Summary of findings [Explanations]
Background
Low-back pain (LBP) is a major health disorder with a high prevalence rate and heavy burden of cost internationally. The point prevalence of LBP varies between reports and countries from 26.4% in the USA (Deyo 2006) to 19% in Denmark (Harreby 1996), 27% in Hong Kong (Tse 2003), 28.7% in Canada (Cassidy 1998), 16% in England (McKinnon 1997), 14.7% in Australia (Strauss 1993), 13.4% in Norway and 18.2% in Sweden (Ihlebaek 2006). The costs of LBP are enormous and are attributed to both tangible costs (i.e. medical care and indemnity payments) and intangible costs (i.e. production loss, employee retraining, litigation) (Woolf 2003). In the UK, it was estimated that the direct costs of LBP were £1.6 billion and the total costs (direct and indirect) ranged from £6.6 billion to £12.3 billion (Maniadakis 2000). In the US, a comparative cost of illness study showed that the annual per capita health and disability costs for LBP were comparable with heart disease and diabetes in a major US corporation (Druss 2000). Also, LBP is one of the main causes for work absenteeism (Andersson 1999). Expenditures are expected to grow with the trend of an aging population worldwide.
One of the features of back pain is its tendency to recur. In a prospective study in North Carolina, 208 patients, randomly recruited after the first episode of LBP, were followed for 22 months. Thirty-five per cent to 44% of all patients experienced a recurrence at six-month follow-up and 50% to 59% at 22-month follow-up (Carey 1999). In other studies, the LBP recurrence rate was found to be even higher, with over 60% of all patients experiencing a recurrence at one-year follow-up (Bergquist 1977; Von Korff 1993) These high figures suggest that it is important to find an effective method to prevent recurrences.
For an individual, a new episode of back pain is at the very least an unpleasant experience and is sometimes very debilitating. One complaint of patients about their treatment of back pain is that they do not receive concrete information and instructions from their care providers (Verbeek 2004). Prescribing specific exercises or activities to prevent a recurrence of back pain could help to meet these expectations.
The effectiveness of interventions for treating back pain has been extensively studied. It has been found that staying active is more effective than resting in bed for treating acute back pain (Hagen 2004). In another systematic review, exercise therapy was found to be slightly more effective than no treatment and other conservative treatments in reducing pain and improving function in patients with chronic LBP (Hayden 2005). However, no information about LBP recurrences was used in this review and patients were classified by the duration of their LBP.
It is conceivable that continuing to do exercises could help to prevent recurrences of back pain (Soukup 1999). Some studies have shown that using a specific type of exercise during treatment helped in avoiding recurrences (Cairns 2006; Hides 2001). In a randomised controlled trial using a specific stabilizing exercise for patients after their first episode of LBP, the patients in the exercise group were 2.1 times less likely to suffer from LBP recurrences than those in the control group at three-year follow-up (Hides 2001).
This is a relevant question for clinicians, because it means that the focus of treatment should also be directed towards a more preventive perspective. There are reviews that summarized the literature on the prevention of pain severity and duration, and the reduction of sick days and disability from LBP (Lahad 1994; Linton 2001). The preventive interventions investigated in the two reviews included educational strategies, lumbar supports, exercises, ergonomics, and risk factor modification. Based on randomised trials, only exercise was shown to have a consistent, limited effect on the prevention of new episodes of low-back pain. In these reviews, it was unclear if the back pain episodes were first or recurrent episodes. However, so far no one has reviewed the evidence provided only from randomised controlled trials for preventing recurrences after an episode of back pain.
Objectives
The primary objective of this study is to investigate the effectiveness of exercises for preventing new episodes of low-back pain or low-back pain-associated disability.
Methods
Criteria for considering studies for this review
Types of studies
Only randomised controlled trials (RCTs) are included. We did not use language restrictions for studies but we did not find any relevant studies in languages other than English.
Types of participants
Inclusion criteria
We included studies with both male and female adults, aged 18 or older, who currently had, or had ever had at least one prior episode of non-specific LBP. Non-specific LBP is defined as low-back pain below the costal margin and above the inferior gluteal folds with or without leg pain, that has no specific underlying pathology.
Exclusion criteria
Studies on back pain due to infections, metastatic diseases, neoplasm, osteoarthritis, rheumatoid arthritis, or fractures were excluded as well as studies on back pain related to pregnancy.
