Validation of the global lung initiative 2012 multi-ethnic spirometric reference equations in healthy urban Zimbabwean 7-13 year-old school children: a cross-sectional observational study

Differences in percentage predicted spirometric values obtained with thirteen reference equations applied to healthy children

BACKGROUND

There is limited information on the discrepancy between the spirometric values calculated with diverse spirometric prediction equations in normal children.

OBJECTIVE

To determine the differences in percentage predicted (PP) values calculated through thirteen prediction equations (PEs) in healthy Chilean children.

METHODS

We compared the PP values for FVC, FEV1, FEF25-75% and FEV1/FVC obtained by applying thirteen PEs, using GLI-2012 as a gold standard reference equation and including race neutral GLI-2022 in the analysis; PP values are from a group of 208 healthy Chilean children aged 7 to 17 years.

RESULTS

In boys, the range of differences for FVC between PEs compared to the reference group went from -5.47% to 20.82% and from -6.4% to 19.74% in girls. For FEV1, in girls, the range of differences went from -5.96% to 18.01% and from -5,04% to 20.67% in boys. Significant differences between GLI-2012 PPs and the other PEs were observed more frequently in girls than in boys (p < 0.001).

CONCLUSIONS

There is a wide difference between the spirometric PPs values by different PEs, including race neutral GLI-2022. Our findings, especially given the potential interpretative and clinical implications, might suggest the need for conducting standardized, multicenter studies in Latin America to determine which PEs would better fit pediatric populations in this region.

Compatibility of the global lung function 2012 spirometry reference values in children, adolescents and young adults: a systematic review

INTRODUCTION

The Global Lung Function Initiative (GLI 2012) has published multiethnic spirometry reference values. To identify studies that evaluated the compatibility (applicability, validity, representativeness, agreement and/or adequacy) of the reference equations proposed by the GLI 2012 for spirometry tests in different populations.

METHODS

Systematic searches were carried out on the PubMed, LILACS (Latin American and Caribbean Health Sciences Literature), Scopus, Web of Science and Google Scholar databases. Cross-sectional observational studies published between 2012 and 2013 onwards that evaluated the compatibility of the GLI 2012 in children, adolescents and young adults (3-20 years old) were included. The references were manually searched and the Joanna Briggs Institute Critical Appraisal Checklist for Cross-Sectional Analytical Studies was applied to assess the methodological quality of the studies included.

RESULTS

All of the 5632 studies identified were classified as low risk of bias, but only 21 were deemed eligible for inclusion. Of these, 8 reported satisfactory GLI 2012 compatibility for their populations (Argentina, Spain, Columbia, Djibouti, Norway, Poland, Jordan and Zimbabwe), 5 cautious applicability, and the remaining 8 considered the equation unsatisfactory, since it over or underestimated spirometric parameters.

CONCLUSION

The GLI 2012 equations are not applicable to all populations and must be tested before being adopted.

Longitudinal lung function trajectories in response to azithromycin therapy for chronic lung disease in children with HIV infection: a secondary analysis of the BREATHE trial

BACKGROUND

Chronic lung disease (CLD) is common among children with HIV (CWH) including in those taking antiretroviral therapy (ART). Azithromycin has both antimicrobial and anti-inflammatory effects and has been effective in improving lung function in a variety of lung diseases. We investigated lung function trajectories among CWH with CLD on ART enrolled in a randomized controlled trial of adjuvant azithromycin. We also investigated factors that modified the effect of azithromycin on lung function.

METHODS

The study used data from a double-blinded placebo-controlled trial conducted in Malawi and Zimbabwe of 48 weeks on azithromycin (BREATHE: ClinicalTrials.gov NCT02426112) among CWH aged 6 to 19 years taking ART for at least six months who had a forced expiratory volume in one second (FEV1) z-score <-1.0. Participants had a further follow-up period of 24 weeks after intervention cessation. FEV1, forced vital capacity (FVC) and FEV1/FVC were measured at baseline, 24, 48 and 72-weeks and z-scores values calculated. Generalized estimating equations (GEE) models were used to determine the mean effect of azithromycin on lung-function z-scores at each follow-up time point.

