The impact of changing to the Global Lung Function Initiative reference equations for transfer factor in paediatrics

The Global Lung Function Initiative (GLI) all age reference equations for carbon monoxide transfer factor were published in 2017 and endorsed by the ERS/ATS. In order to understand the impact of these new reference equations on the interpretation of results in children referred from haematology and oncology paediatric services, we retrospectively analysed transfer factor results from any paediatric patient referred from haematology oncology in the period 2010–2018. We examined TLCO, KCO and VA from 241 children (age range; 7–18, 130 male). The predicted values from Rosenthal and GLI were plotted against height. The difference in interpretation of results was analysed by looking at the percentage of patients <LLN for each parameter. Overall, the Rosenthal predicted values for TLCO were higher than GLI. Predicted KCO using Rosenthal was higher in all observations. In contrast, the Rosenthal predicted VA was generally lower than the GLI value. The GLI predicted values for transfer factor show considerable differences compared with currently used paediatric UK reference values, differences that will have a significant impact on interpretation of results.

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Global lung function initiative: Reference equations for the transfer factor for carbon monoxide (TLCO)

10.1183/13993003.congress-2016.oa283 ◽

2016 ◽

Author(s):

Sanja Stanojevic ◽

Brian Grham ◽

Brendan Cooper ◽

Bruce Thompson ◽

Kim Carter ◽

...

Keyword(s):

Carbon Monoxide ◽

Lung Function ◽

Transfer Factor ◽

Reference Equations

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Effects of adopting the Global Lung Function Initiative 2017 reference equations on the interpretation of carbon monoxide transfer factor

European Respiratory Journal ◽

10.1183/13993003.01905-2019 ◽

2020 ◽

Vol 55 (5) ◽

pp. 1901905

Author(s):

Danny J. Brazzale ◽

Leigh M. Seccombe ◽

Liam Welsh ◽

Celia J. Lanteri ◽

Claude S. Farah ◽

...

Keyword(s):

Carbon Monoxide ◽

Lung Function ◽

Transfer Factor ◽

Teaching Hospitals ◽

Younger Adults ◽

Adult Females ◽

Reference Set ◽

Reference Equations ◽

Lower Limit Of Normal ◽

A Current

The recently published Global Lung Function Initiative (GLI) carbon monoxide transfer factor (TLCO) reference equations provide an opportunity to adopt a current, all-age, widely applicable reference set. The aim of this study was to document the effect of changing to GLI from commonly utilised reference equations on the interpretation of TLCO results.33 863 TLCO results (48% female, 88% Caucasian, n=930 aged <18 years) from clinical pulmonary function laboratories within three Australian teaching hospitals were analysed. The lower limit of normal (LLN) and proportion of patients with a TLCO below this value were calculated using GLI and other commonly used reference equations.The average TLCO LLN for GLI was similar or lower than the other equations, with the largest difference seen for Crapo equations (median: −1.25, IQR: −1.64, −0.86 mmol·min−1·kPa−1). These differences resulted in altered rates of reduced TLCO for GLI particularly for adults (+1.9% versus Miller to −27.6% versus Crapo), more so than for children (−0.8% versus Kim to −14.2% versus Cotes). For adults, the highest raw agreement for GLI was with Miller equations (94.7%), while for children it was with Kim equations (98.1%). Results were reclassified from abnormal to normal more frequently for younger adults, and for adult females, particularly when moving from Roca to GLI equations (30% of females versus 16% of males).The adoption of GLI TLCO reference equations in adults will result in altered interpretation depending on the equations previously used and to a greater extent in adult females. The effect on interpretation in children is less significant.

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Speech Methodologies in Cleft Palate Assessment: A Pilot Project to Compare Two Phonetically Different Sentence Sets

Journal of Clinical Speech and Language Studies ◽

10.3233/acs-2013-20106 ◽

2013 ◽

Vol 20 (1) ◽

pp. 49-72

Author(s):

Jennie Smith ◽

Tim Pring ◽

Debbie Sell

Keyword(s):

