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Incidence and costs of injuries in The Netherlands

Willem Jan Meerding, Saakje Mulder, Ed F. van Beeck
DOI: http://dx.doi.org/10.1093/eurpub/ckl006 271-277 First published online: 13 February 2006

Abstract

Background: Injuries are a major and persistent public health problem, but a comprehensive and detailed overview of the economic burden is missing. We therefore estimated the number of emergency department (ED) attendances and health care costs as a result of injury. Methods: We estimated lifetime health care costs of injuries occurring in The Netherlands in the year 1999. Patient groups were defined that are homogeneous in terms of health service use. Health service use and costs per patient group was estimated with data from national databases and a prospective study among 5755 injury patients. Results: Total health care costs due to injury in 1999 were €1.15 billion, or 3.7% of the total health care budget. Major cost peaks were observed among males between ages 15 and 44 due to a high incidence, and among females from age 65 onwards due to a high incidence and high costs per patient. For the age groups 0–14, 15–44, 45–64, and 65+ ED attendances per 1000 person years were 85, 85, 43, and 49, respectively, and costs per capita were €38, €59, €43, and €210, respectively. Costs per patient rise about linearly up to age 60 and about exponentially thereafter. From age 25 onwards, females have higher costs per patient than males. Hip fracture (20%), superficial injury (13%), open wounds (7%), and skull–brain injury (6%) had the highest total costs. Most costs were attributable to falls (44%) and traffic injuries (19%). Conclusion: Young adult males, elderly females, falls, hip fractures, and minor injuries without medical need for hospitalization account for a substantial share of health care costs.

  • emergency service
  • health care costs
  • hospitalization
  • incidence
  • wounds and injuries

Introduction

Injuries account for a considerable share in the global burden of disease, which is estimated at 12% for the established market economies and even higher shares for other global regions.1 In addition to their impact on public health, injuries are a major source of health care costs, similar to the costs of cancer and stroke.2 Because injuries have a very heterogeneous origin, more detailed information on health care costs by specific injuries (diagnoses and external causes) helps to identify previously unnoticed health problems within this field. Being a unidimensional measure, costs enable rapid comparisons among types of injury that differ with respect to incidence, severity, and health care need.3 Such information assists in prioritizing the development of preventive policies and of trauma care, is an important input into economic evaluations of interventions, and may be a first step in identifying the health care inefficiencies.

Previous studies have identified substantial resources going to patients with lower extremity fractures, including hip fracture,4,5 accidental falls (30–33% of costs), and road traffic accidents (14–27%).68 However, most studies were limited to specific injuries, health care sectors, and age groups,3,812 or did not distinguish among injury diagnoses.2,13 A detailed overview of national medical costs covering the broad spectrum of external causes and injury diagnoses is lacking.

To fill this knowledge gap, we estimated health care costs of injury by an incidence-based cost model linked to an injury surveillance system. We described how health care costs are distributed by type of injury, external cause, health service, and demographic indicators. It is comprehensive for it covers all injuries and external causes, and all health services including long-term care. The Netherlands is an ideal setting for such a study, since almost 100% of the population is covered by health insurance, and most important health care sectors have administrative databases with national coverage.

Methods

Model description

We developed an incidence-based model8 to measure and describe the lifetime health care costs of injuries occurring in a specified period. The present paper contains results for the year 1999. A full description of the model is available elsewhere.14 We considered all injuries of chapter 17 of the international classification of diseases (ICD, 9th revision),15 except injuries due to medical adverse events (ICD-9 995–999, E870–E879, E930–E949), early complications of trauma (ICD-9 958), late effects of injury (ICD-9 905–909), and injuries occurring in hospitalized patients. Incidence was restricted to patients who attended a hospital Emergency Department (ED), so patients who are fully treated by primary care practitioners or at the injury scene were excluded.

We included all health services that are relevant for the treatment and rehabilitation of injury patients, except for dental care and institutions for mentally and physically disabled persons, because causal information was lacking.

