Showing papers by "Angela Wade published in 2016"
TL;DR: Use of equipment-specific prediction equations for RVRTC outcomes will enhance interpretation of infant lung function results; particularly during longitudinal follow-up.
Abstract: The raised volume rapid thoracoabdominal compression (RVRTC) technique is commonly used to obtain full forced expiratory manoeuvres from infants, but reference equations derived from ‘in-house’ equipment have been shown to be inappropriate for current commercially available devices. Aim To explore the impact of equipment differences on RVRTC outcomes, derive robust equipment-specific RVRTC reference ranges and investigate their potential clinical impact on data interpretation. Method RVRTC data from healthy subjects using Jaeger BabyBody or the ‘Respiratory Analysis Software Program, RASP’ systems were collated from four centres internationally. Data were excluded if gestational age Results RVRTC data from 429 healthy infants (50.3% boys; 88% white infants) on 639 occasions aged 4–118 weeks were available. When plotted against length, flows were significantly higher with RASP than Jaeger, requiring construction of separate equipment-specific regression equations. When comparing results derived from the new equations with those from widely used published equations based on different equipments, discrepancies in forced expiratory volumes and flows of up to 2.5 z-scores were observed, the magnitude of which increased with age. According to published equations, 25% of infants with CF fell below the 95% limits of normal for FEV 0.5 , compared with only 10% when using the new equations. Conclusions Use of equipment-specific prediction equations for RVRTC outcomes will enhance interpretation of infant lung function results; particularly during longitudinal follow-up.
31 citations
TL;DR: Until improved and more robust prediction equations can be derived, it is recommended the use of ‘ GLI-Black’ equations for interpreting most South-Asian data, although ‘GLI-Other’ may be more appropriate for North Indian data.
Abstract: METHODS: Spirometry datasets from South-Asian children were collated from four centres in India and five within the UK. Records with transcription errors, missing values for height or spirometry, and implausible values were excluded(n = 110).RESULTS: Following exclusions, cross-sectional data were available from 8,124 children (56.3% male; 5-17 years). When compared with GLI-predicted values from White Europeans, forced expired volume in 1s (FEV1) and forced vital capacity (FVC) in South-Asian children were on average 15% lower, ranging from 4-19% between centres. By contrast, proportional reductions in FEV1 and FVC within all but two datasets meant that the FEV1/FVC ratio remained independent of ethnicity. The 'GLI-Other' equation fitted data from North India reasonably well while 'GLI-Black' equations provided a better approximation for South-Asian data than the 'GLI-White' equation. However, marked discrepancies in the mean lung function z-scores between centres especially when examined according to socio-economic conditions precluded derivation of a single South-Asian GLI-adjustment.CONCLUSION: Until improved and more robust prediction equations can be derived, we recommend the use of 'GLI-Black' equations for interpreting most South-Asian data, although 'GLI-Other' may be more appropriate for North Indian data. Prospective data collection using standardised protocols to explore potential sources of variation due to socio-economic circumstances, secular changes in growth/predictors of lung function and ethnicities within the South-Asian classification are urgently required.
15 citations