Preventable head and facial injuries by providing free bicycle helmets and education to preschool children in a head start program

doi:10.4236/health.2011.311116

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Vol.3, No.11, 689-697 (2011)

doi:10.4236/health.2011.311116

Health

Preventable head and facial injuries by providing free

bicycle helmets and education to preschool children

in a head start program

Thein Hlaing Zhu1*, Mary O. Aaland1, Connie Kerrigan2, Renee Schiebel2, Heather Henry2,

Lisa Hollister1

1Parkview Hospital Adult and Pediatric Level II Trauma Center, Fort Wayne, USA;

*Corresponding Author: [email protected], [email protected]

2Parkview Community Nursing Program, Parkview Community Health Improvement Program, Fort Wayne, USA.

Received 26 August 2011; revised 12 October 2011; accepted 27 October 2011.

ABSTRACT

The objectives of the study were to determine

helmet use rates, incidence rates (IRs) of head

and facial injuries for population attributable

fraction (PAF) estimation, and to elucidate the

magnitude of and changes in PAFs as the result

of helmet use changes among preschool chil-

dren. A study consisting of cross-sectional (sur-

vey) and longitudinal (follow-up) component

was designed by including a randomly selected

group of participants (n = 322) from 10 Head

Start sites provided with free bicycle helmets

along with a s ubgr ou p of pr ior hel met owners (n

= 68) from the other random group (n = 285). All

participants received bicycle helmet education.

Helmet use surveys were conducted in May (1st

Survey) and November 2008 (2nd Survey). The

helmet owners were followed up to determine

IRs, and incidence rate ratios (IRRs) for head

and facial injuries. PAFs were computed using

IRs as well as helmet use rates and IRRs. Hel-

met use rates increased significantly from the

1st to the 2nd Survey. The mean follow-up per-

son-time was 5 months. The IRs for head, face

(all portions), and face (upper/mid portions) in-

juries were higher in non-helmeted than hel-

meted riders. By using IRs, PAFs for the 3 inju-

ries among the riders in both groups of helmet

owners were 77%, 22%, and 32% respectively.

The PAFs for each of the above injuries de-

creased by about 10% as helmet use rates in-

creased. The magnitude of and changes in

preventable head and facial injuries following

free bicycle helmet distribution and education

among helmeted riders was elucidated in this

Head Start preschool children population.

Keywords: Head Injury; Facial Injury; Free Helmet

Distribution; Head Start; Preschool Chil dren; PAF

1. INTRODUCTION

Head Start Programs exist in every state in the United

States, and 908,412 children were enrolled in 2007 na-

tionwide; of these, about 90% were preschool age [1].

Head Start is a federally funded preschool program that

provides health, education and social services to children

from low-income families that are at or below the fed-

eral poverty level. The Community Action of Northeast

Indiana (CANI) Head Start Program in Fort Wayne,

Indiana serves over 800 preschool children.

The trauma program of the Parkview Hospital Level II

Trauma Center in Fort Wayne, Indiana planned to dis-

tribute 800 free helmets to preschool children ages 3-5

years at the CANI Head Start sites in 2007-2008 to en-

courage helmet use both at school and home. Of these,

about 400 helmets were available for the first year bicy-

cle season and the remaining 400 for the next year sea-

son. One research question that intrigued the research

personnel before implementing the program was, “to

what extent could head and facial injuries be prevented

if this population is provided free bicycle helmets and

education?” In other words, could we measure the popu-

lation attributable fractions for head and facial injuries

among helmeted riders?

In reviewing the literature, the methodology for esti-

mation of population attributable fraction (PAF) of bicy-

cle related head injuries could be calculated by two for-

mulas: one calculation using the incidence rates of inju-

ries and the other calculation based on bicycle helmet

use rate and helmet effectiveness [2]; the same author

demonstrated that PAF decreased as helmet use rate in-

creased by simulation model. Again, bicycle helmet ef-

T. H. Zhu et al. / Health 3 (2011) 689-697

690

fectiveness against head and facial injuries by case-con-

trol studies were shown for all ages [3,4] and for < 6

years old children [5]. Previous studies on population-

based head injury rates among children 5 years old and

under were based on hospital records [6,7]. Studies based

on all cases (hospital as well as non-hospital cases) aris-

ing from the community to estimate either head and/or

facial injury incidences are rare. The present study ob-

jectives were 1) to determine helmet use rates, incidence

rates of head and facial injuries among helmeted and

non-helmeted riders in the preschool population for PAF

estimation; 2) to elucidate the magnitude of and changes

in PAFs as the result of helmet use changes in the same

population.

