Global Health and Life Expectancy
2.10.2017
The Organization for Economic Co-operation and Development (OECD) defines life expectancy (LE) as the number of years, on the average, that an individual can expect to live assuming that the death rate at the time of the estimate remains constant. It is usually calculated at birth or a particular period and varies based on several factors including gender, socio economic status, country of birth, place of residence and death rate at the time of calculation. A decline in death rate results in a corresponding increase in actual life spans compared to the life expectancy calculated at the time of birth. However, an increase in death rate will result in decrease in actual life spans, compared to that calculated at birth. Life expectancy is a significant and frequently used health status indicator because it reflects the overall wellbeing and quality of life in a country or region. Increase in LE is a consequence of several factors, including higher standards of living, healthy lifestyle, better education and accessibility to health services. LE is also useful in understanding the demographics and needs of a population.
On the other hand, healthy life expectancy (HLE) is the number of years- on the average, that an individual is estimated and expected to live in good health at a specific age, after taking mortality and morbidity data into account, as well as the health status of the specified population. Unlike LE, HLE takes into consideration, factors such as quality of life and specific health status or conditions of the population. It can be used to determine and monitor the health status of populations. Using HLE estimates of countries, important needs such as future health services, health program evaluation and health trends analysis can be prepared for, and carried out effectively. In the United States, the Centre for Disease Control and Prevention (CDC) used data from the National Vital Statistics Systems (NVSS), U.S. Census Bureau and Behavioural Risk Factor Surveillance System (BRFSS) to estimate HLEs for persons aged 65 years, by sex and race. Findings from these calculations showed that from 2007 to 2009, women had a greater HLE than men at 65 years across the US while whites had a greater HLE than blacks, except in Nevada and New Mexico.
The difference between life expectancy (LE) and healthy life expectancy (HLE) is that the former describes the average number of years a person can expect to live based on current mortality rates for the population while the latter estimates the approimate healthy years that a person can expect to live on the basis of the current mortality rates plus the distribution of health status in the population. The difference between LE and HLE is a function of health status which represents the quality of the life. Consequently, LE is usually longer than HLE, however, the extra number of years expected to be lived may not necessarily be healthy and worthwhile. According to World Health Organization (WHO), in 2015, the global population had an average LE of 71.4 years at birth while the average HLE was 63.1 years. Considering the 2015 data presented by WHO, people remain very healthy and are able to work or contribute to the economy up to 63 years, however, at 71, chronic diseases become more prominent, significantly reducing the quality of life. It is important to know that these numbers are only averages and will differ from individual to individual based on more personalized and specific factors.