If you’ve ever had low back pain, you know how debilitating it can be. Most people will do whatever it takes to avoid a recurrence. Not only is it painful, but time lost from work and play reduce quality of life. Scientists are studying ways to prevent recurrence of low back pain. They have looked at risk factors and predictive factors trying to help patients find ways to stop back pain from coming back after the first episode.
One of the problems researchers run into is knowing how to tell when an episode of back pain is just a continuation of the last bout or an actual recurrence. Defining recurrence is the topic of this study. When looking at the different ways researchers define recurrence from study to study may seem like splitting hairs. But when trying to assess which treatment works best, the concept of recurrence becomes an important measuring stick.
According to the authors of this paper, a true recurrence really means the patient recovered fully from the first episode. The new symptoms are truly considered a separate incident. But the gray area comes when trying to say just when one episode ended and a new episode began. And there’s some question as to whether features such as pain intensity, duration, or frequency should factor into the definition.
For example, does the pain have to last more than one hour? two hours? half a day? or longer? before it can be considered an episode? Is there a minimum level of intensity that qualifies? Does it have to be at least five on a scale from zero (no pain) to 10 (most pain)? Does the location of the pain matter in the definition? Maybe when back pain is severe enough to limit activities or cause the person to seek treatment, then the incident becomes an episode.
So the first step in answering the question of how to define recurrence was to look at how all other studies defined it and search for common ground. To accomplish this task, all studies on low back pain from 1958 to 2008 were searched. Once the potential studies were gathered together, they looked for the ones that focused on reducing the risk of recurrence.
A total of 53 articles were found. Only 20 of those studies actually gave a definition of recurrence. The rest (33 articles) said they were measuring recurrence but didn’t say how they defined the occurrence. Very few studies even considered recovery or give a definition of it.
The only real consensus or agreement on a definition for recurrence came from one author who happened to publish four studies on the topic. It seems each new study creates a different definition of recurrence (when they even bother to define it at all). This approach just adds chaos to confusion.
Without a consistent definition, it is not possible to combine the data from all the studies in order to look for trends in treatment success. The same is true when trying to compare treatment results from one study to another — if there isn’t agreement on what recovery and recurrence are, then it’s like comparing apples to oranges. When everyone is on the same page with the same definitions, then a true summary of findings can be published. This leads to helpful clinical guidelines for treatment that can be followed by everyone.
The authors of this systematic review suggest that persistence of pain from a first episode that never really recovered is different from recurrence. Persistence of pain occurs in someone who did not recover from the first bout of low back pain. If those patients are included in a study, it’s even more difficult to tell whether or not a particular method of treatment worked. There needs to be clear, separated pain episodes to distinguish recurrence from a continuation of the original pain.
The definition of low back pain recurrence can range anywhere from the patient’s pain returned to the patient had at least a month without back pain before the pain returned and lasted for more than 24 hours. Here’s what the authors of this study have recommended.
First, of course, it should be acknowledged that a standard definition is needed. Then, there must be general consensus among researchers to adopt that standard definition. When all studies use the same outcome measure, then the success of different treatment approaches can be compared. And at the very minimum, the definition should include a minimum duration and intensity.
The authors propose using a level two pain intensity on a scale from zero to 10 lasting at least 24 hours to signal a new episode of low back pain. And the pain must occur after at least 30 days pain free from the last bout of back pain. This last parameter (i.e., pain-free for at least one month) represents the working definition of recovery. Pain-related disability (e.g., pain severe enough to limit activities for more than one day) should be part of the complete definition of an episode of low back pain.
When a majority of studies use the same definitions of recovery and recurrence, then efforts can be made to pool study results together. This type of systematic review allows for a more accurate assessment of treatment outcomes.
Since less than 10 per cent of all studies use the same definition, we have a long way to go in turning this trend around. But it is an important step in reducing the cost of treatment and the time lost from work, not to mention providing patients with low back pain respite from suffering and disability.