Types of interventions
Inclusion criteria
Studies with an exercise intervention aimed at the prevention of recurrences of LBP were included. Exercise were defined as physical activity that is planned or structured and may be done to improve or maintain one or more components of physical fitness (ACSM 2006). The types of exercises were not limited.
We divided exercises into strengthening exercises, endurance training and aerobic exercises. We defined strengthening exercises as exercises to strengthen back and trunk muscles by repeated movements with loads. Endurance training was defined as exercises to increase the endurance of back and trunk muscles by repeated movements with loads. Aerobics were defined as any form of activities to improve cardiopulmonary fitness.
Interventions were further divided into post-treatment interventions and treatment interventions. Post-treatment interventions were defined as interventions that were provided to patients after their regular treatment for an episode of back pain had been finished with the explicit aim to prevent new occurrences of back pain. Treatment interventions were defined as treatment for a current episode of back pain with the aim to also prevent new episodes of back pain.
Exclusion criteria
Studies using an exercise intervention that was combined with other interventions such as psychotherapy, specific medication, back school, electro-physical therapies, or lumbar traction were excluded.
Types of outcome measures
The primary outcome was recurrences of LBP, measured either as frequency or duration of new episodes of LBP within a specified time-period or the time to a LBP recurrence (time between the previous episode or start of the study and the LBP episode). An episode of LBP was defined as a period of pain in the lower back lasting for more than 24 hours, preceded and followed by a period of at least one month without low-back pain (De Vet 2002). A recurrence of LBP was defined as an episode of pain, sickness absence or disability resulting from the pain as defined by Wasiak 2009.
The follow-up times for outcome measures were categorized as short-term, with a follow-up of less than half a year; medium-term, from one-half to two years; and long-term, from two to five years after the intervention. We realise that this is an arbitrary categorisation but it seems to fit the increasing frequency of recurrences of back pain, which is the main focus of this review.
Search methods for identification of studies
Electronic searches
We used the search strategy that was developed by the Cochrane Back Review Group (Furlan 2009; van Tulder 2003). We searched CENTRAL (The Cochrane Library 2009, issue 3), MEDLINE, EMBASE and CINAHL up to July 24, 2009. The full search strategies for MEDLINE and EMBASE are outlined in Appendix 1 and Appendix 2; the others are available on request.
Other sources
The reference lists of relevant reviews and papers were screened for additional studies and we also used citation tracking of all relevant trials. We contacted the following authors for additional information: Cherkin, Lonn, Soukup and Donchin.
Data collection and analysis
Study selection
Using the inclusion and exclusion criteria, a pair of review authors (BC, JV, WT) on a rotatory basis independently screened the identified titles and abstracts to choose potentially relevant studies. We obtained the full text of articles for those that appeared to meet the inclusion criteria in order to make the final selection. Disagreements were solved by discussion. A third review author was consulted if disagreements persisted.
Data Extraction
A pair of review authors (BC, JV, WT) on rotatory basis independently extracted the data. We extracted data on participant characteristics, intervention parameters, results of outcomes of interest, duration of outcome measurements, country and sponsorship of the studies. We also checked for any adverse events due to exercises reported in the studies.
To make sure all reviewer authors interpreted the criteria in the same way, we pre-tested all the forms to be used to assess study eligibility and risk of bias and to extract data by using a set of similar studies on a related topic that was not included in this review. We did not blind the articles since the review authors are familiar with the literature and would recognise the trials.
Risk of bias assessment
The risk of bias was independently assessed by a pair of review authors (BC JV WT) on a rotatory basis, who used a consensus method when disagreements occurred. A third review author was consulted if disagreement persisted.
We used the criteria recommended by the Cochrane Back Review Group (Furlan 2009; van Tulder 2003) to assess the risk of bias of the selected RCTs. The criteria and their operational definitions are outlined in Appendix 3. Each of the criteria was scored "yes", "no" or "unclear", depending on the information supplied in the report. Studies were classified as having a low risk of bias if they fulfilled six or more of the eleven criteria and had no serious flaws. Studies that fulfilled fewer than six criteria were determined to have a high risk of bias. Studies were determined to have an unclear risk of bias if one or more key domains were assessed as unclear (Higgins 2008).