We calculated lifetime health care costs of injury by multiplication of incidence, transition probabilities (e.g. chance of nursing home admission), health care volumes (e.g. length of stay), and unit costs (e.g. costs per day in nursing home). Incidence, transition probabilities and health care volumes were subdivided by patient groups that are homogeneous in terms of health service use. For each type of health service separately, we tested known predictors of health service use: age, sex, injury location and type, and indicators of injury severity,3,16,17 and patient groups were defined accordingly. Injuries were clustered by location and type into 39 groups (table 1 presents an aggregation into 25 groups) based on the literature and after consultations with national and international experts in traumatology, orthopedics, and rehabilitation. We considered hospitalization, number of injuries, and motor vehicle involvement to be indicators of injury severity.

View this table:
Table 1

Diagnostic groups used in studya and corresponding ICD-9 codes

1Skull–brain injury800–01, 803–04, 850–54, 950–51
2Facial injury (excluding wounds)802, 870–71, 918
3Vertebral column/spinal cord injury805–06, 839.0–5, 846–47, 952
4Internal organ injury860–69, 900–02, 926, 929
5Rib/sternum fracture807.0–3, 809
6Collar bone/shoulder fracture810–11
7Upper arm fracture812.0–3
8Elbow/lower arm fracture812.4–5, 813.0–3, 813.8–9
9Wrist fracture813.4–5, 814
10Hand/finger fracture815–17
11Upper extremity dislocation, strain or sprain831–34, 840–42
12Upper extremity traumatic amputation or crushing injury880.2, 881.2, 882.2, 883.2, 884.2, 885–87, 903, 927
13Pelvis fracture808
14Hip fracture820
15Shaft of femur fracture821.0–1
16Knee/lower leg fracture821.2–3, 822–23
17Ankle fracture824
18Foot/toe fracture825–26
19Lower extremity dislocation, strain or sprain835–38, 843–45
20Lower extremity traumatic amputation or crushing injury890.2, 891.2, 892.2, 893.2, 894.2, 895–97, 904, 928
21Superficial injury (including contusions)910–17, 919–24
22Open wound872–84 (excluding 880.2, 881.2, 882.2, 883.2, 884.2), 890–94 (excl. 890.2, 891.2, 892.2, 893.2, 894.2)
23Burn940–49
24Poisoning960–89
25Other and non-specified injuryb807.4–6, 818–19, 827–30, 839.6–9, 848, 925, 930–39, 953–57, 959, 990–95
  • a: Excluded are late consequences of trauma (ICD-9 905–09), early complications of trauma (ICD-9 958), and injuries due to medical adverse events (ICD-9 996–99)

  • b: Includes other fractures, other strains and sprains, injury to peripheral nerves, injury due to foreign body, other injury

Data sources

Injury cases were extracted from the Dutch Injury Surveillance System (LIS) for non-hospitalized cases and the hospital discharge register for hospitalized cases. LIS is a continuous monitoring system that records unintentional and intentional injuries treated at 17 geographically distributed EDs in The Netherlands, resulting in a representative 12% sample. The hospital discharge register has national coverage.

For inpatient hospital care and medical procedures, nursing home care, and rehabilitative services, we estimated health service use from databases with national coverage.1820 Injury patients were selected based on the registered primary diagnosis. In case of multiple injuries, we determined the primary injury in LIS by application of an algorithm giving priority to spinal cord injury, skull–brain injury, lower extremity injury above injuries in other body parts, and to fractures above other types of injury.3

The proportions of patients who incurred emergency services and general practitioner (GP) services preceding ED treatment were calculated with data from LIS.

We performed a patient follow-up among a sample of 5755 injury patients who had attended any ED participating in LIS between 14 July 1997 and 18 October 1998. We collected data on all other health service use: inhospital intensive care, outpatient visits, GP visits, outpatient physical therapy, home care, medication, and aids and appliances. Hospitalized patients and severe, less common injuries were overrepresented in the sample. Victims from self-inflicted injury and institutionalized persons were excluded. Postal questionnaires were sent 2, 5 and 9 months after the injury event. As a result, health service use estimated from the questionnaires is up to 9 months, whereas health service use derived from national databases can be considered lifetime.

Data analysis

For each health care sector for which national data were available, independent determinants of individual health service use were derived by crosstable analysis, and patient groups were defined accordingly. Length of stay in nursing homes was adjusted for the presence of comorbidity, to exclude days that are not attributable to the injury.

