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Estimates of the Incidence and Costs Associated With Handlebar-Related Injuries in Children
Flaura K. Winston, MD, PhD;
Harold B. Weiss, PhD, MPH;
Michael L. Nance, MD;
Cara Vivarelli-O'Neill, MPH;
Stephen Strotmeyer, MPH;
Bruce A. Lawrence, PhD;
Ted R. Miller, PhD
Arch Pediatr Adolesc Med. 2002;156:922-928.
ABSTRACT
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Background The US Consumer Product Safety Commission is considering handlebar regulation
regarding impact performance to address the risk of abdominal and pelvic organ
injuries in bicyclists.
Objective To provide national estimates of incidence and costs of handlebar-related
abdominal and pelvic organ injuries.
Design and Setting Censuses of hospital discharge data from 19 states were extrapolated
to determine national estimates. The percentage of abdominal and pelvic injuries
associated with handlebars was estimated based on a case series from a pediatric
trauma center. Costs were estimated using standard methods.
Participants All subjects younger than 20 years treated as inpatients and discharged
from acute care hospitals for non–motor vehicle bicycle-related injury
in 19 states in 1997 and at a pediatric trauma center located in one of the
states between January 1, 1996, and December 31, 2000.
Main Outcome Measures Incidence of bicycle-related handlebar abdominal and pelvic organ injury,
total hospital charges, lifetime medical payments, lifetime productivity loss,
and lifetime monetized quality-adjusted life-years.
Results An estimated 1147 subjects (95% confidence interval, 1082-1215; 1.49
per 100 000 subjects 19 years and younger) in the United States had serious
non–motor vehicle–involved bicycle-related abdominal or pelvic
organ injury leading to hospitalization in 1997, and 886 (95% confidence interval,
828-944; 1.15 per 100 000 subjects 19 years and younger) of these injuries
likely were associated with handlebars. The estimated national costs associated
with handlebar-related abdominal and pelvic organ injuries were $9.6 million
in total hospital charges, $10.0 million in lifetime medical costs (including
claims processing), $11.5 million in lifetime productivity losses, and $503.9
million in lifetime monetized quality-adjusted life-years.
Conclusions Handlebar-related abdominal and pelvic organ injuries pose a serious
health risk to children and result in substantial health care costs. Requirements
for safer handlebar designs may provide one avenue to achieve a health and
economic benefit.
INTRODUCTION
FOR MORE than 30 years, the danger of serious abdominal and pelvic organ
injuries posed by bicycle handlebars has been known. Impact with handlebars
has been shown to produce traumatic abdominal wall hernia1-4;
renal, intestinal, liver, splenic, and pancreatic injuries5-11;
abdominal wall rupture12; abdominal aorta rupture13; transection of the common bile duct14;
traumatic arterial occlusion15; groin injuries16-17; and death.18
These injuries typically occur in the setting of otherwise minor incidents—falls
from bicycles not involving motor vehicle crashes, during which the handlebars
act as blunt spears, causing injuries on impact.19
Based on the known injury risk and the availability of safer handlebar designs,
the US Consumer Product Safety Commission is considering regulation of the
performance of handlebars regarding their energy dissipation and distribution
during impact and is reviewing comments to a petition posted in the Federal Register.20
Previous reports of the incidence of handlebar-related injuries have
been limited to the experience of individual health care settings. To our
knowledge, there has been no previous attempt to extrapolate these data to
provide national estimates of the incidence or costs of handlebar-related
abdominal and pelvic organ injuries in child bicyclists. The purpose of this
study is to provide estimates of the national perspective on the health and
economic burden of handlebar-related abdominal and pelvic organ injuries to
children.
SUBJECTS AND METHODS
Previous literature19 has demonstrated
that handlebar-related injuries occur predominantly with bicycle crashes or
falls not involving motor vehicles; therefore, the analyses in this article
were restricted to non–motor vehicle bicycle crashes and falls. The
incidence of hospitalization for bicycle-related abdominal and pelvic organ
injuries for subjects younger than 20 years was determined from a census of
hospital discharge data from 19 states for 1997. The estimated proportion
of these injuries that was related to handlebars was determined from a case
series analysis in a hospital in one of these states. These data were extrapolated,
based on US Census information, to arrive at national estimates. Costs associated
with these injuries were estimated, based on accepted health economic procedures
described herein.
