Burden of injury in childhood and adolescence in 8 European countries

All over the globe, injuries in childhood and adolescence have a major impact on individual and population health. Each day, the ideals of thousands of our vivid and promising youth are suddenly destroyed by road traffic crashes, injuries at home or during leisure time, or acts of violence. This is largely unnecessary, since an abundance of simple and effective countermeasures are available (e.g. use of bicycle helmets, reduced speed limits, barrier fencing on swimming pools, lower tap water temperatures), but these are underused[1]. For this reason, even in high-income countries, injury is still the leading cause of death and disability among children and adolescents[2, 3]. In Europe, each year more than 40,000 children die from injury, [4] and for every child fatality, there are several thousand victims of injury or violence who live with varying degrees of disability or psychological scarring[1]. According to WHO, "awareness of the problem and its preventability, as well as political commitment to act to prevent child injury, remain unacceptably low"[1]. Therefore, as a first step in addressing this problem, among health policy makers awareness should be raised and priority areas with the highest potential health gains should be identified.

This can be accomplished by providing decision makers with summary measures of population health, such as the disability-adjusted life year (DALY)[5]. The DALY is the sum of years lost due to premature mortality (YLL) and years lived with disability (YLD). A high number of DALYs reflects a greater burden of death and disability. The DALY was aimed at national and international health policies, to develop unbiased epidemiological assessments for major disorders, and to provide an outcome measure that could also be used for cost-effectiveness analysis[6].

The human impact of childhood and adolescence injury in terms of DALYs in Europe by country, age, sex, injury type and external cause specifically has not been addressed yet. Expected variation in the burden of injury among the European countries may be caused by differences in exposure, injury risk and type of sustained injury, differences in demography, (socio)economic and cultural factors, safety technology, injury-prevention strategies, and the effectiveness of trauma care. Assessment of the variation of the burden of injury and its separate components can be used to identify high-risk groups in Europe as well as in specific European countries, and it can be used to prioritise injury-prevention programmes.

In this paper we assess the impact and variation in the burden of injury in childhood and adolescence in eight European countries. This is expressed in the summary measure of DALYs and its components, namely premature mortality (years of life lost, YLL) and disability (years lived with disability, YLD). To show potential health gains, we estimate the impact on mortality and (life-long) disability if childhood and adolescence injuries were reduced to the level of current best injury prevention practices in Europe.

The differences in the burden of injury in childhood and adolescence are large, with an enormous gap between the safest countries in Western Europe (the Netherlands and UK) and the relatively unsafe countries (Latvia and Slovenia) in the east. Both differences in premature mortality and disability contribute to the variation in injury burden. In all countries, the highest burden by far is observed among males aged 15-24 years, which is caused by high premature mortality. Skull-brain and spinal cord injury resulted in the highest total YLD due to life-long disability. Superficial injury resulted in the highest short-term disability, due to a high incidence, despite the short course of disability.

The high burden and observed variation of child and adolescence injury in Europe is largely unnecessary, since an abundance of simple and effective intervention strategies are available but underused. As a consequence, large potential health gains can be reached if childhood and adolescence injuries were reduced to the level of current best injury prevention practices in Europe, which we assume is the Netherlands, with the lowest burden of injury. A recent study of WHO supports this assumption by stating that 'the Netherlands and the UK having the lowest child injury mortality rates in the world, Europe has the opportunity to share lessons learnt throughout the region'[4]. We showed that by reducing mortality and disability of childhood and adolescence injuries to the best current level almost 900 thousand DALYs can be avoided across Europe. This means that each day around 25,000 healthy life years can be gained in the European Union, mainly caused by saving 24 child lives each day. Although the Netherlands represent current best practice, it would be appropriate to note that this should be a floating, improving best practice standard.

This warrants immediate action for injury prevention targeted at high-risk groups and high risk areas. At the European level, males aged 15-24 years are a major high-risk group, since they account for half of the total injury burden in childhood and adolescence (mainly because of traffic accidents and intentional injuries) in all participating countries. In an earlier study in which comparative data on the burden of injury patients in all age categories in Europe was described [9], it was even found that compared to the whole population the highest number of DALYs per 1000 persons is observed in males aged 15-24 years for all age groups. At the country level, specific combinations of external causes and types of injury deserve special attention. The high injury mortality in Latvia, for example, is partly caused by a relatively high mortality rate for suicide and self-inflicted injury for males aged 15-24 years. But most of all, our study draws attention to the enormous gap within Europe between countries in the west and east, as strongly reflected by the fivefold difference in DALYs from child injuries between the Netherlands and Latvia. This inequality already starts among toddlers, extends at school ages and gets further amplified in adolescence. Previous studies have shown that the latter partially could be counteracted by policies aimed at the reduction of excessive drinking in the east[20, 21]. But far more action is needed to reduce health inequalities across Europe[22].

The need for immediate action is further stressed, because the reported burden of injury estimates are probably conservative. The burden of injury has been shown to be notably high in comparison to other causes of mortality and loss of health. The GBD estimated that injuries accounted for 16% of DALYs among children and adolescents worldwide[23].

Burden of injury studies are only as good as the weakest link in the chain, which is the epidemiological data[24]. Agenda setting for the collection of good quality epidemiological data is an important issue to emerge from our study. For instance, incidence data for non-admitted ED patients with traffic or intentional injuries was not available in all participating countries. Although this hampered straightforward international comparisons of short-term YLD, its influence is probably modest, since the majority of the injuries of non-admitted ED patients are home and leisure injuries (75%),[9] and their share in the total burden is low (for most countries, less than 2%). More important is that the burden of injury estimates presented in the current study do not picture the impact of injury among children completely. The burden of disabling and life-long sequelae of burn injuries and direct and indirect effects of intoxication were omitted because accurate incidence data were not available. Yet more striking is that psychological consequences of injury were not included, whereas evidence suggests that posttraumatic stress disorder (PTSD) and acute stress disorder are highly prevalent among children hospitalized for injury[25, 26].

In addition, underestimations of YLD have probably been reported for specific countries. A good example is Slovenia, where YLD resulting from lifelong disability has been underestimated since information about spinal cord and complex soft tissue injury was largely underestimated in their hospital discharge register.

Furthermore, in the original GBD study that aspired to estimate the total burden of disease worldwide as the sum of the burden of all separate diseases age-weighting was used. With age-weighting the altering levels of dependency with age are taken into account, meaning that years lived at youngest and oldest age is given less weight. Age-weighting has been highly criticized on equity grounds, the absence of empirical foundation and validation, and because the age weights do not convey actual social values[18, 19, 27, 28]. On these grounds, we chose not to apply age-weighting in the current study. However, if age-weighting was applied, it would affect the resulting burden of injury estimates, since mortality among adolescents, which causes the lion's share of DALYs lost, would get even more emphasis compared to mortality among young children.

As shown in this article, unintentional and intentional injuries in childhood and adolescence cause a high disability and mortality burden in Europe. In all developmental stages large inequalities between west and east are observed. This study has shown the huge potential benefits that can be realized by implementing interventions that are proven ways to reduce both the likelihood and severity of injury. However, according to the WHO injuries are remarkably neglected, compared with the attention devoted to research and policy for other leading causes of DALYs worldwide[4]. Our children deserve better and need improved protection now.