For all other health service use we used questionnaire data. Because the response rates of the patient follow-up were 41%, 78%, and 64% for the first, second, and third questionnaire, respectively, data were adjusted for non-response by reverse probability weighing of responders, with use of the regression coefficients of significant predictors of non-response: young adulthood and old age (75+), male sex, unadmitted, good health status, home injury or violence, and specific injuries. Because of the skewed distribution of health service use, we estimated the probability of health service use with multivariate logistic regression and multiplied this with the average health service use conditional upon positive use. Only significant (P < 0.05) predictors of health service use (see under `model description') were included in the final models.

Unit costs

For each type of health service we determined costs per volume unit that reflect real resource use (table 2). All unit costs were estimated according to national guidelines for health care costing.21 We assumed that health care fees were representative of real resource use for GP consultations, inpatient medical procedures, home care, and rehabilitative treatment. Unit costs of emergency and ordered transport, inpatient hospital days (excluding medical procedures), outpatient visits, nursing home days, other rehabilitative services, physical therapy, pharmaceuticals, and aids and appliances were calculated from national production and financial statistics.

View this table:
Table 2

Unit costsa

ResourceUnit costs
GP consultation€16
Attendance of Emergency Department€180b
Outpatient department visit€99
Day case€240
Hospitalization€382/day
Intensive care€1486/day
Medical proceduresReimbursement fees
Rehabilitation€263/day €63/h treatment
Nursing home€138/day
Physiotherapy€19/treatment
Home care€18/h domestic care €33/h nursing care
Ambulance journey€373/emergency journey €143/scheduled journey
  • a: Euro in year 1999

  • b: Average costs. Costs based on time deployment and materials, depending on injury diagnosis and severity

Costs of ED visits were decomposed and estimated as follows. Visit duration as recorded in LIS was considered as a proxy indicator of nursing costs. Visit duration (log transformed, dependent variable) and predictors of health service use (independent variables) were entered in a multivariate linear regression analysis. Costs (labour time) of physicians by injury group were determined by expert guesses from two ED physicians. National data on hospital costs were used to calibrate the estimated labour costs, and to calculate material, diagnostic, and overhead costs of ED visits. All costs are expressed in 1999 Euros.

Results

All injury incidence (70 per 1000 person years) shows a high peak among young adult males, and rises beyond age 60 for both sexes, although stronger for females (figure 1). For the age groups 0–14, 15–44, 45–64, and 65+, ED attendances per 1000 person years were 85, 85, 43, and 49, respectively. Intentional injuries account for <5% of all injuries, 52% of injuries are home injuries (26% falls, 27% non-falls). The proportions of traffic, sports, and occupational injuries are 14%, 17%, and 10%, respectively.

Figure 1

Injury frequency and incidence per 1000 person years by age and sex, The Netherlands 1999

Total medical costs of injury were €1.15 billion or 3.7% of total health care costs. Costs per capita were €66 for males and €79 for females, and costs per patient were €790 for males and €1380 for females. Total health care costs of injury reach a first peak among males aged 15–44 years due to a high incidence (figure 2). An even higher second peak is found among females beyond age 65, which is due to an increasing incidence and costs per injured patient with age, combined with their longer life expectancy compared with males. For the age groups 0–14, 15–44, 45–64, and 65+, costs per capita were €38, €59, €43, and €210, respectively.

Figure 2

Total health care costs of injury (€1000) and costs per patient (€) by age and sex, The Netherlands 1999

From age 25 onwards females show higher costs per patient than males, which is largely due to a higher consumption of home care and nursing home care.

Table 3 shows the proportions of incidence and of total health care costs divided by injury diagnoses, and their costs per patient. The four injuries with the highest health care costs are hip fracture (20%), superficial injury (13%, mainly bruises, abrasions, and contusions), open wounds (7%), and skull–brain injury (6%). Hip fractures and skull–brain injury rank 14 and 11, respectively, in terms of incidence, but result in high medical costs per patient. The high frequency of superficial injury and open wounds (51%) results in a large proportion of health care costs (20%). Out of seven injury groups with the highest total costs, four are lower extremity injury. All fractures combined are responsible for 51% of total costs and 21% of total incidence.

