Anaemia in Indians aged 10-19 years: Prevalence, burden and associated factors at national and regional levels

Abstract

Anaemia control programmes in India are hampered by a lack of representative evidence on anaemia prevalence, burden and associated factors for adolescents. The aim of this study was to: (1) describe the national and subnational prevalence, severity and burden of anaemia among Indian adolescents; (2) examine factors associated with anaemia at national and regional levels. Data (n = 14,673 individuals aged 10-19 years) were from India's Comprehensive National Nutrition Survey (CNNS, 2016-2018). CNNS used a multistage, stratified, probability proportion to size cluster sampling design. Prevalence was estimated using globally comparable age- and sex-specific cutoffs, using survey weights for biomarker sample collection. Burden analysis used prevalence estimates and projected population from 2011 Census data. Multivariable logistic regression models were used to analyse factors (diet, micronutrient deficiencies, haemoglobinopathies, sociodemographic factors, environment) associated with anaemia. Anaemia was present in 40% of girls and 18% of boys, equivalent to 72 million adolescents in 2018, and varied by region (girls 29%-46%; boys 11%-28%) and state (girls 7%-62%; boys 4%-32%). Iron deficiency (ferritin < 15 μg/L) was the strongest predictor of anaemia (odds ratio [OR]: 4.68, 95% confidence interval [CI]: [3.21,6.83]), followed by haemoglobinopathies (HbA2 > 3.5% or any HbS) (OR: 2.81, 95% CI: [1.66,4.74]), vitamin A deficiency (serum retinol <20 ng/ml) (OR: 1.86, 95% CI: [1.23,2.80]) and zinc deficiency (serum zinc < 70 μg/L) (OR: 1.32, 95% CI: [1.02,1.72]). Regional models show heterogeneity in the strength of association between factors and anaemia by region. Adolescent anaemia control programmes in India should continue to address iron deficiency, strengthen strategies to identify haemoglobinopathies and other micronutrient deficiencies, and further explore geographic variation in associated factors.

Keywords: India; adolescent; anaemia; micronutrients; public health.

Figure 1

Sample flow diagram. CNNS, Comprehensive National Nutrition Survey; CRP, C‐reactive protein.

Figure 2

Conceptual framework for factors associated with anaemia in adolescents. Boxes with a solid outline are factors included in the regression analysis and boxes with a grey dotted outline are factors not included. Data on food security were collected in the Comprehensive National Nutrition Survey, but were not publicly available at the time of writing. WASH, water sanitation and hygiene.

Figure 3

Prevalence and severity of anaemia among Indian adolescents, 2016–2018. Panel (a) shows prevalence at the national level by age group and sex. Panel (b) shows prevalence for all ages (10–19 years) by region and sex. The ‘Any anaemia’ column to the right of each panel shows the total prevalence of anaemia (severity categories combined). Severity categories are defined according to standard age‐ and gender‐specific World Health Organization cutoffs: 10–11 years: <11.5 g/dl (mild: 11.0–11.4; moderate: 8.0–10.9; severe: <8.0); 12–14 years: <12 g/dl (mild: 11.0–11.9; moderate: 8.0–10.9; severe: <8.0); 15–19 years males: <13 g/dl (mild: 11.0–12.9; moderate: 8.0–10.9; severe: <8.0]; 15–19 years females: <12 g/dl (mild: 11.0–11.9; moderate: 8.0–10.9; severe: <8.0). See Supporting Information: Table S2 for states included within each region.

Figure 4

Prevalence and burden of anaemia among Indian adolescent girls and boys aged 10–19 years by state, 2016–2018. Prevalence categories are defined according to WHO public‐health significance cut‐offs (see Supporting Information: Table S1). Burden numbers are in thousands (a) Girls aged 10–19 years, % anaemic, (b) girls aged 10–19 years, number anaemic (thousands), (c) boys aged 10–19 years, % anaemic and (d) boys aged 10–19 years, number anaemic (thousands).