Diagnostic outcomes of the 2023 race-neutral and 2012 race-specific global lung function initiative spirometry equations in healthy Algerian adults: a cross-sectional comparative analysis.

Abstract

In 2023, the Global Lung Function Initiative (GLI) introduced race-neutral spirometric reference equations (2023-GLI-RNEs) to address concerns of racial bias inherent in earlier 2012-GLI race-specific models. While the 2012-GLI Caucasian equations (2012-GLI-CEs) were previously identified to reflect contemporary adults' Algerian spirometry, the 2023-GLI-RNEs applicability remains untested. This study aimed to compare the diagnostic outcomes of the 2023-GLI-RNEs and the 2012-GLI-CEs in a healthy adult Algerian population. A cross-sectional study was conducted on 488 Algerian healthy adults (49.6% female) aged 18-85 years. Participants underwent standardized plethysmography/spirometry in accordance with the most updated international guidelines. Z-scores and percent predicted values for FEV₁, FVC, and FEV₁/FVC ratio were computed using both 2012-GLI-CEs and 2023-GLI-RNEs. Diagnostic classifications (e.g. normal pattern, obstructive ventilatory impairment (OVI), non-specific ventilatory impairment (NSVI), or spirometric restrictive pattern (SRP), isolated low FEV₁ (ILF)) were compared across the two equations. Classification changes between the two norms appeared to be relatively limited. Percent predicted FEV₁ and FVC values were significantly but slightly higher when interpreted using 2023-GLI-RNEs by 6% and 7% points, respectively, and the percent predicted FEV₁/FVC value was marginally lower by -0.9%. Compared to 2012-GLI-CEs, 2023-GLI-RNEs identified more cases of OVI (4.10% vs. 6.35%, respectively, p = 0.003), fewer cases of NSVI or SRP (2.05% vs. 0.20%, respectively, p = 0.008) or ILF (1.84 vs. 0.00%, respectively, p = 0.008), and comparable cases of normal spirometry (92.01% vs. 93.44%, respectively, p = 0.230). In a sample of healthy Algerian adults' spirometric data, 2023-GLI-RNEs and 2012-GLI-CEs produced broadly comparable classifications of normal spirometry, although modest but statistically significant differences were observed in several abnormal spirometric categories.