RESULTS

Overall, 347 adolescents (51% male, median age 15 years) were randomized to azithromycin or placebo. The median duration on ART was 6.2 (interquartile range: 3.8-8.6) years and 56.2% had an HIV viral load < 1000copies/ml at baseline. At baseline, the mean FEV1 z-score was - 2.0 (0.7) with 44.7% (n = 155) having an FEV1 z-score <-2, and 10.1% had microbiological evidence of azithromycin resistance. In both trial arms, FEV1 and FVC z-scores improved by 24 weeks but appeared to decline thereafter. The adjusted overall mean difference in FEV1 z-score between the azithromycin and placebo arms was 0.004 [-0.08, 0.09] suggesting no azithromycin effect and this was similar for other lung function parameters. There was no evidence of interaction between azithromycin effect and baseline age, lung function, azithromycin resistance or HIV viral load.

CONCLUSION

There was no observed azithromycin effect on lung function z-scores at any time point suggesting no therapeutic effect on lung function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02426112. First registered on 24/04/2015.

Does working in an extremely cold environment affects lung function?: 10 years follow-up

OBJECTIVE

The aim of this study is to investigate whether there is an association between brief but repeated exposures to extremely cold temperatures over many years and pulmonary function.

METHODS

We performed a retrospective analysis of the data collected over 10 years in the context of the extended medical examinations of storeworkers exposed to extremely cold temperatures. We considered forced vital capacity (FVC), forced expiratory volume in one second (FEV1), Tiffeneau-Pinelli index (FEV1/FVC), CO diffusion capacity (DL,CO) and Krogh-factor (CO diffusion capacity relative to recorded alveolar volume, DL,CO/VA) reported as %-predicted. We analysed trends in outcome parameters with linear mixed models.

RESULTS

46 male workers participated in at least two extended medical examinations between 2007 and 2017. Overall 398 measure points were available. All lung function parameters had values above the lower limit of normality at the first examination. In the multivariate model including smoking status and monthly intensity of cold exposure (≤ 16 h/month vs. > 16 h/month) FEV1%-predicted and FVC %-predicted had a statistically significant positive slope (FEV1, 0.32% 95% CI 0.16% to 0.49% p < 0.001; FVC 0.43% 95% CI 0.28% to 0.57% p < 0.001). The other lung function parameters (FEV1/FVC %-predicted, DL,CO %-predicted, DL,CO/VA %-predicted) showed no statistically significant change over time.

CONCLUSIONS

Long term intermittent occupational exposure to extreme cold temperatures (-55 °C) does not appear to cause irreversible deleterious changes in lung function in healthy workers, thus the development of obstructive or restrictive lung diseases is not expected.

A scoping review of lung function in children and adolescents living with HIV in the era of antiretroviral treatment

BACKGROUND

Human immunodeficiency virus (HIV) in children and adolescents remains an important health challenge in many countries and is commonly associated with lung disease. The introduction of antiretroviral therapy (ART) has greatly improved survival but chronic lung disease is a common ongoing challenge. We conducted a scoping review of studies that have reported lung function in school-aged children and adolescents living with HIV.

METHODS

A systematic literature search was performed by searching Medline, Embase, and PubMed databases, limited to articles published between 2011 and 2021 in English language. Inclusion criteria were studies involving participants living with HIV aged 5-18 years and having spirometry data. The primary outcome was lung function as measured by spirometry.

RESULTS

Twenty-one studies were included in the review. Most study participants were living in the sub-Saharan African region. The prevalence of reduced forced expiratory volume in 1 s (FEV1 ) ranged from 25.3% to 73% across studies, reduced forced vital capacity (FVC) ranged from 10% to 42% and reduced FEV1 /FVC ranged from 3% to 26%. The mean z-score of FEV1 ranged from -2.19 to -0.73, mean zFEV1 /FVC ranged from -0.74 to 0.2, and mean FVC ranged from -1.86 to -0.63.

CONCLUSION

There is a high prevalence of lung function impairment in children and adolescents living with HIV, which persists in the ART era. Further studies are needed of interventions that might improve lung function in these vulnerable populations.

Sputum bacterial load and bacterial composition correlate with lung function and are altered by long-term azithromycin treatment in children with HIV-associated chronic lung disease

BACKGROUND

Long-term azithromycin (AZM) treatment reduces the frequency of acute respiratory exacerbation in children and adolescents with HIV-associated chronic lung disease (HCLD). However, the impact of this treatment on the respiratory bacteriome is unknown.

