Compression and decompression patterns of mortality in India

Suryakant Yadav, International Institute for Population Sciences (IIPS)
Perianayagam Arokiasamy, International Institute for Population Sciences (IIPS)

India is experiencing an accelerated pace of demographic transition. Demographic trends are transitioning from third to fourth stage of demographic transition in general and moving to fourth stage in low fertility states. In the interim, country is also experiencing epidemiological shifts. Epidemiological trends are transitioning from second to third stage of epidemiological transition, while IMR and CMR have declined to 55 and 16 respectively (SRS, 2007). According to NSSO data, the overall prevalence of morbidity has declined from 110 in 1996 to 88 in 2006. Given the background, this study attempts to establish the compression and decompression patterns of mortality and the dynamics of changes of mortality pattern by age in India and states. Inter Quintile Range is used to estimate the variability at age at death. Decomposition of IQR is used to establish the compression and decompression pattern of mortality in India and states. Data from Sample Registration System (SRS) provide information on the age specific death rates (a.s.d.r). Analyses show that the mortality pattern is shifting outward after age 45 and above. Death rates (a.s.d.r) have decreased over time and thus evidencing flattening of mortality pattern. Over period of time, the variability in age at death is found to be convex in nature. With decrease in variability there is an increase of 5.8 years in mean length of life and variability (SD) has decreased by 2.7 points in third quintile and 0.76 points in first quintile during 1969 to 2005. Compression of mortality is evidenced and in older ages there is expansion of mortality pattern with increase in life expectancy. Expansion is more in case for females. Further, with decline in mortality rates from 208 to 170 deaths per thousand and expanding outward during 1995 to 2005 in oldest age group, mortality patterns may follow sigmoid curve.