Cleft Palate ◽

Pilot Project ◽

Wilcoxon Test ◽

Consecutive Series ◽

Video Recordings ◽

Significant Difference ◽

The Difference ◽

Audio Video ◽

Age Range ◽

The Impact

Objective: To investigate the impact of the phonetic content of two sentence sets on speech outcomes, specifically the effects of nasal phonemes. Method: Audio-video recordings of a consecutive series of 15 participants (age range 4–22 years), with cleft palate (syndromic or non-syndromic), with and without velopharyngeal dysfunction were taken. Participants repeated Sentence Set 1 (with nasals across sentences) and Sentence Set 2 (without nasals except the three nasal target sentences) during a routine speech recording. Two experienced Specialist Speech and Language Therapists, blinded to the study’s purpose, analyzed participants’ speech using the Cleft Audit Protocol for Speech-Augmented (CAPS-A). On day 1, recordings included Sentence Set 1. On day 2, 23 days later, recordings included Sentence Set 2. Main results: The difference between Sentence Set 1 and Sentence Set 2 ‘total scores’ (sum of scores on all CAPS-A parameters) was significant. The Pearson Product Moment showed high correlation. A Wilcoxon test revealed a significant difference between Sets 1 and 2 on the hypernasality parameter, and this alone accounted for the significant difference in total scores. Conclusion: The inclusion or exclusion of nasal consonants in the sentence set significantly affected perceptual ratings of hypernasality but none of the other CAPS-A parameters, highlighting the need for further investigation into perceptual nasality ratings.

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Effect of corrected GLI reference equations on carbon monoxide transfer factor interpretation

European Respiratory Journal ◽

10.1183/13993003.04459-2020 ◽

2021 ◽

pp. 2004459

Author(s):

Warren R. Ruehland ◽

Celia J. Lanteri ◽

Pam Matsas ◽

Danny J. Brazzale

Keyword(s):

Carbon Monoxide ◽

Transfer Factor ◽

Reference Equations

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Normal spirometry predictive values for the Western Indian adult population

European Respiratory Journal ◽

10.1183/13993003.02129-2019 ◽

2020 ◽

Vol 56 (3) ◽

pp. 1902129

Author(s):

Dhiraj Agarwal ◽

Richard A. Parker ◽

Hilary Pinnock ◽

Sudipto Roy ◽

Deesha Ghorpade ◽

...

Keyword(s):

Lung Function ◽

Adult Population ◽

Additive Model ◽

Forced Expiratory Volume ◽

Routine Practice ◽

Generalised Additive Model ◽

Predictive Values ◽

Reference Equations ◽

Predicted Values ◽

Severity Of The Disease

Interpretation of spirometry involves comparing lung function parameters with predicted values to determine the presence/severity of the disease. The Global Lung Function Initiative (GLI) derived reference equations for healthy individuals aged 3–95 years from multiple populations but highlighted India as a “particular group” for whom further data are needed. We aimed to derive predictive equations for spirometry in a rural Western Indian adult population.We used spirometry data previously collected (2008–2012) from 1258 healthy adults (aged 18 years and over) by the Vadu Health and Demographic Surveillance System. We constructed sex-stratified prediction equations for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and FEV1/FVC using the Generalised Additive Model for Location, Scale and Shape (GAMLSS) method to derive the best fitting model of each outcome as a function of age and height.When compared with GLI Ethnicity Codes 1 (White Caucasian) and 5 (Other/Mixed), the Western Indian adult population appears to have lower lung volumes on average, though the FEV1/FVC ratio is comparable. Both age and height were predictive of mean FEV1 and FVC; and for females, the variability of response was also dependent on age. FEV1/FVC appears to have a very strong age effect, highlighting the limitations of using a fixed 0.7 cut-off value.The use of GLI normal values may result in overdiagnosis of lung disease in this population. We recommend that the values and equations generated from this study should be used by physicians in their routine practice for diagnosing disease and its severity in adults from the Western Indian population.

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Stitching and switching: the impact of discontinuous lung function reference equations: Figure 1–

European Respiratory Journal ◽

10.1183/09031936.00173011 ◽

2012 ◽

Vol 39 (5) ◽

pp. 1256-1257 ◽

Cited By ~ 20

Author(s):

Jane Kirkby ◽

Paul Aurora ◽

Helen Spencer ◽

Stephanie Rees ◽

Samantha Sonnappa ◽

...

Keyword(s):

Lung Function ◽

Reference Equations ◽

The Impact

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Childhood pneumonia, pleurisy and lung function: a cohort study from the first to sixth decade of life

Thorax ◽

10.1136/thoraxjnl-2019-213389 ◽

2019 ◽

Vol 75 (1) ◽

pp. 28-37 ◽

Cited By ~ 2

Author(s):

Jennifer L Perret ◽

Caroline J Lodge ◽

Adrian J Lowe ◽

David P Johns ◽

Bruce R Thompson ◽

...

