Article, Pediatrics

Children treated for lawn mower-related injuries in US emergency departments, 1990-2014

a b s t r a c t

Objective: Investigate the epidemiology of lawn mower-related injuries to children in the US. Methods: A retrospective analysis was conducted of children younger than 18 years of age treated in US emergen- cy departments for a lawn mower-related injury from 1990 through 2014 using data from the National Electronic Injury surveillance System.

Results: An estimated 212,258 children b 18 years of age received emergency treatment for lawn mower-related injuries from 1990 through 2014, equaling an average annual rate of 11.9 injuries per 100,000 US children. The annual injury rate decreased by 59.9% during the 25-year study period. The leading diagnosis was a laceration (38.5%) and the most common body region injured was the hand/finger (30.7%). Struck by (21.2%), cut by (19.9%), and contact with a hot surface (14.1%) were the leading mechanisms of injury. Patients b 5 years old were more likely (RR 7.01; 95% CI: 5.69-8.64) to be injured from contact with a hot surface than older patients. A projectile was associated with 49.8% of all injuries among patients injured as bystanders. Patients injured as passengers or bystanders were more likely (RR 3.77; 95% CI: 2.74-5.19) to be admitted to the hospital than lawnmower operators.

Conclusions: Lawn mower-related injuries continue to be a cause of serious morbidity among children. Although the annual injury rate decreased significantly over the study period, the number of injuries is still substantial, in- dicating the need for additional Prevention efforts. In addition to educational approaches, opportunities exist for improvements in mower design and lawn mower safety standards.

(C) 2017

Introduction

Despite stricter safety specifications and product design changes, lawn mowers continue to be an important source of serious pediatric morbidity in the United States (US) [1-18]. Between 1990 and 2004, an estimated 140,700 children under 20 years of age were treated in

Abbreviations: ANSI, American National Standards Institute; CI, Confidence Interval; CPSC, United States Consumer Product Safety Commission; ED, Emergency Department; NEISS, National Electronic Injury Surveillance System; NMIR, No-mow-in-reverse; OPEI, Outdoor Power Equipment Institute; RR, Relative risk; US, United States.

? Address Where Work was Done:Center for Injury Research and Policy, The Research

Institute at Nationwide Children’s Hospital; 700 Children’s Drive; Columbus, OH 43205.

* Corresponding author at: Center for Injury Research and Policy, The Research Institute at Nationwide Children’s Hospital, 700 Children’s Drive, Columbus, OH 43205, United States.

E-mail address: [email protected] (G.A. Smith).

US emergency departments (EDs) for lawn mower-related injuries [12]. Initial treatment of pediatric lawn mower-related injuries costs about $90 million annually [19]. The long-term physical, psychological, and financial effects of these traumatic injuries can be devastating for those injured and for their families [8,17,19-22].

Lawn mower-related injuries have previously been described, but many studies were published years ago [1-3,6,9,19,23,24]. Previous studies using data from the National Electronic Injury Surveillance Sys- tem (NEISS) examined fewer years and conducted less comprehensive analyses than the current study [8,10,13,14,17]. Most did not evaluate the case narratives included in the NEISS database to investigate mech- anism of injury and other variables regarding the circumstances of the injury. Other studies were limited in focus, analyzing data from a single hospital system [3,4,9,11] or about a type of mower [14].

This study comprehensively analyzes data over a 25-year period using a nationally representative database to evaluate the

http://dx.doi.org/10.1016/j.ajem.2017.03.022

0735-6757/(C) 2017

epidemiologic characteristics, including mechanism of injury, of lawn mower-related injuries to children in the US. It also provides a discus- sion of relevant injury Prevention strategies.

Methods

Data sources and case selection criteria

This study analyzed data for lawn mower-related injuries among children younger than 18 years old treated in EDs from January 1, 1990 through December 31, 2014. Data were obtained from the Nation- al Electronic Injury Surveillance System (NEISS), which is operated by the US Consumer Product Safety Commission (CPSC) to monitor con- sumer product-related and sports and recreation-related injuries treat- ed in US EDs. NEISS collects data daily from a sample of approximately 100 EDs, which represent a stratified probability sample of the N 5300 hospitals with a 24-hour ED with 6 or more beds in the US and its terri- tories [25]. The NEISS database contains information on patient age, gender, locale of injury, injury diagnosis, injured body region, disposi- tion from the ED, product(s) involved, and a brief narrative of the cir- cumstances of the injury incident.

