GOLD and ABCD—a good start, but now for the evidence? the preceding year. Since the two methods of assessing exacerbation risk will not lead to the same classification, GOLD advises that the method resulting in the highest risk should prevail. Although the new GOLD classification is a bold step in the right direction for patient management, the problem with this model is that evidence for the ABCD categories is currently scarce. However, unlike NICE, who did not include specific symptom scores or exacerbation rates in their assessment algorithm, GOLD did suggest several classification measures and published cut-off limits for symptoms and also for exacerbations on the basis of frequent-exacerbator data. In The Lancet Respiratory Medicine, MeiLan K Han and colleagues7 present data from the COPDgene large patient cohort study to address how the GOLD classification category assignments apply to patients with COPD, and also how the individual assessment measures affect the category assignment. Health-status data measured with the CAT questionnaire were not available, but patients completed the more comprehensive St Georges Respiratory Questionnaire (SGRQ), which relates closely to CAT and where scores can be converted between the two measures, CAT and SGRQ.8 Han and colleagues concluded that group assignment varies according to the symptom measure used (mMRC Published online August 18, 2012

Published Online August 18, 2012 S2213-2600(12)70045-0 See Online/Article S2213-2600(12)70044-9

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Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality, and increasing evidence shows that there is considerable heterogeneity in COPD populations. Patients experience exacerbations which are episodes of worsening symptoms and these can have significant effects on the disease course.1 Some patients are particularly susceptible to these exacerbations and are at risk of worse outcomes. Those with two or more treated exacerbations per year are referred to as frequent exacerbators.2 Although in large COPD populations associations are identified between forced expiratory volume (FEV1) and health status,3 there is generally poor individual correlation between COPD symptoms, FEV1, and exacerbations. Comorbidity is also an important feature of COPD and can affect the natural history of the disease.4 Thus, although spirometry is needed to diagnose COPD, a multidimensional assessment method is required to capture other effects of the disease, and to guide therapy. In 2010, an upgrade of the National Institutes for Health and Clinical Excellence (NICE) COPD guideline specifically addressed the issue of multidimensional assessment. NICE published an algorithm for use after the diagnosis of COPD with spirometry, and showed that pharmacological therapy should be guided by symptom severity and by the presence of exacerbations.5 This algorithm was followed in 2011 by the GOLD (Global initiative for Chronic Obstructive Lung Disease) COPD strategy update, which proposed a more complex multidimensional classification system that was based on FEV1, exacerbation history, and symptom scores (measured using either the modified Medical Research Council [mMRC] or the COPD Assessment Test [CAT] score).6 Patients with mild symptoms are placed in GOLD categories A or C, whereas patients with more severe symptoms are placed in categories B and D. Two methods are available for assessing exacerbation risk. One method is based on patient history of exacerbations, with two or more exacerbations in the preceding year indicating high risk, thereby stratifying patients to groups C and D. However, FEV1 is also included as an alternative method of assessing exacerbation risk, meaning that patients can be placed in the high-risk group C on the basis of only an FEV1 below 50% predicted, despite a relatively small symptomatic burden and low exacerbation frequency in



or SGRQ). This finding is not unexpected because the mMRC questionnaire only assesses dyspnoea but the CAT and SGRQ assess other factors that affect health status. Irrespective of what symptom measure was used, the number of patients in category C was small (between 5% [SGRQ] and 8% [mMRC]) and most had been classifed into this category on the basis of a low FEV1. As Han and colleagues suggest, it would be best to choose one measure and acquire an evidence base for this measure with appropriate cutoff points. These cutoffs are potentially important, because in the GOLD document, choice of therapy is associated with A, B, C, and D categories. The GOLD strategy acknowledges the importance of frequent exacerbations and used two treated exacerbations per year as a definition of high risk, assigning these patients to a category of C or D. Again, one does not expect a substantial number of exacerbators in group C because exacerbations are closely related to symptom counts and higher CAT9 and SGRQ scores.10 This finding is consistent with results from the study where the authors reported few exacerbations in category C and exacerbation rates in C were similar to those in the higher-symptom, lowexacerbation-risk category B. However, substantial heterogenity was noted in group D for high exacerbation risk, and the highest exacerbation rates were recorded in this group when criteria were met for both FEV1 and exacerbation history. But is the patient reported exacerbation history of two or more events per year an accurate determinant of higher risk? A history of previous exacerbations is the best predictor of future exacerbation risk,2,10 but we now know that patients with COPD often do not report exacerbations to health care professionals10 and thus any exacerbation history should also include questions about untreated events. Furthermore, hospital admission for COPD exacerbations is associated with a poor prognosis11 and thus any admissions should automatically place a patient into category D, regardless of lung function. Patients with frequent exacerbations can also have mild and moderate disease2 and therefore fall into category D. The new GOLD update is a significant step forward and the cohort data described by Han and colleagues shows how the GOLD update can be applied to the management of patients with COPD. The choice of