Clinical relevance
We intended to assess the clinical relevance of the included studies according to the following questions as recommended by the Cochrane Back Review Group (Furlan 2009; van Tulder 2003).
- Are the patients described in detail so that you can decide whether they are comparable to those that you see in your practice?
- Are the interventions and treatment settings described well enough so that you can provide the same for your patients?
- Were all clinically relevant outcomes measured and reported?
- Is the size of the effect clinically important?
- Are the likely treatment benefits worth the potential harms?
When doing so, we realised that it is difficult to assess clinical relevance for preventive interventions as they have a benefit at both individual and group level. Even though the improvements for an individual could be marginal, they still could be worthwhile at the group level.
Data Analysis
Separate analyses were made for post-treatment exercises that were provided after regular treatment had ended and treatment exercises that were provided as regular treatment for the current episode of back pain and at the same time intended to prevent future episodes of back pain.
Data synthesis
We first decided if studies were sufficiently clinically homogeneous to be able to synthesize the results into one summary measure. Clinically homogeneous studies were defined as those with similar populations, interventions, and outcomes measured at the same follow-up point. We pooled studies with sufficiently reported numerical data, judged to be clinically homogeneous, with RevMan 4.2 software (RevMan 2003) and later converted to RevMan 5. We tested for statistical heterogeneity and assessed if studies were statistically heterogeneous as judged by the I² measure. If I² was greater than 50% we used a random-effects model for pooling.
Measures of treatment effect
The results of each trial were plotted as means and standard deviations (SD) for continuous outcomes, risk ratios (RR) for dichotomous outcomes and Hazard Ratios (HR) for time-to-event data.
Regardless of whether there were sufficient data available to use quantitative analyses to summarize the data, we assessed the overall quality of the evidence for each outcome using the GRADE approach as described in the Cochrane Handbook (Higgins 2008) and the Cochrane Back Review Group method guidelines (Furlan 2009).
Sensitivity analysis
The results were analysed again by only including studies that had a low risk of bias to find out if the risk of bias altered the synthesized results.
Dealing with missing data
We contacted the following authors of the studies to provide information on missing data: Soukup, Cherkin, Donchin and Lonn. Soukup provided extra information on the nature of the measurement of recurrences. Cherkin was not able to provide additional information on the number of recurrences. Donchin provided extra information on the number of subjects with recurrent LBP. Lonn confirmed in which articles their three-armed study with different follow-up times was reported.
We computed Standard Deviations from P values for the duration of episodes in Faas 1998, and for the number of recurrences in Soukup 1999. We calculated Hazard Ratios from the Gehan-test in Soukup 1999.
Assessment of publication bias
We did not assess publication bias with a funnel plots or Egger's test because we had fewer than five studies in all comparisons (Egger 1997).
Subgroup analysis
We had intended to stratify the included studies by types of exercises such as strengthening, endurance training, and aerobics, to find out the effects of different types of exercises on recurrence of LBP. However, all interventions included all types of exercises except for Hides 2001 who looked specifically at improving the multifidus muscle. The two studies that used the McKenzie exercises were combined separately.
Results
Description of studies
See: Characteristics of included studies; Characteristics of excluded studies.
We identified a total of 2053 potentially relevant articles with 102 articles from CENTRAL, 178 from MEDLINE, 1596 from EMBASE and 177 articles from CINAHL. After screening the titles and abstracts of the potential articles, we selected 33 articles to evaluate their full texts and finally included 13 articles in this review. The flow of relevant articles selection is displayed in Figure 1.
 | Figure 1. Flowchart for inclusion/exclusion of studies |
The Characteristics of included studies table shows the summary of methods, participants, interventions, outcomes and study quality of the included studies (Cherkin 1998; Donchin 1990; Faas 1998; Hagen 2003; Hides 2001; Kellett 1991; Ljunggren 1997; Soukup 1999; Stankovic 1990). Four articles reported on the outcomes of the study at two follow-up times (Soukup 1999); this was also the case with another two articles (Stankovic 1990). Thus we had 13 articles reporting on nine studies and nine different interventions.
Four interventions were post-treatment exercises, intended to specifically prevent recurrences of back pain (Donchin 1990; Kellett 1991; Ljunggren 1997; Soukup 1999). The other five interventions were exercises that formed part of the treatment for back pain that were also intended to prevent recurrences of back pain.
