Randomised controlled trial of thermostatic mixer valves in reducing bath hot tap water temperature in families with young children in social housing: A protocol

Denise Kendrick,Sherie Smith,Elizabeth Towner,Lindsay Groom,David Radford,Jane Stewart,Nick Hopkins,Carol Coupland,Ceri Phillips,Michael Hayes,Robert Murphy,George O'Donnell,Jackie Ryan,Debbie Mccabe

doi:10.1186/1745-6215-9-14

Abstract

BackgroundEach year in the UK 2000 children attend emergency departments and 500 are admitted to hospital following a bath water scald. The long term effects can include disability, disfigurement or psychological harm and repeated skin grafts may be required as the child grows. The costs of treating a severe scald are estimated at 250,000 GBP. Children living in the most deprived wards are at greatest risk of thermal injuries; hospital admission rates are three times that for children living in the least deprived wards.Domestic hot water, which is usually stored at around 60 degrees Celsius, can result in a second-degree burn after 3 seconds and a third-degree burn after 5 seconds. Educational strategies to encourage testing of tap water temperature and reduction of hot water thermostat settings have largely proved unsuccessful. Legislation in the USA mandating pre-setting hot water heater thermostats at 49 degrees Celsius was effective in reducing scald injuries, suggesting passive measures may have a greater impact. Thermostatic mixer valves (TMVs), recently developed for the domestic market, fitted across the hot and cold water supply pipes of the bath, allow delivery of water set at a fixed temperature from the hot bath tap. These valves therefore offer the potential to reduce scald injuries.Design/MethodsA pragmatic, randomised controlled trial to assess the effectiveness of TMVs in reducing bath hot tap water temperatures in the homes of families with young children in rented social housing. Two parallel arms include an intervention group and a control group where the intervention will be deferred.The intervention will consist of fitting a TMV (set at 44 degrees Celsius) by a qualified plumber and provision of educational materials. The control arm will not receive a TMV or the educational materials for the study duration but will be offered the intervention after collection of follow-up data 12 months post randomisation.The primary outcome measure will be the bath hot tap water temperature. Fifteen families per arm are required to detect a reduction in the mean bath hot tap water temperature from 60.4 degrees Celsius (SD 9.1) in the control group to 46 degrees Celsius in the intervention group, with 90% power and a 5% significance level (2 sided). Secondary outcome measures including acceptability will require a sample size of 120 participants.DiscussionWhilst TMVs have the potential to reduce scald injuries, to date there have been no randomised controlled trials assessing their effectiveness, acceptability and cost effectiveness.Trial RegistrationISRCTN21179067

Highlights

Each year in the UK 2000 children attend emergency departments and 500 are admitted to hospital following a bath water scald
Families will be excluded if they are not Glasgow Housing Association (GHA) tenants, if their bathroom pipe work is found to be unsuitable for fitting a Thermostatic mixer valves (TMVs) or if they are already participating in on-going tap water scald prevention studies
We considered that a randomised controlled trial was necessary to evaluate the effectiveness of TMVs as a non-randomised comparison may result in systematic differences between the intervention and control arms in interest and motivation to reduce bath hot tap water temperature

Summary

Introduction

Each year in the UK 2000 children attend emergency departments and 500 are admitted to hospital following a bath water scald. Thermostatic mixer valves (TMVs), recently developed for the domestic market, fitted across the hot and cold water supply pipes of the bath, allow delivery of water set at a fixed temperature from the hot bath tap. These valves offer the potential to reduce scald injuries. The cost of treating a severe scald has been estimated at £250,000 [1] Those at greatest risk of burn and scald injuries are those living in the most deprived wards, where the hospital admission rate is three times that for children living in the least deprived wards [3]

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