A new, three-dimensional approach to the GOLD COPD assessment tool

Background: The 2-dimensional, 4-quadrant 2017 Global Initiative for Chronic Obstructive Lung Disease (GOLD) COPD A-D assessment tool (GOLD₂₀₁₇) does not include lung function variables to classify patients into different risk groups. The previous 2011 tool (GOLD₂₀₁₁) classified cases in the upper-quadrants (higher risk groups) regardless of whether they had a history of exacerbations or worse lung function. We hypothesized that a modified, three-dimensional classification (GOLD_3D) that separately includes assessment of lung function and exacerbations history would improve the ability to predict adverse events.

Methods: A total of 1303 COPD patients were included in a historical cohort study. The ability of GOLD_3D to predict outcomes (all-cause death and hospitalizations due to severe exacerbation) was compared with GOLD₂₀₁₇ and GOLD₂₀₁₁.

Results: Mean follow-up was 45.0 ± 28.0 months. Two hundred and twenty-eight patients (17.5%) died and 337 (25.9%) subjects suffered at least a severe exacerbation that required hospital admission. The area under the receiver-operating characteristics curve for mortality prediction was slightly but significantly higher for GOLD_3D than for GOLD₂₀₁₁. The area under the curve for prediction of severe exacerbations was significantly higher for GOLD_3D than for GOLD₂₀₁₁ and GOLD₂₀₁₇. A worse ventilatory obstruction was associated in most cases with a higher mortality risk and a higher exacerbation risk for the GOLD2017 A-D groups.

Conclusions: The proposed GOLD_3D classification system upgrades the previous ones, and is advantageous in predicting future adverse events.