The post-treatment interventions consisted of a mixture of back stretching, leg stretching, muscle contractions and muscle relaxation exercises. In one study, the Mensendieck method of exercises was followed (Soukup 1999). All interventions contained additional advice or information on back pain, such as might be found in a back school. The control treatment in these studies was no intervention (Donchin 1990; Kellett 1991; Soukup 1999) and general exercises (Ljunggren 1997).
The treatment interventions consisted of: general exercises led by a physiotherapist in one study (Faas 1998), promoting physical activity and exercises in one study (Hagen 2003), specific multifidus muscle exercises in one study (Hides 2001) and McKenzie exercises in two studies (Cherkin 1998; Stankovic 1990). The control interventions were sham ultra-sound therapy (Faas 1998), usual care (Faas 1998; Hagen 2003; Hides 2001), an educational booklet (Cherkin 1998) and a mini-back school (Stankovic 1990).
In seven studies, recurrences were measured as the number of persons with a recurrence or the rate of recurrence (Cherkin 1998; Donchin 1990; Faas 1998; Hagen 2003; Hides 2001; Soukup 1999; Stankovic 1990). The time to recurrence was measured in one study only (Soukup 1999). The number of recurrences was measured in three studies (Hides 2001; Kellett 1991; Soukup 1999). Episodes of sickness absence and the duration of sick leave were also measured in some of the studies. Three studies had long-term follow-up (Hagen 2003; Hides 2001; Stankovic 1990) and all the other studies measured outcomes at medium-term follow-up.
Participants in the treatment studies were acute back pain patients in four studies and sub-acute patients in one study (Hagen 2003); chronic patients were not included in any studies.
Three studies were carried out in Norway, one in Australia, two in Sweden, one in the US, one in the Netherlandsand and one in Israel. Seven studies were carried out in the 1990s and two in the first decennium of the 21st century.
Risk of bias in included studies
Details of the results of the risk of bias assessment of the included studies are shown in Figure 2.
 | Figure 2. Review authors' judgements for each risk of bias item for each study. |
We used the following categorisation for limitations in study design to downgrade the level of evidence. Four studies were assessed as having a low risk of bias (Cherkin 1998; Faas 1998; Hagen 2003; Hides 2001). These studies only failed to meet the blinding requirement which is very difficult to meet in exercise studies where neither the provider, patient nor outcome assessor can be blinded. One study was rated as having a high risk of bias (Kellett 1991), because it had an unclear randomisation procedure in addition to several other risks of bias. The rest of the studies were rated as having an unclear risk of bias, because most studies failed to meet criteria such as concealed allocation, co-intervention avoidance, and intention-to-treat analysis. The level of evidence was downgraded because of serious limitations in study design only when the evidence was based in whole or in part, on results of Kellett 1991.
Effects of interventions
See: Summary of findings for the main comparison Post-treatment exercise compared to no intervention for preventing recurrences of low-back pain
The recurrence rate as the percentage of persons with a recurrence in the control and intervention groups at one-half to two years follow-up was, on average, 58% (range 32% to 80%); at two to five years follow-up, the rate was, on average, 72% ( range 58% to 88%).The average number of recurrences across studies, in both the control and the intervention group, was 1.5 per person at one-half to two year follow-up (range 0.3 to 4.2 per person); at two to five year follow-up, the average number of recurrences was 2.0 per person (range 1.0 to 3.0 per person). This confirms the general notion that back pain recurs -- often more than once.
Post-treatment exercise versus no intervention
There were three studies that evaluated post-treatment exercise versus no intervention (Donchin 1990; Kellett 1991; Soukup 1999). The number of subjects with recurrences was significantly lower with a RR of 0.50 (95% CI 0.34 to 0.73) at medium-term follow-up in two studies (Donchin 1990; Soukup 1999), but not at long-term follow-up, with a RR of 0.75 (95% CI 0.53 to 1.07) (Soukup 1999). One study measured the time to recurrence, which yielded a HR of 0.43 (95% CI 0.21 to 0.87) at medium-term follow-up (Soukup 1999), and a slightly higher HR 0.50 (95% CI 0.28 to 0.90) at long-term follow-up (Soukup 1999). The number of recurrences was measured in two studies (Kellett 1991; Soukup 1999) with a mean difference (MD) of -0.35 (95% CI -0.60 to -0.10) at medium-term follow-up, and in one study (Soukup 1999) at long-term follow-up with a MD of -1.97 (95% CI -3.84 to -0.10).
