Change in health status in COPD: a seven-year follow-up cohort study

Health status is a prognostic factor included in the assessment of chronic obstructive pulmonary disease (COPD). The aim of our study was to examine the associations of clinical factors with change in health status over a 7-year follow-up period. In 2005, 970 randomly selected primary and secondary care patients with a COPD diagnosis completed questionnaires including the Clinical COPD Questionnaire (CCQ); and in 2012, 413 completed the CCQ questionnaire again. Linear regression used difference in mean total CCQ score between 2005 and 2012 as the dependent variable. Independent variables were CCQ score at baseline 2005, sex, age, educational level, body mass index (BMI), smoking status, heart disease, diabetes, depression, number of exacerbations in the previous 6 months, dyspnoea (modified Medical Research Council (mMRC)). Health status worsened from mean total CCQ (s.d.) 2.03 (1.26) in 2005 to 2.16 (1.37) in 2012 (P=0.011). In linear regression with adjustment for baseline CCQ; older age, lower education, higher mMRC and BMI below 25 kg/m² at baseline were associated with worsened health status in 2012. When sex, age and all statistically significant measures were included simultaneously in the analysis of the main study group, higher mMRC and BMI below 25 kg/m² were were associated with deteriorated health status (P<0.0001). A higher level of dyspnoea and lower weight were associated with worse health status in COPD. Strategies for decreasing dyspnoea and awareness of the possible increased risk of worsening disease in under- and normal-weight COPD patients are clinically important.