Background

Trends in life expectancy across both developed and developing countries show that people are living longer. In line with these global developments mortality rates in India have decreased, which has led to significant gains in life expectancy. Figure 6.1 shows that the crude birth rate has more than halved over the last century. There has also been a steady fall in crude death rates from a high of 47 in 1911–21 to a low of just over 7 in 2010. This fall in mortality has driven a significant increase in life expectancy throughout India. In 1901–11 average life expectancy was just 22 years. This was doubtless caused by very high rates of infant mortality. Yet by 2006–10 this had risen to 66 years. As noted in earlier chapters in this volume these demographic changes have been accompanied by changes in the patterns of death and disease. This shift from communicable diseases to non-communicable diseases (NCDs) as the main causes of mortality and morbidity is referred to as the epidemiological transition (Omran, 1971). Hence, despite these great improvements in extending life expectancy there are concerns that healthy life expectancy has not always kept pace with these increases as many people are living with lifestyle-related chronic diseases like diabetes, heart diseases, impairments and mental illness. Evidence from studies conducted in developed countries indicates that morbidity rates will mean that a proportion of one's life expectancy is liable to be lost through disability (Ghosh and Arokiasamy, 2009).

Therefore, addressing and studying these changing morbidity patterns in India is of upmost importance in their own right but also because they have long been recognised as measurable indicators of well-being (Shariff, 1995).

India is not alone in experiencing this epidemiological transition. Since the 1970s, all of South Asia has experienced significant reductions in premature death and disability from communicable and nutritional diseases such as pneumonia, diarrheal diseases and malnutrition. At the same time NCDs have been emerging as leading causes of death and now NCDs account for between one-third and two-thirds of all deaths and disability in the region (Siegel et al., 2014).