METHOD

African children with HCLD (defined as forced expiratory volume in 1 s z-score (FEV1z) less than - 1.0 with no reversibility) were enrolled in a placebo-controlled trial of once-weekly AZM given for 48-weeks (BREATHE trial). Sputum samples were collected at baseline, 48 weeks (end of treatment) and 72 weeks (6 months post-intervention in participants who reached this timepoint before trial conclusion). Sputum bacterial load and bacteriome profiles were determined using 16S rRNA gene qPCR and V4 region amplicon sequencing, respectively. The primary outcomes were within-participant and within-arm (AZM vs placebo) changes in the sputum bacteriome measured across baseline, 48 weeks and 72 weeks. Associations between clinical or socio-demographic factors and bacteriome profiles were also assessed using linear regression.

RESULTS

In total, 347 participants (median age: 15.3 years, interquartile range [12.7-17.7]) were enrolled and randomised to AZM (173) or placebo (174). After 48 weeks, participants in the AZM arm had reduced sputum bacterial load vs placebo arm (16S rRNA copies/µl in log₁₀, mean difference and 95% confidence interval [CI] of AZM vs placebo - 0.54 [- 0.71; - 0.36]). Shannon alpha diversity remained stable in the AZM arm but declined in the placebo arm between baseline and 48 weeks (3.03 vs. 2.80, p = 0.04, Wilcoxon paired test). Bacterial community structure changed in the AZM arm at 48 weeks compared with baseline (PERMANOVA test p = 0.003) but resolved at 72 weeks. The relative abundances of genera previously associated with HCLD decreased in the AZM arm at 48 weeks compared with baseline, including Haemophilus (17.9% vs. 25.8%, p < 0.05, ANCOM ω = 32) and Moraxella (1% vs. 1.9%, p < 0.05, ANCOM ω = 47). This reduction was sustained at 72 weeks relative to baseline. Lung function (FEV1z) was negatively associated with bacterial load (coefficient, [CI]: - 0.09 [- 0.16; - 0.02]) and positively associated with Shannon diversity (0.19 [0.12; 0.27]). The relative abundance of Neisseria (coefficient, [standard error]: (2.85, [0.7], q = 0.01), and Haemophilus (- 6.1, [1.2], q < 0.001) were positively and negatively associated with FEV1z, respectively. An increase in the relative abundance of Streptococcus from baseline to 48 weeks was associated with improvement in FEV1z (3.2 [1.11], q = 0.01) whilst an increase in Moraxella was associated with decline in FEV1z (-2.74 [0.74], q = 0.002).

CONCLUSIONS

AZM treatment preserved sputum bacterial diversity and reduced the relative abundances of the HCLD-associated genera Haemophilus and Moraxella. These bacteriological effects were associated with improvement in lung function and may account for reduced respiratory exacerbations associated with AZM treatment of children with HCLD. Video Abstract.

Changes in interpretation of spirometry by implementing the GLI 2012 reference equations: impact on patients tested in a hospital-based PFT lab in a large metropolitan city

BACKGROUND

The 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 an all-Caucasian cohort with European ancestry to the GLI-2012 on the interpretation of spirometry in a multiethnic population and aimed to identify the ethnic groups affected by discrepant interpretations.

METHODS

Clinically indicated spirometry in a multiethnic population (aged 20-80 years) collected from 2018 to 2021 was analysed. The predicted and lower limit of normal (LLN) values were calculated using three sets of reference equations: Canadian, GLI-race/ethnic-based (GLI-Race) and GLI-race/ethnic-neutral (GLI-Other). We compared the prevalence of concordance in the abnormal diagnoses (defined as <LLN) for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), and FEV₁/FVC among the three reference values, and evaluated whether race/ethnicity was associated with discordance.

RESULTS

Data from 406 participants were evaluated (non-Caucasian 43.6%). There was 85%-87% concordance for normal/abnormal FVC and FEV₁ interpretations among the Canadian, GLI-Race and GLI-Other reference equations. In all ethnic groups, application of the Canadian references for interpretation led to a higher prevalence of abnormal (<LLN) FVC and FEV₁compared with GLI-Race and GLI-Other. This trend was more prominent in Black, South-East Asian and Mixed/other ethnic groups when comparing the Canadian to the GLI-Race equations. In contrast, the discordance rates were similar among ethnic groups when compared with the GLI-Other reference equations. Interpretation of FEV₁/FVC had a high rate of agreement among all equations.