View this table:
Table 3

Total costs, incidence, and costs per patient by injury diagnosis, The Netherlands 1999

Injury groupTotal costsIncidenceCosts per patient
%rank%rankrank
14Hip fracture20.411.61413 6001
21Superficial injury13.4234.0141024
22Open wound6.6317.2239025
1Skull–brain injury6.342.11131007
19Lower extremity dislocation, strain or sprain5.257.7370019
16Knee/lower leg fracture5.261.31741006
3Vertebral column/spinal cord injury3.870.62166004
17Ankle fracture3.881.712230010
8Elbow/lower arm fracture3.492.89130012
9Wrist fracture3.4103.9791016
24Poisoning2.9111.613190011
10Hand/finger fracture2.9124.3570018
25Other or non-specified injury2.8134.4467021
13Pelvis fracture2.5140.32498003
15Shaft of femur fracture2.5150.22512 8002
7Upper arm fracture2.3160.92027008
2Facial injury (excluding wounds)1.9174.2646023
18Foot/toe fracture1.8182.61069020
11Upper extremity dislocation, strain or sprain1.7193.0859022
4Internal organ injury1.6200.42342005
6Clavicle/shoulder fracture1.3211.41695015
20Lower extremity traumatic amputation or crushing injury1.2221.018120013
5Rib/sternum fracture1.2230.52226009
23Burn1.1241.51577017
12Upper extremity traumatic amputation or crushing injury1.1251.019110014
Total100.0100.01000
Total costs, total injury incidence€1149 million1 100 000
Costs, incidence/1000 person years€72 20070

Superficial injuries dominate costs up to age 65. Beyond this age, hip fractures have the highest costs (table 4). Up to age 75, open wounds and skull–brain injury (including concussion) are among the six injuries with the highest costs. The importance of injuries to the upper extremities in terms of health care costs is relatively high during childhood, and from age 15 onwards injuries to the lower extremities (e.g. knee and lower leg fractures, hip fractures) increasingly dominate health care costs.

View this table:
Table 4

Six injury groups accounting for highest percentage of health care costs for selected age groups, The Netherlands 1999

0–14%15–44%45–64%65+%
1Superficial injury21.5Superficial injury19.9Superficial injury11.9Hip fracture46.8
2Elbow/lower arm fracture11.4Open wound9.9Skull–brain injury8.8Superficial injury6.3
3Open wound9.8Lower extremity dislocation, strain or sprain9.8Hip fracture7.3Knee/lower leg fracture5.6
4Wrist fracture7.6Skull–brain injury7.3Open wound7.2Pelvis fracture4.7
5Skull–brain injury7.4Poisoning5.1Ankle fracture6.6Skull–brain injury4.1
6Hand/finger fracture4.6Knee/lower leg fracture4.7Vertebral column/spinal cord injury6.5Shaft of femur fracture3.8
Costs/1000 person years€38 300€58 500€43 100€210 200

External cause information is crucial for preventive policies. Of total costs, 57% can be attributed to home injuries (44% to falls), 19% to traffic accidents, 10% to sports injuries, and 5% to occupational injuries. The majority of hip fracture costs is attributable to falls (78%, figure 3). The same accounts for ankle fractures (55%), elbow/lower arm fractures (51%), and wrist fractures (61%). Traffic accidents account for a relatively large proportion of costs of skull–brain injuries (49%), sports accidents for lower extremity dislocations/sprains and strains (32%), and occupational injuries for open wounds (15%).

Figure 3

Health care costs of top 10 and other injuries by accident category, The Netherlands 1999

Health care costs are skewly distributed with admitted patients accounting for approximately two-thirds of costs and 9.4% of total incidence. Hospital costs dominate total health care costs of injury with a share of about two-thirds, followed by home care (9.4%), nursing homes (6.4%), and physical therapy (6.1%) (table 5). Although the hospital admission rate increases with age, the share of hospital care among total costs decreases with age due to the importance of nursing home care and home care in the care for elderly.

