGRQ in patients with COPD stage I-IV during three visits. Spirometry, 6 MWT, MRC scale, BODE index, and patients perspectives on questionnaires were recorded in all visits. Standard Error of Measurement (SEM) was used to calculate the Minimal Clinical Important Difference (MCID) of all questionnaires.ResultsWe enrolled 90 COPD patients. Cronbach's alpha for both CAT and CCQ was high (0.86 and 0.89, respectively). Patients with severe COPD reported worse health status compared to milder subgroups. CAT and CCQ correlated significantly (rho =0.64, p < 0.01) and both with the SGRQ (rho = 0.65; CAT and rho = 0.77; CCQ, p < 0.01). Both questionnaires exhibited a weak correlation with lung function (rho = −0.35;CAT and rho = −0.41; CCQ, p < 0.01). Their reproducibility was high; CAT: ICC = 0.94 (CI 0.92-0.96), total CCQ ICC = 0.95 (0.92-0.96) and SGRQ = 0.97 (CI 0.95-0.98). The MCID calculated using the SEM method showed results similar to previous studies of 3.76 for the CAT, 0.41 for the CCQ and 4.84 for SGRQ. Patients suggested both CAT and CCQ as easier tools than SGRQ in terms of complexity and time considerations. More than half of patients preferred CCQ instead of CAT.ConclusionsThe CAT and CCQ have similar psychometric properties with a slight advantage for CCQ based mainly on patients’ preference and are both valid and reliable questionnaires to assess health status in COPD patients.

Highlights

Health status provides valuable information, complementary to spirometry and improvement of health status has become an important treatment goal in Chronic Obstructive Pulmonary Disease (COPD) management
We found no differences among GOLD severity stages in terms of age, gender, Body mass index (BMI) and pack-years smoking (Table 1)
The relationship between St. George Respiratory Questionnaire (SGRQ) and Clinical COPD Questionnaire (CCQ) show that the adjusted CCQ scores are lower across the scaling range and increasing with increasing health status impairment, with a mean bias of 0.6 CCQ units

Summary

Introduction

Health status provides valuable information, complementary to spirometry and improvement of health status has become an important treatment goal in COPD management. GOLD guidelines proposed health status, dyspnea measurement and number of exacerbations as key elements in addition to spirometry in order to manage and treat COPD [3]. This is mainly based on the fact that spirometry is only weakly associated with various health status questionnaires and does not give a real image of the COPD patients wellbeing [4]. Numerous quality of life and/or health status questionnaire tools have been developed in an attempt to find an easy and reliable tool to use in every day clinical practice [5,6,7,8,9,10]. Even though most COPD-specific health status questionnaires show similar basic content, there is heterogeneity in the amount and quality of the items addressed [11]

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