CONCLUSION

Interpretation using Canadian reference equations was associated with a higher prevalence of restrictive physiology compared with the GLI-2012 equations, particularly if the GLI-Race were used. These observations were mostly found in non-white Caucasian groups, highlighting the need to choose reference equations that reflect closely the ethnic mix of the population being evaluated in order to optimise patient management.

Reference equations for evaluation of spirometry function tests in South Asia, and among South Asians living in other countries

BACKGROUND

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.

METHOD

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.

RESULTS

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.

CONCLUSION

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.

Evaluation of the Global Lung Function Initiative 2012 reference values for spirometry in an Iranian population

Spirometry is an important measurement in detecting and monitoring of chronic obstructive pulmonary disease. The validity of the multi-ethnic Global Lung Function Initiative 2012 (GLI-2012) spirometric norms have been debated in some countries. The aim of the present study was to evaluate the applicability of the GLI reference norms in the Iranian population. A cross-sectional study was performed on 622 healthy non-smoker population (204 males and 418 females, age range: 4 ± 82 years) between July 16 and August 27, 2019 in Iran. Z-scores for spirometric data [FEV₁ (forced expiratory volume in 1 s), FVC (forced vital capacity) FEV₁/FVC, and FEF_25-75% (forced expiratory flow averaged over the middle portion of FVC)] were calculated. According to the agreement approved, a mean Z-score outside the range of ± 0.5 was considered clinically significant. The mean (SD) Z-score values of FEV₁, FVC, FEV₁/FVC and FEF_25-75% were 0.44 (1.21), 0.49 (1.14), 0.11 (1.03), and - 1.13 (0.99) in males and 0.61 (1.14), 0.89 (1.26), 0.17 (0.88) and - 0.49 (0.96) in females, respectively. The Z-score of FEV₁/FVC was below the lower limit of normal (LLN) in 3.43% of men and 2.01% of women (in ≥ 21 years), while these values were significantly higher in people under 21 years old (46.2% in boys and 40.0% in girls). The GLI reference values are not perfect for the Iranian population, especially in children below 10 years old. The use of the GLI reference values was appropriate in population above 21 years; however, they would overestimate the prevalence of airway obstruction in individuals below 21 years.

Growth improvement following antiretroviral therapy initiation in children with perinatally-acquired HIV diagnosed in older childhood in Zimbabwe: a prospective cohort study

BACKGROUND

Children who initiate antiretroviral therapy (ART) before age 5 years can recover height and weight compared to uninfected peers, but growth outcomes are unknown for children initiating ART at older ages. We investigated factors associated with growth failure at ART initiation and modelled growth by age on ART.

METHODS

We conducted secondary analysis of cohort of children aged 6-15 years late-diagnosed with HIV in Harare, Zimbabwe, with entry at ART initiation in 2013-2015. Factors associated with height-for-age (HAZ), weight-for-age (WAZ) and BMI-for-age (BAZ) z-scores <- 2 (stunting, underweight and wasting respectively) at ART initiation were assessed using multivariable logistic regression. These outcomes were compared at ART initiation and 12 month follow-up using paired t-tests. HAZ and BAZ were modelled using restricted cubic splines.

RESULTS

Participants (N = 302; 51.6% female; median age 11 years) were followed for a median of 16.6 months (IQR 11.0-19.8). At ART initiation 34.8% were stunted, 34.5% underweight and 15.1% wasted. Stunting was associated with age ≥ 12 years, CD4 count < 200 cells/μl, tuberculosis (TB) history and history of hospitalisation. Underweight was associated with older age, male sex and TB history, and wasting was associated with older age, TB history and hospitalisation. One year post-initiation, t-tests showed increased WAZ (p = 0.007) and BAZ (p = 0.004), but no evidence of changed HAZ (p = 0.85). Modelling showed that HAZ and BAZ decreased in early adolescence for boys on ART, but not girls.

CONCLUSION

Stunting and underweight were prevalent at ART initiation among late-diagnosed children, and HAZ did not improve after 1 year. Adolescent boys with perinatally acquired HIV and late diagnosis are particularly at risk of growth failure in puberty.

