Does the use of a bedroom thermometer in infancy reduce the incidence of respiratory ill-health, particularly infections and coughs

ISRCTN	ISRCTN13672502
DOI	https://doi.org/10.1186/ISRCTN13672502
ClinicalTrials.gov (NCT)	Nil known
Clinical Trials Information System (CTIS)	Nil known
Protocol serial number	B4469, WT 217065/Z/19/Z, 102215/2/13/2
Sponsor	University of Bristol
Funders	Wellcome Trust, Medical Research Council, University of Bristol, Lullaby Trust

Submission date: 07/06/2024
Registration date: 05/07/2024
Last edited: 05/07/2024

Recruitment status: No longer recruiting
Overall study status: Ongoing
Condition category: Respiratory

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Children’s health depends partly on protection from temperature extremes, in particular, there is an association with overheating in cases of cot deaths. As part of the Back-to-Sleep campaign (to reduce cot deaths), 30 years ago, it was suggested that a thermometer in the room where the infant slept would ensure that temperature extremes were recognised, and action taken to keep infants safe. This study was designed to test whether having such a thermometer resulted in subsequent ill-health in young children, particularly respiratory problems.

Who can participate?
Mothers enrolled in the Avon Longitudinal Study of Parents & Children (ALSPAC) with an expected delivery date between 1st May and 31st December 1992.

What does the study involve?
Half the mothers were sent a simple thermometer to keep in their child’s bedroom. This indicated whether the room was too hot, too cold or just right. Twice a week, the mother was asked to note down the date and temperature on a chart supplied by the study.

What are the possible benefits and risks of participating?
There are no particular benefits except for a free thermometer for the intervention arm. Participating in ALSPAC relies on altruism. A possible risk is exposing infants to external air from windows being opened to regulate the bedroom temperature which may contain environmental pollutants and allergens. Possible anxiety to parents if they struggle to control the temperature of the room.

Where is the study run from?
The ALSPAC offices (Bristol)

When is the study starting and how long is it expected to run for?
The intervention started on 1st May 1992 and data collection is ongoing. We stopped collecting data on the temperature monitoring approx 31/12/1993. However, we used data collected on the ALSPAC cohort up to age 18 years to examine allergies and respiratory problems in the cases and controls within this RCT. The ALSPAC cohort continues to this day.

Who is funding the study?
The thermometers were kindly donated by the South Western Electricity Board (SWEB), the postage and printing by HTV West (the local television station in 1992) and the funds for linkage and statistical analysis by Cot Death Research (now the Lullaby Trust). The UK Medical Research Council and Wellcome (grant ref: 217065/Z/19/Z) and the University of Bristol have provided core support for ALSPAC since 2000 and continue to do so. A full list of ALSPAC funding is available here: https://www.bristol.ac.uk/alspac/external/documents/grant-acknowledgements.pdf

Who is the main contact?
Professor Jean Golding, jean.golding@bristol.ac.uk

Contact information

Prof Jean Golding
Public, Scientific, Principal investigator

Centre for Academic Child Health, Population Health Sciences, Bristol Medical School, Canynge Hall, Whatley Road, Clifton
Bristol
BS8 2PS
United Kingdom

ORCID ID	0000-0003-2826-3307
Phone	+44 (0)7717513902
Email	jean.golding@bristol.ac.uk

Mrs Yasmin Iles-Caven
Public, Scientific

Centre for Academic Child Health, Population Health Sciences, Bristol Medical School, Canynge Hall, Whatley Road, Clifton
Bristol
BS8 2PS
United Kingdom

