| Title: | Physiological quotients for discriminating mortality and respiratory outcomes: a UK biobank cohort study |
| Journal: | ERJ Open Research |
| Published: | 6 Aug 2026 |
| DOI: | https://doi.org/10.1183/23120541.00846-2026 |
Publication 21064
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Abstract
Background Spirometry is traditionally interpreted using reference-based metrics derived from equations such as those from the Global Lung Function Initiative (GLI). Physiological quotients, which express lung function relative to a lower physiological boundary, have been proposed as an alternative approach. We aimed to compare the prognostic performance of physiological quotients with conventional reference-based metrics including both the GLI 2012 ethnicity-specific and the GLI 2023 Global equations, in a large population-based cohort. Methods We analysed data from 270 599 UK Biobank participants aged 40-69 years with baseline spirometry. Physiological quotients were calculated for FEV 1 , FVC, and FEV 1 /FVC using previously established first percentile boundaries. Associations with all-cause and cause-specific mortality, respiratory hospitalisation, respiratory symptoms, and self-reported respiratory diagnoses were examined using Cox proportional hazards and logistic regression models. Results Over a median follow-up of 15.7 years, 26 197 (10%) participants died. Lower physiological quotients were consistently associated with adverse outcomes. Each 1- sd decrement in FEV 1 Q, FVCQ, and FEV 1 /FVCQ was associated with higher all-cause mortality (HRs 1.06-1.09), cardiovascular mortality (HRs 1.06-1.20), respiratory mortality (HRs 1.28-1.77), and respiratory hospitalisation (HRs 1.04-1.41). Discrimination for all-cause mortality was modest (C-statistics 0.64-0.65), moderate for cardiovascular mortality (0.72-0.73), and good for respiratory mortality (0.76-0.79). Discrimination of respiratory hospitalisation was modest but slightly higher for FEV 1 Q and FVCQ (0.65) than for percent predicted values and z-scores (0.61-0.62). Across mortality outcomes, discriminative performance was similar between physiological quotients, percent predicted values, and z-scores. Conclusion Physiological quotients demonstrated prognostic performance comparable to conventional reference-based spirometric metrics for mortality outcomes, while showing modest advantages for respiratory morbidity. </p>
3 Authors
- Ben Knox-Brown
- Karl P Sylvester
- Andre F. S. Amaral
1 Application
| Application ID | Title |
|---|---|
| 360278 | Physiological quotients: Redefining lung function interpretation |
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