The Benefits and Risks of Iron interventionS in Children (BRISC) trial: Statistical analysis plan

Effects of iron supplements and iron-containing micronutrient powders on the gut microbiome in Bangladeshi infants: a randomized controlled trial

Anemia is highly prevalent globally, especially in young children in low-income countries, where it often overlaps with a high burden of diarrheal disease. Distribution of iron interventions (as supplements or iron-containing multiple micronutrient powders, MNPs) is a key anemia reduction strategy. Small studies in Africa indicate iron may reprofile the gut microbiome towards pathogenic species. We seek to evaluate the safety of iron and MNPs based on their effects on diversity, composition, and function of the gut microbiome in children in rural Bangladesh as part of a large placebo-controlled randomized controlled trial of iron or MNPs given for 3 months (ACTRN12617000660381). In 923 infants, we evaluate the microbiome before, immediately following, and nine months after interventions, using 16S rRNA gene sequencing and shotgun metagenomics in a subset. We identify no increase in diarrhea with either treatment. In our primary analysis, neither iron nor MNPs alter gut microbiome diversity or composition. However, when not adjusting for multiple comparisons, compared to placebo, children receiving iron and MNPs exhibit reductions in commensal species (e.g., Bifidobacterium, Lactobacillus) and increases in potential pathogens, including Clostridium. These increases are most evident in children with baseline iron repletion and are further supported by trend-based statistical analyses.

Supplementation With Iron Syrup or Iron-Containing Multiple Micronutrient Powders Alters Resting Brain Activity in Bangladeshi Children

BACKGROUND

Anemia and iron deficiency have been associated with poor child cognitive development. A key rationale for the prevention of anemia using supplementation with iron has been the benefits to neurodevelopment. However, little causal evidence exists for these gains.

OBJECTIVES

We aimed to examine effects of supplementation with iron or multiple micronutrient powders (MNPs) on brain activity measures using resting electroencephalography (EEG).

METHODS

Children included in this neurocognitive substudy were randomly selected from the Benefits and Risks of Iron Supplementation in Children study, a double-blind, double-dummy, individually randomized, parallel-group trial in Bangladesh, in which children, starting at 8 mo of age, received 3 mo of daily iron syrup, MNPs, or placebo. Resting brain activity was recorded using EEG immediately after intervention (month 3) and after a further 9-month follow-up (month 12). We derived EEG band power measures for delta, theta, alpha, and beta frequency bands. Linear regression models were used to compare the effect of each intervention with that of placebo on the outcomes.

RESULTS

Data from 412 children at month 3 and 374 at month 12 were analyzed. At baseline, 43.9% were anemic and 26.7% were iron deficient. Immediately after intervention, iron syrup, but not MNPs, increased the mu alpha-band power, a measure that is associated with maturity and the production of motor actions (iron vs. placebo: mean difference = 0.30; 95% CI: 0.11, 0.50 μV²; P = 0.003; false discovery rate adjusted P = 0.015). Despite effects on hemoglobin and iron status, effects were not observed on the posterior alpha, beta, delta, and theta bands, nor were effects sustained at the 9-month follow-up.

CONCLUSIONS

The effect size for immediate effects on the mu alpha-band power is comparable in magnitude with psychosocial stimulation interventions and poverty reduction strategies. However, overall, we did not find evidence for long-lasting changes in resting EEG power spectra from iron interventions in young Bangladeshi children. This trial was registered at www.anzctr.org.au as ACTRN12617000660381.

Effects of iron supplementation on neural indices of habituation in Bangladeshi children

BACKGROUND

Iron deficiency and anemia have been associated with poor cognition in children, yet the effects of iron supplementation on neurocognition remain unclear.

OBJECTIVE

We aimed to examine the effects of supplementation with iron on neural indices of habituation using auditory event-related brain potentials (ERPs).

