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Iowa Orthop J. 2010; 30: 115–118.
PMCID: PMC2958282




The purposes of this study were (a) to evaluate the distribution by primary payer (public vs. private) of U.S. pediatric patients aged 5-18 years who were hospitalized with a sports-related lower extremity fracture and (b) to discern the adjusted mean hospital length of stay and mean charge per day by payer type.


Children who were aged 5 to 18 years and had diagnoses of lower extremity fracture and sports-related injury in the 2006 Healthcare Cost and Utilization Project Kids’ Inpatient Database were included. Lower extremity fractures are defined as International Classification of Diseases, 9th Revision, Clinical Modification codes 820-829 under Section “Injury and Poisoning (800-999),” while sports-related external cause of injury codes (E-codes) are E886.0, E917.0, and E917.5. Differences in hospital length of stay and cost per day by payer type were assessed via adjusted least square mean analysis.


The adjusted mean hospital length of stay was 20% higher for patients with a public payer (2.50 days) versus a private payer (2.08 days). The adjusted mean charge per day differed about 10% by payer type (public, US$7,900; private, US$8,794).


Further research is required to identify factors that are associated with different length of stay and mean charge per day by payer type, and explore whether observed differences in hospital length of stay are the result of private payers enhancing patient care, thereby discharging patients in a more efficient manner.


School-aged youth sports injuries pose a serious threat to the health and well-being of young people. At least 4.3 million sports and recreational injury episodes occur each year to school-aged children in the United States.1 Lower extremity fracture (LEF) is the most

frequent traumatic orthopaedic injury,2 and the most common principal diagnosis of all hospitalizations for sports-related injuries.3

These LEF injuries can have profound negative consequences for young people in terms of their physical, mental, and emotional health.4,6 They can also place a tremendous burden on the patient's family, the health care system, and society as a whole.7

Much of the previous research on sports-related injuries in children focused on injuries that were treated in emergency departments (ED) or outpatient clinics because most of these injuries do not require hospitalization.8 Though a recent paper described the characteristics of pediatric sports injuries that resulted in hospitalization,3 it dealt with all hospitalizations resulting from sports injury and did not study payer-based hospital length of stay (LOS) and hospital charges. There is no published literature using national data to describe the LOS and hospital charges by payer type resulting from sports-related LEF injuries in the pediatric population.

The purposes of this retrospective study were (a) to evaluate the distribution by primary payer (public vs. private) of U.S. pediatric patients aged 5-18 years who were hospitalized with a Sports-Related LEF and (b) to discern the adjusted mean hospital length of stay and mean charge per day for this group of patients by payer type.


Data Source

This study used sample data from the Healthcare Cost and Utilization Project (HCUP) Kids’ Inpatient Database (KID),9 which is the only national dataset on hospital use, outcomes, and charges designed to study children's use of hospital services in the United States. The 2006 KID contains approximately 3.1 million pediatric discharges from 3,739 community, non-rehabilitation hospitals in 38 states representing all 4 geographic census regions (northeast, midwest, west, and south). This KID database includes a sampling of all hospital discharges where the patient was age 20 or less at admission during the year 2006. The sample is weighted by design to be representative of all community hospitals in the American Hospital Association annual survey of hospitals, thus allowing for extrapolation to a national estimation of 7.6 million pediatric hospital discharges. Patient demographic variables include age at time of admission, sex, race, and median household income quartiles based on the ZIP code of the family's residence. Hospitalization variables include admission month and source, diagnostic and procedure codes, duration of stay, total charges, expected payer, and discharge disposition. Hospitals included in this database are divided into strata using 6 characteristics: ownership/control, bed size, teaching status, rural/urban location, US region, and hospital type (pediatric vs. other). Bed capacity is categorized into small, medium, or large, and varied in specific bed capacity depending on whether the hospital was located in a rural area or was an urban non-teaching or urban teaching hospital.

Sample of Patients

All patients in the KID in 2006 who were aged 5 to 18 years and had a diagnosis of a sports-related injury and LEF were selected. Three International Classification of Diseases, 9th Revision, Clinical Modification,10 external cause of injury codes (E-codes) that were used for the sports patient selection were as follows: E886.0, tackles in sports that cause fall on same level from collision, pushing, or shoving, by or with other person; E917.0, striking against or struck accidentally by objects or persons in sports without subsequent fall; and E917.5, striking against or struck accidentally by objects or persons in sports with subsequent fall. Although other injuries may have been sports related, only these 3 E-codes were used specifically to identify sports injuries in this study. The LEF codes10 are 820-829 under Section “Injury and Poisoning (800-999).” Having applied the above entry criteria to the KID database, we got 2,039 discharges records. After applying sampling weights provided by HCUP to extrapolate national estimate, the final data represented 3,345 discharges nationwide. Note that, since all data are discharge level, individuals who were hospitalized multiple times will have multiple records in the KID.

