The National Institute for Occupational Health (NIOH) in South Africa, through its Epidemiology and Surveillance Section, has initiated a national surveillance project to determine the increase in mortality from specific diseases within occupation groups.
The NIOH, a division of the National Health Laboratory Service, focuses on surveillance of occupational disease, specialised laboratories and health hazard evaluations, applied laboratory and epidemiological research, the statutory autopsy services in terms of the Occupational Diseases in Mines and Works Act, advisory services, as well as teaching and training in occupational health and safety.
The NIOH is a World Health Organization (WHO) Collaborating Centre and has also been recognised as a Centre of Excellence.
Surveillance, as part of the institute’s core function, is crucial in the identification and prevention of occupation-related morbidity and mortality. In South Africa, innovative methods are needed because of the paucity of routinely collected and analysed data.
Dr Nisha Naicker, Head of the NIOH Epidemiology and Surveillance Section, is the driver of this project that aims to get a clearer understanding of mortality by occupation and identify trends and emerging patterns in workplaces.
In the absence of national surveillance data, registration data from Statistics South Africa and the Department of Home Affairs was used to establish the National Occupational Mortality Surveillance database of South Africa (NOMS-SA).
“The Epidemiology unit sifted through massive amounts of data to determine the ratios of mortality within occupation groups, and the underlying cause of death in 2016, based on death certificate information,” said Dr Naicker.
The team utilized the South African National Burden of Disease Study list of highest ranked causes of deaths to assess mortality risk among occupations.
”Proportionate mortality ratios (PMRs) were calculated to approximate the risk associated in each occupation. A PMR of more than 100 indicates that the proportion of deaths from a particular cause in the specified occupation is higher than the general population,” explained Dr Naicker.
Analysis of the 2016 data showed that there were 468,573 reported deaths of persons over the age of 15 with only 59,707 (12.7%) of individuals that had a specified occupation. Elevated risk of HIV/AIDS mortality was noted in service workers and armed forces personnel (PMR=132), elementary occupations (PMR=132) and plant/machine operators (PMR=120).
Tuberculosis mortality was significantly higher in elementary occupations (PMR=121), plant/machine operators (PMR=118) and agricultural workers (PMR=113). Diabetes mortality was high in professionals (PMR=121) while the elevated risk of ischemic heart disease mortality was noted in managers (PMR=340), professionals (PMR=244), technicians (PMR=243), clerks (PMR=220), agricultural (PMR=210) and craft workers (PMR=160).
Elevated risk of interpersonal violence was highest among elementary workers (PMR=153), service workers and armed forces personnel (PMR=143), agricultural workers (PMR=137) and plant/machine operators (PMR=110).
“It was concluded that continuous surveillance of mortality by occupation is critical in South Africa. The method used here provides a clearer picture of illness by occupation, and we are optimistic that through this kind of surveillance, the NIOH can support recommendations for targeted prevention programmes and policies in future,” said Dr Naicker.