Methodologic challenges in preventing playground equipment-related injuries

School of Kinesiology and Health Science

Methodologic challenges in preventing playground equipment-related injuries

Alison K.Macpherson PhD Linda Rothman, MHSc

Colin Macarthur, MBBCh, PhDAndrew Howard, MD MSc FRCSC


Background• Playground injuries result in more severe

injuries than any other mechanism of common childhood injury (except road traffic)

• 3313 children visited Ontario Emergency Departments for playground injuries in 2002/03

• 5 to 9 year old children often injured on playgrounds

• Severe injuries are usually falls• Fall heights > than 1.5 m and poor surfacing

main risk factors for injury


A dangerous playground

Can fall onto concrete here

Falling height >2m here

Surfacing in poor condition


Background• Most common severe

playground injury is upper extremity (UE) fracture

• 10% of ED injury visits among 5-9 year old Canadian children1

• One of major determinants of playground injury is inadequate surfacing

1 Brown J.A. A comparison of injuries on various types of playground equipment

2 Canadian Institutes of Health Information


Are equipment-related injuries more severe?

• CHIRPP database was used to identify all fractures occurring on playgrounds seen in the emergency room at the Hospital for Sick Children between 1997 – 2002

• Fractures graded as major (i.e., require reduction) or minor (i.e., no reduction required)

• Examined falls from standing height compared to falls from playground equipment


Fall height and injury severity • Falls from playground equipment resulted in a much

greater proportion of major fractures than did falls from standing height

– The odds of a severe fracture from falling from equipment was 5 times greater than when falling from standing height (OR = 5.03, 95% CI: 3.56, 7.14)

49304Standing height

331408Play equipment

Major FracturesMinor Fractures


• Injuries sustained from falling from playground equipment are more severe than injuries sustained from standing height falls

• This research suggested that efforts at injury prevention should examine the safety of playground equipment

• The Toronto District School Board removed and replaced unsafe playground equipment starting in 2000


Design• Randomized Comparison of Wood Fibre versus granitic sand surfaces

beneath play equipment• Injury Outcomes

Vs.


OBJECTIVES

• Primary Objective:– Upper extremity (UE) fracture rates – Fibar surfacing vs. granite sand surfacing

• Secondary Objective– Overall playground injury rates, head injury rates – Fibar surfacing vs. granite sand surfacing


METHODS

• Cluster Randomized– New Playground, New

Surface, 19 randomized to Fibar and 18 to sand

• 37 schools eligible

• Followed for 2 ½years


METHODS

• Outcome measures– OSBIE incident

reports– Parent telephone

interview with consent

– Medical record verification

• Exposure to play equipment measured in spring 2006


37 schools eligible and randomizedn = 15,074 students

19 allocated to receive Fibar wood chip surface

-5 discontinued (4 no new play equipment/surface put in, 1 school put in rubber)

18 allocated to receive granite sand surface

4 discontinued (2 refused to participate, 2 no new play equipment/surface put in)

12 received Fibar

2 received granite sand

7 received granite sand

7 received Fibar

12 analyzedRandomized analysis

9 analyzed Cohort analysis

7 analyzedRandomized analysis

19 analyzedCohort analysis


RESULTS

• No significant differences in compliant schools and all schools (cohort) in:– Surface installation costs– Exposure to all play equipment (mean student

count/minute/school)– # of monkey bars– # of monkey bars > recommended height (2.2m)– # with appropriate depth measured (>7 inches)


RESULTS

• Total of 259 injuries

• 44 UE fractures– 22 falling onto surface– 1 on play equipment (not falling)– 46% wrist fractures, ¼ elbow fractures

• 1 concussion, not on equipment, no hospital admission


RESULTS

Compliant Schools All Schools

Sand Fibar Sand Fibar

All Injuries

Total 106.2 92.4 111.8 79.8

Falling onto Surface 4.9 23.1 6.6 19.8

Other Play Equipment Injuries

8.6 12.3 10.2 13.6

UE Fractures

Total 8.6 16.2 8.8 18.3

Falling onto surface 1.2 8.5 2.2 9.7

Other Play Equipment Injuries 0 0.8 0 0.7

Crude rates per 1,000 student months


RESULTS

Compliant Schools All Schools

Sand Fibar P value Sand Fibar P Value

All Injuries

Total 127.2 (45.6,333.7)