Data regarding lawn mower-related injuries (product codes 1401, 1402, 1422, 1439, and 1448) reported to the NEISS were obtained for the 25-year study period. The narrative for each case was reviewed to identify miscoding and to create new variables describing injury cir- cumstances. Cases were excluded from analysis if the outcome was fatal (2 cases) or if the injury was unrelated to a lawn mower. The US Census Bureau’s July 1 intercensal and postcensal residential population estimates were used to calculate injury rates in this study [26].

Study variables

NEISS case narratives were used to code for mechanism of injury, user type (operator, passenger, bystander, other), and mower part or object associated with the injury (projectile, mower blade, or other). Case coding definitions were refined through an iterative process com- paring coding agreement among authors to achieve consistent assign- ment of categories.

The NEISS codes for locale of incident were regrouped into: home (included the NEISS categories of home, farm, and manufactured/mo- bile home), and non-home (included school, sports/recreation place, street/highway, industrial place, and other public place).

Mechanism of injury categories consisted of: 1) fell and struck/ struck on (included tripped and fell), 2) struck by, 3) fell off, 4) run over, 5) backed over, 6) cut by, 7) caught/entrapped, 8) contacted a hot surface, 9) tip-over/roll-over, and 10) other (included mower mal- function, overextension, and other specified mechanisms). The “backed over” category included cases in which the patient was backed over by a ride-on mower. A case was coded as “cut by” if the narrative specified that the patient was struck or hit by the blade, if a body part went under the mower deck with the blades, if the patient stepped on some- thing while mowing, or if the narrative indicated an unspecified lacera- tion or amputation. For cases with more than one mechanism mentioned, such as “patient fell off mower and then was run over,” rules for assigning a mechanism were established as followed: 1) being backed over took precedence over falling off the mower; 2) falling off took precedence over striking on/falling and striking/tripping and falling, being run over, and being caught/trapped in the mower; 3) being run over took precedence over being caught/entrapped; and 4) striking on/falling and striking/tripping and falling took precedence over contact with a hot surface.

The NEISS injury diagnoses were grouped into: 1) laceration (includ-

ed the NEISS categories of laceration, puncture, and avulsion), 2) burn (included thermal, chemical, scald, radiation, and electrical burn, and burns not specified), and 3) soft tissue injury (included contusion/abra- sion, crushing, and hematoma). Fracture, amputation, foreign body, and

sprain/strain were each kept as separate categories without regrouping. All remaining NEISS codes for injury diagnosis were grouped into “other.”

For body part injured, NEISS categories were grouped into: 1) head/ neck (included head, ear, face, mouth, and neck), 2) trunk (included upper trunk, lower trunk, and pubic region), 3) upper extremity (included shoulder, upper arm, elbow, lower arm, and wrist), 4) lower extremity (included upper leg, knee, lower leg, and ankle), 5) hand/finger, 6) foot/toe, 7) globe of eye, and 8) other (included all remaining NEISS codes).

Disposition from ED categories were grouped into three categories:

1) admitted (including NEISS categories: treated and transferred to another hospital, treated and admitted for hospitalization, and held for observation), 2) treated and released, and 3) left against medical advice.

Data analysis

Data were analyzed using IBM SPSS Statistics for Windows, Version

19.0 (IBM Corp., Armonk, NY) and SAS Enterprise Guide 7.11 HF3 (SAS Institute Inc., Cary, NC) statistical software. Complex survey procedures, which accounted for the NEISS sampling design, were used to calculate national estimates and the Taylor series linearization method was used to calculate the variance of the estimates. All estimates reported in this study are stable estimates unless stated otherwise. An estimate is deemed potentially unstable if the estimate is b 1200 cases, the sample size is b 20 cases, or the coefficient of variation is N 33% [27]. Trend anal- yses were performed using weighted linear regression with weights equal to the inverse of the variance of the estimated statistics. The esti- mated annual rate of change from the regression model, denoted by “m,” was reported along with the p-value associated with the t-test used to test for its statistical significance. Other statistical analyses in- cluded Rao-Scott ?2 test for association and calculation of Relative risks (RRs) with 95% confidence intervals (CIs). Statistical significance was determined at the level ? = 0.05. This study was approved by the Institutional Review Board of the authors’ institution.