2. MATERIALS AND METHODS

2.1. Study Setting

A pilot sample survey of 221 families at 6 CANI Head

Start sites in September 2007 showed that 90% of 3-5

year old children owned a bicycle or wheeled riding toy

and 20% of them possessed a helmet. Ten of 11 sites that

portray a diverse population with multiple languages and

ethnicities in Allen, Noble and Whitley counties were

selected and the one with predominant majority of white

children (n = 34) was excluded. All sites provide morn-

ing (AM) and afternoon (PM) classes except one site,

which offers only AM classes.

2.2. Study Design

It has been stated that randomized controlled trials are

neither feasible nor ethical for study of bicycle helmet

effectiveness against head injury and that cohort studies

are also unfeasible due to low incidence of the event [8].

To achieve our objectives, we devised a study design

consisting of cross-section (survey) and longitudinal

(follow-up) component in helmet owners as follows:

First, the principal investigator and a team member se-

lected two groups by a toss of a coin so that each group

consisted of either the AM or PM classes from each of

the 8 sites. From the remaining two sites, the site with

only AM classes (10th site) was combined with the other

site (9th site) that had fewer children in its PM classes to

form into a subgroup that had comparable number of

children with those in AM classes of the 9th site, and

then these two subgroups were again selected by a toss

of a coin to join the above two groups. Second, one of

the two groups was randomly selected to be provided

with 400 free bicycle helmets and helmet education (HE).

This group formed the main focus of our study. The

other group was provided with bicycle helmet education

only (E) (and all would receive the remaining 400 free

helmets in 2009 bicycle season). As some participants of

the E group could own bicycle helmets (expected from

the pilot study), we also took this subsample into our

study to increase the sample size and it was termed as

H’E group where H’ represented those participants who

owned a helmet at the beginning of the study (prior hel-

met owners). We employed the HE and H’E groups to

conduct surveys for estimation of helmet use rates at the

beginning and end of study, and for follow-up study for

estimation of IRs, incidence rate ratios (IRRs). PAFs

were ultimately computed. Wearing a helmet was con-

sidered as exposure and without wearing a helmet was

non-exposure while riding a bicycle or wheeled riding

toy. The person-time determination for estimation of IRs

among helmeted and non-helmeted riders is described in

section 2.6.

2.3. Participants, Provision of Helmets and

Education

The eligibility criteria for a case were: a child 3 - 5

years old and his/her siblings in the same age range, reg-

istered with the CANI Head Start Program, possession

of a bicycle or a wheeled riding toy, and the child’s

caregiver speaking English or Spanish. The study started

to recruit participants’ caregivers in mid-May 2008 by a

team of 7 Parkview Hospital community nurses and 6

Spanish speaking CANI personnel. The study ended on

November 15, 2008.

The provision of free helmets was done by the nurses

to the HE group in area site classrooms. The helmets

were manufactured by Bell Sports Inc, Rantoul, IL, USA

and comply with the Consumer Product Safety Commis-

sion bicycle safety standards. If a caregiver from the E

group expressed a concern about obtaining a helmet be-

fore the end of the study, a voucher was issued to receive

a free helmet and fitting from the hospital’s safety store.

Two professional health educators provided the class-

room education to both caregivers and children from

both groups through a video (which had already been

used regularly for 9 years in area schools) on rules of

bicycling and the importance of proper helmet use to

prevent head injury, as well as a classroom melon drop

demonstration with and without a helmet at the time of

recruitment. Besides the video, the caregivers received

information pamphlets on the risks of head injury from a

bicycle crash, the effectiveness of helmets’, strategy’s to

fit helmets, and encouraging their use while children are

still young. Spanish language was used in translation for

questionnaires, and other forms, and for communication

with the Hispanic caregivers. Each family that submitted

completed questionnaires was presented with a retail gift

card. One family was awarded a grand prize of a large

TV by random drawing. Approval from the Parkview

T. H. Zhu et al. / Health 3 (2011) 689-697

691691

Health Institutional Review Board to undertake this

study was obtained in April 2008.