Keyword(s):

Carbon Monoxide ◽

Lung Function ◽

Lower Limit ◽

Transfer Factor ◽

Study Cohort ◽

Z Score ◽

Lung Volumes ◽

Current Asthma ◽

Childhood Pneumonia ◽

Lower Limit Of Normal

IntroductionAdult spirometry following community-acquired childhood pneumonia has variably been reported as showing obstructive or non-obstructive deficits. We analysed associations between doctor-diagnosed childhood pneumonia/pleurisy and more comprehensive lung function in a middle-aged general population cohort born in 1961.MethodsData were from the prospective population-based Tasmanian Longitudinal Health Study cohort. Analysed lung function was from ages 7 years (prebronchodilator spirometry only, n=7097), 45 years (postbronchodilator spirometry, carbon monoxide transfer factor and static lung volumes, n=1220) and 53 years (postbronchodilator spirometry and transfer factor, n=2485). Parent-recalled histories of doctor-diagnosed childhood pneumonia and/or pleurisy were recorded at age 7. Multivariable linear and logistic regression were used.ResultsAt age 7, compared with no episodes, childhood pneumonia/pleurisy-ever was associated with reduced FEV1:FVC for only those with current asthma (beta-coefficient or change in z-score=−0.20 SD, 95% CI −0.38 to –0.02, p=0.028, p interaction=0.036). At age 45, for all participants, childhood pneumonia/pleurisy-ever was associated with a restrictive pattern: OR 3.02 (1.5 to 6.0), p=0.002 for spirometric restriction (FVC less than the lower limit of normal plus FEV1:FVC greater than the lower limit of normal); total lung capacity z-score −0.26 SD (95% CI −0.38 to –0.13), p<0.001; functional residual capacity −0.16 SD (−0.34 to –0.08), p=0.001; and residual volume −0.18 SD (−0.31 to –0.05), p=0.008. Reduced lung volumes were accompanied by increased carbon monoxide transfer coefficient at both time points (z-score +0.29 SD (0.11 to 0.49), p=0.001 and +0.17 SD (0.04 to 0.29), p=0.008, respectively).DiscussionFor this community-based population, doctor-diagnosed childhood pneumonia and/or pleurisy were associated with obstructed lung function at age 7 for children who had current asthma symptoms, but with evidence of ‘smaller lungs’ when in middle age.

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Impact of using different predictive equations on the prevalence of chronic byssinosis in textile workers in Pakistan

Occupational and Environmental Medicine ◽

10.1136/oemed-2021-107680 ◽

2021 ◽

pp. oemed-2021-107680

Author(s):

Asaad Ahmed Nafees ◽

Muhammad Zia Muneer ◽

Sara De Matteis ◽

Andre Amaral ◽

Peter Burney ◽

...

Keyword(s):

Lung Function ◽

Controlled Trial ◽

Forced Expiratory Volume ◽

Textile Workers ◽

Middle Income ◽

Low Middle Income Countries ◽

Reference Equations ◽

Predicted Values ◽

Definition Of ◽

Randomised Controlled

ObjectiveByssinosis remains a significant problem among textile workers in low/middle-income countries. Here we share our experience of using different prediction equations for assessing ‘chronic’ byssinosis according to the standard WHO classification using measurements of forced expiratory volume in 1 s (FEV1).MethodsWe enrolled 1910 workers in a randomised controlled trial of an intervention to improve the health of textile workers in Pakistan. We included in analyses the 1724 (90%) men who performed pre-bronchodilator spirometry tests of acceptable quality. We compared four different equations for deriving lung function percentage predicted values among those with symptoms-based byssinosis: the third US National Health and Nutrition Examination Survey (NHANES-III, with ‘North Indian and Pakistani’ conversion factor); the Global Lung Function Initiative (GLI, ‘other or mixed ethnicities’); a recent equation derived from survey of a western Indian population; and one based on an older and smaller survey of Karachi residents.Results58 men (3.4%) had symptoms-based byssinosis according to WHO criteria. Of these, the proportions with a reduced FEV1 (<80% predicted) identified using NHANES and GLI; Indian and Pakistani reference equations were 40%, 41%, 14% and 12%, respectively. Much of this variation was eliminated when we substituted FEV1/forced vital capacity (FVC) ratio (<lower limit of normality) as a measure of airway obstruction.ConclusionAccurate measures of occupational disease frequency and distribution require approaches that are both standardised and meaningful. We should reconsider the WHO definition of ‘chronic’ byssinosis based on changes in FEV1, and instead use the FEV1/FVC.

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