Multi-ethnic reference values for spirometry for the 3-95-yr age range: the global lung function 2012 equations.

BackgroundAccurate diagnosis of obstructive lung disease in paediatric populations depends on the use of spirometry reference equations that reflect the regional and ethnic diversity of the population studied.ObjectivesTo evaluate the diagnostic variability between the Global Lung Initiative 2012 (GLI2012) and Polgar reference equations in a multi-ethnic cohort of South African (SA) children.MethodsThis retrospective cohort study analysed spirometry data from 171 children, aged 6 - 18 years, attending a paediatric pulmonology clinic in Durban, SA, from January 2012 to December 2021. Key spirometry parameters (forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio) were calculated using both the GLI2012 and Polgar reference equations. Diagnostic outcomes across ethnic groups were compared to assess the variability and potential diagnostic implications of each reference standard.ResultsComparison of spirometry outcomes using the GLI2012and Polgar reference equations revealed diagnostic variability across ethnic groups. GLI2012identified a higher rate of obstructive lung disease, with abnormality rates of 24.6% among white children, 0.6% among black African children and 2.3% among Asian children, compared with Polgar, which reported rates of 23.9%, 0% and 1.6%, respectively. There was a statistically significant difference in FEV1/FVC ratios before and after administration of a bronchodilator between the two reference equations (mean (standard deviation) pre-bronchodilator FEV1/FVC ratio 0.86 (0.06) for both equations; post-bronchodilator ratio 0.88 (0.09) for GLI2012and 0.85 (0.09) for Polgar (p=0.023)). There was no statistically significant difference in the proportion of children diagnosed with obstructive lung disease by age or ethnicity when comparing GLI2012 with Polgar.ConclusionThis study underscores the diagnostic variability that arises from using global spirometry reference equations in a multi-ethnic paediatric population, particularly in SA. Future studies should include a more diverse ethnic representation to enhance data relevance.Study synopsisWhat the study adds. This study reveals significant variability in rates of paediatric obstructive lung disease across ethnic groups in South Africa, emphasising discrepancies between the Global Lung Initiative 2012 and Polgar reference equations. It underscores the limitations of non-region-specific lung function standards, which may result in misclassification and inconsistent diagnoses in diverse populations.Implications of the findings. Developing African-specific reference standards is crucial for accurate diagnosis and effective clinical interventions. Future longitudinal studies should track lung function growth across ethnic and socioeconomic groups, offering deeper insights and enhancing diagnostic precision. Expanding research to include more diverse ethnic representation will strengthen the applicability of findings and support equitable healthcare for paediatric respiratory conditions across the continent.

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BackgroundSpirometry testing in respiratory disease research, diagnosis, and management relies on reference equations. The Global Lung Function Initiative (GLI) reference equations are based on data from 26 countries, but sub-Saharan...

Rationale: Advances in plethysmographic measurement techniques have made it possible to obtain lung function data in infants [1] and children. However, application remains limited by the lack of appropriate transitional normative data from infancy to childhood, especially for effective specific airway resistance (sReff). Objectives: On previously collected lung function data, updated prediction equations were modeled spanning from infant's years to childhood, using the LMS method. Methods: Normative lung function data from 67 healthy young infants aged 2.3 to 28.2 (10.8±6.3) months and children aged 5.1 to 16.8 (10.4±2.9) years were evaluated, and prediction equations for functional residual capacity (FRCpleth), and sReff were computed. Applying the LMS method in R environment using GAMLSS package [2] the changing distribution of the measurements is summarized by three curves representing the median (M), coefficient of variation (S) and skewness (L) in relation to age. Results: The present prediction equations feature the first attempt to provide continuous normative data of infants with a smooth transition into childhood (Table 1). Table 1 M S L FRCpleth Boys 127.77 + 162.52$*$age 0.1213 + 0.0046$*$age – 0.00031$*$agê2 + 0.000025$*$agê3 0.48 Girls 128.42 + 167.91$*$age 0.0685 + 0.03835$*$age – 0.00423$*$agê2 + 0.000147$*$agê3 0.48 sReff Boys 0.39 + (age/(130.24 + 21.51$*$age – 94.6$*$SQRT(age))) 0.12 + (age/(247.9 + 33.88$*$age – 149.5$*$SQRT(age))) 0.86 Girls 0.39 + (age/(59.88 + 14.38$*$age – 47.7$*$SQRT(age))) 0.17 + 0.00034$*$agê2 0.37 Conclusions: Updated prediction equations of plethysmographic data for infants and children applying LMS statistics provide a new basis for longitudinal evaluation of lung function in children with lung disease.