Post-treatment exercise did not influence the number of persons on sick leave as a result of recurrences at medium or long-term follow-ups, but did decrease the number of days on sick leave due to recurrences in two studies (Kellett 1991; Soukup 1999) at medium-term follow-up with MD of - 4.37 (95% CI -7.74 to - 0.99).
In summary, we found moderate quality evidence (serious limitations in design) from two RCTs (Donchin 1990; Soukup 1999, N = 130) that post-treatment exercises were more effective compared with no intervention in reducing the number of subjects with recurrences at medium-term follow-up (RR 0.50; 95% CI 0.34 to 0.73), and moderate quality evidence (serious limitations in design) from two RCTs (Kellett 1991; Soukup 1999, N = 154) that they were more effective at reducing the number of recurrences of back pain at medium-term follow-up. For sick leave at medium-term follow-up, there is very low quality evidence (serious limitations in design and very serious inconsistency) from two RCTs (Kellett 1991; Soukup 1999, N = 154) that the number of days on sick leave decreased more with post-treatment exercises than with no intervention.
Post-treatment exercise plus TerapiMaster machine versus general exercises
One study (Ljunggren 1997) evaluated the effect of an additional exercise machine on the number of days on sick leave. This did not significantly reduce the number of days on sick leave.
Exercise treatment versus care as usual
Exercise as a treatment for acute back pain did not influence the number of persons with recurrences in one big study (Faas 1998) and lowered the number of persons with recurrences in another small study (Hides 2001). The exercises in the latter study were specifically focused on improving the strength of the multifidus muscle. In the same study, the number of recurrences did not decrease nor did the number of subjects on sick leave because of recurrences. In another big study in which persons were encouraged to exercise individually (Hagen 2003), there was no difference in the rate of recurrences between control and intervention groups.
Thus, there was very low quality evidence (limitations in design and serious inconsistency) that the recurrence rate at medium-term follow-up (RR 0.63; 95% CI 0.23 to 1.76) from two RCTs (Faas 1998; Hides 2001, N = 358) and at long-term follow-up (RR 0.74; 95% CI 0.35 to 1.55) from two RCTs (Hagen 2003; Hides 2001, N = 493) was similar between the exercise and the care as usual group.
Exercise treatment versus sham treatment
Exercise treatment was compared to ultra-sound sham treatment in one study (Faas 1998; N = 473) but it resulted in neither fewer persons with recurrences nor a shorter duration of recurrent back pain.
McKenzie exercises versus back pain education
McKenzie exercises were compared to back pain education in two studies (Cherkin 1998; Stankovic 1990), which yielded different results on the number of subjects with recurrences. The small study Stankovic 1990 (N = 96) found a significant decrease, both at medium and long-term follow-ups, but the big study Cherkin 1998 (N = 323) did not find a decrease. However, the pooled results found no significant difference in the number of subjects who had recurrences (RR 0.75; 95% CI 0.42 to 1.35; N = 294) in the medium-term follow-up.
There was no significant difference in the number of days on sick leave between those who had McKenzie exercises and those who received back pain education at medium (MD -13.10; 95% CI -30.79 to 4.59; N = 95) and long-term (MD -19.80; 95% CI -86.53 to 46.93; N = 89) follow-ups in one study (Stankovic 1990).
In summary, there was very low quality evidence (limitations in design, serious inconsistency and imprecision) from two RCTs (Cherkin 1998; Stankovic 1990, N = 294) that McKenzie exercises are similar to back pain education at reducing recurrences of back pain at medium-term follow-up and very low quality evidence (very serious imprecision) from one RCT (Stankovic 1990) that the number of sick leave days is similar after back pain education in the medium and long-term follow-ups.
Sensitivity analyses
Meta-analyses were conducted with only the studies at low risk of bias. One post-treatment study was at an especially high risk of bias (Kellett 1991). Leaving this study out did not decrease the evidence for post-treatment exercise considerably.
Adverse events due to exercises
There were no reports of adverse events mentioned in any of the selected studies.
