Background
Upper extremity injuries account for a substantial proportion of all injury patients visiting the Emergency Departments (EDs). Besides the impact of upper extremity injuries on health and daily life, they impose an economic burden on the community.
The upper extremity consists of the shoulder (i.e., clavicle and scapula), upper arm (i.e., proximal humerus and humeral shaft), elbow (i.e., distal humerus, proximal radius and ulna), forearm (i.e., ulna and radius), wrist (i.e., distal radius and ulna, carpal bones), and hand (i.e., metacarpal bones and the phalanges). Injuries seen in the upper extremity include fractures, dislocations, sprains, contusions, wounds, and superficial lesions.
Population-based knowledge on the economic impact of upper extremity injuries is essential for the allocation of health care services, optimization of preventive measures and research purposes; it also provides a forecast for the future. Most epidemiologic studies on upper extremity injuries primarily focused on one distinct subgroup such as a separate type of injury, anatomical region, or age group [
1‐
15]. In most studies, data from single hospitals or regional data were used [
2,
3,
8,
11‐
13,
15‐
17]. Few publications used a national injury database [
1,
4,
5,
7,
9,
18,
19]. Data regarding the associated health care costs are generally lacking. Some studies report direct costs of upper extremity injuries, mostly fractures [
2,
19‐
23]. No papers reported on both incidence trends and costs of all injuries to the upper extremity.
Due to budgetary restraints and increasing costs for health care services, economic analyses are becoming more important. The aim of this study was to examine recent long-term population-based trends in the incidence of upper extremity injuries in the Dutch population between 1986 and 2008 and to give a detailed overview of the associated health care costs in 2007.
Discussion
Upper extremity injuries accounted for 42% of all injury-related visits to the Emergency Departments (EDs). In the past 25 years the overall incidence of upper extremity injuries in the Netherlands increased by 13%. Throughout the years, the incidence was age and gender related. The increase in incidence of upper extremity injuries is most evident in patients aged 60 years and above. Fractures are the most expensive type of injury, especially in women.
Our data demonstrate an evident influence of age and gender on the incidence of certain upper extremity injuries. The 10–14 year old boys group is prone to wrist fractures, as shown before [
34,
35]. During this age, an increased calcium demand combined with maximal skeletal growth and an increased physical activity leads to more fractures [
35]. Young males have a higher upper extremity injury incidence than females of the same age, which seems in line with previous findings that young males experience more road traffic incidents and sports trauma [
3,
19]. Women suffer significantly more fractures when aged 65 years and over, which seems attributable to the increasing occurrence of postmenopausal osteoporosis in elderly women [
6,
9,
10,
36]. An equal rise in humeral fractures in females of this age-group supports this. In addition, the higher rate of falls may also explain the rise in fractures in the elderly [
29,
30].
Several studies describe incidence rates on injuries that were also included in the current study. Since these used another reference population form the standardization, absolute numbers may differ. However, trends remain indicative. Lofthus
et al. reported that incidence rates on wrist fractures in females aged 50 and over range from 554 to 1,098 per 100,000 [
16]. This seems slightly higher than the incidence found in our study (average 489, range 430–621 per 100,000), but this may be due to differences in the reference population. In literature, dislocation of the glenohumeral joint ranged from 11.2-27.0 per 100,000 person years [
1,
37,
38]. This is lower than the incidence (51.2 per 100,000) found in our study, which also contained dislocation of the acromioclavicular joint. In accordance with our data, all studies displayed a higher incidence of shoulder dislocations in men than in women [
1,
37,
38].
