Opinion | The Indian puzzle of life expectancy rising with age4 min read . Updated: 15 May 2019, 10:32 PM IST
An important measure of national well-being depends on survival in the first year of birth
Is it possible for life expectancy to increase with increasing age? Presumably not. However, India experiences this paradox, explained by its historically low life expectancy at birth. More on that later. But, what does life expectancy really mean? Life expectancy at birth refers to the average number of years an individual is expected to live, given mortality rates. As a concept, life expectancy is much broader than usually understood. It is a fluid concept that differs on the basis of various factors. First, it varies across time horizons based on varying conditions such as war, spread of epidemics and environmental conditions. Second, it varies across age cohorts, again given mortality rates. Third, it also differs across space for the same time, depending on variations in geographical, economic, social and gender factors. Despite consistent improvements in life expectancy at birth, India’s life expectancy at birth is still lower than the global average. According to the last census, Indian life expectancy has merely increased from 60 years in 1992 to 67.9 years in 2012. Based on data from abridged life tables of the census, one can draw two major inferences. First, life expectancy at every age is higher for females than for males. This can be explained by a biological phenomenon, which confers a higher survival advantage to females over males throughout their lifetime. The second observation is that life expectancy declines as age increases. For instance, life expectancy at age 1 for females and males is 71.9 and 68.3 respectively. Thereafter, as one attains age 5, life expectancy declines to 68.8 for females and 64.9 for males and, subsequently, at age 20, it further declines to 54.6 and 50.6 respectively. This is consistent with the fact that as one ages, the number of years one is expected to survive thereafter declines.
However, if one observes India’s life tables for age cohort 0-1, life expectancy does not adhere to the above logic, which is otherwise applicable throughout the ages of 1 to 70. The age cohort 0-1, therefore, presents a paradox. The life expectancy for females and males at birth is 69.6 and 66.4 respectively, which increases to 71.9 and 68.3 years once they attain the age of 1.
Clearly, instead of declining, life expectancy is increasing with age. Seemingly, a newborn in India has a lower probability of surviving in the first year as compared to the probability of survival after the age of one year.
Life expectancy statistics between age 0 and 1 present a seemingly minor anomaly, they have significant implications for India’s life expectancy at birth, a key measure of national well-being.
The first-year survival rate brings down the overall average life expectancy of Indians.
An analogy could be drawn with the National Aeronautics and Space Administration’s (Nasa’s) space shuttle Challenger, which ended in a tragedy that killed all its crew on 28 January 1986. The cause was speculated to be some major malfunction. However, later, the proximate cause was identified as the failure of its O-ring seal, an inconspicuous part.
Here, the O-ring is a metaphor for a small matter of detail that explains a major phenomenon.
In this analysis, we wish to understand the reason for historically low life expectancy at birth in India. High infant mortality rates (IMR) can potentially explain this anomaly, the O-ring in this case. Statistics of the Organisation for Economic Co-operation and Development (OECD) show a strong correlation between IMR and life expectancy at birth. Countries with robust interventions aimed at IMR reduction have better life expectancy at birth. Furthermore, within the 0-1 age cohort, the neonatal mortality rate (NNMR), or rate of deaths occurring in the first 28 days, is the primary factor impacting IMR. Studies show that risk of such a death is almost 30 times higher than in the post-neonatal period. No wonder the median NNMR and IMR for India stood at 24 and 32, respectively, in 2017-18. Loosely, this means that of every 1,000 births in India, around 24 deaths occur in the first month and the other 8 between 28 days to 1 year.
Several observations corroborate these high mortality rates. One of these observations is the high infant malnutrition in India. National Family Health Survey 4 (2015-16) data show high incidence of stunting, atrophy and underweight under-five children (38.4%, 21% and 35.8% respectively).
Other causal factors broadly include immunizable diseases, poor sanitation and breastfeeding practices. A deeper analysis links these factors to maternal education and state intervention. The former relates to awareness and latter to state-administered health supplements, immunization and sanitation access.
The government has accelerated progress through programmes such as Mission Indradhanush, Swachh Bharat Mission, National Rural Health Mission and Poshan Abhiyan. Despite these measures, however, the progress has been rather slow.
Undoubtedly, the impact that interventions focused on the first year of birth can have on the survival of individuals is profound. That being recognized, any strategy to raise life expectancy at birth should be aimed at tackling causal factors of IMR and NNMR by designing an appropriate microstructure of interventions.