An evaluation of thermostatic mixer valves to reduce bath water temperature in homes of families with young children living in social housing Denise Kendrick.

An evaluation of thermostatic mixer valves to reduce bath water

temperature in homes of families with young children living in social

housing

Denise Kendrick

Professor of Primary Care Research

University of Nottingham

Jane Stewart Senior Research Fellow

Nottinghamshire Healthcare Trust (NHS Nottinghamshire County)

And co- authors

The problem – bath hot tap water scalds in young children

• Each year 2,000 ED attendances, 500 admissions

• Most admissions children < 5years

• Steep social gradient– most deprived most vulnerable

• Domestic hot water temperatures can scald in about a second

• Cost of severe scald ~ £250 000

What is a Thermostatic Mixer Valve (TMV)?

• Engineering solution to reduce the temperature of hot bath tap water temperature

• No active participation by parents required• Mixes hot and cold bath tap water to pre-set

temperature - 46 ºC • Takes 6 hours for a scald at this temperature

Aims of the study

• To assess TMVs for their:

• Effectiveness and cost effectiveness in reducing bath hot water temperature

• Acceptability to families

• Impact on bath time safety practices

– In families with children under the age of 5 years living in social housing

Methods• Randomised controlled trial

– Questionnaire at baseline

• Delivered the intervention – TMV– Educational leaflet– Laminated leaflet on how to use TMV

– Water temperature checks at baseline, 3 and 12 months

– Questionnaire at 12 months follow up

• Fieldwork in Glasgow

Participants124 families completed baseline questionnaire

Intervention arm62

(46 TMVs fitted)

Control arm62

Water temps: baseline n=233 months n=1512 months n=16

Water temps: baseline n=273 months n=1512 months n=15

12 month questionnaire49 still tenants/participating

12 month questionnaire44 still tenants/participating

40 returned (91.9%)

40 returned(81.6%)

Characteristics of participantsCharacteristics Intervention arm

n=62 Control arm

n=62

Mother completed questionnaire 57 (91.9) 58 (93.6)

Single adult household 40 (64.5) 47 (75.8)

Number of children in the home 12

29 (46.8)21 (33.9)

25 (40.3)26 (41.9)

Age respondent left full time education ≤16 38 (73.1) [10] 43 (72.9) [3]

Number of adults in paid employment 01

39 (65.0) [2]16 (26.7)

40 (65.6) [1]17 (27.9)

Family receives state benefits 50 (82.0) [1] 56 (90.3)

Ethnic group of respondent White ScottishBlack African

54 (88.5) [1]6 (9.8)

54 (88.5) [1]3 (4.9)

[ ] missing values

Acceptability of bath hot tap water(baseline)

[ ] missing values

Intervention arm

Control arm

Satisfaction (number (%)) n=62 n=62

Very happy or happy with bath hot tap water temperature 39 (62.9) 37 (59.7)

Bath water is:Very hot – need to add a lot of

cold water to the bathHot – need to add some cold

water to the bath

41 (67.2) [1]

19 (31.2)

38 (61.3)

24 (38.7)

Bath time safety practices

(baseline)

[ ] missing values

Safety practices Intervention arm n=62

Control arm N=62

Runs bath using cold water first 2 (3.2) 9 (14.8) [1]

Bath water temperature checked for every bath

54 (88.5) [1] 54 (88.5) [1]

Child has been left alone in the bath

27 (43.6) 13 (21.0)

Child has been left alone in bathroom whilst bath is running

19 (30.7) 12 (19.4)

Hot bath tap water temperatures at baseline, 3 and 12 months

4050

6070

8090

100

Bas

elin

e w

ater

tem

pera

ture

(de

gre

es C

elsi

us)

Control arm Intervention arm

4050

6070

8090

100

3 m

onth

wat

er t

empe

ratu

re (

degr

ees

Cel

sius

)

Control arm Intervention arm

4050

6070

8090

100

12 m

onth

wat

er t

empe

ratu

re (

deg

rees

Cel

sius

)

Control arm Intervention arm

Were parents satisfied with the TMV?

Intervention arm responders with TMV fitted (n=34)

Very happy or happy with TMV 30 (88.2)

Would recommend TMV to a friend 28 (87.5) [2]

Would not be happy if kitchen and bath hot tap water were same temperature

23 (69.7) [1]

Since having TMV…

Child less likely to be scalded 32 (94.1)

Doesn’t take longer to run bath 22 (68.8) [2]

Easier to control bath water temperature

29 (90.6) [2]

Bath water isn’t hot enough 12 (36.4) [1]

Can no longer top up bath with hot water whilst in the bath

9 (27.3) [1]

Acceptability of bath hot tap water (follow up)

Intervention arm

Responders n=40 (%)

Control arm

Responders n=40 (%)

Relative Risk (95% CI)

Very happy or happy with bath hot tap water temperature

32 (82.1) [1]

23 (57.5)1.43 (1.05, 1.93)

Bath water is:Very hot – need to add a lot

of cold water to the bathHot – need to add some cold

water to the bathWarm enough - don’t need to

add any cold water to the bath

7 (18.0) [1]

16 (41.0)

14 (35.9)

22 (55.0)

18 (45.0)

0 (0.0)

0.33 (0.16, 0.68)†

Bath time safety practices (follow up)

Intervention arm responders n=40(%)

Control arm responde

rs n=40(%)

Relative Risk (95% CI)

Runs bath using cold water first*5 (12.5) 11 (27.5) 0.55 (0.22, 1.39)

Bath water temperature checked for every bath

32 (84.2) [2] 40 (100.0) 0.84 (0.73, 0.97)

Child has been left alone in the bath* 13 (32.5) 8 (20.5) [1] 1.11 (0.51, 2.41)

Child has been left alone in bathroom whilst bath is running*

12 (30.8) [1] 9 (22.5) 1.28 (0.62, 2.68)

Health economic analysisProfessor Ceri Phillips - Swansea University

•NHS costs to treat a scald – •range from £25, 226 - £71, 902

• Cost-effectiveness analysis indicated a potential saving to the NHS of

£3, 229, 008

• £1.41 saved for every £1 spent

Summary

• TMVs are effective in reducing bath hot tap water temperature

• Majority of parents satisfied with the TMV and the temperature

• Would recommend a TMV to a friend

• Feel child less likely to be scalded

• However, parents checking temperature of bath water less often

• A third of people reported bath water not hot enough

Implications• Suggests that parents are willing to

trade some inconvenience for increased safety

• TMVs should be considered as a scald prevention intervention for families with children

• Important to reinforce bath time safety messages about checking the water temperature and leaving children alone in the bath

• Cost effective solution – requires interagency working – spend money in one sector to save money in another

Funding

• Policy Research Programme (PRP) at the Department of Health -Accidental Injury Prevention Research Initiative (001/0009)

• The final study design, data collection, analysis, interpretation of results, and paper writing was the sole responsibility of the authors. The views and opinions expressed in this paper do not necessarily reflect those of the funding body. This is an independent report commissioned and funded by the Policy Research Program in the Department of Health. The views expressed are not necessarily those of the Department.

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