101.3 (47.0,212.9)

0.81 144.1(59.0,334.1)

97.0 (53.7,172.6)

0.53

Falling onto Surface 7.3 (1.4,22.6)

25.3 (11.3,54.7)

0.33 10.2(2.5,30.0)

23.0 (11.2, 45.2)

0.17

Other Play Equipment Injuries

9.5(2.4, 82.1)

9.0 (2.9, 39.9)

0.95 14.0 (4.6, 65.9)

10.7(4.8, 27.4)

0.70

UE Fractures

Total 8.7 (3.4,17.4)

16.2 (9.5,25.4)

10.3 (3.3, 25.1)

22.7 (12.3,41.3)

Falling onto surface 1.9* (0.04,6.9)

9.4 (3.7, 21.4)

4.5(0.26,15.9)

12.9(5.1, 30.1)

Other Play Equipment Injuries**

- - - -

*p<.05, **< 1 events, cannot calculate rates

Cluster Analysis: Rate of injury per 100,000 student months


DISCUSSION• Cluster analysis : When falling on surface

– Injury• 3 X greater rate of injury on fibar (randomized)• 2 X greater rate on fibar (cohort)

– UE Fracture• 5 X greater on fibar (randomized) • 3 X greater on fibar (cohort)

• Injury rate lower in all groups than our prior data estimated


CONCLUSION

• Low overall numbers of injury– highlights success of wide scale intervention of

equipment and surface upgrade to meet current safety standards

• Sand safer in terms of upper extremity fracture and injuries in general


Implication

• To prevent fractures, use sand!

Vs.


ADDITIONAL ANALYSES

• Relationship between a socioeconomic indicator at the school level and playground injuries


Objective

• to examine socioeconomic variation in playground equipment prior to and subsequent to equipment replacement


Methods

• Injury data collected from January 1998-December 1999 and January 2004 – June 2007 (OSBIE incident reports)

• 374 elementary schools in Toronto, Canada


METHODS

Schools categorized into:- pre intervention (before equipment removed) - post intervention (after equipment replaced)All outdoor injuries categorized into:

–Non-equipment injuries–equipment injuries

Poisson regression used to determine the relationship between injury rates and school SES Comparisons made using injury rate per 1000 student months


SES using Learning Opportunities Index

• Learning Opportunities Index (LOI) used by school board • Based on: family income, proportion of single parent

families, housing (detached, apartment buildings), parental education, neighborhood immigration, the number of students at the school who arrived in Canada in the past 5 years, and records of student mobility

• LOI scores range from 0 (wealthiest) to 0.97 (poorest)• Schools with the highest LOI score receive support from

the Ministry of Education’s Learning Opportunities Grant to help equalize learning opportunities


Results

• Pre (January 1998-December 1999) :- 5, 378 injuries were reported by 364 schools

• Post (January 2004 – June 2007): - 8,380 injuries were reported by 374 elementary schools


Injury rates per 1000 student months pre and post replacement

0

0.5

1

1.5

2

2.5

All injuries Non-equipment

Equipment

Pre

Post


Relative risk of injury by SES pre and post replacement

Pre Post

All injuries 1.65 (1.50-1.82) 2.07 (1.91-2.24)

Non-equipment injuries

1.68 (1.50-1.89) 2.41 (2.20-2.64)

Equipment injuries

1.52 (1.24-1.86) 1.13 (0.95-1.32)


Strengths and Limitatations

Strengths

• Standardized data collection

• Clear time period before and after replacement

Limitations

• SES attributed at the school level

• Potential variation in threshold for completing incident reports


Discussion

• There was a change in the SES gradient in school equipment-related injuries subsequent to upgrading the equipment

• The SES gradient remained for non-equipment injuries

• Modifying the build environment appears to be an effective way to make schoolyards safer

• Ongoing research may determine reasons for SES gradient in non-equipment injuries


A Safer Playground for Younger Ages


Conclusion

• Changing the built environment (upgrading play equipment) can mitigate socio-economic differences in playground equipment injury rates

Methodologic challenges in preventing playground equipment-related injuries

Documents

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