The continuing decline in mortality rates among young adults in Switzerland may suggest that the various prevention campaigns particularly targeting this age group of the population have been successful. Each year in Switzerland, out of every 1000 young adults (aged 15-39), only one woman and two men lose their lives. From a demographic research perspective, however, these positive findings mask significant gaps in understanding the mechanisms which result in early death in young adults and the ways to counter this. Indeed, despite these advances due to the general decline in mortality at all ages, young adults continue to suffer from excess mortality compared to what would be expected given their overall good health. In comparison to child and adult mortality, this anomaly persists and causes a distinct “hump” in age-specific mortality rates, which is primarily due to higher rates of fatal accidents and suicides among young people. These causes of death – which are currently in decline – underline the influence of either socio-cultural factors, as in the post-world-war-two period, or socio-political factors, as with the raised awareness of road safety issues which began in the 1970s and the prevention campaigns which followed. Finally, on the basis of our studies it appears that this excess mortality is particularly unequal among today’s young people. In view of the observation, for example, that unemployment doubles the risk of death, it seems imperative that the fight against young adult excess mortality should start by defining a strategy to better target the most vulnerable young people.

The mortality hump

Since national statistics have been available, life expectancy in Switzerland has dramatically risen, from around 40 years in 1876 to around 85 today. This tremendous success has been achieved thanks to several interrelated factors such as the improvement in general living conditions, social progress, particularly in education and the protection of workers, and the advances in medical knowledge. For example, a crucial factor in the decline in infant mortality has been the introduction of mandatory national vaccination campaigns. In recent decades, most gains in longevity have been at the oldest ages, thanks in particular to the cardiovascular revolution and a significant decline in fatalities from cancer.

Between these two extremes of the life course, the issue of young adults has attracted little political or scientific interest. One of the reasons for this relative indifference probably lies in the fact that between about 8 and 12 years of age, the risk of death systematically reaches a minimum and that this floor has steadily reduced over time. In relation to adolescents and young adults, however, the story is more complex and many studies have shown the existence of what is commonly referred to as an excess mortality hump, which indicates a risk of mortality specific to this life phase and which is in addition to the regular progression of the senescence process inherent in biological ageing.

A phenomenon in search of an explanation

This excess mortality hump has however never been fully explained, with hasty judgements often taking precedence over the scientific approach, and highlighting risky behaviours that would be the hallmark of a tormented youth incapable of evaluating the consequences of its actions. This perspective has been reinforced by work carried out by psychologists who have drawn attention to an unavoidable, even necessary, crisis of adolescence, embodied in literature by the sufferings of the young Werther, consumed to the point of self-destruction by his heartache. This fatalistic interpretation of mortality in young adults has probably been reinforced by the observation, certainly real but also over-simplistic, that the causes of death at these ages are mainly violent in nature, particularly as a result of accident or suicide.

From a public health point of view, these causes, often referred to as “societal diseases”, are perceived as more difficult to combat than infectious or physiological diseases. Politically, they are also often considered as a matter of individual responsibility, beyond the possible, or even desirable, scope of action of public health policies. It is therefore not surprising that the implementation of prevention campaigns for road safety such as Switzerland’s Via Secura is particularly laborious and strongly contested by opponents. These multiple obstacles mean that today little is known about the evolution of mortality specifically in relation to young adults, or about the root causes underlying this phenomenon. This observation applies to Switzerland but in reality is generally true for all the world's populations.

However, it can be convincingly argued that this distinction between avoidable and unavoidable diseases, as well as between individual and collective responsibility, is largely artificial. On the one hand, as studies on lifestyles have shown, individuals opt for behaviours, including in relation to health, in response to their social, cultural and economic environments. On the other hand, the behaviour of young people is merely a reflection of the prevalent attitudes in general society; violent societies, either physically or morally, give rise to violent behaviour, of which young adults are often both the main perpetrators and the main victims. It is therefore illusory to want to isolate young adults from the rest of the population, if only because today’s older people were yesterday’s youth and the criticisms they sometimes aim at their younger counterparts have already been made against them in their day, by their elders. It was therefore necessary to adopt a more rigorous approach in order to identify, in a scientific way, the forces which bring about this risk of mortality specifically in young adults, a task undertaken within the framework of the NCCR LIVES, and which has made it possible to draw several conclusions.

