Does the 2017 revision improve the ability of GOLD to predict risk of future moderate and severe exacerbation?

In 2017 update, GOLD separated spirometry from ABCD classification.

The aim was to investigate the predictive reliability of GOLD 2017 grading system in terms of future moderate and severe exacerbations.

COPD patients were classified into A to D groups according to GOLD 2011 and 2017. Patients who were assigned to C/D groups according to GOLD 2011 were divided into subgroups C 1/D1, C2/D2, C3/D3 according to FEV₁ % of predicted and exacerbation history. C1/D1 patients defined as FEV₁  < 50% predicted and without ≥2 exacerbations or hospitalization in the last year.

A total of 225 patients were enrolled. Among them, 25.8% were in groups C1/D1 according to GOLD 2011. These patients shifted to A/B according to GOLD 2017. C1/D1 patients had a significantly higher risk of future moderate and severe exacerbation compared to A/B (P = 0.018). The risk of future moderate and severe exacerbation was significantly higher in patients with a FEV₁  < 50% (P = 0.018).The risk of future moderate and severe exacerbation was higher in GOLD 2017 groups A and B compared to GOLD 2011 groups A and B.

Low FEV₁ was an important risk factor for future exacerbations. Downstaging of C1/D1 patients caused heterogeneity in A/B with including patients with low and high risk of future exacerbation. This resulted in a low discriminative power of GOLD 2017 regarding the risk of future exacerbation in groups A and B. This may cause underestimation of disease severity and inadequate treatment especially in A/B patients with low FEV₁ .