The SGRQ is the most widely documented comprehensive measure; scores < 25 are uncommon in diagnosed COPDpatients(43) and scores ≥ 25 are very uncommon in healthy persons.(44,45) Therefore, it is recommended that a symptomscore equivalent to SGRQ score ≥ 25 should be used as the threshold for considering regular treatment for symptomsincluding breathlessness, particularly since this corresponds to the range of severity seen in patients recruited to thetrials that have provided the evidence base for treatment recommendations.

The CAT™† is an 8-item questionnaire that assesses health status in patients with COPD (Figure).(41) It was developedto be applicable worldwide and validated translations are available in a wide range of languages. The score rangesfrom 0 to 40, correlates very closely with the SGRQ, and has been extensively documented in numerouspublications.(42)