This section presents the results of the clinical course of chronic non-specific low back pain for both the percentage of improvement and the absolute recovery. In addition, for each of the 5 outcomes, comparisons with other studies are discussed. The clinical course based on the 5 outcomes described in Chapters 4-7 showed a slight improvement for all outcomes during the 1-year period after treatment (Table 1). On average, about 60% of the patients reported a 30% improvement in back pain intensity, disability and work participation at their 12-month follow-up. Patients also reported a 60% improvement in quality of life (SF-36), and an improvement on the Physical Component Scale (PCS) at 5-months for the outcome ‘10% improvement of recovery’. On the Mental Component Scale (MCS) of the SF-36, 21% of the patients reported a 10% improvement at 5-months. However, when recovery was defined with a cut-off percentage [pain intensity 10 mm, disability 20 points, work participation (0-100% working) of 90% at follow-up, and GPE on a 5-point scale dichotomized into ‘clinically improved’ vs. clinically not improved’4, 6-9] the results were lower, i.e. 29%, 38%, 52% and 60% for back pain intensity,
disability, work participation, and clinical improvement on the GPE, respectively. With regard to comparison with other studies, many used a different methodology, or were population-based investigating the general population, or a primary care or another type of group. Moreover, they often used a different cut-off point to classify patients as being ‘recovered’ and used different points of measurement over time to evaluate patient recovery.13-19 Although all these differences hamper
a direct comparison, some general comparisons can be made.
The results of our study on the clinical course of back pain intensity (Chapter 4) and on disability (Chapter 5) showed some similarities compared with earlier studies.13-21 In the study of Costa et al. (2009), of the 259 patients who had not
recovered (not pain-free, still had disability from back pain, and had not returned to work in their previous capacity for 30 consecutive days), on entry to that study 47% had recovered after 1 year.22 Results of two systematic reviews showed that
50% of the patients had recovered from low back pain within 1 year.21,23 Studies
with 1-year follow-up (such as a Dutch population study that measured three times over a 10-year period) found that 30% of the population were free of back pain at
all follow-up points (low back pain was considered long standing if persisting for > 3 months).24 One Swiss study with a 5-year follow-up reported similar results, i.e. 35%
(low back pain problems at least once a month in the last 12 months) pain free at follow-up.25 Another study by Enthoven et al. (2004) showed that 52% of chronic
and recurrent low back pain patients reported pain (VAS > 10 mm) and back-related disability (Oswestry, > 10%) at the 1 and 5-year follow-up.16
In the present study, an interesting finding was that there was more improvement in disability than in pain intensity. This finding is consistent with results from earlier trials26, 27 and a systematic review28 in which patients received a program on cognitive
behaviour principles. Grotle et al. (2010) found only a moderate change in disability after 1 year (25% reduction) in patients with chronic low back pain.29 However, a
recent meta-analysis found a greater change in pain than in disability over 1 year30;
however, the studies included in the latter review did not include exercise programs with cognitive behavioural principles, which may explain the differences in findings.
Our study also showed that, directly after the 2-month multidisciplinary cognitive behaviour therapy at the SJC rehabilitation centre, patients experienced the greatest change in improvement post-baseline in all outcomes compared with the 5 and 12-month follow-up. At the 5-month follow-up in which the patients followed a 3-month self-management program2 the differences compared with a
2-month program were relatively small. A similar pattern was reported during the first 4-6 weeks in a recent meta-analysis30 and in other studies13,16,19 describing a
slowly advancing reduction in average pain and disability between 6 and 52 weeks. Our study population received therapy aimed at physical/functional recovery, which may partly explain the positive increase in work participation (Chapter 6). A systematic review by Guzman et al. (2002) provides evidence that intensive multidisciplinary bio-psycho-social rehabilitation with a functional restoration approach, improves pain and function in patients with chronic non-specific low back pain and increases the ability to work.28 Social disadvantage (e.g., income,
health care access, immigration status, language barriers), social factors at work (e.g. supervisor & co-workers support, job stress and burn-out), spousal support and family conflict may increase the time period before some patients are able to return to work.31 Thus, many factors can interfere with the course of improving
patients’ work participation. For sub-acute low back pain there is moderate evidence showing that multidisciplinary rehabilitation (which includes a workplace visit or a more comprehensive occupation healthcare intervention) results in patients returning to work faster.32 A work place visit might be a positive addition to the
For the course of quality of life (SF-36 PCS, MCS) and GPE (Chapter 7) fewer studies are available with which to compare our results.8,16,33-35 Our study showed more improvement
on the PCS of the SF-36 at the 5-month follow-up compared with other studies.33,34
This lack of consistency may be the result of differences in study methods33,34; for
instance, in other studies patients did not follow a therapy program, but could contact their clinicians if required. The MCS of the SF-36 showed more similarity with an earlier study that also followed patients after a multidisciplinary therapy for 6 months.35
In relationship to the course of GPE, in our systematic review1 only one study
reported that, in a non-surgical group of chronic low back pain patients, 29% assessed themselves as improved at the 2-year follow-up. Other studies also showed improvement from the patient’s perspective over a 12-month period; however, because they used other scales and different cut-off points comparison is difficult.36,37 In our study we found that 60% of the patients reported a clinically
relevant improvement at the 12-month follow-up.
In summary, the clinical course of patients with chronic non-specific low back pain who did not recover during primary and secondary care seems to improve after a rehabilitation program, with success rates up to 60% at 12-months follow- up depending on the definition of recovery and the type of outcome measure used.