2.4. Definitions

Helmet use was defined as a child wearing a helmet

“always” or “most of the time” while riding, and non-

use was defined as when the child “did not wear” or

wore a helmet “some of the time” while riding the ve-

hicle [9].

The definitions for head and facial injuries followed

closely to those of Thompson et al. [10] and were

phrased understandable to the caregivers. A head injury

was defined as consisting of superficial cuts/scrapes

(lacerations/abrasions), bruises on the scalp, bumps to

the head and passing out (possible concussion) and bro-

ken bones in the head (skull fractures). A facial injury

for all areas consisted of superficial cuts/scrapes, and

bruises to the face, including the forehead, eye (external),

nose, mouth (intra-oral), cheek, ear (external), chin (lower

jaw), and facial bone fractures. The upper and mid-por-

tion of face was taken as occurring to the forehead, eye,

nose, cheek or ear.

2.5. Data Sources and Measurement

2.5.1. Helmet Use Study Component

The nurses provided a simple, self-administered, pre-

tested, and structured questionnaire to the caregivers to

record helmet use in HE and E groups at the beginning

(1st Survey) and end of study (2nd Survey). H’E was

identified after the 1st Survey. The questionnaire con-

tained data on the caregivers including highest education

attained, ethnicity, and language spoken. The data gath-

ered on the children included sex, type of vehicle pos-

sessed, helmet ownership, and the numbers of helmet

use while riding the vehicle. To supplement the helmet

use by questionnaire method, the nurse used observation

method by asking the caregiver during the home visit

(see below) to let the child ride the bicycle or other rid-

ing vehicle, and observed whether the child rode and

wore a helmet with or without prompting in the HE

group as was done in one study [11].

2.5.2. Injury Study Component

Another simple, self-administered, pretested, and

structured questionnaire was also given to the caregivers

for recording demographic information of both caregiv-

ers and children, and injuries that occurred during the

follow-up. The variables for each injury included,

among others, the date of injury, helmet wearing status,

nature of injury, anatomic location of injury, and type of

treatment sought. In addition, a systematic random sam-

ple of 20% of families by site from the HE and E groups

were selected to use as a validation subsample of study

subjects to carry out a one-time home visit by the field

team members. It began 4 weeks after the recruitment

for determining any discrepancies on recording injuries

and to verify injury location diagnoses.

All questionnaires were collected at the Head Start

sites, by US mail services, and at home visits. Telephone

calls were periodically made to increase the response

rate.

2.6. Statistical Analysis

Helmet uses among helmet owners were analyzed by

HE and H’E groups and Survey. Statistical tests were

performed using 2-tail P value <0.05 as statistical sig-

nificance [12].

A child possessing a helmet could have multiple epi-

sodes of bodily injuries including head and/or face from

falls while riding, switching helmet wearing to non-

wearing and vice versa, during the following-up period.

Based on this context, assignment of person-time (per-

son-days) contributing to an injury including the head

and face within a child was determined as the period of

exposure up to the moment of that injury event while

riding by wearing a helmet or period of non-exposure

without wearing a helmet. In other words, a child could

have a number of exposure and non-exposure person-

days depending upon helmet wearing status at the time

of injury event while riding. Those children without re-

porting any injuries and therefore unable to know their

helmet wearing experience were excluded from the per-

son time determination. Based on these assumptions, the

person-days for incidence rates (IRs) were computed

from the participants’ start and end dates of follow-up

and the dates of injuries as follows:

1) For a child, either with one or more injury events,

wearing or not wearing a helmet at one or all injury

dates, person-days = End Date – Start Date.

2) For a child with 2 or more events, person-days for

the 1st or with the same continuously wearing or not

wearing occurring events = Injury Date (of 1st or that of

last continuous event) – Start Date. For subsequent dif-

fering wearing event (s), person-days = Injury Date (of

that or last event] – Injury Date (of previous event) and

were repeated if such alternate (s) of wearing/non-

wearing continued to occur. But the person-days for the

final injury event = End Date – Last Counted Injury

Date so that the child total person-days were completely

distributed by helmet wearing status.