METHODS

This substudy was nested within a 3-arm, double-blind, double-dummy, individual randomized trial in Bangladesh, in which 3300 8-mo-old children were randomly selected to receive 3 mo of daily iron syrup (12.5 mg iron), multiple micronutrient powders (MNPs) (including 12.5 mg iron), or placebo. Children were assessed after 3 mo of intervention (mo 3) and 9 mo thereafter (mo 12). The neurocognitive substudy comprised a randomly selected subset of children from the main trial. Brain activity elicited during an auditory roving oddball task was recorded using electroencephalography to provide an index of habituation. The differential response to a novel (deviant) compared with a repeated (standard) sound was examined. The primary outcome was the amplitude of the mismatch response (deviant minusstandard tone waveforms) at mo 3. Secondary outcomes included the deviant and standard tone-evoked amplitudes, N2 amplitude differences, and differences in mean amplitudes evoked by deviant tones presented in the second compared with first half of the oddball sequence at mo 3 and 12.

RESULTS

Data were analyzed from 329 children at month 3 and 363 at mo 12. Analyses indicated no treatment effects of iron interventions compared with placebo on the amplitude of the mismatch response (iron syrup compared with placebo: mean difference (MD) = 0.07μV [95% CI: -1.22, 1.37]; MNPs compared with placebo: MD = 0.58μV [95% CI: -0.74, 1.90]) nor any secondary ERP outcomes at mo 3 or 12, despite improvements in hemoglobin and ferritin concentrations from iron syrup and MNPs in this nested substudy.

CONCLUSION

In Bangladeshi children with >40% anemia prevalence, iron or MNP interventions alone are insufficient to improve neural indices of habituation. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12617000660381.

Cost-effectiveness of universal iron supplementation and iron-containing micronutrient powders for anemia among young children in rural Bangladesh: analysis of a randomized, placebo-controlled trial

BACKGROUND

Universal provision of iron supplements or iron-containing multiple micronutrient powders (MNPs) is widely used to prevent anemia in young children in low- and middle-income countries. The BRISC (Benefits and Risks of Iron Interventions in Children) trial compared iron supplements and MNPs with placebo in children <2 y old in rural Bangladesh.

OBJECTIVES

We aimed to assess the cost-effectiveness of iron supplements or iron-containing MNPs among young children in rural Bangladesh.

METHODS

We did a cost-effectiveness analysis of MNPs and iron supplements using the BRISC trial outcomes and resource use data, and programmatic data from the literature. Health care costs were assessed from a health system perspective. We calculated incremental cost-effectiveness ratios (ICERs) in terms of US$ per disability-adjusted life-year (DALY) averted. To explore uncertainty, we constructed cost-effectiveness acceptability curves using bootstrapped data over a range of cost-effectiveness thresholds. One- and 2-way sensitivity analyses tested the impact of varying key parameter values on our results.

RESULTS

Provision of MNPs was estimated to avert 0.0031 (95% CI: 0.0022, 0.0041) DALYs/child, whereas iron supplements averted 0.0039 (95% CI: 0.0030, 0.0048) DALYs/child, over 1 y compared with no intervention. Incremental mean costs were $0.75 (95% CI: 0.73, 0.77) for MNPs compared with no intervention and $0.64 ($0.62, $0.67) for iron supplements compared with no intervention. Iron supplementation dominated MNPs because it was cheaper and averted more DALYs. Iron supplementation had an ICER of $1645 ($1333, $2153) per DALY averted compared with no intervention, and had a 0% probability of being the optimal strategy at cost-effectiveness thresholds of $200 (reflecting health opportunity costs in Bangladesh) and $985 [half of gross domestic product (GDP) per capita] per DALY averted. Scenario and sensitivity analyses supported the base case findings.

CONCLUSIONS

These findings do not support universal iron supplementation or micronutrient powders as a cost-effective intervention for young children in rural Bangladesh.This trial was registered at anzctr.org.au as ACTRN1261700066038 and trialsearch.who.int as U1111-1196-1125.

Benefits and Risks of Iron Interventions in Infants in Rural Bangladesh

BACKGROUND

Universal provision of iron supplements (drops or syrup) or multiple micronutrient powders to young children in low-to-middle-income countries where anemia is prevalent is recommended by the World Health Organization and widely implemented. The functional benefits and safety of these interventions are unclear.