Bronchiectasis in African children: Challenges and barriers to care

Bronchiectasis (BE) is a chronic condition affecting the bronchial tree. It is characterized by the dilatation of large and medium-sized airways, secondary to damage of the underlying bronchial wall structural elements and accompanied by the clinical picture of recurrent or persistent cough. Despite an increased awareness of childhood BE, there is still a paucity of data on the epidemiology, pathophysiological phenotypes, diagnosis, management, and outcomes in Africa where the prevalence is mostly unmeasured, and likely to be higher than high-income countries. Diagnostic pathways and management principles have largely been extrapolated from approaches in adults and children in high-income countries or from data in children with cystic fibrosis. Here we provide an overview of pediatric BE in Africa, highlighting risk factors, diagnostic and management challenges, need for a global approach to addressing key research gaps, and recommendations for practitioners working in Africa.

Age and body mass index affect fit of spirometry GLI references in schoolchildren

Background

References from the Global Lung Function Initiative (GLI) are widely used to interpret children's spirometry results. We assessed fit for healthy schoolchildren.

Methods

LuftiBus in the School was a population-based cross-sectional study undertaken in 2013–2016 in the canton of Zurich, Switzerland. Parents and their children aged 6–17 years answered questionnaires about respiratory symptoms and lifestyle. Children underwent spirometry in a mobile lung function lab. We calculated GLI-based z-scores for forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), FEV₁/FVC and forced expiratory flow for 25–75% of FVC (FEF_25–75) for healthy White participants. We defined appropriate fit to GLI references by mean values between +0.5 and −0.5 z-scores. We assessed whether fit varied by age, body mass index, height and sex using linear regression models.

Results

We analysed data from 2036 children with valid FEV₁ measurements, of whom 1762 also had valid FVC measurements. The median age was 12.2 years. Fit was appropriate for children aged 6–11 years for all indices. In adolescents aged 12–17 years, fit was appropriate for FEV₁/FVC z-scores (mean±sd −0.09±1.02), but not for FEV₁ (−0.62±0.98), FVC (−0.60±0.98) and FEF_25–75 (−0.54±1.02). Mean FEV₁, FVC and FEF_25–75 z-scores fitted better in children considered overweight (−0.25, −0.13 and −0.38, respectively) than normal weight (−0.55, −0.50 and −0.55, respectively; p-trend <0.001, 0.014 and <0.001, respectively). FEV₁, FVC and FEF_25–75 z-scores depended on both age and height (p-interaction 0.033, 0.019 and <0.001, respectively).

Conclusion

GLI-based FEV₁, FVC, and FEF_25–75 z-scores do not fit White Swiss adolescents well. This should be considered when using reference equations for clinical decision-making, research and international comparison.

This study suggests GLI-based FEV₁, FVC and FEF_25–75% z-scores over-detect abnormal lung function in Swiss adolescents, and more so among slimmer adolescents, which has important implications for clinical care, research and international comparisonshttps://bit.ly/3sbGtAS

Spirometry Abnormalities and Its Associated Factors Among Primary School Children in a Nigerian City

BACKGROUND

There is paucity of data on objectively measured lung function abnormalities in Nigerian children using diagnostic testing methods such as spirometry. Such assessments could prompt early diagnosis and therapeutic interventions.

METHODS

This was a cross sectional study among children aged 6 to 12 years in South-Eastern Nigeria. We selected participants from one school using a multistage stratified random sampling technique. A structured respiratory questionnaire was administered to obtain necessary data. The lung functions of the children were measured by spirometry. We used Lower Limits of Normal (LLN) based on GLI reference equations for African-American and mixed ethnicities to define abnormal spirometry. We studied the association between the exposures and lung function using logistic regression/chi-squared tests.

RESULTS

A total of 145 children performed acceptable and repeatable tests. There were 73 males (50.3%), mean age of 9.13 years (+1.5) and age range 6 to 12 years. Frequency of respiratory symptoms was cough- 64 (44.1%) and wheeze in 19 (13.1%). Using GLI for African-Americans, fifty-five (37.9%) children had abnormal spirometryobstructive pattern in 40 (27.6%) and restrictive pattern in 15 (10.3%). The two references showed significant differences in interpretation of abnormality (χ2 = 72.86; P < .001). Respiratory symptom-wheeze was an independent determinant of abnormal lung function in this population.(OR = 0.31; 95%CI: 0.10-0.94; P = .04).

CONCLUSION

There is a high burden of respiratory symptoms and abnormal spirometry among these children. The need for objective evaluation of lung function especially for children with respiratory symptoms is evident.

