A method to develop vocabulary checklists in new languages and their validity to assess early language development

Neurocognitive outcomes in Malawian children exposed to malaria during pregnancy: An observational birth cohort study

BACKGROUND

Annually 125 million pregnancies are at risk of malaria infection. However, the impact of exposure to malaria in pregnancy on neurodevelopment in children is not well understood. We hypothesized that malaria in pregnancy and associated maternal immune activation result in neurodevelopmental delay in exposed offspring.

METHODS AND FINDINGS

Between April 2014 and April 2015, we followed 421 Malawian mother-baby dyads (median [IQR] maternal age: 21 [19, 28] years) who were previously enrolled (median [IQR] gestational age at enrollment: 19.7 [17.9, 22.1] weeks) in a randomized controlled malaria prevention trial with 5 or 6 scheduled assessments of antenatal malaria infection by PCR. Children were evaluated at 12, 18, and/or 24 months of age with cognitive tests previously validated in Malawi: the Malawi Developmental Assessment Tool (MDAT) and the MacArthur-Bates Communicative Development Inventories (MCAB-CDI). We assessed the impact of antenatal malaria (n [%] positive: 240 [57.3]), placental malaria (n [%] positive: 112 [29.6]), and maternal immune activation on neurocognitive development in children. Linear mixed-effects analysis showed that children exposed to antenatal malaria between 33 and 37 weeks gestation had delayed language development across the 2-year follow-up, as measured by MCAB-CDI (adjusted beta estimate [95% CI], -7.53 [-13.04, -2.02], p = 0.008). Maternal immune activation, characterized by increased maternal sTNFRII concentration, between 33 and 37 weeks was associated with lower MCAB-CDI language score (adjusted beta estimate [95% CI], -8.57 [-13.09, -4.06], p < 0.001). Main limitations of this study include a relatively short length of follow-up and a potential for residual confounding that is characteristic of observational studies.

CONCLUSIONS

This mother-baby cohort presents evidence of a relationship between malaria in pregnancy and neurodevelopmental delay in offspring. Malaria in pregnancy may be a modifiable risk factor for neurodevelopmental injury independent of birth weight or prematurity. Successful interventions to prevent malaria during pregnancy may reduce the risk of neurocognitive delay in children.

Early child development in children who are HIV-exposed uninfected compared to children who are HIV-unexposed: observational sub-study of a cluster-randomized trial in rural Zimbabwe

INTRODUCTION

Exposure to maternal HIV may affect early child development (ECD), although previous studies have reported heterogeneous findings. We evaluated ECD among children who were HIV-exposed uninfected (CHEU) and children who were HIV-unexposed (CHU) recruited to the SHINE trial in rural Zimbabwe.

METHODS

SHINE was a community-based cluster-randomized trial of improved infant feeding and/or improved water, sanitation and hygiene. Pregnant women were enrolled between 2012 and 2015. We assessed ECD in a sub-study at 24 months of age, between 2016 and 2017, using the Malawi Developmental Assessment Tool (MDAT; assessing motor, cognitive, language and social development); MacArthur-Bates Communicative Development Inventory (CDI) (assessing vocabulary and grammar); A-not-B test (assessing object permanence); and a self-control task. Mothers and infants were tested longitudinally for HIV. We used generalized estimating equations to compare ECD scores between CHEU and CHU, accounting for the cluster-randomized design. Primary results were adjusted for trial-related factors that could affect measurement reliability of ECD: study nurse, age of child, calendar month of birth, sex and randomized arm.

RESULTS

A total of 205 CHEU and 1175 CHU were evaluated. Mean total MDAT score was 90.6 (SD 8.7) in CHEU compared to 92.4 (9.1) in CHU (adjusted mean difference -1.3, 95% CI: -2.3, -0.3), driven mostly by differences in gross motor (-0.5, 95% CI: -0.9, -0.2) and language scores (-0.6, 95% CI: -1.1, -0.1). There was evidence that fine motor scores were lower in CHEU (adjusted mean difference -0.4, 95% CI: -0.8, 0.0) but no evidence of a difference in social scores (0.1, 95% CI: -0.2, 0.4). Mean MacArthur-Bates CDI vocabulary score was 57.9 (SD 19.2) in CHEU compared to 61.3 (18.8) in CHU (adjusted mean difference -2.9 words, 95% CI: -5.7, -0.1). Object permanence and self-control scores were similar between groups.

CONCLUSIONS

CHEU in rural Zimbabwe had total child development and vocabulary scores that were approximately 0.15 standard deviations lower than CHU at two years of age. More detailed and specific studies are now needed to unravel the reasons for developmental delay in CHEU and the likelihood that these delays persist in the longer term.