View this table:
Table 5

Breakdown of costs by resource use (% of total costs for each age group), The Netherlands 1999

0–14 (%)15–44 (%)45–64 (%)65+ (%)Total (%)
Hospital care85.767.967.761.767.1
    Nursing20.221.832.947.933.8
    Operations4.63.94.94.04.2
    Outpatient22.416.912.24.911.9
    Emergency Department38.525.217.74.817.2
Rehabilitation hospitals1.15.76.21.03.4
Nursing homes0.90.81.814.16.4
General practitioners2.21.91.90.81.5
Ambulance services5.37.37.23.85.7
Physical therapy4.18.27.74.06.1
Home care0.27.56.714.39.4
Pharmaceuticals0.30.30.20.10.2
Aids and appliances0.30.40.50.10.3
100.0100.0100.0100.0100.0
Costs per capita, males (€)43724412366
Costs per capita, females (€)33444227179
Costs per capita, males and females (€)38594321072
Total costs (million €)1134031674641147

Discussion

Young adult males, elderly females, hip fractures, accidental falls, and minor injuries without medical need for hospitalization account for a substantial share of health care costs. High costs are either due to a high incidence (young adult males, minor injuries), high costs per patient (hip fracture, skull–brain injury), or a combination of both (elderly females). Costs per patient are higher for females than for males from young adulthood onwards due to higher costs of care.

The biggest strength of our study is that it presents comprehensive estimates of health care costs, including all relevant health care sectors, major and minor injuries, and intentional and unintentional injuries. Costs have been estimated with a uniform methodology, and are therefore fully comparable across injuries and external causes. For those health care sectors that are most important for injuries in terms of health care use—hospital inpatient care, medical procedures, rehabilitation clinics, and nursing homes—we used registries with national coverage.

We included only injured patients who attended an ED. In The Netherlands the total number of injury patients on an ED is about 1.1 million per year. A similar number of patients are fully treated by a GP or other primary health care providers.22 These are predominantly patients with minor injuries such as cuts, abrasions, superficial injuries, dislocations, strains, sprains, small burns, and poisonings. Assumed that the costs per patient will not be larger than those of superficial injuries treated at the ED, they will add 2–10% to our cost estimate, resulting in an even higher share of minor injuries.

For outpatient care and primary health services we recorded consumption up to 9 months after the injury event, and we excluded institutions for permanently disabled persons. As a result, we underestimated lifetime health care consumption that is particularly relevant for injuries with long-term needs such as permanent brain injury, spinal cord injury, and injuries involving joint damage. However, for the vast majority of injuries health care needs are in the first year post-injury.23

Injury-specific health care consumption was adjusted for comorbidity. Nursing home length of stay was estimated with data from patients without other disabling conditions. In the patient survey we only asked for health care use related to the injury. Still, hospital costs may include additional days because of pre-existing chronic conditions, particularly in elderly. This is justifiable because the injury was the cause for admission and the additional costs would not have occurred without the injury.

About 5% of ED patients had multiple injuries. The main injury was then identified by a published algorithm.3,16 Because costs were attributed to the main injury, costs of injuries that often occur in combination with more severe injuries were underestimated.

Out of pocket expenses and production losses associated with work absence and occupational disability were not included. From a macro-economic viewpoint, particularly the costs of adults and of occupational, sports and traffic injuries will be underestimated. We hypothesize that for non-hospitalized patients the costs of production losses will be even larger than their health care costs. Future research should verify this hypothesis.

The comprehensive macro-level approach of the present study makes comparisons with other studies difficult. Most cost of injury studies apply to specific injuries10 or external causes,11,24 or are restricted to hospitalized patients or specific age groups.3,9,25

Our cost estimates for traffic injuries were much higher than in Norway (18% versus 7%), whereas our proportion of costs for persons beyond 65 years was lower (40% versus 50%).23 Costs of injuries amounted to 3.7% of total health care budget, which compares favourably with 10% in the US7 and 8% in Australia.26 Compared with another comprehensive Dutch cost of illness study,2 the present study estimates higher costs for home care, and higher costs for injuries that do not need hospitalization (e.g. superficial injury, upper extremity fractures). In a classical study from the US, medical costs of injury were estimated at about $250 per capita (adjusted for inflation up to the year 1999) or about three times our estimate.8 The US study included all injuries, including those not treated in an ED, whereas the injury incidence in the US is about 1.5 times higher than in The Netherlands (e.g. traffic injuries and falls). Also, a higher price level and high administrative costs, both related to underlying health system features, are major causes of higher health care costs in the US than in Europe.27,28 In addition, our study attributes more costs to home care and emergency services, and less to pharmaceuticals.