Prevalence and antimicrobial resistance profiles of respiratory microbial flora in African children with HIV-associated chronic lung disease

BACKGROUND

HIV-associated chronic lung disease (CLD) is common among children living with HIV (CLWH) in sub-Saharan Africa, including those on antiretroviral therapy (ART). However, the pathogenesis of CLD and its possible association with microbial determinants remain poorly understood. We investigated the prevalence, and antibiotic susceptibility of Streptococcus pneumoniae (SP), Staphylococcus aureus (SA), Haemophilus influenzae (HI), and Moraxella catarrhalis (MC) among CLWH (established on ART) who had CLD (CLD+), or not (CLD-) in Zimbabwe and Malawi.

METHODS

Nasopharyngeal swabs (NP) and sputa were collected from CLD+ CLWH (defined as forced-expiratory volume per second z-score < - 1 without reversibility post-bronchodilation with salbutamol), at enrolment as part of a randomised, placebo-controlled trial of azithromycin (BREATHE trial - NCT02426112 ), and from age- and sex-matched CLD- CLWH. Samples were cultured, and antibiotic susceptibility testing was conducted using disk diffusion. Risk factors for bacterial carriage were identified using questionnaires and analysed using multivariate logistic regression.

RESULTS

A total of 410 participants (336 CLD+, 74 CLD-) were enrolled (median age, 15 years [IQR = 13-18]). SP and MC carriage in NP were higher in CLD+ than in CLD- children: 46% (154/336) vs. 26% (19/74), p = 0.008; and 14% (49/336) vs. 3% (2/74), p = 0.012, respectively. SP isolates from the NP of CLD+ children were more likely to be non-susceptible to penicillin than those from CLD- children (36% [53/144] vs 11% [2/18], p = 0.036). Methicillin-resistant SA was uncommon [4% (7/195)]. In multivariate analysis, key factors associated with NP bacterial carriage included having CLD (SP: adjusted odds ratio (aOR) 2 [95% CI 1.1-3.9]), younger age (SP: aOR 3.2 [1.8-5.8]), viral load suppression (SP: aOR 0.6 [0.4-1.0], SA: 0.5 [0.3-0.9]), stunting (SP: aOR 1.6 [1.1-2.6]) and male sex (SA: aOR 1.7 [1.0-2.9]). Sputum bacterial carriage was similar in both groups (50%) and was associated with Zimbabwean site (SP: aOR 3.1 [1.4-7.3], SA: 2.1 [1.1-4.2]), being on ART for a longer period (SP: aOR 0.3 [0.1-0.8]), and hot compared to rainy season (SP: aOR 2.3 [1.2-4.4]).

CONCLUSIONS

CLD+ CLWH were more likely to be colonised by MC and SP, including penicillin-non-susceptible SP strains, than CLD- CLWH. The role of these bacteria in CLD pathogenesis, including the risk of acute exacerbations, should be further studied.

The applicability of the global lung initiative equations and other regional equations on a sample of healthy Middle Eastern adolescents

BACKGROUND

The Global Lung Initiative 2012 (GLI-2012) spirometry equations are multi-ethnic equations that cover all ages between 3 and 95. However, there is a need to evaluate the suitability of these equations to a sample of Middle Eastern adolescents prior to being applied in clinical practice. The aim of this study is to evaluate the suitability of GLI-2012 equations and two regional equations to a sample of Jordanian adolescents.

METHODS

Spirometric measures were collected from 1036 healthy 14 to 17-year-old Jordanian children. z-scores, predicted values, percent predicted values, and frequency of measures below lower limit of normal (LLN) were calculated for each adolescent using the studied equations.

RESULTS

The means of z-scores produced by GLI-2012 equations for Caucasians in forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC% and mid forced expiratory flow (FEF25-75) for boys were 0.12, -0.06, 0.34 and 0.09, respectively, while for girls they were -0.09, -0.16, 0.19 and -0.05, respectively. The mean of z-scores produced by GLI-2012 Other or Mixed equations in FEV1, FVC, FEV1/FVC% and FEF25-75 for boys were 0.74, 072, 021 and 0.33, respectively, and for girls were 0.53, 0.56,0.02 and 0.2, respectively. The frequency of measures below LLN as produced by GLI 2012 for Caucasians were significantly different from the expected 5% in FEV1 and FEF25-75 in boys only, whereas Other or Mixed produced frequencies significantly different from the expected 5% in most of the parameters.

CONCLUSION

Spirometry reference equations formulated for Jordanian adolescents may improve the diagnosis and treatment of asthma in Jordan.