Theory

This study provides a comprehensive epidemiological analysis of na- tionally representative emergency department data covering a 25-year period regarding an important source of ongoing pediatric injury mor- bidity. In addition, within the context of study findings, it describes rel- evant injury prevention strategies.

Results

An estimated 212,258 (95% CI: 176,130-248,386) children b 18 years of age were treated for lawn mower-related injuries in US EDs from 1990 through 2014 (Table 1). This equaled an average of 8490 (95% CI: 7045-9935) injuries annually or 11.9 (95% CI: 9.8-13.9) injuries per 100,000 US children. The number of injuries per year de- creased significantly by 53.9% (m = -191.8; p b 0.001) from 10,420

(95% CI: 6960-13,880) in 1990 to 4808 (95% CI: 2985-6631) in 2014

(Fig. 1). The annual injury rate per 100,000 children b 18 years of age de- creased significantly by 59.9% (m = -0.32; p b 0.001) from 16.2 (95% CI: 10.8-21.6) in 1990 to 6.5 (95% CI: 4.1-9.0) in 2014. The mean and

median age of injured patients was 9.9 years (standard deviation: 0.12) and 10.6 years (interquartile range: 4.2 to 14.2), respectively. The age distributions of the injured patients were bimodal with peaks at 2 and 15 years of age (Fig. 2).

The majority of children injured by a lawn mower were boys (77.2%) and 42.1% were 13-17 years of age (Table 1). Of the 73.2% of cases with a known locale of injury, 97.1% occurred at home. Mechanism of injury was specified in 96.3% of cases, and among these, “struck by” (21.2%) was the most common mechanism of injury, followed by “cut by” (19.9%) and “contact with hot surface” (14.1%). “Back-over” incidents

Table 1

Characteristics of children treated in United States emergency departments for lawn mower-related injuries by age group, NEISS 1990-2014.

Characteristics

Age group

Total

0-4 yrs

5-12 yrs

13-17 yrs

N (%a)

N (%a)

N (%a)

N (%a)

95% CI

Study total (row %)

51,005 (24.0)

71,896 (33.9)

89,357 (42.1)

212,258 (100.0)

176,130-248,386

Gender

Male

36,356 (71.3)

53,482 (74.4)

73,909 (82.8)

163,747 (77.2)

136,513-190,982

Female

14,648 (28.7)

18,414 (25.6)

15,375 (17.2)

48,437 (22.8)

39,247-57,628

Subtotal

51,005 (100.0)

71,896 (100.0)

89,284 (100.0)

212,185 (100.0)

176,130-248,386

Incident location Home

38,450 (98.7)

53,001 (97.7)

62,344 (95.6)

153,795 (97.1)

125,749-181,841

Other

516 (1.3)b

1234 (2.3)

2838 (4.4)

4588 (2.9)

3155-6022

Subtotal

38,966 (100.0)

54,235 (100.0)

65,182 (100.0)

158,383 (100.0)

129,519-187,247

Mechanism of injury Struck by

5870 (11.7)

16,881 (24.2)

20,760 (24.5)

43,511 (21.2)

35,079-51,943

Cut by

4463 (8.9)

11,436 (16.4)

24,790 (29.2)

40,689 (19.9)

33,659-47,718

Contacted hot surface

20,014 (39.8)

4638 (6.6)

4159 (4.9)

28,811 (14.1)

23,153-34,469

Struck on/fell and struck/tripped and fell

5492 (10.9)

10,767 (15.4)

6484 (7.6)

22,743 (11.1)

17,914-27,571

Fell off

6641 (13.2)

8596 (12.3)

3223 (3.8)

18,460 (9.0)

14,718-22,201

Caught/entrapped

2,170 (4.3)

5,610 (8.0)

6,580 (7.8)

14,360 (7.0)

11,395-17,324

Run over

2773 (5.5)

4351 (6.2)

3416 (4.0)

10,540 (5.1)

8488-12,593

Tip-over/roll-over

421 (0.8)b

861 (1.2)b

2259 (2.7)

3541 (1.7)

1960-5121

Backed over

1147 (2.3)b

480 (0.7)b

15 (0.0)b

1641 (0.8)