19-STATE HOSPITAL DISCHARGE DATA FOR 1997
A large multistate database was created by 3 of us (H.B.W., T.R.M.,
and B.A.L.) that incorporated a census of 1997 acute care hospital discharge
data obtained from the following 19 states: Arizona, California, Florida,
Maine, Maryland, Massachusetts, Michigan, Nebraska, New Hampshire, New Jersey,
New York, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia,
Washington, and Wisconsin. These states represented 52% of the children in
the United States, based on the 1997 US Census (US Bureau of the Census, Suitland,
Md). Participating states had either mandatory E-coding or high compliance
with voluntary reporting of E-codes. The data showed a 92.6% E-code completion
rate for all abdominal and pelvic injuries to subjects younger than 20 years.
The database included information regarding the nature and cause of
injury (International Classification of Diseases, Ninth
Revision, Clinical Modification [ICD-9-CM] diagnosis codes and external
cause of injury codes, or E-codes),21 associated
hospital costs, patient demographics, and other variables. Injury severity
was assigned to each case using a computerized injury coder (ICDMAP-90; Tri-Analytics,
Inc, Bel Air, Md), which assigns Abbreviated Injury Scale (AIS) codes,22 Injury Severity Scores (mathematically computed from  1
AIS scores), and AIS-90 body regions, among other variables. E-codes were
used to identify children with a bicycle-related injury and to differentiate
between bicycle crashes that did and did not involve motor vehicles. Crashes
not involving motor vehicles were defined as those including code E826.1 or
E826.9.
1996 THROUGH 2000 CHOP TRAUMA REGISTRY
The Children's Hospital of Philadelphia (CHOP) is the level I pediatric
trauma center for southeastern Pennsylvania and the Delaware Valley (1 of
2 level I pediatric trauma centers in the state). Its trauma registry is a
census of all trauma admissions to the institution. The registry identified
children with a bicycle-related abdominal or pelvic injury between January
1, 1996, and December 31, 2000. Registry information was supplemented by data
from medical office charts, trauma histories, and physical examination forms.
Data reviewed included age, injury description and AIS codes, and textual
description of injury circumstances. The records of patients who were admitted
to the hospital with an AIS score of 2 or greater abdominal or pelvic organ
injuries after non–motor vehicle–involved bicycle crashes (codes
E826.1 or E826.9) were reviewed. Handlebar-related injuries were defined as
those cases in which the medical record documented that the handlebar impact
caused the injury (eg, "struck handlebars"). Telephone follow-up with the
injured child and his or her family was used to verify the information in
the medical record.
Case selection and stratification criteria were similar for the 19-state
hospital discharge database and the retrospective medical chart review at
CHOP. Subjects were selected based on age and ICD-9-CM
E-codes for crashes not involving motor vehicles (as already defined) and
diagnostic codes for abdominal or pelvic organ injury that would translate
to an AIS score of 2 or greater, indicating presence of organ damage. The ICD-9-CM diagnosis codes that were included were 863 through
868, 878, 879.2 through 879.5, 902, 922.2, 922.4, 926.0, and 947.3 through
947.4.
Subjects with the following criteria were excluded from our analysis:
abdominal or pelvic injuries occurring in injury circumstances not involving
bicycle crashes; motor vehicle–related bicycle crashes (eg, code E81X.6);
bicycle crash victims 20 years and older; minor handlebar-related injuries,
including superficial contusions, abrasions, and lacerations (AIS <2 injuries);
and bicyclists without injuries to the abdomen or pelvis. Minor abdominal
or pelvic injuries were excluded because they would not likely result in hospitalization
in and of themselves. Using US census data, national estimates of handlebar-related
abdominal and pelvic organ injury incidence data for the 19 states were extrapolated
to the age-specific US population to determine national estimates. The proportion
of injuries associated with handlebars was derived by multiplying national
estimates of the number of non–motor vehicle bicycle crashes associated
with abdominal or pelvic organ injuries times the proportion of these injuries
associated with handlebars, as determined by the medical record review at
CHOP.
