This is a retrospective cohort study that was conducted using the Kids’ Inpatient Database (KID). The KID is the largest publicly available all-payer pediatric inpatient care database in the United States. It entails information on approximately three million pediatric discharges each year. Patients from the 2000–2012 KID datasets were selected if they were 18 years or younger and suffered a facial fracture(s). Table 1 illustrates all the diagnostic and procedure ICD-9 codes used to identify the study sample and variables of interest.
Table 1
ICD-9 codes used to identify subjects and define variables
Study Variable | ICD-9 Codes |
Maxillofacial Fracture | |
Cranial Vault | 800.00–800.99 |
Nasal fractures | 802.0, 802.1 |
Mandible fractures | 802.20, 802.21, 802.22, 802.23, 802.24, 802.25, 802.26, 802.27, 802.28, 802.29, 802.3, 802.31, 802.32, 802.33, 802.34, 802.35, 802.36, 802.37, 802.38, 802.39, |
Malar & maxillary fractures | 802.4, 802.5 |
Orbital floor (blow-out) fractures | 802.6, 802.7 |
Other facial fractures | 802.8, 802.9 |
Mechanism of Injury | |
Motorcycle accident | E810.2, E810.3 – E825.2, E825.3 |
Car accident | E810.0, E810.1, E810.4 – E825.0, E825.1, E825.4 |
Pedal cycle accident | E826.1 |
Animal riding accident | E8282 |
Fall | E880 – E888 |
Unarmed fight/brawl | E960.0 |
Firearm assault | E965.0 – E965.4 |
Blunt object assault | E968.2 |
Other | |
Alcohol abuse | 305.0, 305.00, 305.01, 305.02 |
Cannabis abuse | 305.2, 305.20, 305.21, 305.22, 305.23 |
Cocaine abuse | 305.6, 305.60, 305.61 |
Attention Deficit Disorder of Childhood | 314.0, 314.00, 314.01 |
Other Fractures | |
Skull Base Fracture | 801 |
Vertebral Column Fracture | 805, 806 |
Rib/Sternum/Larynx/Trachea Fracture | 807 |
Pelvic Fracture | 808 |
Upper Limb Fractures | 810–819 |
Lower Limb Fractures | 820–829 |
Intracranial Injury | |
Concussion | 850 |
Cerebral laceration/contusion | 851 |
Subarachnoid hemorrhage | 852.00–852.19 |
Subdural hemorrhage | 852.20–852.39 |
Extradural hemorrhage | 852.40–852.59 |
Internal Organ Injury | |
Traumatic Pneumothorax/Hemothorax | 860 |
Heart/Lung Injury | 861 |
GI Injury | 863, 864 |
Spleen Injury | 865 |
The primary predictor variables were a set of heterogenous variables that were grouped into patient characteristics, injury characteristics, hospitalization characteristics. The primary outcome variable was total charges (US dollars). Net hospital charges do not include professional fees and non-covered charges. Any emergency department charges that were incurred before hospital admission may have been included in net charges. Patient characteristics included age group (0–2, 3–5, 5–12, 13–18 years), gender (male or female), race (White, Black, Hispanic, Asian, or other), median household income, location, payer information, number of chronic conditions, miscellaneous patient characteristics.
Injury characteristics included maxillofacial fracture (nasal, mandible, malar & maxillary, orbital floor, panfacial), other fractures (cranial vault, skull base, vertebral column, rib/sternum/larynx/trachea, pelvic, upper limb, lower limb), intracranial injury (concussion, cerebral laceration/contusion, subarachnoid hemorrhage, subdural hemorrhage, extradural hemorrhage), internal organ injury (pneumothorax/hemothorax, heart/lung injury, GI injury, spleen injury), and mechanism of injury (motorcycle accident, car accident, pedal cycle accident, animal riding accident, fall, unarmed fight/brawl, firearm assault, blunt object assault). Hospitalization characteristics included admission type, hospital region, hospital transfer (into/out), and hospitalization year (2000–2002, 2003–2005, 2006–2008, 2009–2011, 2012–2014).
Median household income was a categorical variable of income quartiles (Q1, Q2, Q3, and Q4) that was determined according to the patient’s ZIP Code. Location was a three-category scheme used to classify U.S. counties according to its population size and whether it is urban or rural. Payer information denotes the primary payer of treatment (Medicare/Medicaid, private, or self-pay). Number of chronic conditions was a categorical variable (one, two, three, four or more). The miscellaneous patient characteristics included common diagnoses identified in our study sample (alcohol abuse, cannabis abuse, cocaine abuse, or attention deficit disorder of childhood).
Panfacial fractures were defined as concurrent fracturing of the bones within the upper (frontal bone), middle (malar bone & maxilla, orbital floor), and lower thirds of the face (mandible). The ICD9 coding system codes for the cranial vault, which includes the bones of the upper third of the face, namely the frontal bone. Upper limb fractures included those to the clavicle, scapula, humerus, radius/ulna, carpal bones, metacarpal bones, and phalanges. Lower limb fractures included those to the femur, patella, tibia/fibula, ankle, tarsal bones, metatarsal bones, and phalanges of foot. Cerebral laceration and contusion included those to the cerebral cortices, cerebellum, or brainstem. The following structures were considered GI injury: liver, stomach, small intestine, large intestine, pancreas, and appendix. Admission type is binary (elective or emergency). Hospital region is a four-category variable (Northeast, Midwest, South, West).
Descriptive statistics (mean, frequency, range, standard deviations) were computed for all study variables when possible. Independent sample t test and ANOVA were used to determine significant differences in hospital charges for all predictor variables. Linear regression was used to determine independent risk factors for increased/decreased hospital charges. A P value of less than 0.05 was considered statistically significant. We used SPSS version 28 for Mac (IBM Corp., Armonk, NY, USA) to perform all statistical analyses. Since the KID is a database that is both publicly available and anonymized, we did not require institutional board review consistent with our medical center’s policy.