Discussion
We found that the recurrence rate and the number of recurrences of back pain could be reduced and the time to recurrence could be prolonged by providing post-treatment exercises. The number of days on sick leave in the post-treatment follow-up period was reduced by post-treatment exercises but not the rate of sick leave in the post-treatment period. We found conflicting results for the effectiveness of exercise treatment in reducing the number of recurrences or the recurrence rate.
The overall quality of the evidence was moderate with four studies assessed as having a low risk of bias, most studies an unclear risk of bias and only one study a high risk of bias. However, the post-treatment exercise studies in particular had a higher risk of bias, which makes it difficult to draw strong conclusions.
The strength of our review is that we are the first to systematically look into recurrences as an outcome of back pain interventions. Outcome measurement in back pain is difficult as there are many ways to measure back pain. Even though the recurrence rate and the number of recurrences seem a straight forward outcome, studies show that this is not the case (Stanton 2009). Wasiak has studied the differences in recurrence rates based on differences in definitions and found a great difference if he used care-based or lost-work-time-based definitions (Wasiak 2003; Wasiak 2009). This is reflected in the outcomes found in this review, where different definitions of recurrences yielded different results. However, we found that the number of recurrences increased with longer follow-up over most studies. This finding increases the probability of a valid measurement of recurrences.
We divided the studies into post-treatment exercises and treatment exercise studies. This approach can potentially answer the question about whether we should have more exercise-directed treatment during an episode of back pain, or whether we should encourage and possibly supervise exercises after treatment that are geared towards preventing recurrences. This review suggests that the latter is more effective in preventing recurrences of LBP. Even though we made a clear distinction between post-treatment and treatment studies, this was not always clear from the studies themselves. Some studies clearly stated that they were post-treatment and the patients should be at work (Soukup 1999), while others just recruited participants who had experienced at least three episodes of back pain in the past (Donchin 1990). However, the intention of all these studies was to prevent recurrences and the outcomes were measured as recurrences of back pain.
The judgement of clinical relevance was difficult. Most of the included studies described the patients and treatments in detail but we were not able to identify potential harms in the included studies. In prevention studies in general, it is difficult to assess a clinically important size of the effect since even small effects can be worthwhile at the group level. It is mainly a matter of cost-effectiveness that is used to judge if preventive interventions are worthwhile. The effects in the post-treatment studies were considerable, with a relative risk reduction of 25% for the recurrence rate and 22% reduction in the number of recurrences. These effects are certainly clinically worthwhile ( Table 1).
The exercises that were prescribed in the various studies incorporated more or less similar ingredients, except for the multifidus muscles exercises studied by Hides 2001 and the McKenzie exercises, as shown in Table 2. Therefore it is difficult to make inferences about the content of the interventions. There was a wide variation in the rate and number of recurrences between studies that we could not explain and that might be due to differences in measurement, biomechanical exposure or low exercise levels.
The picture that emerges from this review is that post-treatment exercises likely reduce the rate and the number of recurrences and the days on sick leave, and increase the time to recurrence. If the rate of recurrences is reduced, then it is unclear why this is not reflected in the rate of sick leave, but the duration of sick leave is reduced. This would mean that even though the same number of persons start sick leave, they return to work sooner as a result of doing exercises.
For exercise therapy, the evidence is conflicting. It is unclear why post-treatment exercise would be more beneficial than exercise treatment. It could be possible that post-treatment exercises focus more on changing behaviour and treatment exercises are considered treatment and stopped after the treatment programme is finished.
We could not formally assess publication bias due to a lack of comparable studies. However, the studies with the most positive results are small and the results are not replicated in larger studies. It is therefore probable that publication bias plays some role in this review.
Authors' conclusions
Implications for practice It might be beneficial to have additional exercise programmes after formal treatment for back pain has been completed. The content of such a programme is difficult to specify because the contents varied and did not relate to the outcomes. Therefore, any general exercise such as stretching, strengthening, endurance training and posture education could be adequate. Treatment does not seem to influence the number of recurrences in acute and sub-acute back pain patients and is therefore best focused on the treatment outcome for the current episode. |
Implications for research Prevention of recurrences of back pain is a little studied but clinically relevant back pain outcome. Studies that better validate the measurement of recurrences of back pain are needed. Intervention studies should at least address the rate, the number of and the time to recurrences of LBP. Given the low number of studies found, more studies are needed to evaluate post-treatment supervised and non-supervised exercise programmes. |
Acknowledgements
We would like to express our sincere gratitude toward Vicki Pennick, Managing Editor of the Cochrane Back Review Group and Dr. Tang Jin-Ling, Professor of the Department of Community and Family Medicine, The Chinese University of Hong Kong, who provided us with expert advice during the development of this systematic review. Also, we thank Rachel Couban, Trials Search Co-ordinator of the Cochrane Back Review Group, for her professional assistance with the development of the search strategies. We would like to acknowledge the help of the Cochrane Occupational Health Field in the realisation of this review.
