Exercise Therapy for Treatment of Acute Non-specific Low Back Pain: A Cochrane Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: To assess the effectiveness of exercise for acute non-specific low back pain (LBP) vs our main comparisons: (1) sham treatment and (2) no treatment at short term (main follow-up time). DATA SOURCES AND STUDY SELECTION: A comprehensive search up till November 2021 was conducted in numerous databases for randomized controlled trials on the effectiveness of exercise in adults with acute LBP (<6 weeks). Studies examining LBP with a specific etiology were excluded. The primary outcomes were back pain, back-specific functional status, and recovery. DATA EXTRACTION: Two review authors independently conducted the study selection, risk of bias assessment, and data extraction. GRADE was used to assess the certainty of the evidence. DATA SYNTHESIS: We identified 23 randomized controlled trials (2674 participants). There is very low-certainty evidence that exercise therapy compared with sham/placebo treatment has no clinically relevant effect on pain (mean difference [MD] -0.80, 95% confidence interval [CI] -5.79 to 4.19; 1 study, 299 participants) and on functional status (MD 2.00, 95% CI -2.20 to 6.20; 1 study, 299 participants) in the short term. There is very low-quality evidence which suggests no difference in effect on pain and functional status for exercise vs no treatment (2 studies; n=157, not pooled due to heterogeneity) at short-term follow-up. Similar results were found for the other follow-up moments. The certainty of the evidence was downgraded because many randomized controlled trials had a high risk of bias, were small in size, and/or there was substantial heterogeneity. CONCLUSION: Exercise therapy compared with sham/placebo and no treatment may have no clinically relevant effect on pain or functional status in the short term in people with acute non-specific LBP, but the evidence is very uncertain. Owing to insufficient reporting of adverse events, we were unable to reach any conclusions on the safety or harms related to exercise therapy.

Exercise therapy for treatment of acute non-specific low back pain.