ECONOMIC ANALYSES
In addition to the incidence of handlebar-related injury, the outcome
measures in this study included lifetime medical costs, lifetime productivity
loss, and lifetime monetized quality-adjusted life-years (QALYs). (See Table 1 for factors used in derivation
of costs.) The costs per injury used have appeared in several other studies.23-25
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Table 1. Factors for Economic Analyses*
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As recommended by the Panel on Cost-Effectiveness in Health and Medicine,26 we report the present value of future costs computed
at a 3% discount rate and adopt a societal perspective that includes all costs
associated with unintentional injuries—costs to victims, families, government,
insurers, and taxpayers. The incidence-based costs reported estimate the present
value of all expected costs over the child's expected life span. For costs
that will occur in future years, the present value is estimated, defined as
the amount one would have to invest today to pay these costs when they come
due. Costs were not assigned to duplicated medical records, readmissions,
or fatalities. Cost was estimated in 1996 dollars separately for medical and
other direct costs and for quality of life loss.26
Medical Charges and Costs
Hospital charges were taken directly from discharge records. Because
hospitals negotiate payments with third-party payers, these charges were rarely
paid in full, nor do they reflect actual costs. Medical costs of hospital-admitted
injury survivors had 3 major components. The first was inpatient cost, including
professional fees, which depends on length of stay in the hospital. The second
included ambulance, ancillary, and postdischarge costs, such as prescriptions
and follow-up medical care. The third component was the cost of processing
health insurance claims, which depends on the primary payer.
Inpatient costs were taken from hospital discharge data files from New
York (1994) and Maryland (1994-1995), the only states in which cost-control
commissions required hospitals to report their costs per patient publicly
and accurately. The costs were adjusted from state to national price levels
using 1994 American Hospital Association data on mean hospital costs per day
by state.27
Professional fees were factored in using a ratio of professional fees
to hospital payments computed from aggregate 1992-1994 Civilian Health and
Medical Program of the Uniformed Services data. Diagnosis-specific regression
models were then developed to separate the costs of injuries into a fixed
cost per admission and a variable cost per day. These models were used in
conjunction with the actual length of stay to compute a cost estimate for
each acute injury admission in the 19-state hospital data. Subsequent visits
to the hospital for the same injury were accounted for by multiplying the
cost per admission times an estimate of admissions per victim derived from
1994 Missouri hospital discharge data by principal injury diagnosis.
Ambulance, ancillary, and postdischarge costs during the first 6 months
after the injury were taken from the National Medical Expenditures Survey.28 These factors were computed as a percentage of hospital
costs for all injuries. Miller et al28 developed
diagnosis-specific ratios of 6-month to lifetime costs for injured workers.
By diagnosis, the ratios of follow-up and longer-term care were adjusted to
child-specific treatment and recovery patterns using 3 years of private health
insurance claims data from Medstat Systems Inc, Fridley, Minn.24
The adjusted ratios were used to extrapolate from the 6-month medical costs
to lifetime costs.
Finally, medical costs accounted for health insurance claims processing
costs. The ratio of claims processing costs to total claims, which varies
by payer, was derived from insurance statistics.29
These ratios were weighted by the distribution of payers to compute overall
claims processing cost percentages by diagnosis. The payer distributions were
derived from the National Hospital Discharge Survey. Total medical costs were
then inflated from 1994 to 1996 dollars using an index of medical expenditures
per capita.30
Lost Work
Work loss included losses by victims and unpaid caregivers. Our estimation
of victim costs differentiated between short-term work loss and long-term
loss due to permanent work-related disability. Although young children do
not lose work as a result of their injuries, we assumed that a parent or other
adult caregiver must lose work to care for the child. In addition, we assumed
that children who are permanently disabled have reduced work capacity as adults.
Short-term work loss of victims consisted of 2 groups of multiplicative factors:
(1) the number of lost days of wage work and household work and (2) the loss
per day for each of these categories. All computations were done by injury
diagnosis. For injuries to subjects younger than 16 years, these calculations
applied to the adult caregiver, who was assumed to lose a day's work when
comparable injury to an adult would have resulted in a lost work day.
