Effects of household concrete floors on maternal and child health – the CRADLE trial: a randomised controlled trial protocol
Authors: Rahman Mahbubur , Jahan Farjana , Hanif Suhi , Yeamin Afsana , Shoab Abul Kasham , Andrews Jason R. , Lu Ying , Billington Sarah , Pilotte Nils , Shanta Ireen S. , Jubair Mohammad , Rahman Mustafizur , Kabir Mamun , Haque Rashidul , Tofail Fahmida , Hossain Sakib , Mahmud Zahid H , Ercumen Ayse , Benjamin-Chung Jade 
Published: July 2024

Introduction

Early life soil-transmitted helminth infection and diarrhea are associated with growth faltering, anemia, impaired child development, and mortality. Exposure to fecally contaminated soil inside the home may be a key contributor to enteric infections, and a large fraction of rural homes in low-income countries have soil floors. The objective of this study is to measure the effect of installing concrete floors in homes with soil floors on child soil-transmitted helminth infection and other maternal and child health outcomes in rural Bangladesh.

Methods and analysis

The Cement-based flooRs AnD chiLd hEalth (CRADLE) trial is an individually randomised trial in Sirajganj and Tangail districts, Bangladesh. Households with a pregnant woman, a soil floor, walls that are not made of mud will be eligible, and no plan to relocate for 3 years. We will randomise 800 households to intervention or control (1:1) within geographic blocks of 10 households to account for strong geographic clustering of enteric infection. Laboratory staff and data analysts will be blinded; participants will be unblinded. We will install concrete floors when the birth cohort is in utero and measure outcomes at child ages 3, 6, 12, 18, and 24 months.

The primary outcome is prevalence of any soil-transmitted helminth infection (Ascaris lumbricoides,Necator americanus, orTrichuris trichiura) detected by qPCR at 6, 12, 18, or 24 months follow-up in the birth cohort. Secondary outcomes include household floor and child hand contamination withE. coli, extended-spectrum beta-lactamase producingE. coli, and soil-transmitted helminth DNA; child diarrhea, growth, and cognitive development; and maternal stress and depression.

Ethics and dissemination

Study protocols have been approved by institutional review boards at Stanford University and the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). We will report findings on ClinicalTrials.gov, in peer-reviewed publications, and in stakeholder workshops in Bangladesh.

Trial registration number

NCT05372068, pre-results

Strengths and limitations of this study

Using a randomised design in a large sample will allow us to minimize potential confounding by household wealth, which may have influenced prior observational studies’ findings on concrete floors and health.

Measurement of a diverse set of health outcomes within different domains (infections, antimicrobial resistance, child growth, cognitive development, mental health, quality of life) will capture broad potential benefits of the intervention.

Longitudinal measurements will capture any variation in intervention impact as children learn to sit, crawl, walk and spend more time outdoors and their exposures change.

Rich data on intermediate variables on household contamination and maternal bandwidth, time use, and mental health will allow us to investigate whether concrete floors influence child health and development primarily through environmental or maternal pathways.

It is possible that child exposures outside the home will attenuate the effect of concrete floors on child health outcomes.