BACKGROUND: Low back pain (LBP) is the leading cause of disability globally. It generates considerable direct costs (healthcare) and indirect costs (lost productivity). The many available treatments for LBP include exercise therapy, which is practised extensively worldwide. OBJECTIVES: To evaluate the benefits and harms of exercise therapy for acute non-specific low back pain in adults compared to sham/placebo treatment or no treatment at short-term, intermediate-term, and long-term follow-up. SEARCH METHODS: This is an update of a Cochrane Review first published in 2005. We conducted an updated search for randomised controlled trials (RCTs) in CENTRAL, MEDLINE, Embase, four other databases, and two trial registers. We screened the reference lists of all included studies and relevant systematic reviews published since 2004. SELECTION CRITERIA: We included RCTs that examined the effects of exercise therapy on non-specific LBP lasting six weeks or less in adults. Major outcomes for this review were pain, functional status, and perceived recovery. Minor outcomes were return to work, health-related quality of life, and adverse events. Our main comparisons were exercise therapy versus sham/placebo treatment and exercise therapy versus no treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. We evaluated outcomes at short-term follow-up (time point within three months and closest to six weeks after randomisation; main follow-up), intermediate-term follow-up (between nine months and closest to six months), and long-term follow-up (after nine months and closest to 12 months); and we used GRADE to assess the certainty of the evidence for each outcome. MAIN RESULTS: We included 23 studies (13 from the previous review, 10 new studies) that involved 2674 participants and provided data for 2637 participants. Three small studies are awaiting classification, and four eligible studies are ongoing. Included studies were conducted in Europe (N = 9), the Asia-Pacific region (N = 9), and North America (N = 5); and most took place in a primary care setting (N = 12), secondary care setting (N = 6), or both (N = 1). In most studies, the population was middle-aged and included men and women. We judged 10 studies (43%) at low risk of bias with regard to sequence generation and allocation concealment. Blinding is not feasible in exercise therapy, introducing performance and detection bias. There is very low-certainty evidence that exercise therapy compared with sham/placebo treatment has no clinically relevant effect on pain scores in the short term (mean difference (MD) -0.80, 95% confidence interval (CI) -5.79 to 4.19; 1 study, 299 participants). The absolute difference was 1% less pain (95% CI 4% more to 6% less), and the relative difference was 4% less pain (95% CI 20% more to 28% less). The mean pain score was 20.1 (standard deviation (SD) 21) for the intervention group and 20.9 (SD 23) for the control group. There is very low-certainty evidence that exercise therapy compared with sham/placebo treatment has no clinically relevant effect on functional status scores in the short term (MD 2.00, 95% CI -2.20 to 6.20; 1 study, 299 participants). The absolute difference was 2% worse functional status (95% CI 2% better to 6% worse), and the relative difference was 15% worse (95% CI 17% better to 47% worse). The mean functional status score was 15.3 (SD 19) for the intervention group and 13.3 (SD 18) for the control group. We downgraded the certainty of the evidence for pain and functional status by one level for risk of bias and by two levels for imprecision (only one study with fewer than 400 participants). There is very low-certainty evidence that exercise therapy compared with no treatment has no clinically relevant effect on pain or functional status in the short term (2 studies, 157 participants). We downgraded the certainty of the evidence by two levels for imprecision and by one level for inconsistency. One study associated exercise with small benefits and the other found no differences. The first study was conducted in an occupational healthcare centre, where participants received one exercise therapy session. The other study was conducted in secondary and tertiary care settings, where participants received treatment three times per week for six weeks. We did not pool data from these studies owing to considerable clinical heterogeneity. In two studies, there were no reported adverse events. One study reported adverse events unrelated to exercise therapy. The remaining studies did not report whether any adverse events had occurred. Owing to insufficient reporting of adverse events, we were unable to reach any conclusions on the safety or harms related to exercise therapy. AUTHORS' CONCLUSIONS: Exercise therapy compared to sham/placebo treatment may have no clinically relevant effect on pain or functional status in the short term in people with acute non-specific LBP, but the evidence is very uncertain. Exercise therapy compared to no treatment may have no clinically relevant effect on pain or functional status in the short term in people with acute non-specific LBP, but the evidence is very uncertain. We downgraded the certainty of the evidence to very low for inconsistency, risk of bias concerns, and imprecision (few participants).

Mapping Oswestry Disability Index Responses to EQ-5D-3L Utility Values: Are Cost-Utility Results Valid?

OBJECTIVES: To develop and validate approaches for mapping Oswestry Disability Index responses to 3-level version of EQ-5D utility values and to evaluate the impact of using mapped utility values on cost-utility results compared with published regression models. METHODS: Three response mapping approaches were developed in a random sample of 70% of 18 692 patients with low back pain: nonparametric approach (Non-p), nonparametric approach excluding logical inconsistencies (Non-peLI), and ordinal logistic regression (OLR). Performance was assessed in the remaining 30% using R-square (R2), root mean square error (RMSE), and mean absolute error (MAE). To evaluate whether MAEs and their 95% limits of agreement (LA) were clinically relevant, a minimally clinically important difference of 0.074 was used. Probabilities of cost-effectiveness estimated using observed and mapped utility values were compared in 2 economic evaluations. RESULTS: The Non-p performed the best (R2 = 0.43; RMSE = 0.22; MAE = 0.03; 95% LA = -0.40 to 0.47) compared with the Non-peLI (R2 = 0.07; RMSE = 0.29; MAE = -0.15; 95% LA = -0.63 to 0.34) and OLR (R2 = 0.22; RMSE = 0.26; MAE = 0.02; 95% LA = -0.49 to 0.53). MAEs were lower than the minimally clinically important difference for the Non-p and OLR but not for the Non-peLI. Differences in probabilities of cost-effectiveness ranged from 1% to 4% (Non-p), 0.1% to 9% (Non-peLI), and 0.1% to 20% (OLR). CONCLUSIONS: Results suggest that the developed response mapping approaches are not valid for estimating individual patients' 3-level version of EQ-5D utility values, and-depending on the approach-may considerably affect cost-utility results. The developed approaches did not perform better than previously published regression-based models and are therefore not recommended for use in economic evaluations.

