Prognostic assessment of patients with COPD
2009; Elsevier BV; Volume: 374; Issue: 9705 Linguagem: Inglês
10.1016/s0140-6736(09)62082-1
ISSN1474-547X
AutoresBartolomé R. Celli, José M. Marı́n, Claudia Côté, Armando Aguirre‐Jaimes, Ciro Casanova Macario,
Tópico(s)Asthma and respiratory diseases
ResumoMilo Puhan and colleagues (Aug 29, p 704)1Puhan M Garcia-Aymerich J Frey M et al.Expansion of the prognostic assessment of patients with chronic obstructive pulmonary disease: the updated BODE index and the ADO index.Lancet. 2009; 374: 704-711Summary Full Text Full Text PDF PubMed Scopus (384) Google Scholar describe the ADO index (age, dyspnoea, and airflow obstruction) as an alternative to the BODE index (body-mass index, airflow obstruction, dyspnoea, and exercise capacity) in patients with chronic obstructive pulmonary disease (COPD). ADO was developed to predict the risk of death by means of statistical and not clinical reasoning. Puhan and colleagues wrongly state that the BODE index was also developed for that purpose. We developed BODE to better categorise (stage) disease and to predict outcome, and used all-cause and specific-cause mortality to test that hypothesis.2Celli B Cote C Marin J et al.The body-mass index, airflow obstruction, dyspnea, and exercise capacity index in chronic obstructive pulmonary disease.N Engl J Med. 2004; 350: 1005-1012Crossref PubMed Scopus (2948) Google Scholar The ADO index is driven not by the domains of COPD but by age, which is the most important determinant of survival independent of disease diagnosis. Age has limited value in the stratification of a specific disease process. To illustrate this, we calculated ADO and BODE in two patients with COPD (in agreement with the statement that an index should be useful for individual patients). The results are shown in the table.TableClinical characteristics and ADO and BODE scores for two patients with COPDPatient 1Patient 2SexFemaleFemaleAge (years)4891Body-mass index (kg/m2)19·726FEV1 (% predicted)43%65%MRC dyspnoea score326-min walk distance (m)274196ADO index3 points7 pointsBODE index7 points4 pointsMRC=Medical Research Council. A higher score on the ADO and BODE index indicates a higher risk of death. Open table in a new tab MRC=Medical Research Council. A higher score on the ADO and BODE index indicates a higher risk of death. According to the ADO index, the older patient has a higher risk of death than the younger one. But this has little to do with COPD and all to do with life itself. The addition of the 6-min walk distance and body-mass index (both predictors of outcome) provide a dimension that the ADO does not have. Patient 1 was referred for transplant whereas patient 2 is on bronchodilators. We are surprised by the statement that changes in indices such as BODE cannot be used as surrogate markers of outcome, when the results of at least three studies support this potential application.3Imfeld S Bloch K Weder W Russi E The BODE index after lung volume reduction surgery correlates with survival.Chest. 2006; 129: 873-878Crossref PubMed Scopus (69) Google Scholar, 4Cote C Celli B Pulmonary rehabilitation and the BODE index in COPD.Eur Respir J. 2005; 26: 630-706Crossref PubMed Scopus (253) Google Scholar, 5Martinez F Han M Andrei A et al.Longitudinal change in the BODE index predicts mortality in severe emphysema.Am J Respir Crit Care Med. 2008; 178: 491-499Crossref PubMed Scopus (95) Google Scholar We do agree that ADO or any age-derived index should not be used for that purpose because age cannot be improved. We would like to express our conviction that statistics are there to help clinicians and not the other way around. From the evidence, ADO and BODE do predict mortality but BODE is better than ADO for categorising COPD severity. We declare that we have no conflicts of interest. Prognostic assessment of patients with COPD – Authors' replyBartolome Celli and colleagues argue that we wrongly stated why the BODE index was developed. However, we do not see any contradiction between what we stated (“to predict risk of death”) and their statement (“to predict outcome”—ie, death). What is the purpose of categorising disease severity other than for estimating prognosis? Without knowing the risk of death, categorising disease severity does not seem to provide meaningful information. Full-Text PDF
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