Development and evaluation of the Ingwavuma receptive vocabulary test: A tool for assessing receptive vocabulary in isiZulu-speaking preschool children

BACKGROUND

This study used local resources- community members, photographer and speech therapists to develop a new test for screening receptive language skills and sought to determine its feasibility for use with a larger population in KwaZulu-Natal province, South Africa.

OBJECTIVES

The aim of this study was to develop a one-word receptive vocabulary test appropriate for screening and diagnosis of isiZulu-speaking preschool-aged children. The objectives were (1) to determine sensitivity and specificity of the Ingwavuma Receptive Vocabulary Test (IRVT) and (2) to determine the relationship of IRVT scores with age, gender, time and the confounding variables of stunting and school.

METHOD

The study was quantitative, cross-sectional and descriptive in nature. The IRVT was piloted before being administered to 51 children (4-6 years old). Statistical analysis of test item prevalence, correlations to confounding variables and validity measurements were conducted using Statistical Package for Social Scientists version 25 (SPSS 25).

RESULTS

The IRVT was able to profile the receptive skills for the preschool children in Ingwavuma. The mean raw score for boys was 35, and 32 for girls. There was a significant Pearson correlation between test scores and age (0.028, p 0.05) with a high effect size (Cohen's d = 0. 949), gender (r = -0.032, p 0.05) with a medium effect size (Cohen's d = 0.521) and school (r = 0.033, p 0.05) with a small effect size (Cohen's d = 0.353). The sensitivity and specificity values were 66.7% and 33%, respectively. The test reliability (Cronbach's alpha) was 0.739, with a good test-retest reliability.

CONCLUSION

The IRVT has potential as a screening test for isiZulu receptive vocabulary skills amongst preschool children. This study contributes to a development of clinical and research resources for assessing language abilities.

Lexical Diversity in Cypriot-Greek-Speaking Toddlers: A Preliminary Longitudinal Study

BACKGROUND/AIMS

The number of different words (NDW), an essential measure of lexical diversity, is extremely valuable towards providing data regarding children's language development. However, in Cyprus, practitioners are deprived of the opportunity to utilize NDW, as no normative data exist for toddlers who speak Cypriot Greek (CYG).

METHODS

The language samples of 36 monolingual CYG-speaking toddlers (aged 36, 40, 44, and 48 months) with a typical course of language development were collected and quantitatively analyzed. Based on the language sample analysis, we ascertained typical NDW values at the aforementioned ages and tested through a linear mixed-effects model whether gender and age affected NDW.

RESULTS

The results showed that age significantly predicted NDW increase; gender did not emerge as a significant predictor of NDW, but this may be due to the small statistical power.

CONCLUSION

This study intends to provide the first step towards longitudinal investigation of the level of NDW for CYG-speaking children with a typical course of language development. The provided data, which could serve as preliminary norms, may be used - under some restrictions for the time being - during language assessment. Moreover, these acquired data could contribute to the development of an NDW database for diverse CYG-speaking populations of different age ranges in the future.

Effects of improved complementary feeding and improved water, sanitation and hygiene on early child development among HIV-exposed children: substudy of a cluster randomised trial in rural Zimbabwe

Introduction

HIV-exposed uninfected children may be at risk of poor neurodevelopment. We aimed to test the impact of improved infant and young child feeding (IYCF) and improved water, sanitation and hygiene (WASH) on early child development (ECD) outcomes.

Methods

Sanitation Hygiene Infant Nutrition Efficacy was a cluster randomised 2×2 factorial trial in rural Zimbabwe ClinicalTrials.gov NCT01824940). Pregnant women were eligible if they lived in study clusters allocated to standard-of-care (SOC; 52 clusters); IYCF (20 g small-quantity lipid-based nutrient supplement/day from 6 to 18 months, complementary feeding counselling; 53 clusters); WASH (pit latrine, 2 hand-washing stations, liquid soap, chlorine, play space, hygiene counselling; 53 clusters) or IYCF +WASH (53 clusters). Participants and fieldworkers were not blinded. ECD was assessed at 24 months using the Malawi Developmental Assessment Tool (MDAT; assessing motor, cognitive, language and social skills); MacArthur Bates Communication Development Inventory (assessing vocabulary and grammar); A-not-B test (assessing object permanence) and a self-control task. Intention-to-treat analyses were stratified by maternal HIV status.

Results

Compared with SOC, children randomised to combined IYCF +WASH had higher total MDAT scores (mean difference +4.6; 95% CI 1.9 to 7.2) and MacArthur Bates vocabulary scores (+8.5 words; 95% CI 3.7 to 13.3), but there was no evidence of effects from IYCF or WASH alone. There was no evidence that that any intervention impacted object permanence or self-control.

Conclusions

Combining IYCF and WASH interventions significantly improved motor, language and cognitive development in HIV-exposed children.