Detailed information was available about short-term work loss days.
The number of work days an injury survivor or caregiver loses in the short
term was computed by diagnosis from 1987-1993 National Health Interview Survey
data on the probability that a worker will lose work when injured and from
1993 Bureau of Labor Statistics data on the mean days lost when an occupational
injury causes work loss. Lost household workdays were based on information
showing that workers who have only short-term disability return to household
work 10% faster than those who return to wage work.29
The National Health Interview Survey and Bureau of Labor Statistics data guided
development of analytic estimates for the other categories. A key assumption
underlying the estimates is that a given injury costs the victim or caregiver
the same number of days of ability to work, whether or not the victim or caregiver
is employed.
Days of lost ability to work were valued using the method recommended
by the Panel on Cost-Effectiveness in Health and Medicine.26
The panel suggested valuing a day of lost wage work from published national
statistics about the wage and fringe benefit loss per day of wage work by
age and sex. Household work loss per day by age and sex was taken from a published
survey analysis.28 That analysis considered
household work hours per day, the distribution of hours among tasks (eg, cooking
and yard work), and wage data by occupation.
Permanent work-related disability probabilities and the percentage of
lifetime earning capacity lost to permanent disability were derived from a
large national sample of worker injuries.31
Permanent disability was valued as a percentage of the expected value of lifetime
work. That value was the sum of the discounted present value, less lost capacity
due to the injury, of expected earnings and household work by age and sex
across the victim's remaining life span.
Lost Quality of Life
The largest cost of injury is generally the pain, suffering, and lost
quality of life experienced by victims and their families. For fatalities,
the QALYs equal the years of expected life lost discounted to present value.
For nonfatal injuries, we used diagnosis-specific QALY estimates from the Databook on Nonfatal Injury.28
Those estimates were computed in 3 steps. First, physicians rated the typical
observable losses over time for victims of every injury diagnosis cataloged
in a common diagnosis system.28 The ratings
covered 6 dimensions: bending, grasping, and lifting; cognitive; mobility;
sensory; cosmetic; and pain. Second, data were added about the probability
of permanent work-related disability by diagnosis. Third, with values for
different functional losses from surveys of the general population,32-33 the observable losses were converted
into an estimated percentage loss in quality of life measured on a QALY scale.
The surveys met the criteria subsequently established by the Panel on Cost-Effectiveness
in Health and Medicine: they were preference-based and assigned scores of
0 to death and 1 to perfect health.
To put quality of life in terms that are comparable to other costs,
we translated the QALY estimates into dollars. A value of statistical life
(VSL), defined as the amount many people collectively spend on risk reduction
in the expectation of saving 1 life (eg, how much 10 000 people spent
or would be willing to spend for a 1 in 10 000 reduction in their risk
of death), was chosen. For consistency with other studies, we used a conservative
VSL of $3 million, which is consistent with findings on how much people are
willing to pay to reduce their risk of death. This VSL was derived from more
than 50 sound studies that used survey methods or analyzed what people routinely
pay for small risk reductions—eg, the price of car safety features or
the extra wages that must be paid to induce workers to take risky jobs.34-35 Two meta-analyses suggested a VSL
range of $1.5 to $4.5 million,34-35
while less critical literature reviews suggested a $3 to $7 million range.36-37
The value of the loss of 1 QALY was then estimated from the VSL, based
on economic theory.25, 38-39
Specifically, we subtracted lifetime work loss from the VSL to avoid double-counting
and then divided the remainder by the expected years of life remaining at
the time of the QALY loss, discounted to present value. With our VSL, the
value per QALY is $97 200. Validation of this QALY estimate has been
modest. Several studies35, 40-42
showed that the pain and suffering component of jury verdicts can be predicted
from the QALY losses (r2>0.5), with juries
valuing QALYs consistent with a VSL of $1.7 to $4 million. Therefore, QALY
costs reflect real and tangible losses.