Three observations to be made from the demographic studies

Firstly, the young adult excess mortality applies as much to young women as to young men, even if for the latter the phenomenon is more pronounced. From an international point of view, it can be identified as far back as public statistics allow us to go, namely to the mid-18th century. However this is not a universal phenomenon, because it has completely disappeared in certain specific contexts such as between the 1950s and the 1970s for women and the cohort of men born around 1930, and this was true in almost all the countries in the northern hemisphere. This suggests that the favourable economic context of the “golden” post-war years, accompanied by gender norms resulting in women being isolated from many risk factors, created the socio-economic and cultural conditions favourable to the disappearance of a specific form of vulnerability in young adults. Above all this indicates irrefutably that it is not an unavoidable phenomenon, as has long been believed.

Secondly, the causes of death associated with this excess mortality are not as limited as initially thought. Indeed, until the mid-20th century the largest proportion of excess mortality in young adults was attributable to pulmonary tuberculosis and, for women, to maternal mortality. This international observation also applies to Switzerland, where vital statistics allow us to draw a similar conclusion. Thus, between 80% (women) and 90% (men) of the life expectancy improvements in 15 to 39-year-olds between 1885 and 1940 can be attributed to the fight against tuberculosis, to which we can add 20% due to the decline in puerperal fever in women. It was only since the more widespread popular use of motor vehicles in the post-war period that traffic accidents became the main cause of youth mortality, before being overtaken by suicides (see the figure below). Young adults, however, are by no means the only victims of these new causes of death, but the general decline in mortality rates has increasingly highlighted them as the main causes of death among young adults.

Mortality rate of 15-39-year-olds in Switzerland (1951-2015)

Source: World Health Organisation (2018), calculations by the author

Thirdly, in discussions about what public policies to adopt in order to combat the new troubles of young people, the issue of social inequality has rarely been at the forefront. Indeed, while for some time we have seen a notable decline in the number of road deaths and suicides, which means that the mortality rate among young people is probably less under the spotlight than it was 10 or 20 years ago, significant inequalities remain. For example, it can be shown that, among 15-to-35-year-olds living in Switzerland between 1990 and 2008, being unemployed doubles the risk of death, dropping out of school increases it by 60%, and growing up in a single-parent household increases it by 50%, as does being of non-European origin. Conversely, the mortality risk for a young person with a tertiary education is only about half of the risk for someone of a similar age with only compulsory education. Since these risk factors are often combined, they produce ratios of 1 to 100 between the most protected and the most vulnerable individuals. In fact, it can be shown that almost two-thirds of young adults living in Switzerland are not affected by the excess mortality hump, and that the vulnerability of disadvantaged young people is sufficient to explain this phenomenon.

A call for a more differentiated approach

This threefold empirical observation leads us to review our perception of young adult excess mortality, in Switzerland as elsewhere. Not only is this not an unavoidable phenomenon, but its causes have also changed over time to reflect the historical conditions in which individuals become adults. In addition, the efforts made so far in terms of prevention, especially in relation to road safety, have certainly led to a general decrease in the excess mortality rates of young people in Switzerland, but they have been unable to resolve the sometimes immense inequalities between young people from privileged backgrounds and those who are most vulnerable. A genuine policy to fight against excess mortality rates in young people would therefore start with the definition of a strategy to better target the most fragile young people. These public health objectives should be part of the fight that has already been initiated against school and economic dropout, which is currently the main risk factor for the excess mortality rates in young adults in Switzerland.

References

• Remund A. (2015), Jeunesses vulnérables? Mesures, composantes et causes de la surmortalité des jeunes adultes, Doctoral thesis in Demography under the supervision of Prof. Michel Oris, University of Geneva.
• Remund A., Camarda C.G. and Riffe T. (2018), A cause-of-death decomposition of the young adult mortality hump, Demography, vol. 55, pp. 957-978.
• Remund A., The young adult mortality hump in Switzerland: the role of socioeconomic vulnerability, Population (forthcoming).
• Remund A. (2014), La surmortalité des jeunes adultes : réalité individuelle ou artefact des inégalités sociales?, in: Pennec, S., Girard, C. and J.-P. Sanderson, C. (eds.), Trajectoires et âges de la vie, Bari : AIDELF.
• World Health Organization, WHO Mortality Data base, Department of Information, Evidence and Research, http://www.who.int/healthinfo/statistics/mortality_rawdata/en/, retrieved on 5 April 2018.

Biography

Dr. Adrien Remund, senior researcher at the Institute of Demography and Socioeconomics at the University of Geneva, adrien.remund@unige.ch