1019-2263

Other

1234 (2.5)

6253 (8.9)

13,145 (15.5)

20,632 (10.1)

15,457-25,807

Subtotal

50,223 (100.0)

69,873 (100.0)

84,832 (100.0)

204,927 (100.0)

170,564-239,291

User type

Operator

1015 (7.5)b

16,644 (56.1)

48,253 (93.5)

65,912 (69.5)

53,117-78,707

Bystander

5015 (37.1)

4875 (16.4)

1240 (2.4)

11,130 (11.7)

8458-13,803

Passenger

2785 (20.6)

2980 (10.0)

1058 (2.1)b

6823 (7.2)

4499-9147

Other

4718 (34.9)

5152 (17.4)

1066 (2.1)b

10,936 (11.5)

8379-13,494

Subtotal

13,533 (100.0)

29,650 (100.0)

51,618 (100.0)

94,801 (100.0)

76,557-113,046

Object associated with injury Projectile

4161 (8.3)

11,418 (16.7)

11,358 (13.9)

26,937 (13.5)

21,340-32,534

Mower blade

1663 (3.3)

4868 (7.1)

11,308 (13.8)

17,839 (8.9)

14,260-21,418

Other

44,079 (88.3)

52,081 (76.2)

59,158 (72.3)

155,318 (77.6)

128,579-182,058

Subtotal

49,903 (100.0)

68,367 (100.0)

81,825 (100.0)

200,095 (100.0)

166,407-233,782

a Column percentages may not sum to 100.0% due to round error.

b Estimate is potentially unstable due to sample size b 20 cases, estimate b 1200, or coefficient of variation N 33.0%.

accounted for 0.8% (1641 estimated cases) of injuries, and of these, 69.9% (1147, estimate is potentially unstable) were to patients b 5 year of age. Patients b 5 years of age were more likely to be injured by contact with a hot surface than older patients (RR: 7.01; 95% CI: 5.69-8.64;

39.8% vs 5.7%), while patients 5-17 years of age were more likely to be injured as a result of being “struck by” (RR: 2.08; 95% CI: 1.64- 2.64; 24.3% vs 11.7%) or “cut by” (RR: 2.64; 95% CI: 2.16-3.21; 23.4%

vs 8.9%) than younger patients. Information for “user type” was

Fig. 1. Estimated number and rate of children treated in United States emergency departments for lawn mower-related injuries by year and gender, NEISS 1990-2014.

Fig. 2. Estimated number and rate of children treated in United States emergency departments for lawn mower-related injuries by child age and gender, NEISS 1990-2014.

available for 43.8% of cases, and of these, 69.5% were operators, 11.7% were bystanders, and 7.2% were passengers. The majority of patients age 5-12 years (56.1%) and 13-17 years (93.5%) were injured as an op- erator, while the majority of patients b 5 years of age were injured as a bystander (37.1%) or passenger (20.6%). Of the 94.0% of cases with a mower part or object associated with the injury, projectiles and mower blades were associated with 13.5% and 8.9% of the injuries, re- spectively. Almost half (49.8%) of the bystanders were injured by

projectiles. Patients who were bystanders were 3.30 times (95% CI: 2.78-3.92; 49.8% vs 15.1%) more likely to be injured by a projectile than operators and passengers combined.

The most common types of lawn mower-related injuries were lacer- ations (38.5%) and burns (15.0%; Table 2). Though less common, ampu- tations accounted for 4.4% of the injuries. Patients b 5 years of age were more likely to sustain a burn than older patients (RR: 6.01; 95% CI: 4.93- 7.33; 41.0% vs 6.8%), while patients 5-17 years of age were more likely

Table 2

Characteristics of lawn mower-related injuries treated in United States emergency department among children by age group, NEISS 1990-2014.