RESULTS
19-STATE HOSPITAL DISCHARGE DATA FOR 1997
In 1997, 7148 subjects younger than 20 years were discharged from hospitals
in the 19 states with any bicycle-related injury, and 668 (9.3%) of these
sustained an AIS score of 2 or greater abdominal or pelvic organ injury. Among
the children with serious abdominal or pelvic organ injury, 588 (88.0%) were
injured in bicycle crashes not involving motor vehicles.
Among the latter group, the focus of this study (Table 2), 506 (86.1%) were male and 441 (75%) were white. Ages were
distributed as follows: 13 (2.2%) younger than 5 years, 171 (29.1%) aged 5
to 9 years, 291 (49.5%) aged 10 to 14 years, and 113 (19.2%) aged 15 to 19
years. Abbreviated Injury Scale scores among the 588 cases were as follows:
407 (69.2%) AIS 2, 30 (5.1%) AIS 3, 59 (10.0%) AIS 4, and 92 (15.6%) AIS 5.
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Table 2. Costs and Hospital Lengths of Stay for 588 AIS 2 Abdominal
and Pelvic Organ Injuries From 1997 19-State Hospital Discharge Data*
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1996 THROUGH 2000 CHOP TRAUMA REGISTRY
Between January 1, 1996, and December 31, 2000, 444 pediatric patients
were identified through the CHOP trauma registry with a bicycle-related injury.
Fifty-six child bicyclists were admitted to CHOP for treatment of abdominal
or pelvic organ injuries with AIS scores of 2 or greater, with 44 (78.6%)
of these injured in bicycle crashes not involving motor vehicles. Handlebars
were unequivocally documented as impacting the abdomen in 34 (77.3%) of the
44 non–motor vehicle crashes. In the remaining 10 cases, there were
4 in which handlebars were mentioned (eg, "flew over handlebars"), but no
clear abdominal impact could be substantiated. Handlebar involvement could
not be demonstrated in any of the motor vehicle–related crashes associated
with abdominal or pelvic injury. Abbreviated Injury Scale scores among the
34 cases were distributed as follows: 8 (23.5%) AIS 2, 16 (47.1%) AIS 3, 8
(23.5%) AIS 4, and 2 (5.9%) AIS 5.
NATIONAL ESTIMATES FOR INJURY INCIDENCE AND COSTS
We estimated that, in 1997 in the United States, 1147 subjects (95%
confidence interval, 1082-1215; 1.49 per 100 000 subjects 19 years and
younger) had serious non–motor vehicle bicycle-related abdominal or
pelvic organ injury leading to hospitalization, and 886 (95% confidence interval,
828-944; 1.15 per 100 000 subjects 19 years and younger) of these injuries
may have been associated with handlebars. Hospital charges resulting from
these injuries totaled $9.6 million, while costs came to $523.9 million. Children's
handlebar-related injuries in 1997 caused $10.0 million in lifetime medical
costs, $11.5 million in lifetime productivity losses, and $503.9 million in
total lifetime monetized QALYs.
COMMENT
To our knowledge, this study provides the first national estimates of
the incidence and cost of handlebar-related abdominal and pelvic organ injuries.
In 1997 in the United States, nearly 900 subjects younger than 20 years had
abdominal or pelvic organ injury associated with handlebars, resulting in
nearly $10 million in direct hospital charges alone. These estimates indicate
that handlebar-related injuries pose a serious health risk to children at
a substantial health care cost.
Our results likely underestimate the incidence and cost of handlebar-related
injuries. We focused on handlebar-related injuries in crashes not involving
motor vehicles. The injury event in the case of a motor vehicle and bicycle
crash is complex, and the handlebar component is typically overlooked or underappreciated.
In addition, increasing numbers of children are riding other devices with
handlebars, such as scooters, further suggesting that our estimates understate
the incidence and cost of pediatric handlebar-related injuries. Also, child
bicyclists were the focus of this article because they are most at risk for
handlebar-related injuries. Adults, however, have injuries from handlebars,
as well. Therefore, safer handlebars would be advantageous for all bicyclists.
Other groups have begun to highlight abdominal organ injury from handlebars.