Honoring Asian diversity by collecting Asian subpopulation data in health research.

The use of race-based coefficients in pulmonary function testing has led to the recent development of the race-neutral Global Lung Function Initiative (GLI) reference equation (hereafter GLI Global). The performance of GLI Global in comparison to race-adjusted coefficients (hereafter GLI 2012) has not been well characterized. To compare the implications of GLI 2012 vs GLI Global reference equations for lung function trajectory. This cohort study at Massachusetts General Hospital analyzed data of patients aged 18 to 95 years who completed spirometry testing between January 1, 1997, and December 31, 2020. Data analysis was performed from January 2023 to November 2024. GLI Global and GLI 2012 reference equations to define lung function. Proportion of patients with recategorized lung function (FEV1 and FVC) based on the 2 reference equations and their lung function trajectory over time. Lung function metrics included forced expiratory volume in the first second of expiration (FEV1), forced vital capacity (FVC), and FEV1 to FVC ratio. The z scores for FEV1 and FVC were calculated using the GLI 2012 and GLI Global reference equations, with a score lower than -1.64 considered abnormal. Patients were categorized into 1 of 4 groups based on their z scores: normal to normal (normal z score on both equations); abnormal to normal (abnormal z score based on GLI 2012 equations but normal based on the GLI Global equation); normal to abnormal (normal z score on GLI 2012 equations but abnormal on the GLI Global equation); and abnormal to abnormal (abnormal z score on both equations). The sample included a total of 24 662 patients (988 Black [4.0%] and 22 297 White [90.4%] patients; 13 108 women [53.2%]) with a mean (SD) age of 57.6 (15.7) years who completed a median (IQR) of 3.0 (2.0-5.0) sets of spirometry over a median (IQR) of 2.6 (0.8-6.6) years between 1997 and 2020. Among Black patients, 190 (19.2%) had either their FEV1 or FVC recategorized from normal to abnormal using the GLI Global reference equation. The subset of Black patients whose lung function was recategorized from normal to abnormal exhibited FEV1 decline (-2.06%; 95% CI, -3.47% to -0.64%; P = .56) that was similar to decline in Black patients whose lung function was characterized as abnormal (-1.89%; 95% CI, -2.58% to -1.19%; P = .84) using both the GLI Global and GLI 2012 reference equations. Among White patients, 3348 (15.0%) had either their FEV1 or FVC recategorized from abnormal to normal using the GLI Global equation. FEV1 decline in these patients (-1.82%; 95% CI, -2.55% to -1.08%; P = .70) was similar to the decline in White patients with normal spirometry (-1.97%; 95% CI, -2.26% to -1.69%; P = .70) regardless of the reference equation used. Patterns in FVC trajectory among both Black and White participants were not consistent among participants whose spirometry was recategorized between normal and abnormal compared with those whose spirometry remained normal or remained abnormal regardless of the reference equation used. This cohort study found that Black patients whose lung function was recategorized from normal to abnormal using the GLI Global reference equation exhibited FEV1 decline similar to that in Black patients whose lung function was classified as abnormal regardless of which equation was used. This finding suggests that a race-neutral approach to spirometry interpretation may allow a more accurate identification of lung pathology in Black patients.