Characteristics

Age group

0-4 yrs

5-12 yrs

13-17 yrs

Total

N (%a)

N (%a)

N (%a)

N (%a)

95% CI

Study total (row %)

51,005 (24.0)

71,896 (33.9)

89,357 (42.1)

212,258 (100.0)

176,130-248,386

Body region injured

Hand/finger

21,693 (42.5)

15,626 (21.8)

27,588 (31.1)

64,907 (30.7)

53,659-76,155

Lower extremity (excl. foot/toe)

6294 (12.3)

15,653 (21.9)

16,474 (18.5)

38,422 (18.2)

31,385-45,459

Foot/toe

5377 (10.5)

11,070 (15.5)

15,855 (17.8)

32,301 (15.3)

26,578-38,024

Head/neck (excl. globe of eye)

11,409 (22.4)

11,452 (16.0)

7435 (8.4)

30,296 (14.3)

23,915-36,678

Upper extremity (excl. hand/finger)

2765 (5.4)

7871 (11.0)

7526 (8.5)

18,161 (8.6)

14,732-21,590

Trunk

1892 (3.7)

4352 (6.1)

5566 (6.3)

11,810 (5.6)

8586-15,034

Globe of eye

1069 (2.1)b

4127 (5.8)

5457 (6.1)

10,653 (5.0)

8247-13,059

Other

505 (1.0)b

1425 (2.0)b

2941 (3.3)

4871 (2.3)

3011-6732

Subtotal

51,005 (100.0)

71,575 (100.0)

88,842 (100.0)

211,422 (100.0)

175,824-247,021

Diagnosis

Laceration

14,914 (29.2)

31,631 (44.1)

35,033 (39.3)

81,578 (38.5)

67,467-95,690

Burn

20,882 (41.0)

5628 (7.8)

5,344 (6.0)

31,855 (15.0)

25,718-37,991

Soft tissue injury

6046 (11.9)

11,580 (16.1)

13,423 (15.0)

31,048 (14.6)

24,791-37,306

Fracture

2830 (5.5)

7943 (11.1)

9248 (10.4)

20,021 (9.4)

16,249-23,794

Sprain/strain

632 (1.2)b

4086 (5.7)

7521 (8.4)

12,239 (5.8)

9228-15,251

Amputation

2344 (4.6)

3019 (4.2)

3908 (4.4)

9271 (4.4)

7328-11,214

Foreign body

291 (0.6)b

2503 (3.5)

4172 (4.7)

6966 (3.3)

5285-8647

Other

3054 (6.0)

5404 (7.5)

10,573 (11.8)

19,031 (9.0)

13,793-24,268

Subtotal

50,993 (100.0)

71,793 (100.0)

89,223 (100.0)

212,009 (100.0)

176,289-247,728

ED disposition

Treated and released

45,543 (89.3)

65,162 (90.7)

83,892 (93.9)

194,597 (91.7)

161,223-227,972

Admitted

5425 (10.6)

6691 (9.3)

5265 (5.9)

17,381 (8.2)

13,542-21,220

Left against medical advice

7 (0.0)b

27 (0.0)b

199 (0.2)b

233 (0.1)b

25-442

Subtotal

50,975 (100.0)

71,880 (100.0)

89,357 (100.0)

212,212 (100.0)

176,499-247,925

a Column percentages may not sum to 100.0% due to round error.

b Estimate is potentially unstable due to sample size b 20 cases, estimate b 1200, or coefficient of variation N 33.0%.

to be diagnosed with a fracture than younger patients (RR: 1.92; 95% CI: 1.45-2.55; 10.7% vs 5.5%). The hand/finger (30.7%) was the most com- monly injured body region, followed by the lower extremity (18.2%) and foot/toe (15.3%; Table 1). Of the injuries to the globe of the eye, 48.2% were a result of being struck by a projectile. Most (91.7%) patient were treated and released. Overall, 8.2% of injured children were admit- ted to the hospital, while 21.0% of bystanders, 18.8% of passengers, and 5.1% of operators were admitted. Patients who were bystanders or pas- sengers were 3.77 times (95% CI: 2.74%-5.19; 20.1 vs 5.3%) more likely to be admitted than operators.

Discussion

Approximately 8500 children b 18 years of age were injured annual- ly during the study period, equaling about one child every hour. Howev- er, the injury rate decreased by more than half from 1990 to 2014. The cause of this decline is unknown, but is likely attributable to multiple factors. Voluntary safety specifications for both walk-behind and ride- on lawn mowers were first published in 1987 by the American National Standards Institute (ANSI) and the Outdoor Power Equipment Institute (OPEI) and have been revised periodically since then [18]. Improve- ments in lawn mower design based on these safety specifications are likely to be an important contributing factor to the observed decline in lawn mower-related injuries. Increased awareness of lawn mower-re- lated hazards resulting from widespread education on mower safety also may have influenced the observed declining trend [6,7,28,29].