The Canadian Hospital Injury Reporting and Prevention Program, an emergency
department–based injury surveillance program of 10 pediatric hospitals
and 5 general hospitals, reported on the incidence of handlebar-related abdominal
injuries.43 Although only 30% of all pediatric
bicycle handlebar-associated injuries (all severities, including minor AIS
1 injuries) were to the abdomen or pelvis, 76% of the child handlebar-related
hospitalizations were because of abdominal or pelvic injuries. Furthermore,
recent data from the Canadian Hospital Injury Reporting and Prevention Program
(through March 31, 2001) indicate that 70% of abdominal injuries of all severities
to child bicyclists were suspected or definitely associated with handlebars
and that 99% of handlebar-associated abdominal injuries were in crashes not
involving motor vehicles (Steven McFaull, MSc, written communication, April
26, 2001). These data corroborate our findings that handlebar impacts are
likely associated with abdominal organ injury and that most handlebar-associated
injuries occur in bicycle crashes not involving motor vehicles.
Although most abdominal and pelvic organ injuries in children can be
managed nonoperatively, the cost nonetheless can be high. Clarnette and Beasley5 noted a solid organ injury (ie, an injury to the liver,
spleen, pancreas, or kidney) in 62.5% and a hollow organ injury (ie, an injury
to the intestines, stomach, or bladder) in 12.5% of children with a handlebar
injury at their center. Patients with a solid organ injury typically require
an inpatient hospital stay of 4 to 6 days, including a mean of 1 day in the
intensive care unit.44 In addition, significant
laboratory and radiological charges are incurred as a part of the evaluation
and subsequent monitoring of the physiologic response to the injury. Patients
with a hollow organ injury (7% of CHOP patients with abdominal or pelvic organ
injuries with AIS scores of 2), such as a duodenal hematoma or intestinal
perforation, have a significantly longer hospital course. Children sustaining
a hollow organ perforation required a mean hospital stay of 8.7 to 9.2 days,
including an operation in all cases.45 Children
sustaining blunt, nonperforating intestinal injury (duodenal hematoma) often
had hospital stays exceeding 2 weeks (range, 3-47 days).46
LIMITATIONS
This analysis required using 2 data sources to determine handlebar involvement:
a large hospital discharge data set from 19 states, extrapolated using US
Census data to generate national estimates of abdominal and pelvic injuries,
and a trauma registry with detailed medical records at a pediatric trauma
center. The CHOP population had a distribution of abdominal organ injury severity
that was somewhat higher than that of the 19-state population. Because our
extrapolations assumed that the distribution of bicycle handlebar-related
injuries in the hospital-verified population did not vary by AIS score (the
actual differences in handlebar relatedness by AIS score were 66.7% AIS 2,
88.9% AIS 3, and 71.4% AIS 4-5), the estimates would have been 10.8% lower
if the extrapolation by AIS had been stratified. On the other hand, the populations
were compared according to other factors and were comparable with respect
to hospitalizations for child bicyclist abdominal and pelvic organ injury,
as evidenced by similar distributions of abdominal and pelvic organ injuries
among child bicyclists (19-state database, 9.3%; CHOP trauma registry, 12.6%)
and by similar relationships between non–motor vehicle child bicyclist
crashes and abdominal and pelvic organ injuries (19-state database, 88.0%;
CHOP trauma registry, 78.5%). Because of these small differences, the extrapolation
to generate useful national estimates seems reasonable.
We did not use the US Consumer Product Safety Commission's National
Electronic Injury Surveillance System (NEISS) to generate national estimates
of handlebar-related injuries, because we did not believe that this method
would produce reliable results. Although CHOP is a NEISS site, a review of
5 years' worth of data revealed that none of the handlebar-related injuries
treated at CHOP were included in NEISS. This discrepancy is likely explained
because diagnoses in NEISS are based on those recorded in the emergency department
record alone (without review of the inpatient record), which would likely
not include the definitive diagnosis. The definitive diagnosis of organ damage
is often made with subsequent diagnostic testing conducted after hospital
admission.
Although more than 90% of cases of pediatric injury in the 19-state
hospital discharge data set contained E-codes, these data are subject to little,
if any, validation and quality control in most states. As a result, there
might have been some misclassification of E-codes.
