Agreement Between Venous and Capillary Haemoglobin Concentrations in Bangladeshi Children (P10-105-19). (13th June 2019)

• Record Type: Journal Article
• Authors: Larson, Leila; Hasan, Mohammed Imrul; Braat, Sabine; Baldi, Andrew; Alam, Mohammad Saiful; Biggs, Beverley-Ann; Hamadani, Jena; Pasricha, Sant-Rayn
• Is Part Of: Current developments in nutrition. Volume 3(2019)Supplement 1
• Publication Date: 2019-06-13
• Subjects: Nutrition -- Periodicals; Nutritional Physiological Phenomena; Nutrition; Periodicals; Periodicals; Fulltext; Internet Resources; Periodicals; 612.3
• DOI: 10.1093/cdn/nzz034.P10-105-19
• Languages: English
• ISSNs: 2475-2991

Abstract

Abstract: Objectives: There are concerns that capillary haemoglobin (Hb) concentrations do not agree with venous Hb, which has implications for global estimates of anaemia largely derived from capillary Hb. In children enrolled in the Benefits and Risks of Iron Supplementation in Children (BRISC) trial, we examined differences between Hb concentrations collected from venous and capillary blood samples, and predictors of these differences. Methods: Hb concentrations were measured in 3300 children at 8 months of age. Capillary Hb concentrations were measured during screening of children for inclusion in the trial. Venous Hb was measured up to 10 days after screening, during enrolment. All Hb measurements used the HemoCue® 301. In children who received both capillary and venous measurements, Hb means, standard deviations, and anaemia prevalence statistics were derived. Paired t-tests were used to compare means across groups. Pearson's correlation coefficients and a Bland-Altman plot were used to examine agreement between capillary and venous Hb. A kappa coefficient was used to examine agreement in diagnosis of anaemia between the two methods. Lastly, differences in mean venous and capillary Hb concentrations between phlebotomists were calculated using ANOVA. Results: All 3300 children will have completed baseline Hb measurements by February 2019. The current abstract presents preliminary data up to December 2018 for 2485 children. Venous and capillary Hb concentrations were moderately correlated (r = 0.62). Prevalence of anaemia using venous samples was 44.8% and using capillary samples was 69.5%. Accounting for chance, the % agreement (kappa coefficient) between the methods for diagnosis of anaemia was 34.8%. Mean Hb concentrations were significantly higher in venous than capillary samples (mean ± SD: 11.0 ± 1.0 vs 10.4 ± 1.0 g/dL, P < 0.001). This is confirmed in the Bland-Altman plot. No differences in Hb were observed between phlebotomists. Conclusions: Significant differences exist in the diagnosis of anaemia using capillary vs venous samples. Capillary Hb measurements should not be used as a surrogate for venous Hb as they may incorrectly estimate the prevalence of anaemia. Results indicated that global estimates of anaemia based on capillary Hb may be misrepresenting true estimates. Funding Sources: NHMRC.