The handling of missing data in trial-based economic evaluations: should data be multiply imputed prior to longitudinal linear mixed-model analyses?

INTRODUCTION: For the analysis of clinical effects, multiple imputation (MI) of missing data were shown to be unnecessary when using longitudinal linear mixed-models (LLM). It remains unclear whether this also applies to trial-based economic evaluations. Therefore, this study aimed to assess whether MI is required prior to LLM when analyzing longitudinal cost and effect data. METHODS: Two-thousand complete datasets were simulated containing five time points. Incomplete datasets were generated with 10, 25, and 50% missing data in follow-up costs and effects, assuming a Missing At Random (MAR) mechanism. Six different strategies were compared using empirical bias (EB), root-mean-squared error (RMSE), and coverage rate (CR). These strategies were: LLM alone (LLM) and MI with LLM (MI-LLM), and, as reference strategies, mean imputation with LLM (M-LLM), seemingly unrelated regression alone (SUR-CCA), MI with SUR (MI-SUR), and mean imputation with SUR (M-SUR). RESULTS: For costs and effects, LLM, MI-LLM, and MI-SUR performed better than M-LLM, SUR-CCA, and M-SUR, with smaller EBs and RMSEs as well as CRs closers to nominal levels. However, even though LLM, MI-LLM and MI-SUR performed equally well for effects, MI-LLM and MI-SUR were found to perform better than LLM for costs at 10 and 25% missing data. At 50% missing data, all strategies resulted in relatively high EBs and RMSEs for costs. CONCLUSION: LLM should be combined with MI when analyzing trial-based economic evaluation data. MI-SUR is more efficient and can also be used, but then an average intervention effect over time cannot be estimated.

Can EQ-5D-3L utility values of low back pain patients be validly predicted by the Oswestry Disability Index for use in cost-effectiveness analyses?

PURPOSE: To assess whether regression modeling can be used to predict EQ-5D-3L utility values from the Oswestry Disability Index (ODI) in low back pain (LBP) patients for use in cost-effectiveness analysis. METHODS: EQ-5D-3L utility values of LBP patients were estimated using their ODI scores as independent variables using regression analyses, while adjusting for case-mix variables. Six different models were estimated: (1) Ordinary Least Squares (OLS) regression, with total ODI score, (2) OLS, with ODI item scores as continuous variables, (3) OLS, with ODI item scores as ordinal variables, (4) Tobit model, with total ODI score, (5) Tobit model, with ODI item scores as continuous variables, and (6) Tobit model, with ODI item scores as ordinal variables. The models' performance was assessed using explained variance (R2) and root mean squared error (RMSE). The potential impact of using predicted instead of observed EQ-5D-3L utility values on cost-effectiveness outcomes was evaluated in two empirical cost-effectiveness analysis. RESULTS: Complete individual patient data of 18,692 low back pain patients were analyzed. All models had a more or less similar R2 (range 45-52%) and RMSE (range 0.21-0.22). The two best performing models produced similar probabilities of cost-effectiveness for a range of willingness-to-pay (WTP) values compared to those based on the observed EQ-5D-3L values. For example, the difference in probabilities ranged from 2 to 5% at a WTP of 50,000 €/QALY gained. CONCLUSION: Results suggest that the ODI can be validly used to predict low back pain patients' EQ-5D-3L utility values and QALYs for use in cost-effectiveness analyses.

The statistical approach in trial-based economic evaluations matters: get your statistics together!