The reliability of the extrapolation to national estimates from the
19 states depends on the similarity between the 52% of the population covered
and the population in the rest of the country. Although essentially a convenience
sample, it was a large sample, and distributions would have to vary substantially
in the other states to change the estimates to any significant degree. The
sample evaluated included large populations from all regions of the country.
In addition, many of the large-population states contain extensive rural and
urban areas. To compare the similarity of the burden of age-specific bicycle
injuries in the surveyed states vs the nonsurveyed states, we calculated the
3-year (1996-1998) mortality rates for bicycle crashes with and without motor
vehicle involvement for subjects 19 years and younger in both groups. The
bicycle motor vehicle–related fatality rates were 0.35 and 0.33 per
million population in the 19-state sample and in all other states, respectively.47 The fatality rate unrelated to motor vehicle involvement
was 0.03 per million population in the 19-state sample and in all other states.
Given that the 19-state bicycle-related age-specific mortality rates are similar
to the national rates, the 19-state morbidity sample was probably similar
to the rest of the states that were not included in the hospital discharge
sample.
Identification of the handlebar as causative in abdominal and pelvic
organ injury was based on review of the hospital medical records of children
identified through the CHOP trauma registry. A case was listed as handlebar-related
if specific mention was made of the handlebar in the medical record. This
likely represents an underestimate, as those cases in which the handlebar
was causative but not indicated in the medical record would not be captured.
The reliance of the extrapolation of handlebar relatedness from one trauma
center is also a limitation. However, we found in a large state in which trauma
center designation was included in the hospital discharge data that two thirds
of all cases of hospitalized bicycle injuries in children with abdominal or
pelvic AIS scores greater than 1 were taken to a trauma center.
Although the large 19-state hospital discharge database was used to
generate national estimates of injuries, the data sets used in the cost estimates
had several inherent biases. Although the permanent disability cost estimates
associated with productivity losses take into account the longer life span
of children, the cost estimates are not child-specific in all respects. In
particular, the costs do not reflect parental productivity losses amassed
in the long-term care of the permanently disabled child. Furthermore, because
children's earnings are in the future, their present value also is less than
the present value of earnings losses of young adults, even though more years
of future work are lost. Some of the minor cost contributors in this analysis
also have limitations, because data used to estimate them are 10 to 15 years
old. Inflating these old estimates to current dollars may introduce some inaccuracy,
but they contribute too little to total costs to justify the expense of collecting
new estimates.
Societal cost estimates that include monetized QALYs cannot be compared
with most other estimates that do not use them. Policy choices could be distorted
when analysts who choose to do so can, at will, inflate the costs of the condition
they are studying by adding in the monetized QALYs. Resources would be preferentially
allocated toward effective interventions that had the good fortune to be assessed
by an analyst choosing to express matters in terms of dollar costs and benefits
including monetized QALYs. Without QALY monetization, children's handlebar-related
injuries would cost $21 million and 5000 QALYs (a life-year loss equivalent
to 175 child deaths) in 1997. To offer a fair comparison including monetized
QALYs, unintentional firearm injuries of subjects 14 years and younger cost
$3.85 billion annually48—about 7.5 times
the cost of handlebar-related injuries.
PREVENTION IMPLICATIONS
Handlebar-related organ injury largely occurs in minor, non–motor
vehicle–involved events that should cause little more than a bruise
or abrasion. Unfortunately, safety improvements to reduce morbidity associated
with handlebar injuries have been slow in coming, even though the risk to
child bicyclists of handlebar impacts has been known for more than 30 years.
When products, such as handlebars, continue to cause significant morbidity
and mortality, voluntary or mandatory standards may be needed. Product modifications
offer a potential for the reduction in frequency and severity of handlebar-related
injuries and may therefore address one mechanism of bicycle-related injuries
in childhood.
