- Continuous and fluctuating pain are the most common pain recovery patterns. This means that return to work may not accurately measure pain resolution.
- The study introduces the possibility of predicting patients' likely recovery patterns, based on age, history of back injuries and other characteristics.
Why was this study done?
People with back injuries may experience different patterns of recovery. Knowing how people recover may help clinicians who are treating patients with back injuries. Past research has looked at pain intensity, disability, duration of compensation claims and work absences to determine how back injuries resolve over time. This study identified different patterns of pain recovery among workers with back injuries over the course of one year. It also looked at how factors such as age or salary were distributed across each group.
How was the study done?
Researchers conducted telephone interviews with 678 workers who filed new lost-time claims with the Ontario Workplace Safety and Insurance Board (WSIB) for back injuries. These workers were asked to provide information about their pain symptoms and disability at the time of injury and at four follow-up interviews during the year. Researchers also collected information on each worker's health and demographics. The workers were classified into categories according to their reports of pain.
What did the researchers find?
Four patterns of pain recovery emerged:
- Continuous: high pain intensity with no improvement over time (43 per cent of workers)
- Fluctuating: fluctuating pain throughout the one-year study period; substantial recovery in the first four months; no recovery thereafter (33 per cent of workers)
- Moderate reduction: slow but steady recovery; still experiencing pain at the final follow-up (12 per cent of workers)
- Large reduction: quick recovery with little to no pain (12 per cent of workers)
Age, past history of back injuries, and having other health conditions such as arthritis or bronchitis were among the factors that seemed to determine how people recovered.
What are some strengths and weaknesses of the study?
This approach produced a detailed picture of how back pain can change in a year. However, the injuries in these participants may have been more severe than average, since the study was restricted to those who were unable to work.