Children b 5 years old in our study were more likely to be injured from contact with a hot mower surface and sustain a burn compared with older children. This is consistent with previous research [12]. Young children are curious and tend to explore their environments without awareness of hazards, such as hot surfaces. The most recent re- vision of the ANSI/OPEI voluntary safety specifications, released in 2012, includes a new testing protocol for shielding hot mower surfaces [30]. However, the protocol uses a 95th percentile adult male maneuvering a finger probe while seated in the mower operating position, and does not consider the circumstances of injury to young children who may ap- proach the mower from positions other than the operator’s seat. In this study, most children 5-12 years of age were injured as the mower oper- ator. The developmental immaturity of this age group to properly oper- ate mowing equipment is likely a contributing factor to the occurrence of these injuries. Because of the coordination, strength, and judgment required to operate mowing equipment, the AAP recommends that chil- dren not operate a walk-behind lawn mower until at least 12 years of age and a ride-on mower until at least 16 years of age [6].

Children injured as passengers or bystanders were more likely to be admitted to the hospital. This demonstrates the risk of serious injury to children who are not directly using a lawn mower, and the need to pro- tect non-operators of mowers, especially young children. Children should never be carried as a passenger on a ride-on mower, because they can easily be injured in a fall or tip-over [6]. An important cause of injury among bystanders is being struck by a thrown object. In this study, bystanders were more than three times more likely to be injured by projectiles than lawn mower passengers or operators. A rotary mower blade can launch an object at a speed of N 200 miles an hour [31]. Because of their short stature, young children may be more likely to be struck in the head or trunk by a projectile, resulting in an injury that is more severe than a strike to the lower extremity of an adult. In addition, almost half of the injuries to the globe of the eye in this study resulted from a projectile. This supports the use of protective eye- wear by lawn mower operators.

Though relatively uncommon, lawn mower-related back-overs can cause devastating injuries. These injuries often result in major amputa- tions and other permanent disabilities with associated Financial burden. These injuries also may lead to post-traumatic stress disorder, anxiety, and depression [21]. An estimated 1641 back-over injuries occurred na- tionwide during the 25-year study period. Children b 5 years of age

accounted for 69.9% of the back-over injuries; however, this estimate is potentially unstable because the estimate is b 1200 cases. Typical cir- cumstances associated with back-over injuries involve a child b 5 years of age running out to join a family member mowing the lawn on a ride- on mower, who does not see or hear the child approaching from behind. The operator shifts into reverse without looking behind the mower and backs over the child, which results in amputation or other serious injury.

Automatic Safety measures that are designed into the lawn mower are the best way to prevent injuries from mowers [30]. Rollers and shields can help keep hands and feet from penetrating under the mower, while also protecting the blades from large objects. Prevention of amputations from mowers is especially important because they are often severe, can require multiple surgical interventions, and result in permanent disability [2,19,23,32]. To help prevent back-over injuries, every ride-on mower should be equipped with a tamper-resistant no- mow-in-reverse (NMIR) mechanism. ANSI/OPEI B71.1-2003 required all ride-on mowers (except zero-turn radius and front-mount mowers) manufactured after September 1, 2004 to be equipped with a NMIR fea- ture, which disengages the blades when the mower is shifted into re- verse. However, most of these mowers also are equipped with an override switch that allows the operator to reengage the blades while in reverse. Currently, this switch is located in front of the operator on al- most all mower models with NMIR override. Operators are able to reen- gage the mower blades while traveling in reverse without ever looking behind them, which negates the safety purpose of the NMIR mecha- nism. Manufacturers should place the override switch on the back of the mower behind the operator’s seat to force the operator to turn around and look behind him/her before reengaging the blades. Current- ly, only a handful of models have the override switch on the back. In ad- dition, some ride-on mowers automatically reset the override switch to “off” when the operator shifts into a forward gear (the safest design), while others only reset when the operator manually turns off the over- ride or when the engine is shut off (less safe designs). A rearward prox- imity warning device, rearward camera, and even a simple rearview mirror are additional potential strategies for reducing the risk of back- over injuries.