BACKGROUND: Baseline imbalances, skewed costs, the correlation between costs and effects, and missing data are statistical challenges that are often not adequately accounted for in the analysis of cost-effectiveness data. This study aims to illustrate the impact of accounting for these statistical challenges in trial-based economic evaluations. METHODS: Data from two trial-based economic evaluations, the REALISE and HypoAware studies, were used. In total, 14 full cost-effectiveness analyses were performed per study, in which the four statistical challenges in trial-based economic evaluations were taken into account step-by-step. Statistical approaches were compared in terms of the resulting cost and effect differences, ICERs, and probabilities of cost-effectiveness. RESULTS: In the REALISE study and HypoAware study, the ICER ranged from 636,744€/QALY and 90,989€/QALY when ignoring all statistical challenges to - 7502€/QALY and 46,592€/QALY when accounting for all statistical challenges, respectively. The probabilities of the intervention being cost-effective at 0€/ QALY gained were 0.67 and 0.59 when ignoring all statistical challenges, and 0.54 and 0.27 when all of the statistical challenges were taken into account for the REALISE study and HypoAware study, respectively. CONCLUSIONS: Not accounting for baseline imbalances, skewed costs, correlated costs and effects, and missing data in trial-based economic evaluations may notably impact results. Therefore, when conducting trial-based economic evaluations, it is important to align the statistical approach with the identified statistical challenges in cost-effectiveness data. To facilitate researchers in handling statistical challenges in trial-based economic evaluations, software code is provided.

Systematic review of prognostic factors for work participation in patients with sciatica.

Sciatica impacts on the ability to work and may lead to a reduced return to work. This study reviewed and summarised prognostic factors of work participation in patients who received conservative or surgical treatment for clinically diagnosed sciatica. We searched MEDLINE, CINAHL, EMBASE and PsycINFO until January 2018. Cohort studies, using a measure of work participation as outcome, were included. Two independent reviewers performed study inclusion and used the Quality In Prognosis Studies tool for risk of bias assessment and GRADE to rate the quality of the evidence. Based on seven studies describing six cohorts (n=1408 patients) that assessed 21 potential prognostic factors, favourable factors for return to work (follow-up ranging from 3 months to 10 years) included younger age, better general health, less low back pain or sciatica bothersomeness, better physical function, negative straight leg raise-test, physician expecting surgery to be beneficial, better pain coping, less depression and mental stress, less fear of movement and low physical work load. Study results could not be pooled. Using GRADE, the quality of the evidence ranged from moderate to very low, with downgrading mainly for a high risk of bias and imprecision. Several prognostic factors like pain, disability and psychological factors were identified and reviewed, and these could be targeted using additional interventions to optimise return to work. PROSPERO registration number: CRD42016042497.

Early rehabilitation after lumbar disc surgery is not effective or cost-effective compared to no referral: a randomised trial and economic evaluation.