The sum of helmeted or non-helmeted person-days

was taken as the denominator for respective IR. Inci-

dence rate ratios (IRRs) along with 95% CI values were

calculated and the values of helmet effectiveness [13] in

this preschool age were derived. PAFs for head and fa-

T. H. Zhu et al. / Health 3 (2011) 689-697

692

cial injuries were computed as follows [2]:

RIR

PAF IR



 (1)

where PAF = Population Attributable Fraction,

IRt = Incidence rate of injury in all riders,

IRe = Incidence rate of the injury in helmeted riders.



PRR

PAF PRR







 (2)

where Pnh = Proportion of riders who do not wear a hel-

met.

RR or IRR = Relative risk of injury among the non-

helmeted riders Compared to helmeted riders.

Validation for head and facial injuries was done in

both HE and E groups as some of the E group partici-

pants, besides the prior helmet owners, acquired helmets

from vouchers and other sources during the study period.

Follow-up loss analysis from each study component was

confined to the HE group (because of small sample size

in H’E group) by comparing the distribution of demo-

graphic characteristics of children and their caregivers

between the completed follow-up category and the loss

in follow-up category.

3. RESULTS

3.1. Baseline Characteristic Features

The baseline characteristic features of the study par-

ticipants and their caregivers are shown in Ta bl e 1 . The

distribution of demographic variables of participants and

of caregiver’s education and ethnicity between the HE

and H’E was not statistically significant. However, the

distribution of caregiver’s education and ethnicity in the

Helmet Use Study and caregiver’s education in the In-

jury Study between HE and E groups were statistically

significant. Figure 1 shows flow of participants and

study sizes through each stage of the two study compo-

nents.

3.2. Vehicle Ownership, Helmet Distribution

and Use

The majority of the children owned a bicycle (over

80%), followed by a scooter (27%), tricycle (25.0%) and

rollerblades/skates (over 15%). This pattern was ob-

served in the HE and E groups. All participants received

free helmets in the HE group irrespective of their prior

ownership. Participants in the E group received 41 free

helmets by vouchers and a few of them obtained helmets

from other sources. A total of 97 helmet owners, includ-

ing prior helmet owners, were reported at the end of

study in this group. Highly increases in helmet use rates

were observed from the 1st to the 2nd Survey in HE and

H’E groups but statistically significant increase in the

former group (Table 2).

3.3. Incidence of Head and Facial Injuries by

Helmet Wearing Status

The mean ± SD follow-up months for the HE group

and H’E group were 4.8 ± 1.4 and 5.2 ± 1.1, respectively.

About 67% of head and facial injuries were related to

bicycle-riding. The IRs for head and facial injuries were

much lower in the helmeted than non-helmeted riders in

HE and in both groups combined (Table 3). As the

number of head and facial injuries in the H’E group were

small, the findings in this group were not shown sepa-

rately and in subsequent tables. The 95% CIs of IRR

values for head and facial injuries (all portions) between

helmeted vs. non-helmeted riders were below 1.0 in HE

group (Table 3).

During home visits, 62 preschool children were

available for the observation. The caregivers agreed to

let 51 children ride in front of the home visiting nurse

and 50 children participated. Of those participated, 34

(68.0%) wore a helmet while riding, with a breakdown

of 21 (42.0%) children remembering to wear a helmet

following a prompt from the caregiver about the helmet,

and 13 (26.0%) wore without the prompt.

3.4. Helmet Effectiveness

Helmet effectiveness was derived from IRRs (Table

3). The bicycle helmet effectiveness value for head in-

jury was 94% for helmet users in the HE group and the

finding was similar in both groups combined. The hel-

met effectiveness was 62% for all facial areas, and that

for the upper and mid-portion of the face was 75% in HE

group, and the values for facial injuries were higher than

those in both groups combined.

3.5. Preventable Fractions

The PAFs as measured by the IRs for the head, face (all

portions) and face (upper/mid portions) in HE group

were 75%, 25% and 37% respectively and the corre-

sponding values for facial injuries were relatively lower

in the combined group (Tabl e 3). The PAF values in HE

group when measured by helmet effectiveness and the

helmet use rate were 84%, 36% and 51% for the above

corresponding injuries at the baseline, and each value

decreased at the end of study as the result of increase in

helmet use rates (Table 4). Again, the corresponding

values for facial injuries were slightly lower in the com-

bined group. However, the overall trend and magnitude

of difference were similar in HE and both groups com-

bined.

