Interpretation of World Health Organization growth charts for assessing infant malnutrition: A randomised controlled trial

Abstract

Aims:The study aims to assess the effects of switching from National Center for Health Statistics (NCHS) growth references to World Health Organization (WHO) growth standards on health-care workers' decisions about malnutrition in infants aged <6 months. Methods: We conducted a single blind randomised crossover trial involving 78 health-care workers (doctors, clinical officers, health service assistants) in Southern Malawi. Participants were offered hypothetical clinical scenarios with the same infant plotted on NCHS-based weightfor-age charts and again on WHO-based charts. Additional scenarios compared growth charts with a single final weight against charts with the same final weight plus a preceding growth trend. Reported (i) level of concern, (ii) referral suggestions and (iii) feeding advice were elicited with a questionnaire. Results: Even after adjusting for health-care worker type and experience, using WHO rather than NCHS charts increased: (i) concern: aOR 4.4 (95% CI 2.4-8.1); (ii) odds of referral: aOR 5.1 (95% CI 2.4-10.8); and (iii) odds of feeding advice which would interrupt exclusive breastfeeding (aOR 2.4, 95% CI 1.2-4.9). A preceding steady growth trend line did not affect concern, referral or feeding advice. Conclusions: Health-care workers take insufficient account of linear growth trend, clinical and feeding status when interpreting a low weight-for-age plot. Because more infants <6 months fall below low centile lines on WHO growth charts, their use may increase inappropriate referrals and risks undermining already low rates of exclusive breastfeeding. To avoid their being misinterpreted in this way, WHO charts need accompanying guidelines and training materials that recognise and address this possible adverse effect.

Chronic Malnutrition

“…• This also challenges some prior assumptions that, since the WHO-GS were based on breastfed infants, they "will result in fewer breastfed babies diagnosed as growing poorly" [10,11]. • Figures for edematous malnutrition are not available.…”

“…Weight-for-length <-3 z-scores and/or nutritional edema (kwashiorkor) contrasts with the situation for older children, for whom a sensitive (rather than specific) case definition is perfectly acceptable, since the risks of a short period of top-up therapeutic or supplementary food are minimal, hence the benefit-risk balance of intervention is favorable [11].…”

Health staff understanding, application, and interpretation of growth charts in Nigeria

“…Thus the RTH chart will always tend to offer false reassurance about small 291 infants. The WHO chart was much more likely to lead to correct recognition of slow weight 292 gain, but also, in small children more likely to lead to the mislabelling of children with 293 healthy weight gain, as was seen in the paper describe earlier (Ahmad et al, 2014). However, 294 even for small, weight-faltering infants plotted on the WHO chart, less than half of the 295 respondents recognised the need for closer monitoring or referral.…”

“…There will be a 309 need to identify less obvious cases, such as a child dropping through the normal range, but 310 not yet below it and in small but healthy children, misinterpretation of growth patterns in 311 children below 6 months can increase inappropriate referrals and risk of offering feeding 312 advice that could interrupt exclusive breastfeeding. (Ahmad et al, 2014). 313…”

“…While detecting true undernutrition is important, 120 misinterpretation of normal growth patterns as abnormal in children below 6 months also 121 risk as it can interfere with exclusive breastfeeding (Ahmad et al, 2014 …”