Comparing the occurrence of chronic physical disorders in self-employed individuals with that of employees: A systematic review.

The studies could not be added together, and they measured health in 14 different ways, many using questionnaires written for that one study rather than tools with known reliability. Most studies compared self-employed people with employees doing different kinds of work, and lumped very different self-employed people together; only four compared people in the same occupation. Ten of the 16 studies asked about health at a single point in time, so they cannot show whether self-employment led to the health problem or the health problem led to self-employment. The employee comparison groups tended to be younger, better educated, better paid and more often in nonmanual work, so some of the difference between groups reflects who they were rather than the work they did. Illness counted from hospital and insurance records made self-employed people look healthier than illness reported on questionnaires did. One reason the authors give is that self-employed people lose income when they take time off to see a doctor. Studies published from 1989 to 2019 were included, and working conditions, smoking rates and the wider economy changed a great deal over that period, which the authors say limits how far the older findings should guide prevention. All the studies came from Europe and Asia, with none from other continents, and the authors note that working hours and how much say workers have over their work differ between countries, so the results do not transfer cleanly. The authors also raise the possibility that some of the physical complaints have a psychological component (somatisation), which none of the included studies could measure.

No funding statement and no competing-interest declaration appear anywhere in the article text provided. The only declarations given are that ethical approval and informed consent were not applicable, because this is a literature review.

Do not read this as evidence that self-employment is bad for physical health. The surveys that found more muscle and joint complaints among self-employed people were taken at a single point in time, so they cannot show which came first, the health problem or the job. The same review found self-employed people had lower rates of heart disease and death than manual workers.