T. H. Zhu et al. / Health 3 (2011) 689-697

693693

Table 1. Comparison of baseline characteristic features of two study components.

Helmet Use Study Injury Study

Characteristic

HEa E

b H’Ec χ2 testd

(HE v. E)

χ2 testd

(HE v. H’E)HEa E

b H’Bc χ2 testd

(HE v. E)

χ2 testd

(HE v. H’E)

Participants, n 322 285 68 254 213 54

Sex, % nse nse nse nse

Male 50.0 55.4 55.9 49.6 55.9 51.9

Female 50.0 44.6 44.1 50.4 44.1 48.1

Age (y), % nse nse nse nse

3 27.0 26.3 17.6 29.1 29.6 22.2

4 38.8 38.6 48.5 36.6 39.0 46.3

5 34.2 35.1 33.8 34.3 31.5 31.5

Caregivers, n 246 215 56 190 159 43

Education, % P < 0.05nse P < 0.05 nse

Some schooling 26.4 24.7 19.6 25.3 21.4 20.9

High school diploma 42.7 28.4 32.1 44.2 28.9 30.2

College education 22.4 28.8 35.7 23.2 31.4 37.2

Other 0.8 0.9) 1.8 1.1 1.3 2.3

Missing 7.7 17.2 10.7 6.3 17.0 9.3

Ethnicity, % P < 0.05nse nse nse

Black 43.5 33.5 30.4 38.4 30.2 23.3

Hispanic 25.6 29.8 23.2 26.8 30.2 23.3

White 28.0 30.7 42.9 32.6 32.1 48.8

Other 2.4 5.6 3.6 2.1 6.9 4.7

Missing 0.4 0.5 0 0 0.6 0

aHE = Provision with free helmet distribution and helmet education; bE = Provision with helmet education only; cH’E = A subgroup of E group with prior hel-

met owners (See explanation for prior helmet owners in text); dStatistical tests were done after excluding other and missing categories; ens = Not significant.

Table 2. Helmet use rate by group and survey.

HE Groupb H’E Groupc Combined

Helmet Wearing Statusa

1st Survey 2nd Survey 1st Survey 2nd Survey 1st Survey 2nd Survey

Yes 65.6 80.5 49.3 62.2 59.0 77.4

No 33.4 19.5 50.7 37.8 41.0 22.6

Total 100.0 (99)d 100.0 (221) 100.0 (67) 100 (45) 100.0 (166) 100.0 (266)

Difference between 1st and

2nd Surveys

z = 2.696

P < 0.01

z = 1.351

P > 0.05

z = 4.076

P < 0.001

aHelmet wearing status not documented: 2 cases in 1st Survey and 7 cases in 2nd Survey under HE group, and 1 case in 1st Survey and 1 case in 2nd Survey under

H’E Group; bHE = As in Table 1; cH’E = As in Table 1; dNumber of participants in parentheses.

T. H. Zhu et al. / Health 3 (2011) 689-697

694

Table 3. Incidence rates of head and facial injuries per helmet wearing status in helmet owners.

Helmet Owners (n = 82) in HE Group All Helmet Owners (n = 105)a

Helmet Wearing Status

Head Face

(all portions)

Face

(upper/mid) Head Face

(all portions)

Face

(upper/mid)

No. 10 20 6 12 26 8

Person Time (days) 12,965 12,965 12,965 16,742 16,742 16,742

Helmeted and

Non-Helmeted Riders

IRb/100 children/year 28.15 56.31 16.89 26.16 56.68 17.44

No. 2 12 3 2 15 4

Person Time (days) 10,361 10,361 10,361 12,360 12,360 12,360

Helmeted Riders

IRb/100 children/year 7.05 42.27 10.57 5.91 44.30 11.81

No. 8 8 3 10 11 4

Person Time (days) 2604 2604 2604 4382 4382 4382 Non-Helmeted Riders

IRb/100 children/year 112.14 112.14 42.05 83.29 91.62 33.32

Helmeted vs.