QUESTION: Is referral for early rehabilitation after lumbar disc surgery effective and cost-effective compared to no referral? DESIGN: Multicentre, randomised, controlled trial, and economic evaluation with concealed allocation and intention-to-treat-analysis. PARTICIPANTS: Adults who underwent discectomy for a herniated lumbar disc, confirmed by magnetic resonance imaging, and signs of nerve root compression corresponding to the herniation level. INTERVENTION: Early rehabilitation (exercise therapy) for 6 to 8 weeks, versus no referral, immediately after discharge. OUTCOME MEASURES: In line with the recommended core outcome set, the co-primary outcomes were: functional status (Oswestry Disability Index); leg and back pain (numerical rating scale 0 to 10); global perceived recovery (7-point Likert scale); and general physical and mental health (SF12), assessed 3, 6, 9, 12 and 26 weeks after surgery. The outcomes for the economic evaluation were quality of life and costs, measured at 6, 12 and 26 weeks after surgery. RESULTS: There were no clinically relevant or statistically significant overall mean differences between rehabilitation and control for any outcome adjusted for baseline characteristics: global perceived recovery (OR 1.0, 95% CI 0.6 to 1.7), functional status (MD 1.5, 95% CI -3.6 to 6.7), leg pain (MD 0.1, 95% CI -0.7 to 0.8), back pain (MD 0.3, 95% CI -0.3 to 0.9), physical health (MD -3.5, 95% CI -11.3 to 4.3), and mental health (MD -4.1, 95% CI -9.4 to 1.3). After 26 weeks, there were no significant differences in quality-adjusted life years (MD 0.01, 95% CI -0.02 to 0.04 points) and societal costs (MD -€527, 95% CI -2846 to 1506). The maximum probability for the intervention to be cost-effective was 0.75 at a willingness-to-pay of €32 000/quality-adjusted life year. CONCLUSION: Early rehabilitation after lumbar disc surgery was neither more effective nor more cost-effective than no referral. TRIAL REGISTRATION: Netherlands Trial Register NTR3156. [Oosterhuis T, Ostelo RW, van Dongen JM, Peul WC, de Boer MR, Bosmans JE, Vleggeert-Lankamp CL, Arts MP, van Tulder MW (2017) Early rehabilitation after lumbar disc surgery is not effective or cost-effective compared to no referral: a randomised trial and economic evaluation. Journal of Physiotherapy 63: 144-153].

Predictors of long-term function in older community-dwelling people who have presented to an emergency department after a fall: a cohort study.

AIM: To identify factors predictive of function 12 months after a fall and emergency department (ED) presentation. METHODS: This was a prospective cohort study with 608 older people who had a fall. After presentation and discharge from the ED, a baseline assessment was initially undertaken and then repeated after 12 months. The Human Activity Profile Adjusted Activity Score (HAP-AAS) at the 12-month follow-up assessment was the functional outcome measure. RESULTS: Over the follow-up period, 37.3% (95% CI 33.4, 41.2) of participants declined in their HAP-AAS score. Increased age, pre-index fall functional impairment, poorer mobility/balance, and sustaining falls and severe injuries over the 12-month follow-up period were some of the factors predictive of a lower HAP-AAS score. CONCLUSION: This study highlights the importance of preventing falls in the 12 months after discharge from an ED. Some of the factors identified as being predictive of lower function are the same as those previously found to be predictive of falls.

The risk of bias and sample size of trials of spinal manipulative therapy for low back and neck pain: analysis and recommendations.

OBJECTIVE: The purpose of this study was to evaluate changes in methodological quality and sample size in randomized controlled trials (RCTs) of spinal manipulative therapy (SMT) for neck and low back pain over a specified period. A secondary purpose was to make recommendations for improvement for future SMT trials based upon our findings. METHODS: Randomized controlled trials that examined the effect of SMT in adults with neck and/or low back pain and reported at least 1 patient-reported outcome measure were included. Studies were identified from recent Cochrane reviews of SMT, and an update of the literature was conducted (March 2013). Risk of bias was assessed using the 12-item criteria recommended by the Cochrane Back Review Group. In addition, sample size was examined. The relationship between the overall risk of bias and sample size over time was evaluated using regression analyses, and RCTs were grouped into periods (epochs) of approximately 5 years. RESULTS: In total, 105 RCTs were included, of which 41 (39%) were considered to have a low risk of bias. There is significant improvement in the mean risk of bias over time (P < .05), which is the most profound for items related to selection bias and, to a lesser extent, attrition and selective outcome reporting bias. Furthermore, although there is no significant increase in sample size over time (overall P = .8), the proportion of studies that performed an a priori sample size calculation is increasing statistically (odds ratio, 2.1; confidence interval, 1.5-3.0). Sensitivity analyses suggest no appreciable difference between studies for neck or low back pain for risk of bias or sample size. CONCLUSION: Methodological quality of RCTs of SMT for neck and low back pain is improving, whereas overall sample size has shown only small and nonsignificant increases. There is an increasing trend among studies to conduct sample size calculations, which relate to statistical power. Based upon these findings, 7 areas of improvement for future SMT trials are suggested.

