Scientists from The Netherlands have found three new factors that might help predict which patients with low back pain (LBP) will go on to develop chronic LBP. They describe chronic LBP as pain that lasts six months or more.
When it comes to low back pain, many researchers have attempted to find ways to predict who will get better and who won't. It's an important topic because so many people are affected by low back pain. The cost of treatment, lost wages, and lost productivity is in the billions of dollars worldwide.
If we could find ways to predict who might develop chronic low back pain, it might be possible to "head it off at the pass" so-to-speak. The areas studied over the years have been drilled down to four major categories: 1) demographics, 2) work, 3) clinical, and 4) psychosocial. In this study, they looked for the most common combination of factors rather than one single variable that might predict chronic low back pain most often.
Let's take a brief look at each of these groups. Demographics refer to patient-specific factors: age, gender (male or female), level of education, marital status. Work as a potential prognostic factor has been examined in terms of job satisfaction, type of work (manual labor versus sedentary or inactive), job demands, and perceived control on-the-job.
Clinical factors refers to pain (and other symptoms), function, and disability. Pain was measured by intensity, frequency (how often it occurs, previous history of back pain), and duration (how long it lasted). Back pain that radiated down the leg was also counted as a possible important variable. Level of activity and restrictions at home, on-the-job, or during recreational and leisure events made up the function and disability categories.
And finally, the psychosocial category. There is a bit of overlap between this group and some of the others (e.g., marital status and family support, job satisfaction and stress, pain and pain coping, job demands and job control).
Kinesiophobia and fear avoidance behavior are two additional psychosocial variables considered as factors that may predict chronic low back pain. Both of these have been studied and reported on by other research groups.
Kinesiophobia refers to fear of movement or the fear that movement and/or exercise will cause a reinjury. Fear avoidance behaviors are the result of kinesiophobia -- the person stops moving in ways that he or she thinks might cause pain.
This study was done at the VU University Medical Center in Amsterdam, The Netherlands. The research team included physicians, Physical Therapists, faculty, and staff from the Institute for Health and Care Research, Department of Methodology and Applied Biostatistics, Institute for Health Sciences, and the Department of Clinical Epidemiology.
They didn't study patients directly themselves. Instead, they took the results from three high-quality studies (randomized controlled trials) and merged the data. This type of study design makes it possible to compare the effectiveness of different treatment types while looking for predictive or prognostic factors.
All three studies included workers from The Netherlands. There were airline company workers, luggage handlers, heavy steel construction workers, office workers, and health care workers. The majority of people tended to be on the manual labor or heavy duty side of things. The trials compared usual care with graded activity, ergonomic intervention with graded activity, and low to high-intensity back schools.
Data was collected through a wide range of questionnaires completed by the study participants. There were surveys for everything from pain to activity (sports, work, leisure), job requirements (lifting, bending, twisting), coping strategies, job satisfaction, fear avoidance, and kinesiophobia.
Some of the tools used included Numerical Rating Scale (NRS), Baecke Questionnaire, Roland Disability Questionnaire, Dutch Musculoskeletal Questionnaire, Job Content Questionnaire, Tampa Scale for Kinesiophobia, and Fear Avoidance Beliefs Questionnaire. So you can see each potential variable (possible predictive factor) was tested for and given a quantitative (number) score.
With all that digging for information and analyzing the combined data from three studies, what did they find? Their final prognostic model contained three factors: 1) no change in pain intensity and disability during the first three months of low back pain, 2) high pain intensity at baseline, and 3) the presence of kinesiophobia right from the start.
It makes sense that severe back pain that doesn't get better right away is likely to result in chronic (long-term) symptoms. And this factor was no surprise as other studies have found the same thing. Other studies have also reported kinesiophobia as a critical factor in predicting chronic low back pain. This is the first study to find all three combined together as a predictive model.
One thing they did NOT find was that age, gender, pain coping, the presence of back and leg pain, disability status, or fear avoidance had any effect on prognosis. Other studies have reported these variables as possible predictive factors. There are many reasons why this might be so but future studies are needed to investigate this further.
You may be wondering: what about the different ways patients were treated (usual care, ergonomic changes, graded activity)? Well, it turned out that treatment results didn't have much influence on the development of chronic pain, so that piece was dropped from consideration in the final analysis.
In summary, among both blue- and white-collar workers, change in pain intensity and disability status in the first three months of low back pain can be used to gauge prognosis. In particular, these variables can be used to predict who will go on to develop chronic low back pain (lasting six months or more).
Based on this information, physicians treating patients with new onset of acute low back pain are advised to keep close tabs on them. Seeing these folks more often during the initial episode of low back pain might help reduce the number of patients who progress to become chronic pain patients.
At the same time, more studies are needed to identify specific treatments that work for each patient category. Patients with acute low back pain for the first time should be tested for kinesiophobia. The presence of fear of movement early on should be addressed immediately to help keep acute low back pain from developing into chronic pain.
Reference: Martijn W. Heymans, PT, PhD, et al. The Prognosis of Chronic Low Back Pain is Determined By Changes in Pain and Disability in the Initial Period. In The Spine Journal. October 2010. Vol. 10. No. 10. Pp. 847-856.