Trial registration number

NCT01824940.

Multilingual assessment of early child development: Analyses from repeated observations of children in Kenya

In many low‐ and middle‐income countries, young children learn a mother tongue or indigenous language at home before entering the formal education system where they will need to understand and speak a country's official language(s). Thus, assessments of children before school age, conducted in a nation's official language, may not fully reflect a child's development, underscoring the importance of test translation and adaptation. To examine differences in vocabulary development by language of assessment, we adapted and validated instruments to measure developmental outcomes, including expressive and receptive vocabulary. We assessed 505 2‐to‐6‐year‐old children in rural communities in Western Kenya with comparable vocabulary tests in three languages: Luo (the local language or mother tongue), Swahili, and English (official languages) at two time points, 5–6 weeks apart, between September 2015 and October 2016. Younger children responded to the expressive vocabulary measure exclusively in Luo (44%–59% of 2‐to‐4‐year‐olds) much more frequently than did older children (20%–21% of 5‐to‐6‐year‐olds). Baseline receptive vocabulary scores in Luo (β = 0.26, SE = 0.05, p < 0.001) and Swahili (β = 0.10, SE = 0.05, p = 0.032) were strongly associated with receptive vocabulary in English at follow‐up, even after controlling for English vocabulary at baseline. Parental Luo literacy at baseline (β = 0.11, SE = 0.05, p = 0.045) was associated with child English vocabulary at follow‐up, while parental English literacy at baseline was not. Our findings suggest that multilingual testing is essential to understanding the developmental environment and cognitive growth of multilingual children.

Independent and combined effects of improved water, sanitation, and hygiene (WASH) and improved complementary feeding on early neurodevelopment among children born to HIV-negative mothers in rural Zimbabwe: Substudy of a cluster-randomized trial

BACKGROUND

Globally, nearly 250 million children (43% of all children under 5 years of age) are at risk of compromised neurodevelopment due to poverty, stunting, and lack of stimulation. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH) and improved infant and young child feeding (IYCF) on early child development (ECD) among children enrolled in the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial in rural Zimbabwe.

METHODS AND FINDINGS

SHINE was a cluster-randomized community-based 2×2 factorial trial. A total of 5,280 pregnant women were enrolled from 211 clusters (defined as the catchment area of 1-4 village health workers [VHWs] employed by the Zimbabwean Ministry of Health and Child Care). Clusters were randomly allocated to standard of care, IYCF (20 g of small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counseling), WASH (ventilated improved pit latrine, handwashing stations, chlorine, liquid soap, and play yard), and WASH + IYCF. Primary outcomes were child length-for-age Z-score and hemoglobin concentration at 18 months of age. Children who completed the 18-month visit and turned 2 years (102-112 weeks) between March 1, 2016, and April 30, 2017, were eligible for the ECD substudy. We prespecified that primary inferences would be drawn from findings of children born to HIV-negative mothers; these results are presented in this paper. A total of 1,655 HIV-unexposed children (64% of those eligible) were recruited into the ECD substudy from 206 clusters and evaluated for ECD at 2 years of age using the Malawi Developmental Assessment Tool (MDAT) to assess gross motor, fine motor, language, and social skills; the MacArthur-Bates Communicative Development Inventories (CDI) to assess vocabulary and grammar; the A-not-B test to assess object permanence; and a self-control task. Outcomes were analyzed in the intention-to-treat population. For all ECD outcomes, there was not a statistical interaction between the IYCF and WASH interventions, so we estimated the effects of the interventions by comparing the 2 IYCF groups with the 2 non-IYCF groups and the 2 WASH groups with the 2 non-WASH groups. The mean (95% CI) total MDAT score was modestly higher in the IYCF groups compared to the non-IYCF groups in unadjusted analysis: 1.35 (0.24, 2.46; p = 0.017); this difference did not persist in adjusted analysis: 0.79 (-0.22, 1.68; p = 0.057). There was no evidence of impact of the IYCF intervention on the CDI, A-not-B, or self-control tests. Among children in the WASH groups compared to those in the non-WASH groups, mean scores were not different for the MDAT, A-not-B, or self-control tests; mean CDI score was not different in unadjusted analysis (0.99 [95% CI -1.18, 3.17]) but was higher in children in the WASH groups in adjusted analysis (1.81 [0.01, 3.61]). The main limitation of the study was the specific time window for substudy recruitment, meaning not all children from the main trial were enrolled.

CONCLUSIONS

We found little evidence that the IYCF and WASH interventions implemented in SHINE caused clinically important improvements in child development at 2 years of age. Interventions that directly target neurodevelopment (e.g., early stimulation) or that more comprehensively address the multifactorial nature of neurodevelopment may be required to support healthy development of vulnerable children.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01824940.