BackgroundThe Global Lung Function Initiative (GLI-2012) focused on race/ethnicity as an important factor in determining reference values. This study evaluated the effects of changing from Canadian reference equations developed from...

The effect of ethnic origin on pulmonary prediction equations in a Jewish immigrant population

BackgroundThe impact of applying different lung function reference equations and interpretation methods in fibrotic interstitial lung disease (ILD) is poorly understood. We aimed to evaluate disease severity classification, trajectories and prognostic significance of percent-predicted and z-scores of forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DLCO) using the Global Lung Function Initiative (GLI) reference equations in patients with fibrotic ILD, compared to registry-recorded values.MethodsSerial lung function measurements of 5026 patients from three prospective registries were used to calculate percent-predicted and z-scores using 2012- and 2023-GLI FVC reference equations and 2017-GLI DLCO reference equations, which were compared with registry-recorded values. Differences for baseline and longitudinal assessments, classification for lung function impairment severity and progression, and association with transplant-free survival and performance of the ILD-Gender-Age-Physiology model with external validation were assessed.ResultsBaseline FVC and DLCO percent-predicted values were consistently higher using the 2012- and 2023-GLI FVC and 2017-GLI DLCO reference equations compared to registry-recorded values. The agreements for all percent-predicted reference equations were good for lung function severity classification (unweighted κ for FVC 0.69–0.76, DLCO 0.70), but only moderate for the counterpart z-scores (FVC 0.41–0.50, DLCO 0.45). The largest 1-year declines were observed using the 2023-GLI FVC reference equations and the 2017-GLI DLCO reference equations. Lower baseline GLI and registry-recorded FVC and DLCO values were associated with worse transplant-free survival and had similar performance for risk stratification, except for a lack of association of baseline 2023-GLI FVC percent-predicted and z-scores for adjusted analyses in the non-White cohort.ConclusionsUse of different lung function reference equations and interpretation methods may impact disease severity classification and longitudinal trajectory in patients with fibrotic ILD, although prognostic significance is similar, except for 2023-GLI FVC in non-White patients.

Objective: This study examined ethnic disparities in antipsychotic therapy in a population with significant Asian representation. Methods: Using a cross-sectional retrospective study design, self-reported ethnicity data pooled from three cycles of the Canadian Community Health Survey were linked to 2005 administrative data on physician, hospital, and pharmaceutical use in British Columbia, Canada. Logistic regression was used to model the association between ethnicity and the likelihood of filling one or more prescriptions for any antipsychotic, with controls for sex, age, residence, immigrant status, income, health status, and diagnoses of schizophrenia, bipolar disorder, depression, and dementia. Results: Of the 27,658 individuals in the sample, 2.2% filled at least one antipsychotic prescription. The proportion varied across ethnic groups: Chinese, 1.0%; other Asians, 1.2%; whites, 2.3%; nonwhite non-Asians, 2.8%; and mixed ethnicity, 4.3%. After adjustment for patient characteristics and diagnoses of schizophrenia and bipolar disorder, the likelihood of filling a prescription was found to be lower among Chinese (odds ratio [OR]=.47, 95% confidence interval [CI]=.24–.90) and higher among persons of mixed ethnicity (OR=3.19, CI=1.49–6.83). Further adjustment for depression and dementia diagnoses did not significantly change the ORs for the Chinese (OR=.49, CI=.25–.98) and the mixed ethnic groups (OR=2.97, CI=1.30–6.80). Conclusions: Consistent with the existing literature on ethnic disparities in antipsychotic therapy, the study found evidence of persistent disparities in a population that has a significant number of Asians. Further studies should be done to identify possible causes of these disparities and to identify potential interventions that may reduce or eliminate them. (Psychiatric Services 62:1026–1031, 2011)

