Why was this study done?
While a growing body of research has looked at the health effects of prolonged sitting on the job, relatively little has looked at the health effects of prolonged standing. This study set out to help fill this gap by examining the relationships between prolonged sitting, prolonged standing and heart disease.
How was this study done?
The study followed 7,300 workers from Ontario, Canada (who were initially free of heart disease) over a 12-year period (2003-2015). These workers were included in Statistics Canada’s 2003 Canadian Community Health Survey (CCHS), which collected information on personal factors (e.g. age, gender, education levels, ethnicity, immigrant status, marital status), health conditions (e.g. diabetes, arthritis, hypertension, mood and anxiety disorders), health behaviours (e.g. smoking, drinking, body mass index, exercise) and work conditions (e.g. hours worked, shift schedule, physical demands and harmful exposures).
The CCHS also collected job title information, which the researchers used to estimate if a job primarily involved sitting, standing/walking, a combination of sitting/standing/walking or other (such as bending or kneeling), based upon job descriptions in Human Resources and Skills Development Canada’s Career Handbook. The researchers then linked the CCHS information to administrative health records to determine the number of people over the next 12 years who suffered a heart attack or other form of heart disease.
What did the researchers find?
Over the 12-year period, 3.4 per cent of the study group developed heart disease—more men (4.6 per cent) than women (2.1 per cent). Without taking any other factors into account, the risk of heart disease was higher among workers whose jobs required mostly standing (6.6 per cent) than those whose jobs involved most sitting (2.8 per cent). Even after taking a wide range of personal, health condition, health behaviour and work factors into account, the risk of heart disease was still twice as high among workers who primarily stood on the job compared to those who primarily sat.
What are the implications of the study?
The findings suggest that workplaces need focus as much, if not more, on prolonged standing as on prolonged sitting when considering prevention efforts to protect the heart health of employees.
What are some strengths and weaknesses of the study?
A strength of this study was its ability to take into account a wide range of work- and non-work-related factors that might have affected the relationship between sitting, standing and heart disease. In addition cases of heart disease were identified using validated algorithms, based on health care records and hospital discharge information. Limitations of the study included its inability to account for job changes during the 12-year period, and its limited information on the amount of time spent standing and sitting within the occupational groups studied.