Data Analysis

Statistical analyses were conducted using SAS, version 9.1.3.n Descriptive statistics including means, standard deviations/error and percentages were used to characterize the study population in total and by primary payer type. Proportional comparisons were conducted via 2 analysis. Charge data are often skewed, and between group comparisons require use of appropriate analytical methods.12-13

SAS survey procedures were employed to analyze patients and hospitalization characteristics, except for the length of stay and hospital charge variables. Instead, the least square mean analysis in SAS procedure GLM was used to assess the dependent variables length of stay and charge per day by primary payer type, adjusting for continuous variables like age, number of diagnoses, number of procedures, and number of comorbidities, and categorical variables like sex, hospital setting (rural, urban non teaching, urban teaching), hospital bed size (small, medium, large), and region of the country (northeast, midwest, south, west). The variable mean charge per day was derived as the ratio of total charges to length of stay. The level of significance for all statistical tests was set at P<.05.


In 2006, there were 3,345 children hospitalized with sports-related LEF injuries nationwide, representing 6.93% of pediatric LEF patients and accounting for 0.04% of the weighted patients in the database.

Table 1 shows the characteristics of 3,345 national hospital discharges for sports-related LEF in pediatric patients with a mean age of 13.8 years old (not shown). Among those discharges, nineteen percent (=633/3345) reported a public payer as the primary source of insurance coverage, while 81% (=2712/3345) reported having a primary private payer. Patients with a public payer were younger; with 38% aged 5-12 years and 26% aged 16-18 years, as compared to 30% and 35% of those with a private payer. It is clear that patients were predominantly male (87%), while in public payer patients 93% were male. Admission rates among seasons was stable between payer types, summer is the highest rate season, followed by fall, spring, and winter. Fifty-seven percent of private payer patients chose urban teaching hospitals for treatment, and sixty-seven percent of public payer patients did so. Patients from the southern region outnumbered every other regions patients in terms of payer types. It also showed that children with sports injuries were more likely to be admitted to large (60%), urban, teaching hospitals (55%).

Characteristics of U.S. hospital discharges for sports-related LEF pediatric aged 5-18 years by public versus private payer, 2006a

Table 2 presents the adjusted least square (LS) means for hospital length of stay and means for charge per hospital day by primary payer. Here, we only showed the relevant least square means since the calculated standard error and P value were not correct due to the complex design in KID.21 The adjusted LS mean hospital length of stay among patients with a public payer (2.50 days) was about 20% longer than the LOS among patients with a private payer (2.08 days). The adjusted mean charge per day by private payer ($8,794) is about 11.3% higher than that by public payer ($7,900).

Least square means analyses by primary payer (N=3,345)


In this study, we analyzed the KID data and found, nationwide, an estimated 3,345 LEF hospitalizations for sports-related injuries among children who were aged 5 to 18 years in 2006, resulting in annual charges of about $61 million. These will have a major impact on the health and well-being of injured children and their families. These injuries also constitute a substantial economic burden to the health care system as well. To our knowledge, this is the first study to describe the characteristics of pediatric sports injuries that result in LEF hospitalization nationwide by payer type.

The present study showed a clear gender disparity in which males were generally more likely to sustain LEF injuries than females, which is consistent with previous findings that boys were more likely to sustain sports related injuries.14,16 Our findings showed that children with sports injuries were more likely to be admitted to large, urban, teaching hospitals. Also, there were more patients from the southern region than any other region, likely reflecting climate variation.

After adjusting for potentially confounding factors, we revealed that public payer patients were hospitalized about 20% longer than those patients for whom the primary source of health insurance coverage was a private payer. Also, there exists an approximately 11.3% difference in the adjusted mean charge per hospital day by payer type. It is unclear due to the limitations of the present database analysis whether the observed differences in LOS and charge per day are the result of enhancement of care by private payers leading to a more efficient and timely hospital discharge.

There are several limitations here. The cost information provided by the KID is based on hospital charges, not actual costs. In general, they are not the same. Therefore, our estimation of total hospital charges may not reflect fully the financial impact on the patients and their families. There is an underestimation of the total number of hospitalizations because only 3 E-codes that are very specific to sports injuries were used; many other sports injuries may have codes that do not specify the injury as being sports related.8 In addition, not all hospitals in the United States were included in the KID.


This study analyzed characteristics of sports-related LEF injuries that resulted in hospitalization in children by primary insurance payer type. The physical damage and financial burden that resulted from such an injury could have a lifelong impact on the children and their families. Because children are eager to participate in sports activities and research has demonstrated that most of these injuries are preventable,17,19 orthopaedists and pediatricians can be instrumental in preventing pedi-atric sports injuries by participating in patient education, research, and programs that promote safe play.20 More research is needed to identify factors that are associated with different length of stay and mean charge per day by payer type.


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Articles from The Iowa Orthopaedic Journal are provided here courtesy of The University of Iowa