Speaker- Daphne Peerlings

The current Global Initiative for Chronic Obstructive Lung Disease (GOLD) risk assessment highlights the clinical relevance of exacerbations, with a history of previous exacerbations being a strong predictor of future events. However, these cutoffs lack comprehensive validation. The study aimed to address this by validating the existing history cutoffs and exploring alternative thresholds for predicting moderate and severe exacerbation risks and all-cause mortality in Chronic Obstructive Pulmonary Disease (COPD). We utilized data from the German COPD and Systemic Consequences – Comorbidities Network (COSYCONET) study, where patients were assessed during five visits over a four-and-a-half-year period. The patients were assessed on visits two and three to predict one-year risks and visits two and four to predict four-year risks. Patients reported the frequency of moderate and severe exacerbations over the past year. Statistical analyses included outcrop curves, Youden's index, and binomial logistic regressions. 

The baseline characteristics of the 2,291 patients included in the study revealed an average age of around 65 years, with a majority being male. Most patients had a history of moderate or severe exacerbations and presented with moderate to severe lung obstruction. The cohort predominantly consisted of former smokers, with an average smoking history of 41 pack years. During the study follow-up, 9.6% of the participants experienced mortality. In evaluating alternative cutoffs, we examined various categories. The highest Youden index was found to be achieved with thresholds of one or more previous moderate or severe exacerbations. These thresholds were effective for predicting both one-year and four-year risks. Analysis of odds ratios indicated that patients with one or more moderate exacerbations in the past year were two times more likely to experience future moderate or severe exacerbations. The trend was similarly observed for severe exacerbation history. For all-cause mortality, the highest odds ratio was associated with three or more moderate exacerbations in the last year, making patients two times more likely to die within four years. A history of severe exacerbations in the past year was linked to a 1.6-fold increased likelihood of mortality within four years. When comparing our alternative cutoffs to the current GOLD risk assessment categories, we noted that while sensitivity was around 40% and specificity was about 85% for moderate and severe exacerbations, our proposed cutoffs improved sensitivity, particularly for predicting moderate exacerbations in the upcoming year. However, the increased sensitivity was only statistically significant for one-year risk prediction.

Similar results were observed for the four-year risk prediction; however, these differences were not statistically significant. It indicates that the current exacerbation history categories used by the GOLD framework may have limited predictive performance. A revised approach was suggested to distinguish between non-exacerbators and high-risk exacerbators using the new cutoffs based on our findings. Specifically, focusing on patients with one or more moderate or severe exacerbations in the previous year could improve risk assessment and management strategies. 

The discussion focused on using risk assessment tools for COPD patients, specifically questioning the applicability of the GOLD guidelines. It was noted that the GOLD guidelines' risk categories are designed primarily for newly diagnosed patients and are not intended for those already undergoing maintenance therapy. Consequently, these categories may not be relevant for the ongoing assessment of patients already on treatment. A key point raised during the discussion was the relevance of past exacerbations as predictors of future outcomes. Despite GOLD guidelines' focus on initial risk assessment, other literature suggests that previous exacerbations can strongly predict future exacerbations. It indicates a potential gap in the current risk assessment frameworks, which may not fully capture the ongoing risks for patients on maintenance therapy. Additionally, a question was raised about the impact of smoking history on COPD exacerbations. It was suggested that recalcitrant smokers—those who continue smoking despite medical advice—might be at higher risk for frequent exacerbations and subsequent hospitalizations. It raises an important consideration for COPD patients' risk assessment and management strategies. The response indicated that while the data on the specific aspect was not immediately available, it is an area worth investigating further. In summary, while the GOLD guidelines provide a useful framework for initial risk assessment in newly diagnosed COPD patients, there may be limitations when applied to those on long-term treatment. Furthermore, understanding the role of smoking history in exacerbations could enhance risk prediction and management strategies.

European Respiratory Society Congress 2024, 7–11 September, Vienna, Austria