In addition to safer mower design, there are other strategies to pre-

vent lawn mower-related injuries to children, including those promot- ed by the CPSC and AAP [33,34]. Young children should be kept indoors under adult supervision while a mower is in use, and children should never ride as passengers or be towed behind mowers in wagons or trailers. Children should not be allowed to operate a mower until they are developmentally ready, and they should always be taught and su- pervised by an adult before operating mowers independently. The blades should never be disimpacted while the mower is on. To reduce the risk of eye injury from projectiles, operators should wear protective eyewear when mowing. Operators should be aware of their surround- ings at all times, and should always look behind the mower before reversing.

Limitations

This study has several limitations. The number of lawn mower-relat- ed injuries is underestimated because the NEISS does not capture inju- ries treated in medical settings other than EDs or for which medical attention is not sought. An inherent selection bias also exists in the pop- ulation that receives emergency care for injuries. Therefore, the injuries reported in this study may not be representative of the entire spectrum of lawn mower-related injuries. The inconsistency in the level of detail available in NEISS narratives limited evaluation of mechanism of injury and some of the other variables considered in this study. The type of mower was not specified in many cases, and the NEISS does not yet have a separate code for zero-turn-radius mowers. The small number of back-over cases limited detailed statistical analyses of these injuries. Another study limitation was the lack of data quantifying exposure of

children to lawn mowers; however, the use of US Census data to calcu- late population-based injury rates is an acceptable alternative.

Conclusions

Lawn mower-related injuries continue to be a cause of serious mor- bidity among children. Although the annual injury rate decreased signif- icantly over the study period, the number of injuries is still substantial, indicating the need for additional prevention efforts. In addition to edu- cational approaches, opportunities exist for improvements in mower design and strengthening the voluntary safety specifications for lawn mowers in ANSI/OPEI B71.1.

Funding source

Author Karen S. Ren received a research scholarship stipend from the Barnes Medical Student Research Scholarship through the Medical Student Research Scholarship Program at The Ohio State University Col- lege of Medicine while she worked on this study. The funding organiza- tion did not have any involvement in study design; data collection, analysis or interpretation; writing of the manuscript; or the decision to submit the manuscript for publication. The interpretations and con- clusions expressed in this article do not necessarily represent those of the funding organization.

Financial disclosure statement

The authors have no financial disclosures relevant to this study.

Conflict of interest statement

The authors have no conflicts of interest relevant to this study.

References

  1. Alonso JE, Sanchez FL. lawn mower injuries in children: a preventable impairment. J

    Pediatr Orthop 1995;15:83-9.

    Vosburgh CL, Gruel CR, Herndon WA, Sullivan JA. Lawn mower injuries of the pedi- atric foot and ankle: observations on prevention and management. J Pediatr Orthop 1995;15:504-9.