The present study shows the substantial economic burden of injuries with a high incidence (e.g. superficial injury) compared with injuries with high medical need that occur less frequently (e.g. hip fracture). Assuming that health care costs are related to injury severity and medical need, the economic burden of injuries is related to their health burden. Cost estimates can as such be regarded a summary measure of population health similar to disability adjusted life years (DALY), and are particularly useful when data on the burden of injury are not available.

The relevance of cost of illness studies has often been criticized. They would not be an aid for prioritizing health care because they do not give information on the effectiveness, costs, and savings of interventions.29,30 We argue that comprehensive information on the (economic) burden of diseases and injuries is helpful for policy-makers and health professionals to identify areas where further innovation of prevention and trauma care is most needed. Without such information the search for cost-effective interventions will be a blind search. This may result in efficient health care for very specific health problems, whereas at the same time larger health problems are overlooked. Therefore, comprehensive costs of illness (injury) are to be preferred to estimates for single health problems. The latter can be used for unjust single disease advocacy. In contrast, comprehensive cost estimates across all injuries, including traffic, home, leisure, occupational, and intentional injuries, will put specific health problems into perspective and may highlight other health problems that receive insufficient policy attention.

When health problems with a major (economic) burden have been identified, targeted preventive interventions can be developed, which should be evaluated with respect to their (cost-)effectiveness before implementation. For example, this study has identified falls as a major cause of health care costs, even more than double the costs of traffic accidents. Effective fall prevention programmes and guidelines for fall prevention are available that can reduce these costs.31 However, their cost-effectiveness has not yet been assessed. On behalf of the Dutch Ministry of Health, we analysed the cost-effectiveness of fall prevention programmes combining the epidemiologic and economic data underlying the present study, and data on costs and effectiveness of interventions (unpublished report).

In addition to the share in total costs and health burden, effectiveness, and cost-effectiveness, other policy criteria may be used to direct preventive policy towards injuries, such as individual injury severity, and advantages given to disadvantaged groups or minorities. Also here, cost of illness and injury studies may provide helpful information.

Costs divided by type of injury and health sectors may also increase alertness for possible health system inefficiencies. For example, patients with minor injury (dislocations, sprains, strains, superficial injury, open wounds, small burns, poisonings, and foreign body injury) and without medical need for hospitalization account for 50% of ED patients and give cause to substantial costs. Savings might be possible by enforcing policies that shift the treatment of these patients to primary care providers, particularly of those patients who were not referred by their GP.

Contributors

Willem Jan Meerding participated in the design and planning of the study, analysed the data, contributed to the interpretation of the results, and wrote the paper. Ed van Beeck and Saakje Mulder directed the study, contributed to the interpretation of the results, and commented on the paper.

Key points

  • Unlike previous studies, we present a detailed and comprehensive overview of injury incidence and related medical costs covering the broad spectrum of external causes and injury diagnoses.

  • Injuries account for 3.7% of total health care costs. For the age groups 0–14, 15–44, 45–64, and 65+ costs per capita were €38, €59, €43, and €210, respectively. Sex differences in costs per capita are largest in age groups 15–44 (males €72, females €44) and 65+ (males €123, females €271).

  • The four injuries with the highest health care costs are hip fracture (20%), superficial injury (13%), open wounds (7%), and skull–brain injury (6%).

  • Of total costs, 57% can be attributed to home injuries (44% to falls), 19% to traffic accidents, 10% to sports injuries, and 5% to occupational injuries.

  • Strategies that tackle the high costs of accidental falls and of minor injuries without medical need for hospitalization are highly needed, including an assessment of their costs and health benefits.

Acknowledgments

We thank Hidde Toet and Paul den Hertog for their assistance in data collection and analysis. Caspar Looman gave valuable suggestions for the statistical analyses. Financial support was provided by the Dutch Ministry of Health, Welfare and Sports.

References

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