symptom measure is crucial and needs to be simplified and cutoffs for scores need to be determined from further prospective studies. Perhaps a simpler version could include three categories with A and B as mild and more persistent symptoms, respectively, represented by CAT scores, and then a broader higher-risk exacerbation group with inclusion of frequent exacerbators, patients with any hospital admission, or particularly severe or prolonged community-managed exacerbations. The clear message from GOLD to the respiratory community is that management of COPD is done on the basis of current symptom assessment and future risk based mainly on the exacerbation frequency. This message is a great start and a huge leap forward for tackling the disability associated with COPD. Jadwiga A Wedzicha Centre for Respiratory Medicine, Royal Free Campus, University College London, London NW3 2PF, UK [email protected] JAW was a member of the NICE Guideline Development group for the 2010 update. She was not a member of the Scientific Committee that produced the GOLD 2011 update, or a reviewer of the GOLD document, but will be joining the GOLD Science Committee in 2012. 1 2 3









Wedzicha JA, Seemungal TAR. COPD exacerbations: defining their cause and prevention. Lancet 2007; 370: 786–96. Hurst JR, Vestbo J, Anzueto A, et al. Susceptibility to exacerbation in chronic obstructive pulmonary disease. N Engl J Med 2010; 63: 1128–38. Weatherall M, Marsh S, Shirtcliffe P, Williams M, Travers J, Beasley R. Quality of life measured by the St George’s Respiratory Questionnaire and spirometry. Eur Respir J 2009; 33: 1025–30. Mannino DM, Thorn D, Swensen A, Holguin F. Prevalence and outcomes of diabetes, hypertension and cardiovascular disease in COPD. Eur Respir J 2008; 32: 962–69. National Institute for Health and Clinical Excellence (NICE). Chronic obstructive pulmonary disease (updated) (CG101), 2010. http://guidance. (accessed Aug 9, 2012). GOLD. Global Strategy for Diagnosis, Management, and Prevention of COPD Updated, 2011. html (accessed Aug 9, 2012). Han MK, Muellerova H, Curran-Everett D, et al. GOLD 2011 disease severity classification in the COPDGene study: a prospective cohort study. Lancet Respir Med 2012; published online Aug 18. http://dx.doi. org/10.1016/S2213-2600(12)70044-9. Jones PW, Harding G, Berry P, Wiklund I, Chen WH, Kline Leidy N. Development and first validation of the COPD Assessment Test. Eur Respir J 2009; 34: 648–54. Mackay AJ, Donaldson GC, Patel AR, Jones PW, Hurst JR, Wedzicha JA. Usefulness of the chronic obstructive pulmonary disease assessment test to evaluate severity of COPD exacerbations. Am J Respir Crit Care Med 2012; 185: 1218–24. Seemungal TAR, Donaldson GC, Paul EA, Bestall JC, Jeffries DJ, Wedzicha JA. Effect of exacerbation on quality of life in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1998; 157: 1418–22. Suissa S, Dell’Aniello S, Ernst P. Long-term natural history of COPD: severe exacerbations and mortality. Thorax 2012; published online June 8. DOI:10.1136/thoraxjnl-2011-201518. Published online August 18, 2012

GOLD and ABCD--a good start, but now for the evidence?

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