Lung Function Values in Healthy Non-Smoking Urban Adults in Iran

Ethnic differences in lung function are well recognized, hence the use of normative data should therefore be based on reference equations that are derived specifically for different ethnic groups. We have collected data (n = 406) for population-based reference values of lung function from randomly selected samples of healthy non-smoking adults of both gender (aged 20-79 years) for each of the three major ethnic groups (Chinese, Malay and Indians) in Singapore. Lung function forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, diffusion capacity (transfer factor) for carbon monoxide (DLCO), total lung capacity (TLC), residual volume (RV), RV/TLC and functional residual capacity (FRC) was measured using standardization procedures and acceptability criteria recommended by the American Thoracic Society. Lung function values were predicted from age, height, weight, body mass index (BMI) and transformed variables of these anthropometric measures, using multiple regression techniques. Ethnic differences were demonstrated, with Chinese having the largest lung volumes and flow rates, and Indians the smallest. These prediction equations provide improved and additional (TLC, RV, RV/TLC, FRC) population-based reference values for assessment of pulmonary health and disease in Singapore.

There are few data to support accurate interpretation of spirometry data in South Asia, a major global region with a high reported burden of chronic respiratory disease. We measured lung function in 7453 healthy men and women aged ≥18 years, from Bangladesh, North India, South India, Pakistan and Sri Lanka, as part of the South Asia Biobank study. First, we assessed the accuracy of existing equations for predicting normal forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and FEV1/FVC ratio. Then, we used our data to derive (n=5589) and internally validate (n=1864) new prediction equations among South Asians, with further external validation among 339 healthy South Asians living in Singapore. The Global Lung Initiative (GLI) and National Health and Nutrition Examination Survey consistently overestimated expiratory volumes (best fit GLI-African American, mean±sd z-score: FEV1 -0.94±1.05, FVC -0.91±1.10; n=7453). Age, height and weight were strong predictors of lung function in our participants (p<0.001), and sex-specific reference equations using these three variables were highly accurate in both internal validation (z-scores: FEV1 0.03±0.99, FVC 0.04±0.97, FEV1/FVC -0.03±0.99) and external validation (z-scores: FEV1 0.31±0.99, FVC 0.24±0.97, FEV1/FVC 0.16±0.91). Further adjustment for study regions improves the model fit, with highest accuracy for estimation of region-specific lung function in South Asia. We present improved equations for predicting lung function in South Asians. These offer the opportunity to enhance diagnosis and management of acute and chronic lung diseases in this major global population.

The Challenge of Providing Culturally Competent Services

This report was derived from a workshop on cardiovascular risk assessment sponsored by the National Heart, Lung, and Blood Institute, which addressed whether risk equations developed in the Framingham Heart Study (FHS) for predicting new-onset coronary heart disease (CHD) apply to diverse population groups. Preparation for the workshop included a reanalysis and comparison of prospective studies in several different populations in which risk factors were related to cardiovascular outcomes. Some studies included fatal and nonfatal CHD end points, whereas others contained only CHD mortality. Extensive collaboration provided as much uniformity as possible with respect to both risk factors and CHD end points. The FHS has led in defining the quantitative impact of risk factors.1 Many potential risk factors were measured and related to cardiovascular outcomes. Several risk factors proved to be strong, largely independent predictors of cardiovascular disease (CVD). These factors—advancing age, cigarette smoking, blood pressure (particularly systolic), cholesterol in total serum and HDL, and diabetes—served as the basis for the development of risk prediction equations.1 If FHS risk estimates are to be widely used, they must apply widely in the US population. To document their transportability, they must be compared with prospective studies in other populations. Although the FHS is the longest running prospective study, there are other major studies. The cardiovascular end points of these other studies have varied. Some include cardiovascular morbidity and mortality; others have only cardiovascular mortality. Among the end points, CHD is the most extensively reported; for this reason, CHD was the primary focus of the workshop. ### Multivariate Relative Risk Comparisons In preparation for the workshop, multivariate regression coefficients for each risk factor were compared in different populations with those of the FHS. Adjusted relative risk estimates make it possible to determine whether each independent risk factor confers a similar or different relative risk among different …