Data and analyses
- Top of page
- Summary of findings [Explanations]
- Background
- Objectives
- Methods
- Results
- Discussion
- Authors' conclusions
- Acknowledgements
- Data and analyses
- Appendices
- What's new
- History
- Contributions of authors
- Declarations of interest
- Differences between protocol and review
- Index terms
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Appendices
Appendix 1. MEDLINE search strategy
1. exp "Clinical Trial [Publication Type]"/
2. randomized.ab,ti.
3. placebo.ab,ti.
4. dt.fs.
5. randomly.ab,ti.
6. trial.ab,ti.
7. groups.ab,ti.
8. or/1-7
9. Animals/
10. Humans/
11. 9 not (9 and 10)
12. 8 not 11
13. dorsalgia.ti,ab.
14. exp Back Pain/
15. backache.ti,ab.
16. (lumbar adj pain).ti,ab.
17. coccyx.ti,ab.
18. coccydynia.ti,ab.
19. sciatica.ti,ab.
20. sciatica/
21. spondylosis.ti,ab.
22. lumbago.ti,ab.
23. or/13-22
24. exp Exercise/
25. exercis$.mp.
26. physical exercis$.mp.
27. exp Exercise Therapy/
28. exp Exercise Movement Techniques/
29. exp Physical Therapy Modalities/
30. McKenzie.mp.
31. Alexander.mp.
32. William.mp.
33. feldenkrais.mp.
34. exp Yoga/
35. exp Recreation/
36. or/24-35
37. exp Alexander Disease/
38. exp Williams Syndrome/
39. 37 or 38
40. 36 not 39
41. exp Recurrence/
42. recur$.mp.
43. relaps$.mp.
44. reappearance$.mp.
45. reoccurence$.mp.
46. return.mp.
47. or/41-46
48. 12 and 23 and 40 and 47
Appendix 2. EMBASE search strategy
1. Clinical Article/
2. exp Clinical Study/
3. Clinical Trial/
4. Controlled Study/
5. Randomized Controlled Trial/
6. Major Clinical Study/
7. Double Blind Procedure/
8. Multicenter Study/
9. Single Blind Procedure/
10. Phase 3 Clinical Trial/
11. Phase 4 Clinical Trial/
12. crossover procedure/
13. placebo/
14. or/1-13
15. allocat$.mp.
16. assign$.mp.
17. blind$.mp.
18. (clinic$ adj25 (study or trial)).mp.
19. compar$.mp.
20. control$.mp.
21. cross?over.mp.
22. factorial$.mp.
23. follow?up.mp.
24. placebo$.mp.
25. prospectiv$.mp.
26. random$.mp.
27. ((singl$ or doubl$ or trebl$ or tripl$) adj25 (blind$ or mask$)).mp.
28. trial.mp.
29. (versus or vs).mp.
30. or/15-29
31. 14 and 30
32. human/
33. Nonhuman/
34. exp ANIMAL/
35. Animal Experiment/
36. 33 or 34 or 35
37. 32 not 36
38. 31 not 36
39. 37 and 38
40. 38 or 39
41. dorsalgia.mp.
42. back pain.mp.
43. exp BACKACHE/
44. (lumbar adj pain).mp.
45. coccyx.mp.
46. coccydynia.mp.
47. sciatica.mp.
48. exp ISCHIALGIA/
49. spondylosis.mp.
50. lumbago.mp.
51. or/41-50
52. exp Exercise/
53. exercis$.mp.
54. exp Kinesiotherapy/
55. physical exercise.mp.
56. exercise therapy.mp.
57. McKenzie.mp.
58. exp ALEXANDER TECHNIQUE/
59. Alexander.mp.
60. William.mp.
61. exp FELDENKRAIS METHOD/
62. Feldenkrais.mp.
63. exp YOGA/
64. yoga.mp.
