The Global Initiative for Chronic Obstructive Lung Disease (GOLD) was developed in 1987 (www.goldcopd.com) on the model of the Global Initiative for Asthma Management and Prevention (GINA) (www.ginasthma.com). Both initiatives were promoted by the National Heart, Lung, and Blood Institute and organized in collaboration with the World Health Organization. Unrestricted financial support was provided by a consortium of pharmaceutical companies, whose funding has been administered by a private organization (MCRVision, Inc.), which also provided necessary logistic support.

The end product of both initiatives was a series of scientific reports written by panels of experts, initially in the style of a consensus, then subsequently according to an evidence-based model (www.ginasthma.org; www.goldcopd.org). These reports provided the first global guidelines for asthma and chronic obstructive pulmonary disease (COPD). The far-reaching effect of these guidelines and of their dissemination is internationally recognized by the scientific community, health authorities, and patients' organizations. A unique feature (and strength) of both the GINA and GOLD guidelines has been the yearly updates of the management sections (1), based on a careful review of the literature. This issue of the Journal (pp. 532–555) contains the executive summary of the 2006 update of the GOLD guidelines (2), which represents the first revision of the entire original executive summary (3).

Continuous updates of the literature provide the opportunity to identify areas of weakness, probably the most important being the methodology adopted in the GOLD guidelines for classifying evidence. Considering the intense evolution in this area, the methodology of GINA and GOLD is probably outdated and should be made to conform to more modern and accepted approaches (4). In particular, recommendations should not only report the level of evidence but also grade them according to desirable and undesirable consequences (4).

Although a yearly update for GOLD seems appropriate, the reporting of new findings that challenge current recommendations can still be delayed. A recent example is the TORCH study, a large randomized clinical trial examining the effect of a 3-year treatment with the inhaled combination of salmeterol and fluticasone on the survival of patients with moderate to severe COPD (5). The results of this study, which could have a major effect on the GOLD guidelines, were available to the scientific community well before the study's publication. Nonetheless, because of the guidelines' internal rule of considering only published literature, the TORCH study could not be evaluated in the 2006 update (2). A problem that applies to all guidelines is that evaluating only published evidence causes large amounts of relevant information, particularly negative studies, to go unexamined or to be examined too late.

The diagnosis and assessment of severity of COPD recommended by GOLD are still based on the degree of airflow limitation as assessed by spirometry (2); thus, different pulmonary phenotypes (e.g., emphysema vs. bronchiolitis) get lumped together (6). Indeed, there is evidence that (1) pathological abnormalities of COPD may be present even in the absence of airflow limitation (7); (2) the extension and distribution of high-resolution computed tomography scan–documented emphysema correlates broadly with FEV₁ and FEV₁/FVC (8, 9); and (3) chronic cough and sputum in the absence of airflow limitation may indeed represent an early stage of COPD, because their presence predicts the development of airflow limitation (10). Finally, the clinical diagnosis of COPD is not confirmed in a significant proportion of patients at spirometry (11) (Figure 1), suggesting that a more comprehensive approach is required. In light of these diagnostic problems, discussing the different criteria to establish airflow limitation (FEV₁/FVC vs. lower limit of normal), albeit important epidemiologically, appears to have limited clinical relevance (12).

Figure 1. Plot of individual values of % predicted FEV₁ and % FEV₁/FVC in 1,000 patients with a clinical diagnosis of chronic obstructive pulmonary disease (COPD) based on an interview, lung examination, lung function tests, and chest X-ray. In addition to a significant proportion of subjects with normal lung function (stage 0 or at risk), almost 14% of patients clinically diagnosed as having COPD could not be classified because they had an FEV₁/FVC ratio of more than 70%, despite having a reduced FEV₁ (<80% predicted), suggesting that GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria miss an important subgroup of patients with clinically diagnosed COPD. Reproduced by permission from Reference 11.

Download Figure | Download Powerpoint

[More] [Minimize]

Albert Einstein said, “Once we accept our limits, we go beyond them.… The important thing is not to stop questioning.… The whole of science is nothing more than a refinement of everyday thinking.… To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science” (13).

References

Section:

ChooseTop of pageReferences <<CITING ARTICLES