Challenges in Collating Spirometry Reference Data for South-Asian Children: An Observational Study.

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.

Inverse and symmetrical voice: On languages with two transitive constructions

In voice and alignment typology, a categorical distinction is generally made between inverse systems on the one hand and symmetrical voice systems on the other. A major reason for distinguishing between these two types is the assumption that inverse systems are governed by a hierarchy involving grammatical, semantic, and ontological criteria, while symmetrical voice systems are based on discourse-pragmatic factors. However, the two types also have several important properties in common, in particular the fact that they have more than one nonderived transitive construction. Based on data from three native languages of South America, we show that the line between the two types is not always easy to draw, and that features of the inverse type can coexist with those of the symmetrical-voice type in the same language.