Retrospective one-million-subject fixed-cohort survey of utilization of emergency departments due to traumatic causes in Taiwan, 2001–2010

In the US, publicly-available ED visit data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1997 through 2007 were assessed using codes from the International Classification of Diseases, Ninth Revision (ICD-9). ED visit rates increased from 352.8 to 390.5 per 1000 persons during that time (P = .001 for trend), and adults with Medicaid cover accounted for most of the increase in ED visits; in addition, the visit rate increased from 693.9 to 947.2 visits per 1000 enrollees (p = 0.001 for trend) between 1999 and 2007 [14]. According to NHAMCS data from 1997 to 2009, the overall adjusted probability of an ED visit being treatable in a primary care setting increased by 0.19 % (95 % CI = 0.10 to 0.28) per year. This probability increased at a rate of 0.52 % per year for Medicare patient visits (95 % CI = 0.38 % to 0.65 %), more than double that for Medicaid patient visits (0.25 % per year, 95 % CI = 0.13 % to 0.37 %). In contrast, there was no significant change from 1997 to 2009 in the average probability of an ED visit being treatable in a primary care setting in privately-insured patients (0.05 % per year, 95 % CI = −0.07 to 0.16) or uninsured individuals (0.00 % per year, 95 % CI = −0.12 to 0.13) [15]. In Taiwan, the ED visit rate, including traumatic and non-traumatic cases, was approximately 190 visits per 1000 persons in 2001, which increased significantly to 270 visits per 1000 persons in 2010 based on one-million sampled patients who were insured under the official Taiwan health insurance system. Therefore, a greater increase in the ED visit rate as measured by the AAPC, and in particular in the ED visit rate for cases due to traumatic causes, was observed in Taiwan, an Asian developing country.

In the US, older adults (aged 75 and over), non-Hispanic black persons, less wealthy people, and those with Medicaid coverage were more likely to have made at least one ED visit within a 12-month period than other subjects. Persons with Medicaid coverage were more likely to have made multiple visits to an ED within a 12-month period than those with private insurance and the uninsured [16]. Based on data from the USA National Health Interview Survey in 2012, 18 % of children aged 0–17 years visited the ED, and children with Medicaid coverage were more likely than uninsured children and those with private coverage to have visited the ED at least once in the past year [17]. A recent systematic review concluded that in most healthcare systems, frequent ED users were more likely to be older, female, and have a mental health diagnosis, and previous hospitalizations and high primary care use were associated with future frequent ED use [18]. The main finding of the present study was that female subjects and the elderly (aged 65 years or more) exhibited a greater increase in the incidence of ED visits for traumatic reasons in Taiwan.

Overcrowding of EDs is an important issue, and in order to design strategies aimed at avoiding overcrowding, mathematical models used to predict ED patient volume are considered essential. Most of the models used to predict patient volume are linear regression models, including Poisson regression models or time series models that can include calendar- or climate-related variables. These models explain 31–75 % of the patient-volume variability [19‐22]. A significantly increased rate of ED utilization was found in the present study, especially with regards to traumatic cases, of which cases of soft tissue trauma of extremities and various fractures were the categories that exhibited the greatest increasing tendencies. This information is useful to inform Taiwan’s health authorities with regards to the delivery and distribution of medical resources.

In Singapore, a statistical report showed that 40.7 % of ambulance arrivals were attributable to trauma, versus 27.3 % of walk-in arrivals. The majority of trauma cases brought in by ambulance was because of road traffic accidents, followed by accidents in the home [23]. In India, traffic crashes and consequent injuries represent a growing public health concern. Open wounds and superficial injuries to the head (69.3 %), upper extremities (27 %) and lower extremities (24 %) were found to be the most common injuries [24]. Based on data from the state-wide trauma registry in Queensland, Australia, from 2006 to 2010, moped/scooter riders sustained a greater percentage of head/neck (+8.6 %), facial (+3.0 %) and abdominal injuries (+2.3 %), whereas motorcycle riders sustained a greater percentage of upper extremity (+4.0 %), thoracic (+3.9 %), spinal (+3.6 %) and lower extremity injuries (+2.6 %) [25]. In Taiwan, the incidence of traffic accident-related hospitalization was between 9.17 and 11.54 %, and in all inpatients admitted due to road traffic accidents, the orthopedic fractures of (1) fracture of upper limb, (2) fracture of lower limb, and (3) fracture of spine/trunk were the most common injuries, accounting for 29.36 % of all injuries [26]. Road traffic accidents involving motorized two-wheeled vehicle (MTV) riders often result in severe morbidity and mortality. Many studies have focused on this specific issue [27, 28]. In the present study, which focused on traumatic injuries, most traumatic cases presenting at EDs had sustained superficial or open-wound injuries; however, the traumatic categories of sprains/strains of joints and adjacent muscles, fractures of upper limbs, fractures of lower limbs, and fractures of the spine/trunk exhibited significant annual increases in incidence. Most traumatic ED cases in the present study were sent to highest-level hospitals, which is contrary to another study performed in Taiwan showing the use of the ED service in the nearest community hospital to be more acceptable in an emergency situation than medical center treatment for dying cancer patients [29]. More detailed evaluation is needed in future studies to examine the causes of accidents and the subsequent morbidity or mortality.

Some limitations were still persisted in the present study. In Taiwan, no researchers can approach all the NHI beneficiaries’ inpatient and ambulatory medical records. A longitudinal health dataset of one million fixed cohort populations, including their inpatient and ambulatory medical records, was the most popular research databank. However, more detailed personal information such as occupation, education level, living area, or healthy habitus were absent. Up to now, there were three isolated longitudinal datasets containing LHID2000, LHID2005 and LHID2010 that can provide only point estimates for epidemiological studies due to lack of available data of whole Taiwan’s population in each calendar year. In another way, during the study period of 2001–2010, 10 separated cross-sectional surveys in each calendar year might be performed based on the truly dynamic total population but only 0.2 % of the ambulatory care records extracted by systematic sampling method have been allowed to be released to Taiwanese researchers [13]. Finally, the latest longitudinal health dataset (LHID2010) in Taiwan was chosen to perform a descriptive epidemiological analysis that was designed as a retrospective fixed-cohort study.