Introduction

Multidimensional assessment tools, which are simple to establish, are finding an increasingly important place in the evaluation of the prognosis of Interstitial Lung Disease.

Objective

The aim of this study was to evaluate the correlation between Distance-Saturation Product (DSP) and Composite Physiologic Index (CPI) in COVID-19 survivors.

Methods

It was a cross-sectional study (2020-2022) including 497 patients who were referred to the department of pulmonary function tests of Abderrahmane MAMI hospital of Ariana Tunisia, three months after hospitalization for COVID-19 infection. All patients underwent spirometry with measurement of FEV1 and FVC, Diffusion of lungs for Carbone Monoxide (DLCO) and 6-Minute Walk Test with measurement of 6-Minute Walk Distance (6MWD) and Minimal Oxygen Saturation value (MOS).

DSP and CPI were calculated according to these formulas: DSP= 6MDW*MOS, CPI= 91 ? (0.65 * DLCO)- (0.53*FVC) +(0.34*FEV1), respectively.

Results

The mean age of patients was 61.41 ± 10.99 years and mean hospital stay duration was 14.04± 11.73 days. The mean values of FEV1, FVC and DLCO were respectively 88.64 ± 18.45%, 85.86± 16.23% and 73.09 ± 17.97%.

Means of DSP and CPI were respectively 467.28± 123.91 and 28.11± 13.86. Statistical analysis revealed that CPI was significantly correlated with 6MWD (r= -0.462; p <0.001), MOS (r= -0.288; p < 0.001) and DSP (r= -0.473; p< 0.001).

Conclusion

Regarding the significant correlation between DSP and CPI, pulmonologists should place more importance on DSP to help them better predict COVID-19 prognosis because it is a simple tool and requires simple equipment.