METHODS

We conducted a three-group, double-blind, double-dummy, individually randomized, placebo-controlled trial to assess the immediate and medium-term benefits and risks of 3 months of daily supplementation with iron syrup or iron-containing multiple micronutrient powders, as compared with placebo, in 8-month-old children in rural Bangladesh. The primary outcome was cognitive development, as assessed by the cognitive composite score on the Bayley Scales of Infant and Toddler Development, third edition, immediately after completion of the assigned 3-month regimen; scores range from 55 to 145, with higher scores indicating better cognitive performance. Secondary outcomes included the cognitive composite score at 9 months after completion of the assigned regimen; behavioral, language, and motor development, as well as growth and hematologic markers, immediately after completion and at 9 months after completion; and safety.

RESULTS

We randomly assigned 3300 infants to receive iron syrup (1101 infants), multiple micronutrient powders (1099), or placebo (1100) daily. After completion of the assigned 3-month regimen, no apparent effect on the cognitive composite score was observed with iron syrup as compared with placebo (mean between-group difference in change in score from baseline, -0.30 points; 95% confidence interval [CI], -1.08 to 0.48) or with multiple micronutrient powders as compared with placebo (mean between-group difference in change in score from baseline, 0.23 points; 95% CI, -0.55 to 1.00). No apparent effect on any other developmental or growth outcome was observed immediately after completion of the assigned regimen or at 9 months after completion. At 9 months after completion of the assigned regimen, the prevalences of anemia, iron deficiency, and iron deficiency anemia increased in all three trial groups but remained lower among the children who received iron syrup or multiple micronutrient powders than among those who received placebo. The risk of serious adverse events and incidence of symptoms of infection were similar in the three trial groups.

CONCLUSIONS

In this trial involving infants in Bangladesh, 3 months of daily supplementation with iron syrup or multiple micronutrient powders did not appear to have an effect on child development or other functional outcomes as compared with placebo. (Funded by the National Health and Medical Research Council of Australia; BRISC Australian New Zealand Clinical Trials Registry number, ACTRN12617000660381.).

Immediate impact of stay-at-home orders to control COVID-19 transmission on socioeconomic conditions, food insecurity, mental health, and intimate partner violence in Bangladeshi women and their families: an interrupted time series

BACKGROUND

Stay-at-home orders (lockdowns) have been deployed globally to control COVID-19 transmission, and might impair economic conditions and mental health, and exacerbate risk of food insecurity and intimate partner violence. The effect of lockdowns in low-income and middle-income countries must be understood to ensure safe deployment of these interventions in less affluent settings. We aimed to determine the immediate impact of COVID-19 lockdown orders on women and their families in rural Bangladesh.

METHODS

An interrupted time series was used to compare data collected from families in Rupganj upazila, rural Bangladesh (randomly selected from participants in a randomised controlled trial), on income, food security, and mental health a median of 1 year and 2 years before the COVID-19 pandemic to data collected during the lockdown. We also assessed women's experiences of intimate partner violence during the pandemic.

RESULTS

Between May 19 and June 18, 2020, we randomly selected and invited the mothers of 3016 children to participate in the study, 2424 of whom provided consent. 2414 (99·9%, 95% CI 99·6-99·9) of 2417 mothers were aware of, and adhering to, the stay-at-home advice. 2321 (96·0%, 95·2-96·7) of 2417 mothers reported a reduction in paid work for the family. Median monthly family income fell from US$212 at baseline to $59 during lockdown, and the proportion of families earning less than $1·90 per day rose from five (0·2%, 0·0-0·5) of 2422 to 992 (47·3%, 45·2-49·5) of 2096 (p<0·0001 comparing baseline with lockdown period). Before the pandemic, 136 (5·6%, 4·7-6·6) of 2420 and 65 (2·7%, 2·1-3·4) of 2420 families experienced moderate and severe food insecurity, respectively. This increased to 881 (36·5%, 34·5-38·4) of 2417 and 371 (15·3%, 13·9-16·8) of 2417 during the lockdown; the number of families experiencing any level of food insecurity increased by 51·7% (48·1-55·4; p<0·0001). Mothers' depression and anxiety symptoms increased during the lockdown. Among women experiencing emotional or moderate physical violence, over half reported it had increased since the lockdown.

INTERPRETATION

COVID-19 lockdowns present significant economic, psychosocial, and physical risks to the wellbeing of women and their families across economic strata in rural Bangladesh. Beyond supporting only the most socioeconomically deprived, support is needed for all affected families.

FUNDING

National Health and Medical Research Council, Australia.