Even though the age-adjusted incidence rates for men and women were similar, the total costs of upper extremity injuries for females almost doubled those of males. This huge difference is for a considerable part attributable to the higher costs per case in females and the female preponderance in the older Dutch population (Statistics Netherlands) [
26]. Over 75% of total costs were attributable to fractures, making them the most expensive injuries. The majority of the costs for fractures were accounted for by women (69%). Fractures were expected to have the highest costs of all injuries, due to possible hospital admissions, surgical intervention, plaster treatment, X-rays, longer rehabilitation, and physical therapy. An explanation for the extensive costs of fractures in the elderly females could be that osteoporotic bones of postmenopausal women fracture more severely [
37]. Such fractures may require more radiological evaluation and more extensive or expensive surgical interventions. Also, new surgical techniques may have lowered the threshold for surgical interventions. In addition, surgery performed in osteoporotic bone has a higher failure rate which may result in an increased rate of revision surgeries [
39]. A final explanation for the higher costs of fracture care in the elderly women could be that they outlive their partners, which may increase the chance of extended nursing home admission or home care.
To the best of our knowledge, this is the first population-based study to show trends in incidence and cost of fourteen different injuries of the upper extremity at a national level. A few other studies presented cost information of upper extremity injuries, of which most concern high-risk groups [
2,
21] or economic evaluation studies of treatment interventions [
40,
41]. Only Meerding
et al. calculated costs of fractures of the wrist, the clavicle/shoulder, and the upper arm in the Netherlands [
19]. After applying a correction for inflation, Meerding
et al. reported €1,080 for wrist fractures, €1,130 for clavicle/shoulder fractures, and €3,200 for upper arm fractures, as opposed to €1,890, €2,550 and €4,440, respectively, in the current study. The higher costs as observed in the current study may be attributable, at least partly, to a higher number of patients receiving operative treatment for fractures. Higher current costs for (new or improved) implants can also not be ruled out. Finally, recent improvement in the data sources on home and nursing care and on operative interventions may have resulted in a more accurate, most likely higher, estimate of costs in our study.
The main strength of our study is that we used up-to-date population-based data over a longer, continuous time-period. The use of data from a representative national sample of outpatients using data from a national registry is a more reliable representation of the health care problem than extrapolating data from one clinical trial or one hospital only [
24]. Although the registrations in the LIS-database only cover 12% of the Dutch population, international validation studies have shown that the mathematical model that was applied for the calculation of the overall Dutch data has a high level of completeness and validity. Meerding
et al. showed that there was a close agreement between de cases recorded in the LIS and the hospital’s discharge system [
24]. Lyons
et al. reported that there was a particularly good agreement between the extrapolated data from the LIS and the actual incidences of hospital admissions for injuries [
42]. Another strength of our study is that it presents comprehensive estimates of health care costs, including all relevant health care sectors (
i.e., hospital inpatient care, medical procedures, rehabilitation clinics, and nursing homes). The model uses data from the LIS, the National Hospital Discharge Registry, and a patient follow-up survey conducted in 2007. Unfortunately, when performing the follow-up survey, it was not known that 2007 was a year with relatively more missing data. However, due to the very large sample of the survey and the use of a uniform coding method, it was possible to compare the healthcare use and related healthcare costs of all types of upper extremity injuries [
31].
A limitation of the cost model is that indirect health care costs, such as absenteeism and work disability were not taken into account. This could be a suggestion for future research. Furthermore, there may be some statistical uncertainty due to underreporting of combined injuries. For example, patients with wounds concomitant with a fracture will be reported as fractures, not as wounds. Moreover, only patients who visited the ED were recorded in the LIS and LMR databases. Therefore patients who visited their general practitioner were not included.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
SP participated in the design of the study and the statistical analysis and drafting of the manuscript. GITI participated in the design of the study, and assisted in the data analysis and data interpretation, and drafting of the manuscript. MJMP participated in the design of the study, data collection and critical revision of the manuscript. DE participated in the design of the study, data interpretation and critical revision of the manuscript. PP participated in the design of the study, data interpretation and critical revision of the manuscript. DDH participated in the design of the study, data interpretation and critical revision of the manuscript. EMMVL supervised, and participated in the design of the study, data collection, analysis and interpretation, and drafting and critical revision of the manuscript. All authors have read and approved the final manuscript.