Twenty Years of Changes in the Disease Assessment Method of the Global Initiative for Chronic Obstructive Lung Disease
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) has undergone significant evolution over the past two decades, particularly in its approach to assessing chronic obstructive pulmonary disease (COPD). Initially, GOLD relied heavily on spirometry for disease assessment. However, over time, it has shifted towards a more comprehensive evaluation that includes spirometry, symptoms, and exacerbation history. This review aims to provide a detailed overview of these changes, highlighting their implications for clinical practice and patient outcomes.
The first version of GOLD was released in 2001, introducing a standardized approach to the diagnosis and treatment of COPD. GOLD 0 was defined as a high-risk period for COPD and was included in the spirometric grading system. Since then, GOLD has undergone major revisions every 4 to 5 years, with annual updates. The most significant changes have been related to the COPD disease assessment method, particularly in 2006, 2011, and 2017.
In 2006, GOLD updated the definition of COPD, the evaluation by spirometry, and the pathogenesis and treatment strategy of COPD. It classified COPD into four levels based on pulmonary function (GOLD I–GOLD IV). This was a crucial step in standardizing the assessment and management of COPD, providing a clear framework for clinicians.
The 2011 update marked a major shift in the assessment method. GOLD introduced a comprehensive assessment that included not only spirometry but also symptoms and exacerbation history. This multi-modality approach highlighted the importance of exacerbation prevention in COPD management. The ABCD assessment tool was introduced, categorizing patients into four groups based on their symptoms and risk of exacerbations. This system was supported by evidence showing that patients with a high risk of exacerbations tend to have severe or very severe airflow limitation, and higher exacerbation rates are associated with faster loss of forced expiratory volume in the first second (FEV1) and greater worsening of health status.
However, over time, limitations of the 2011 ABCD assessment tool became apparent. Studies found that it was not superior to spirometric grades for predicting mortality or other important health outcomes. Additionally, the prognosis of groups C and D was determined by two indicators: spirometry and exacerbation history, leading to confusion in some cases. The results of spirometry could not fully reflect individual clinical differences, and spirometry alone could not accurately predict the risk of COPD.
To address these concerns, the GOLD 2017 report introduced a refined ABCD assessment tool that separated spirometric grades from the ABCD groups. This new system classified patients solely based on their symptoms and history of exacerbations. The distribution of patients in each group changed significantly under this new system. Studies showed that a substantial proportion of patients previously classified as high-risk (groups C and D) were reclassified as low-risk (groups A and B). For example, in the Phenotypes of COPD in Central and Eastern Europe (POPE) study, 59 patients (1.8% of the cohort) moved from group C to group A, and 686 patients (20.4% of the cohort) moved from group D to group B.
The clinical characteristics of the subgroups also changed under the new assessment system. Patients in the high-risk groups (B and D) demonstrated more characteristics associated with a high risk of acute exacerbation and mortality compared to the old high-risk groups. They had lower body mass index, more symptoms, used more respiratory medications, and had more severe airflow limitation. The mean declines in FEV1 for groups B and D were significantly greater than for group A, indicating greater disease severity in these groups.
The new assessment system also had implications for treatment. Studies found that the pharmacologic concordance rate decreased from 60.9% for GOLD 2011 to 44.9% for GOLD 2017, with over-treatment observed in 29.5% of patients according to GOLD 2011, increasing to 46.1% under GOLD 2017. The major cause of over-treatment was unnecessary use of inhaled corticosteroids (ICS), while under-treatment was often due to a lack of maintenance long-acting bronchodilators. The GOLD 2017 report recognized that spirometry could still be used to guide therapy in selected circumstances, particularly for patients with discrepancies between spirometry and the level of symptoms.
The prognostic significance of the new assessment system was also evaluated. Studies showed that the GOLD 2017 classification performed well in identifying individuals at risk of exacerbations but had a poor ability to predict mortality. Combining spirometric staging with the grouping increased the predictive ability for all-cause and respiratory mortality. Spirometry remains an important parameter at the population level for predicting important clinical outcomes such as mortality and hospitalizations.
The GOLD 2019 update introduced further changes to the medication pathway, including initial treatment, management cycle, and follow-up treatment. Initial drug recommendations were made according to the ABCD group, with follow-up treatment based on symptoms and exacerbations. The blood eosinophil count was introduced as a biomarker for estimating the efficacy of ICS for the prevention of exacerbations. This change provided more personalized pharmacologic treatment and management for patients.
The GOLD 2020 revision retained the disease assessment method of GOLD 2017 but included key changes such as follow-up of non-pharmacologic treatments, factors to consider for initiating ICS treatment, and differential diagnosis of COPD exacerbation. These updates continued to refine the approach to COPD management, emphasizing the importance of individualized treatment.
In conclusion, the evolution of the GOLD assessment method over the past two decades has significantly improved the management of COPD. The shift from a single spirometric assessment to a comprehensive evaluation that includes symptoms and exacerbation history has allowed for more personalized and effective treatment. The new ABCD assessment tool highlights the importance of symptoms and exacerbation history, although spirometry remains crucial for predicting mortality and other important health outcomes at the population level. The changes in treatment strategy resulting from these updates have had a positive impact on patient outcomes, although further research is needed to optimize the assessment system and ensure that all patients receive the most appropriate care.
doi.org/10.1097/CM9.0000000000000920
Was this helpful?
0 / 0