Respondents to the 2012 NHIS self-reported the number of bed days and lost work days they experienced in the previous 12 months due to a variety of medical conditions. A bed day is defined as one-half or more days in bed because of injury or illness in past 12 months, excluding hospitalization. A missed, or lost, work day is defined as absence from work because of illness or injury in the past 12 months, excluding maternity or family leave.

Although the exact cause of these bed and lost work days cannot be determined because some respondents reported multiple health conditions, 70% of persons reporting bed and lost work days reported having a musculoskeletal condition. This is more than twice the proportion reporting depression, the second most common medical condition listed for causing lost work days, and five or more times the proportion for other major health conditions. Overall, the high proportion of workers reporting lost work days or bed days as a result of a musculoskeletal condition results in an economic burden on the economy—much higher than that reported for chronic circulatory or chronic respiratory conditions. (Reference Table 1.8.3 PDF CSV)