|3 Mortality Transition
The historical development of birth and death rates in Finland is shown in Figure 1. The level of mortality remained essentially unchanged until the second half of the nineteenth century, the death rate was high at all times and frequently raised to sharp peaks by epidemics and famines, sometimes aggravated or caused by wars. At such times, the death rate often exceeded the birth rate. After the last great famine catastrophe of 1866-8, mortality entered a new phase of sustained decline by 1880. The decline has continued ever since, interrupted only by civil war and influenza in 1918 and wars with Soviet Union in 1939-44. Around 1950 the decline suddenly accelerated due to the introduction of antibiotics, and the crude death rate reached a level where it is no longer a valid indicator of mortality.
The life expectancy at selected ages according to the 30 life tables is given in Table 1. The decennial averages do not effectively smooth out the peaks and troughs of the early periods but leave in evidence a succession of crisis and non-crisis decades. In the pre-transition era, life expectancy was much higher at age 15 than at birth, demonstrating a very high mortality in childhood which was a common feature of the high-mortality regimes of the past. By about 1880, these two indicators had moved much closer, and in the beginning of the twentieth century they intersected and life expectancy remained decidedly lower at age 15 than at birth as is the rule in low-mortality populations.(Note 1)Figure 1. Births and deaths per 1000 population in Finland 1750-1995.
Table 1. Life expectancy in Finland at ages 0, 15 and 65.
* War deaths excluded.
The advent of antibiotics is visible in a pronounced increase in life expectancies at all ages in the 1946-50 and 1951-55 life tables but this development soon ran its course and was followed by a slowdown, for adult men even by a reversal. Around 1970 a new development - seen in Table 1 but not in Figure 1 - set in: an unprecedented decline in the mortality of the elderly which raised life expectancies at younger ages as well. It seems therefore appropriate to pinpoint 1880, 1945 and 1970 as pivot years between important changes in the transition of mortality in Finland. How do these dates stand, in relation to the theory of epidemiologic transition, first proposed by Omran ?
A secular, momentous decline in mortality - part of the great demographic transition - began in most Western countries in the mid-nineteenth century or soon thereafter. The long era that it eclipsed, aptly called by Omran "the age of pestilence and famine" could rightly be - and often is - called the pre-transition era. Omran, however, called it the first stage of epidemiologic transition and we shall follow this original terminology because it was not an era of basically unchanging, if fluctuating, mortality. In fact, very important permanent changes took place towards the end of it, such as smallpox vaccination, developed by Jenner in the first years of the nineteenth century. This had the major effect of reducing the frequency and magnitude of mortality peaks but did not bring even smallpox under complete control and did by no means spell the end of pestilence.
As to the subsequent stages of transition, Omrans "Age of receding pandemics" (2nd) and "Age of degenerative and man-made diseases" (3rd) have been much criticized for being vaguely and inaccurately defined (e.g. ). The timing of the changeover from second to third stage, which is sometimes set at 1930, is also difficult to determine due to lack of clear reference to a cause-of-death classification. Attempts to demarcate the stages by life expectancy at birth have had very questionable results.
If studies by cause of death fail to satisfactorily separate the second from the third stage in Omran's terms, even less can our investigation of all-cause mortality do it. We find no obvious time point of major change before the end of World War II and therefore consider the period 1880-1945 in Finland as one single stage: the second. We shall name it after bacteriology. Although this new science did not actually start the decline of mortality, it gave an explanation to what had begun and gave a completely new understanding of disease processes, opening the way to remarkable advances in the prevention diagnosis and treatment of diseases and in sanitary engineering. It was during this stage that the essential transition from high to low mortality - and to the modern world - took place.
We place the beginning of the third stage at the sudden acceleration of mortality decline in the late 1940s as antibiotics proved effective against a wide array of diseases and against infections of the most varied kinds at all ages. This demarcation of the third stage has the merits that the cause is clearly defined and that the onset was virtually simultaneous around the world.
Our latest stage coincides with what is increasingly being recognized as the fourth stage of transition and which has been called that of delayed ageing, a definition we find justified.
Having made this division on the basis of all-cause mortality as measured in a life table, we prefer to speak of stages in mortality (instead of epidemiologic) transition. Such a division has to be made with regard to different ages because looking only at life expectancy at birth we would be uncertain about the third stage and would not notice the fourth at all. To recapitulate, we define the stages of mortality transition in Finland as follows:
The respective stages are represented by the following life tables: (Note 2)
1st from 1751-60 to 1871-80, an interval of 120 years
2nd from 1871-80 to 1941-45, an interval of 67.5 years
3rd from 1941-45 to 1966-70, an interval of 25 years
4th from 1966-70 to 1991-95, an interval of 25 years
Total interval 237.5 years
The first stage being the longest and, in Finland as elsewhere, the least known, we shall give more space to a description of it.
|Finnish Life Tables since 1751
Väinö Kannisto, Oiva Turpeinen, and Mauri Nieminen
© 1999 - 2000 Max-Planck-Gesellschaft ISSN 1435-9871