  2. Farley FA, Senunas L, Greenfield ML, et al. Lower extremity lawn-mower injuries in children. J Pediatr Orthop 1996;16:669-72.
  3. Mayer JP, Anderson C, Gabriel K, Soweid R. A randomized trial of an intervention to prevent lawnmower injuries in children. Patient Educ Couns 1998;34:239-46.
  4. Still J, Orlet H, Law E, Gertler C. Lawn mower-related burns. J Burn Care Rehabil 2000;21:403-5.
  5. Bull MJ, Agran P, Gardner HG, et al. Lawn mower-related injuries to children. Pedi- atrics 2001;107:1480-1.
  6. Smith GA, Committee on Injury and Poison Prevention. Technical report: lawn mower-related injuries to children. Pediatrics 2001;107:E106.
  7. Hostetler SG, Schwartz L, Shields BJ, Xiang H, Smith GA. Characteristics of pediatric traumatic amputations treated in hospital emergency departments: United States, 1990-2002. Pediatrics 2005;116:e667-74.
  8. Vollman D, Khosla K, Shields BJ, Beeghly BC, Bonsu B, Smith GA. Lawn mower-relat- ed injuries to children. J Trauma 2005;59:724-8.
  9. Costilla V, Bishai DM. Lawnmower injuries in the United States: 1996 to 2004. Ann Emerg Med 2006;47:567-73.
  10. Lau ST, Lee YH, Hess DJ, Brisseau GF, Keleher GE, Caty MG. Lawnmower injuries in children: a 10-year experience. Pediatr Surg Int 2006;22:209-14.
  11. Vollman D, Smith GA. Epidemiology of lawn-mower-related injuries to children in the United States, 1990-2004. Pediatrics 2006;118:e273-8.
  12. Hammig B, Childers E, Jones C. Injuries associated with the use of riding mowers in the United States, 2002-2007. J Saf Res 2009;40:371-5.
  13. Hammig B, Jones C. Paediatric injuries incurred by being run over by a riding lawn mower: United States, 2002-2008. Int J Inj Control Saf Promot 2010;17:205-7.
  14. Hill SM, Elwood ET. Pediatric lower extremity mower injuries. Ann Plast Surg 2011; 67:279-87.
  15. McNamara WF, Yamout SZ, Escobar MA, Glick PL. Lawn mower-related projectile in- jury. Pediatr Surg Int 2009;25:643-5.
  16. Bachier M, Feliz A. Epidemiology of lawnmower-related injuries in children: a 10- year review. Am J Surg 2016;211:727-32.
  17. American National Standards Institute, Outdoor Power Equipment Institute. ANSI/ OPEI B71.1-2003: consumer turf care equipment – walk-behind mowers and ride- on machines with mowers – safety specifications. American National Standards In- stitute: New York, NY; 2003.
  18. Loder RT, Brown KL, Zaleske DJ, Jones ET. Extremity lawn-mower injuries in chil- dren: report by the Research Committee of the Pediatric Orthopaedic Society of North America. J Pediatr Orthop 1997;17:360-9.
  19. Loder RT, Dikos GD, Taylor DA. Long-term lower extremity prosthetic costs in chil- dren with traumatic lawnmower amputations. Arch Pediatr Adolesc Med 2004; 158:1177-81.
  20. Rusch MD, Grunert BK, Sanger JR, Dzwierzynski WW, Matloub HS. Psychological ad- justment in children after traumatic disfiguring injuries: a 12-month follow-up. Plast Reconstr Surg 2000;106:1451-8 [discussion 1459-1460].
  21. Trautwein LC, Smith DG, Rivara FP. Pediatric amputation injuries: etiology, cost, and outcome. J Trauma 1996;41:831-8.
  22. Love SM, Grogan DP, Ogden JA. Lawn-mower injuries in children. J Orthop Trauma 1988;2:94-101.
  23. Martin LI. Lawnmower injuries in children: destructive and preventable. Plast Surg Nurs 1990;10:69-70 [75-66].
  24. Schroeder T, Ault K. The NEISS sample (design and implementation): 1997 to pres- ent. https://www.cpsc.gov/s3fs-public/pdfs/blk_media_2001d011-6b6.pdf;; 2001.

    [accessed 17.02.03].

    US Census Bureau. Population estimates. http://www.census.gov/popest/;. [accessed

    17.02.03].

    U.S. Consumer Product Safety Commission. NEISS Electronic Injury Surveillance Sys- tem (NEISS) online: explanation of NEISS estimates obtained through the CPSC web- site. https://cpsc.gov/cgibin/neiss/webestimates.html#hist;. [accessed 17.02.03].

  25. American Academy of Pediatrics. Lawn mower safety. AAP parent pages; 2001.
  26. U.S. Consumer Product Safety Commission. Lawn mower safety [press release]. https://www.cpsc.gov/Newsroom/News-Releases/1987/LAWN-MOWER-SAFETY/;; 1987. [accessed 17.02.03].
  27. American National Standards Institute. ANSI/OPEI B71.1-2012: consumer turf care equipment – pedestrian-controlled mowers and ride-on mowers – safety specifica- tions vol 2016. New York, NY: American National Standards Institute; 2012.
  28. Coopwood TB. Missile injuries from power lawn mowers. Tex Med 1976;72:53-4.
  29. Dormans JP, Azzoni M, Davidson RS, Drummond DS. Major lower extremity lawn mower injuries in children. J Pediatr Orthop 1995;15:78-82.
  30. PRWeb. Steer children clear of lawn mower injuries. http://www.prweb.com/re- leases/2011/6/prweb8514669.htm; 2011. [accessed 17.02.03].
  31. U.S. Consumer Product Safety Commission. CPSC fact sheet: riding lawnmowers. https://www.cpsc.gov/PageFiles/122050/588%20Riding%20Lawnmower%20Fact% 20Sheet.pdf; 2013. [accessed 17.02.03].