65. or/52-64
66. Alexander disease.mp. or exp Alexander Disease/
67. Williams Beuren Syndrome.mp. or exp Williams Beuren Syndrome/
68. or/66-67
69. 65 not 68
70. recur$.mp.
71. relaps$.mp.
72. reappearance$.mp.
73. reoccurence$.mp.
74. return.mp.
75. exp RELAPSE/
76. or/69-75
77. 40 and 51 and 69 and 76
Appendix 3. Criteria and definitions for risk of bias assessment (van Tulder 2003)
- Was the method of randomisation adequate? A random (unpredictable) assignment sequence. Examples of adequate methods are computer-generated random numbers table and use of sealed opaque envelopes. Methods of allocation using date of birth, date of admission, hospital numbers, or alternation should not be regarded as appropriate.
- Was the treatment allocation concealed? Assignment generated by an independent person not responsible for determining the eligibility of the patients. This person has no information about the persons included in the trial and has no influence on the assignment sequence or on the decision about eligibility of the patient.
Was knowledge of the allocated interventions adequately prevented during the study?
- Was the patient blinded to the intervention? The review author determines if enough information about the blinding is given in order to score a "yes."
- Was the care provider blinded to the intervention? The review author determines if enough information about the blinding is given in order to score a "yes."
- Was the outcome assessor blinded to the intervention? The review author determines if enough information about the blinding is given in order to score a "yes."
Were incomplete outcome data adequately addressed?
- Was the drop-out rate described and acceptable? The number of participants who were included in the study but did not complete the observation period or were not included in the analysis must be described and reasons given. If the percentage of withdrawals and drop-outs does not exceed 20% for immediate and short-term follow-ups, 30% for intermediate and long-term follow-ups and does not lead to substantial bias a "yes" is scored.
- Did the analysis include an intention-to-treat analysis? All randomised patients are reported/analyzed in the group to which they were allocated by randomisation for the most important moments of effect measurement (minus missing values), irrespective of noncompliance and co-interventions.
Other sources of potential bias:
- Were the groups similar at baseline regarding the most important prognostic indicators? In order to receive a "yes," groups have to be similar at baseline regarding demographic factors, duration and severity of complaints, percentage of patients with neurological symptoms, and value of main outcome measure(s).
- Were co-interventions avoided or similar? Co-interventions should either be avoided in the trial design or be similar between the index and control groups.
- Was the compliance acceptable in all groups? The review author determines if the compliance to the interventions is acceptable, based on the reported intensity, duration, number and frequency of sessions for both the index intervention and control intervention(s).
- Was the timing of the outcome assessment in all groups similar? Timing of outcome assessment should be identical for all intervention groups and for all important outcome assessments.
Appendix 4. Clinical relevance assessment
- Are the patients described in detail so that you can decide whether they are comparable to those that you see in your practice?
- Are the interventions and treatment settings described well enough so that you can provide the same for your patients?
- Were all clinically relevant outcomes measured and reported?
- Is the size of the effect clinically important?
- Are the likely treatment benefits worth the potential harms?
What's new
Last assessed as up-to-date: 23 July 2009.
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History
Protocol first published: Issue 2, 2007
Review first published: Issue 1, 2010
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Contributions of authors
Brian Choi - registered title, formed review team, wrote protocol, developed search strategy with CBRG editorial office assistance, ran searches, selected references, developed and tested data extraction forms, wrote the text of the review.
Jos Verbeek - formed review team, wrote protocol, helped with development of search strategy, ran searches, selected references, developed and tested data extraction forms, wrote the text of the review.
Wilson Tam - ran searches, selected references, developed and tested data extraction forms.
Yu Jiang - ran searches, developed and tested data extraction forms.
Declarations of interest
There is no potential conflict of interest among the review authors.
Differences between protocol and review
In the protocol we stated that we would divide studies into high and low quality. In the time this review was written, the GRADE approach for grading the level of evidence seemed more appropriate to use. Therefore we left our original idea and used the GRADE approach instead.
Index terms
Medical Subject Headings (MeSH)
*Exercise Therapy; Low Back Pain [*prevention & control]; Randomized Controlled Trials as Topic; Recurrence [prevention & control]
MeSH check words
Humans
* Indicates the major publication for the study