According to a report from the Urban Institute, researchers found that that each year, on average, 4.2% of adults age 18 to 62 who are in the labor force report developing a new work-limiting health condition or experiencing a new health shock. Within two years, these workers are three times more likely to have left the labor force than workers who did not experience a health shock.
The report can be obtained at https://www.urban.org/sites/default/files/publication/100748/how_work-limiting_health_shocks_affect_employment_and_income_0.pdf.