Manufacturers have long worked to improve the safety of bicycles by
imposing and following design and safety standards. These standards, however,
do not cover impact attenuation of handlebars. Many bicycles for young riders
have handlebars that are small in diameter, and the small diameter of the
impacting surface causes a greater concentration of the forces on the body
surface (Mark Pozzi, MS, written communication, April 16, 2001). This places
children at increased danger of serious abdominal and pelvic injuries. As
has been demonstrated in actual crashes,19
the handlebar ends can act as blunt-ended spears, causing intra-abdominal
and pelvic organ damage. Furthermore, typical bicycle handlebars are formed
from steel or aluminum tubing, and most have no mechanical means for securing
bar end plugs or caps. As a result, handlebar ends can become uncovered during
a crash and expose the rider's body to bare metal, resulting in serious puncture
wounds.
In addition, bicycles demonstrate a range of safety hazards related
to the handlebar stems and gearshift levers mounted on the handlebars. Most
inexpensive bicycles use handlebar stems with projecting bolt heads and gearshift
levers mounted at the top of the stem. Although this location is less expensive
for the manufacturers, because it reduces the length of control cables and
number of parts required, it presents a serious injury hazard to the rider.
Because of the protrusion of the gearshift levers, there is a serious potential
for concentrations of injury-producing force on an exposed body during a crash,
especially if the gearshift levers are pointed directly rearward at the instant
of contact. However, there are more expensive, higher quality, multispeed
bicycles in which manufacturers have located the gearshift levers on the frame's
down tube, decreasing the likelihood of injury during a crash. Through consumer
awareness, existing technology for handlebars, and potential new design,20 safer handlebars can be manufactured.
Clinicians can play an important role in the prevention and treatment
of handlebar-related injuries. Through anticipatory guidance, clinicians can
educate parents about choosing and maintaining their child's bicycle. This
education might include proper sizing of the bicycle to the child, appropriate
type of bicycle for the child's age and skill level, maintenance of the bicycle
to prevent mechanical failure, and maintenance of handlebar guards. If a child
bicyclist is injured in a fall, clinicians should elicit a complete trauma
history from emergency medical services personnel, children, and witnesses.
Identification of handlebar impact may be essential to identifying serious
occult truncal injuries in child bicyclists.
This article demonstrates a substantial cost associated with preventable,
handlebar-related injuries. Safer handlebar designs that dissipate the impact
force and distribute the force over a broader surface area are feasible and
could potentially minimize the risk of handlebar-related injuries.20 The knowledge that potential solutions exist and
awareness of the substantial cost of handlebar-related injuries should prompt
discussion of feasibility of requiring safer handlebars on all bicycles.
| What This Study Adds
This study provides the first national estimates of the incidence and
cost of handlebar-related abdominal and pelvic organ injuries. It presents
evidence that handlebar-related injuries pose a serious health risk to children
and result in substantial health care costs. Requirements for safer handlebar
designs may provide one avenue to achieve a health and economic benefit.
|
|
AUTHOR INFORMATION
Accepted for publication April 11, 2002.
This study was funded in part by Emergency Medical Services for Children
and Children's Safety Network, Maternal and Child Health Bureau, Rockville,
Md, and Injury Free Coalition for Kids, The Robert Wood Johnson Foundation,
Princeton, NJ.
Dr Winston has a patent pending for a new handlebar design.
We thank Steven McFaull, MSc, and Mark Pozzi, MS, for their helpful
ideas and insights. In addition, we thank TraumaLink, The Children's Hospital
of Philadelphia, for review of the manuscript, and the Center for Injury Research
and Control, University of Pittsburgh.
Corresponding author and reprints: Flaura K. Winston, MD, PhD, TraumaLink,
The Children's Hospital of Philadelphia, 10th Floor, 34th Street and Civic
Center Blvd, Philadelphia, PA 19104.
From TraumaLink (Drs Winston and Nance and Ms Vivarelli-O'Neill) and
the Division of Pediatric General and Thoracic Surgery (Dr Nance), The Children's
Hospital of Philadelphia, the Division of General Pediatrics, Department of
Pediatrics (Dr Winston), and Department of Surgery (Dr Nance), University
of Pennsylvania School of Medicine, Philadelphia, and Center for Injury Research
and Control, University of Pittsburgh, Pittsburgh, Pa (Dr Weiss and Mr Strotmeyer);
and Pacific Institute for Research and Evaluation, Calverton, Md (Drs Lawrence
and Miller).
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