Impact of symptoms of anxiety and depression on COPD Assessment Test scores.

Anxiety and depression are common comorbidities in patients with chronic obstructive pulmonary disease (COPD) and affect patients’ health status [1, 2]. Health status in COPD patients is frequently assessed by the St George’s Respiratory Questionnaire (SGRQ), which is a validated disease-specific questionnaire widely used in clinical trials [3], but complex and time-consuming to complete and score. Consequently, the COPD Assessment Test (CAT) has been developed [4]. This is a disease-specific health status questionnaire containing eight items with good sensitivity, reliability and responsiveness [4]. CAT scores are strongly positively correlated with SGRQ scores in patients with COPD [4]. Therefore, it is reasonable to hypothesise that those COPD patients with symptoms of anxiety and/or depression will report higher CAT scores (equalling worse health status) compared to those without symptoms.