Non-Helmeted Riders

IRRc

95% Confidence interval

0.06

(0.01 - 0.30)

0.38

(0.15 - 0.92)

0.25

(0.05 - 1.25)

0.07

(0.02 - 0.32)

0.48

(0.22 - 1.05)

0.35

(0.09 - 1.42)

Helmet Effectiveness

(1-IRRc) 94% 62% 75% 93% 52% 65%

PAFd (%) 75.0 24.9 37.4 77.4 21.8 32.3

aAll helmet owners in HE and prior helmet owners in H’E groups; bIncidence rate; cIncidence rate ratio; dte

IR IR



PAF , (See explanation for the parameters

in text).

Table 4. Population attributable fraction (PAF%) at baseline and end of study.

Helmet Owners in HE Group All Helmet Ownersa

Relative Riskb Baseline End of StudyDifference

In PAF Relative RiskbBaseline End of Study Difference

In PAF

Head 0.06 0.07

Helmet Use Ratec (%) 65.6 80.5 59.0 77.4

PAFf (%) 84.4 75.3 9.1 84.5 75.0 9.5

Face (All Portions) 0.38 0.48

Helmet Use Ratec (%) 65.6 80.5 59.0 77.4

PAFf (%) 36.0 24.1 11.9 30.8 19.7 11.1

Face (Upper/Mid) 0.25 0.35

Helmet Use Ratec (%) 65.6 80.5 59.0 77.4

PAFf (%) 50.8 36.9 13.9 43.2 29.6 13.7

aAs in Table 3; bRelative risk (IRR) of corresponding injury among helmeted compared to non-helmeted riders; see Table 2; cTaken from Table 2;







PRR

PAF PRR





, (See explanation for the parameters in text).

T. H. Zhu et al. / Health 3 (2011) 689-697

695695

Assessed for Eligibility from

10 Head Start sites

(n = 703)

Excluded (n = 96)

Not meeting inclusion criteria (n=7)

Declined to participate (n=42)

Not completed recruitment paperwork (47)

Study Dataset

(n = 607)

Received free helmet and

education (HE

) (n = 322)

Received education

) (n = 285)

Received helmet education

(H’E

) (n = 68)

Helmet Use Study Injury Study Helmet Use StudyInjury Study

Analysis

(n = 101 prior helmet

owners in 1

Survey

and 228 of 246

helmet

owners in 2

Survey

Loss to

Follow-up

(n = 76)

Loss to

Follow-up

(n = 68)

Analysis

(n = 68 in 1

Survey

and 51 prior helmet

owners in 2

Survey

Loss to

Follow-up

(n = 17)

Loss to

Follow-up

(n = 14)

Analysis

(n = 254)

Analysis

(n = 54)

Random Sampling

Figure 1. Comparing flow of participants and study sizes through each stage of study component. aHE as in Table1; bE as in Table 1;

cH’E as in Table 1; d14 participants that might have lost their helmets and 4 did not give information on helmet ownership.

history of needing medical

rtments or physician offices;

from home visits were correct in 90.5%

e 1).

he source population in the study

bers of helmet owner were small

, showed

3.6. Other Outcomes 4. DISCUSSION

A total of 9 cases gave a

attention at emergency depa

cases did not wear a helmet. All injuries were mainly

due to falling off of the bicycle. No hospitalizations or

deaths were reported from injuries while riding bicycles

or toys.

The reported characteristic features of caregivers for

injury data

Openly accessible at

8/42) of participants in the HE group and 97.6% (40/

41) in the E group. In both groups combined, the posi-

tive and negative predictive values for head injury were

100% (7/7) and (45/45) and the facial injuries (all areas)

were 85% (11/13), and 96% (43/45), respectively.

Approximately 20% to 25% in HE or H’E group by

study components were lost to follow-up (Figur

owever, the distributions of demographic characteris-

tics of children and parent information were not signifi-

cantly different between the completed follow-up vs. the

loss in follow-up categories in both the component stud-

ies under the HE group. The differences in distributions

in H’E group were not analyzed due to small numbers of

loss to follow-up.

The similarity in distributions of demographic vari-

ables of preschool children participants in the HE and E

groups may represent t

area. Although the num

H’E group, it may be a complement to the whole

study by examining the results in HE, and HE and H’E

combined (Ta bles 2-4). The increase in helmet use from

the 1st to the 2nd Survey in the HE and H’E groups among

the preschool children might be due to provision of multi-

faceted bicycle helmet education to the caregivers and

their children, and inclusion of reinforcing factors, such as,

use of Spanish language for Spanish speakers and provi-

sion of incentives [14]. Many helmet wearing occurrences

in children could be due to parental prompting.

