Introduction: LCI is an assessment of ventilation inhomogeneity with potential as a sensitive measure in a range of lung disease. This study reports normative data from subjects of different ethnic groups using a commercial device (ndd EasyOne Pro LAB)

Method: Healthy children, aged 6-12 years, were recruited to perform LCI;, all were naïve to lung function testing. LCI was performed as per recommended guidance using nitrogen multiple breath washout. Subject demographics were recorded, including self-reported ethnicity prompted by the United Kingdom Office for National Statistic ethnicity groupings and Index of Multiple Deprivation (IMD)

Results: 72 children were recruited, 35 (48.6%) White, 2 (2.8%) Black African, 5 (6.9%) from Mixed ethnic groups, 27 (37.5%) Asian, 3 (4.2%) Arab. Children were recruited from a range of socioeconomic backgrounds (mean IMD Decile 5.1, with 25% recruited from the lowest national IMD decile).  Mean LCI was 7.19 (0.6 SD), calculated upper limit of normal (ULN, mean+1.96*SD) was 8.36. The largest groups for comparison were White British, (WB 34, 47.2%) and Indian Subcontinent (IS, identifying as Indian, Pakistani or Bangladeshi) 26 (36.1%); there was no significant difference in LCI between these groups (7.04 (0.64 SD) vs 7.2 (0.55 SD) respectively, p=0.3). ULN for the groups were 8.29 and 8.28 respectively

Conclusion: We report normative data from a healthy cohort of WB and IS children. No difference in LCI was found between these groups.  Recruitment of subjects from a range of ethnic and socioeconomic backgrounds is important in the conduct of high quality research