ORCID ID	0000-0002-9965-9133
Phone	+44 (0)7810340404
Email	cdylic@bristol.ac.uk

Study information

Primary study design	Interventional
Study design	Randomized controlled trial nested within a longitudinal birth cohort
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title	Long-term respiratory health benefits of using a bedroom thermometer in infancy: a randomised controlled trial nested within the ALSPAC pre-birth cohort
Study objectives	To evaluate any health risks and benefits associated with the provision of a bedroom thermometer.
Ethics approval(s)	Ethical approval for the ALSPAC study was obtained from the ALSPAC Ethics and Law Committee (ALEC; IRB00003312) and the Local NHS Research Ethics Committees: Bristol & Weston Health Authority: E1808 Children of the Nineties: Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) 28/11/1989); Southmead Health Authority: 49/89 Children of the Nineties – "ALSPAC", 05/04/1990); Frenchay Health Authority: 90/8 Children of the Nineties, 28.06.1990. Children in Focus: Southmead Health Services: 48/89: ALSPAC – “The 10% Club”, 25/08/1992
Health condition(s) or problem(s) studied	Respiratory symptoms
Intervention	During pregnancy (or shortly after delivery) women are randomly selected (by odd or even date of birth) to receive a simple thermometer to put on the wall of the room in which their baby sleeps, to identify temperatures labelled as hot (>21oC), fine (16-21oC) or cold (<16oC). They then record the ambient temperature twice per week over a year.
Intervention type	Device
Phase	Not Applicable
Drug / device / biological / vaccine name(s)	Simple card wall thermometer
Primary outcome measure(s)	Respiratory signs and symptoms measured using data reported by the mother (and later the child) at 6, 18, 30, 42 months, 4, 5, 6, 7, 8, 10, 13, 14, 16 and 18 years of age.
Key secondary outcome measure(s)	1. Respiratory infections [a cold, influenza, tonsillitis or laryngitis, chest infection] measured using self-completion questionnaires at 6, 18, 30, 42 months, 4, 5, 6, 7, 8, 10, 13, 14, and 16 years of age 2. Cough [cough, cough lasting at least two days, cough medication given] measured using self-completion questionnaires at 6, 18, 30, 42 months, 4, 5, 6, 7, 8, 10, 13, 14 and 16 years of age 3. Ear infections [earache, ear infection, pus discharge from ear(s), grommets inserted] measured using self-completion questionnaires at 6, 18, 30, 42 months, 4, 5, 6, 7, 8, 10, 13, 14 and 16 years of age 4. Respiratory conditions with likely allergic aetiology [wheeze, asthma, hay fever (allergic rhinitis)] measured using self-completion questionnaires at 6, 18, 30, 42 months, 4, 5, 6, 7, 8, 10, 13, 14, 16 and 18 years of age
Completion date	31/12/2050

Eligibility

Participant type(s)	Healthy volunteer, Resident, Population
Age group	Child
Lower age limit	1 Week
Upper age limit	52 Weeks
Sex	All
Target sample size at registration	5000
Total final enrolment	5243
Key inclusion criteria	1. Mother enrolled in the Avon Longitudinal Study of Parents & Children study 2. Expected date of delivery between 1st May and 31st December 1992 3. Gestation at birth >32 weeks 4. Live birth
Key exclusion criteria	1. Preterm births <32 weeks gestation 2. Participant refusing ALSPAC
Date of first enrolment	31/05/1992
Date of final enrolment	31/12/1992

Locations

Countries of recruitment

United Kingdom
England

Study participating centre

University of Bristol

Administrative Centre: University of Bristol, Beacon House, Queens Road, Bristol BS8 1QU. The ALSPAC study was based (at the time of this trial) at the Institute of Child Health, Tyndall Avenue.
Bristol
BS8 1QU
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
IPD sharing plan	ALSPAC data access is through a system of managed open access. The steps below highlight how to apply for access to the data included in this paper and all other ALSPAC data. Note that variable names are included in the tables within this paper. Please read the ALSPAC access policy ( http://www.bristol.ac.uk/media-library/sites/alspac/documents/researchers/data-access/ALSPAC_Access_Policy.pdf) which describes the process of accessing the data and biological samples in detail, and outlines the costs associated with doing so. 1. You may also find it useful to browse our fully searchable research proposals database (https://proposals.epi.bristol.ac.uk/), which lists all research projects that have been approved since April 2011. 2. Please submit your research proposal ( https://proposals.epi.bristol.ac.uk/) for consideration by the ALSPAC Executive Committee using the online process. You will receive a response within 10 working days to advise whether your proposal has been approved. If you have any questions about accessing data, please email alspac-data@bristol.ac.uk (data) or bbl-info@bristol.ac.uk (samples). The ALSPAC data management plan (http://www.bristol.ac.uk/media-library/sites/alspac/documents/researchers/data-access/alspac-data-management-plan.pdf) describes in detail the policy regarding data sharing, which is through a system of managed open access. Detailed information on how the confidentiality of the cohort is maintained may be found on the study website: http://www.bristol.ac.uk/alspac/researchers/research-ethics/. All methods were conducted following the relevant guidelines and regulations. Informed consent for the use of data collected via questionnaires was assumed from participants following the recommendations of the ALSPAC Ethics and Law Committee at the time. Signed informed consent was obtained from the parent for face-to-face examinations before the child was old enough to consent him/herself.

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

17/06/2024: Trial's existence confirmed by ALSPAC ethics committee.