There were a few studies on IR for head injury in pre-

school age children. One study, taking injured patients

resulting from bicycle crashes from one source and

population denominator from another source

at IR among 0 - 4 years old in Washington State for

head injury was 0.068 per 100 population in a year [7]

The rate was much lower when compared to our corre-

sponding rate, as the former study was based on emer-

T. H. Zhu et al. / Health 3 (2011) 689-697

696

of multiple episodes

rs (Ta bl e 3 ). These findings indicate the sig-

our local Head

ta were available

254) of participants in the HE

monstrated the public health importance and our

program’s worth by elucidating the magnitude of pre-

juries in helmeted riders fol-

grateful for the funding support for this research study from

the Physicians’ Council of the American Trauma Society. Additional

arkview Hospital and

Parkview Community Health Improvement Program. We thank Mary

Head

Start program fact sheet. U.S. Department of Health and

ashington DC.

) Population preventable fraction of

gency department data only.

This might be the first innovative longitudinal (fol-

low-up) study in helmet owners to estimate IRs based on

person-days and helmet protective effects for head and

facial injuries. We took advantage

injuries occurring within a child (54/105), including

those treated at home and outpatient clinics. A similar

finding of helmet protective effects between this and

other studies, for instance, helmet protective effect of

85% for head [15], and of 65% for upper and mid-face

injuries [10], signifies the appropriateness of our study

design.

The rates of injuries were much higher in non-hel-

meted children. For instance, the rate for head injury was

14 times (83.29/5.91) higher in non-helmeted than hel-

meted ride

ficance of reduction of head and facial injuries by

helmet wearing while riding and starting at the preschool

age. A similar study of increase in helmet use and de-

crease in incidence of bicycle-related head injury was

shown in 5-14 year-old children [16].

Perhaps, this is also the first study to determine PAF

as an indication of public health importance and demon-

stration of our program’s worth [17] by providing free

bicycle helmets and helmet education in

art Program. For instance, of 100 vehicle-related head

injuries occurring in this target preschool population, 77

of them would be avoided if every educated rider in the

population had worn a helmet; see Table 3. We found

the PAFs decreased as the helmet use rates increased as

shown in simulation by Kopjar [2]. In this study, PAFs

estimated by IRs seem to represent the average values

when compared with those values based on helmet use

rate and helmet effectiveness. The similarity of findings

on helmet use rates by observation and reporting, the

high predictive values for head and facial injuries on

validation, and the similarity of demographic data of

caregivers and their children between completed and

follow-up loss denote the study data were reasonably

reliable. Rockhill et al. mentioned the misuse of PAF

with respective to computational and interpretational

issues [18]. We employed the PAF formulas that were

suitably created for bicycle related injuries [2]. Kopjar

commented that the protective effect of helmets was not

confounded by previous non-use, and there was no evi-

dence of competing risks replacing the ones removed by

helmet use; these conditions were the basic criteria for

external validity of PAF estimates [2].

5. LIMITATIONS

The injury events in the follow-up study were based

mainly on reporting. Person-time da

only from 32.3% (82/

oup and 42.6% (23/54) in the H’E group. Verification

of types of helmet used was not done at the time of in-

jury. Few off-road head and facial injuries were reported

from riding bicycles and other wheeled-riding toys

within the observation period. Among those children

reported without injuries, 45 children in the HE group

and 13 children in the H’E group used bicycles with

training wheels. Due to low incidence of head and facial

injuries, PAFs by ethic groups could not be determined.

In addition, we were unable to collect and assess the

injury data by home visit for the entire follow-up period.

The extent of follow-up loss of participants, the possible

reporting biases, and the findings were mentioned in the

results.

6. CONCLUSIONS

We de

ventable head and facial in

lowing the free bicycle helmet distribution and helmet

education in this Head Start preschool children popula-

tion.

7. ACKNOWLEDGEMENTS

We are

financial requirements were supplemented by P

ee Freeze, the Director of the CANI Head Start Program in Fort

Wayne for allowing the study to take place at 10 sites. Last, but not

least, we appreciate the Parkview Hospital Community Nursing per-

sonnel and the CANI staff for their assistance in the field work.

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