Trend in Adult Mortality in Singapore

Abstract

Singapore has made significant progress in reducing adult mortality over the past 4 decades as illustrated in a recent study published in the medical journal Lancet. According to the study, adult mortality (the risk of dying after the 15th birthday but before the 60th birthday) for Singapore’s men and women has fallen by about 64% and 68% respectively between 1970 and 2010. The study is the most detailed analysis to date of trend in estimated adult mortality in 187 countries from 1970 to 2010. In terms of ranking of lowest adult mortality across countries, Singapore has moved up in position from 72nd for men and 62nd for women in 1970 to 16th for men and 14th for women in 2010.

Although Singapore has made tremendous improvement in reducing our adult mortality over the 40-year period, we cannot afford to be complacent. Singapore needs to continue with our effort to combat the associated risk factors of cancers and heart diseases as these lifestyle diseases are the main cause of early deaths among adults between 15 and 60 years of age in Singapore today.

Trend in Adult Mortality in Singapore

By Phua Hwee Pin1

Introduction

1. Adult mortality, which focuses on adults in the prime of their life2, is an important indicator for monitoring the health of populations. It complements more traditional measures of population health such as infant and childhood mortality and life expectancy, as the factors affecting childhood mortality and adult mortality are not necessarily the same.

2. The Lancet medical journal recently published an article3 analysing adult mortality, based on the risk that an individual who has just turned 15 years will die before reaching 60 years of age, in 187 countries, from 1970-2010.

3. This paper examines the trend in adult mortality in Singapore, as analysed in the Lancet study and compares it with that in other countries.

What is the trend in adult mortality rate in Singapore?

4. The Lancet study examined the trends in adult mortality between 1970 and 2010, over a 40-year period. For Singapore, there was a significant reduction in our adult mortality over this period. The study found that adult mortality in Singapore has dropped by 64% from 24.0% in 1970 to 8.7% in 2010 for men, and by 68% from 14.5% in 1970 to 4.7% in 2010 for women.

5. Our own local data confirmed this Lancet finding. For example, over the past 20 years, the age-standardised4 death rate for adults aged 15-59 years in Singapore has halved, from 223 per 100,000 adults in 1989 to 111 per 100,000 adults in 2009. This translates to a very significant drop of about 3% each year. Both men and women have experienced similar improvement in health as measured by the reduction in death rate (Figure 1).

Figure 1: Rates were age-standardised to the 2000 Singapore adult population

How does Singapore’s performance compare with other developed countries?

6. The Lancet study reported substantial reduction in worldwide adult mortality. Adult mortality has dropped by 19% for men and 34% for women from 1970 to 2010. However, the study revealed wide variations between regions and countries. While the authors observed substantial decline in adult mortality over time in most countries, they also found increasing trends in adult mortality in sub-Saharan Africa as a result of the HIV epidemic and in countries in or related to the former Soviet Union, and stagnation in the decline for large countries in southeast Asia during the period studied.

7. For Singapore, our analysis using results from the study suggested a decline of about 3% each year over the past 40-year period for both men and women. These are comparatively greater than the annual decline noted in some other developed countries. For example, decline in adult mortality in the United States was reported to be less than 1% each year. Figure 2 compares Singapore’s declining trend in adult mortality in both sexes with selected developed countries.

Men

Figure 2: Adult mortality for Singapore and selected developed countries for men and women, 1970-201

Women

Source of data: Data extracted from the table accompanying the Lancet paper: Worldwide mortality in men and women aged 15–59 years from 1970 to 2010: a systematic analysis (Lancet 2010;375:1704–20). They can be accessed via http://www.healthmetricsandevaluation.org/resources/pubs.html (last accessed on 18 June 2010).

What are the drivers of the changes in adult mortality?

9. The authors of the Lancet study suggested that changes in adult mortality between 1970 and 2010 are likely due to diseases of affluence, socioeconomic development; improved health technologies, social dysfunction in the aftermath of the collapse of the Soviet Union, and the HIV epidemic. For Singapore, the decline in adult mortality over the 40-year period ought to be credited to our progress in improved nutrition as we developed economically, control of infectious diseases, access to healthcare advancements, disease prevention and health promotion.

10. In Singapore today, the top causes of death among adults aged 15-59 years are due to cancer and heart diseases which together cause 3 in 5 deaths (Figure 3). Based on our data, adult mortality rate for these lifestyle diseases in terms of age-standardised death rate have shown a long-term declining trend, reflective of our past efforts in preventive health, earlier diagnosis and better treatment of these diseases and their risk factors (Table 4).

Figure 3: Top causes of deaths for adult aged 15-59 years in 2009

*The ICD9 codes used for the 3 leading causes of adult mortality were 140-208 for cancers; 390-398, 402, 404, and 410-429 for heart diseases; 800-999 for accidents (includes poisoning and violence); 430-438 for stroke.

Men

Women

Conclusion

11. Singapore has fared well so far in reducing our adult mortality but there is definitely room for further improvement and we should not be complacent. Singapore needs to continue to combat against smoking, obesity and physical inactivity; and to detect high blood pressure, diabetes and high cholesterol and manage these conditions well, as these are the major risk factors for the leading causes of early deaths in our adult population between 15 and 60 years of age. The Ministry of Health together the Health Promotion Board will continue to work with partners such as the Peoples’ Association, Singapore Sports Council, National Environment Agency, unions, employers and family doctors to do so.

Data Sources
Resident death data for Singapore: Registry of births and deaths, Singapore
Resident population data for Singapore: Department of Statistics, Singapore

Reference
Rajaratnam JK, Marcus JR, Levin-Rector A, Chalupka AN, Wang H, Dwyer L, Costa M, Lopez AD, Murray CJL. Worldwide mortality in men and women aged 15–59 years from 1970 to 2010: a systematic analysis. Lancet. 2010 May 15; 375:1704–20.

¹ Phua Hwee Pin is a Senior Biostatistician with the Epidemiology and Disease Control Division, Ministry of Heath.

² The World Health Organization (WHO) reports adult mortality risk based on premature mortality in adults aged between 15 and 60 years.

³ Worldwide mortality in men and women aged 15-59 years from 1970 to 2010: a systematic analysis. Rajaratnam JK, Marcus JR, Levin-Rector A, Chalupka AN, Wang H, Dwyer L, Costa

⁴ M, Lopez AD, Murray CJ. Lancet. 2010 May 15;375(9727):1704-20.

⁵ Age-standardised rates were calculated by the direct standardisation method using the 2000 Singapore adult population as the standard.