Why was this study done?
A previous study by this research team determined that a workplace-based program helped workers who were absent due to low-back pain return to work (RTW) earlier than similar workers who received usual care. In this study, the researchers wanted to find out if the program worked better for some workers more than others.
How was the study done?
The initial study involved 196 workers who had been off work for two to six weeks due to low-back injury. The workers were randomly assigned into groups: those who took part in a workplace program and those who received “usual care.” Those in the program worked with their supervisor and an occupational health professional or ergonomist to identify and solve RTW barriers together, and then implemented the solutions. Those who received “usual care” only had treatment from an occupational health physician. Researchers compared the number of days of absence among workers in each group. Only work-returns of four weeks or more, to the same job or a similar job at the same pay, were considered successful.
The researchers then looked more closely at the original findings. They compared the number of days of absence in both groups according to factors known to affect the length of absence: age, gender, degree of pain, ability to function due to injury, heavy work, and having taken sick leave in the previous year.
What did the researchers find?
Overall, the workers who took part in the workplace-based program returned to work faster than those who did not. They returned about 30 days earlier, on average. Upon closer analysis, the workplace-based program worked particularly well for older and previously sick workers. Workers 44 years and over who took part in the program returned to work 2.5 times faster than workers of the same age in the usual-care group, whereas workers in the program who had been sick in the previous year returned to work 2.8 times faster. Factors such as gender, ability to function due to the injury, pain and heavy work did not make a difference to the effectiveness of the program.
What are some strengths and weaknesses of the study?
The results are based on a randomized controlled trial, which is the gold standard for testing the effectiveness of a treatment practice. A weakness of this study is that the subgroups were identified after, not before, data collection (although the same potential subgroups would likely have been identified).