Rehabilitation after lumbar disc surgery.

BACKGROUND: Several rehabilitation programmes are available for individuals after lumbar disc surgery. OBJECTIVES: To determine whether active rehabilitation after lumbar disc surgery is more effective than no treatment, and to describe which type of active rehabilitation is most effective. This is the second update of a Cochrane Review first published in 2002.First, we clustered treatments according to the start of treatment.1. Active rehabilitation that starts immediately postsurgery.2. Active rehabilitation that starts four to six weeks postsurgery.3. Active rehabilitation that starts longer than 12 months postsurgery.For every cluster, the following comparisons were investigated.A. Active rehabilitation versus no treatment, placebo or waiting list control.B. Active rehabilitation versus other kinds of active rehabilitation.C. Specific intervention in addition to active rehabilitation versus active rehabilitation alone. SEARCH METHODS: We searched CENTRAL (2013, Issue 4) and MEDLINE, EMBASE, CINAHL, PEDro and PsycINFO to May 2013. SELECTION CRITERIA: We included only randomised controlled trials (RCTs). DATA COLLECTION AND ANALYSIS: Pairs of review authors independently assessed studies for eligibility and risk of bias. Meta-analyses were performed if studies were clinically homogeneous. The GRADE approach was used to determine the overall quality of evidence. MAIN RESULTS: In this update, we identified eight new studies, thereby including a total of 22 trials (2503 participants), 10 of which had a low risk of bias. Most rehabilitation programmes were assessed in only one study. Both men and women were included, and overall mean age was 41.4 years. All participants had received standard discectomy, microdiscectomy and in one study standard laminectomy and (micro)discectomy. Mean duration of the rehabilitation intervention was 12 weeks; eight studies assessed six to eight-week exercise programmes, and eight studies assessed 12 to 13-week exercise programmes. Programmes were provided in primary and secondary care facilities and were started immediately after surgery (n = 4) or four to six weeks (n = 16) or one year after surgery (n = 2). In general, the overall quality of the evidence is low to very low. Rehabilitation programmes that started immediately after surgery were not more effective than their control interventions, which included exercise. Low- to very low-quality evidence suggests that there were no differences between specific rehabilitation programmes (multidisciplinary care, behavioural graded activity, strength and stretching) that started four to six weeks postsurgery and their comparators, which included some form of exercise. Low-quality evidence shows that physiotherapy from four to six weeks postsurgery onward led to better function than no treatment or education only, and that multidisciplinary rehabilitation co-ordinated by medical advisors led to faster return to work than usual care. Statistical pooling was performed only for three comparisons in which the rehabilitation programmes started four to six weeks postsurgery: exercise programmes versus no treatment, high- versus low-intensity exercise programmes and supervised versus home exercise programmes. Very low-quality evidence (five RCTs, N = 272) shows that exercises are more effective than no treatment for pain at short-term follow-up (standard mean difference (SMD) -0.90; 95% confidence interval (CI) -1.55 to -0.24), and low-quality evidence (four RCTs, N = 252) suggests that exercises are more effective for functional status on short-term follow-up (SMD -0.67; 95% CI -1.22 to -0.12) and that no difference in functional status was noted on long-term follow-up (three RCTs, N = 226; SMD -0.22; 95% CI -0.49 to 0.04). None of these studies reported that exercise increased the reoperation rate. Very low-quality evidence (two RCTs, N = 103) shows that high-intensity exercise programmes are more effective than low-intensity exercise programmes for pain in the short term (weighted mean difference (WMD) -10.67; 95% CI -17.04 to -4.30), and low-quality evidence (two RCTs, N = 103) shows that they are more effective for functional status in the short term (SMD -0.77; 95% CI -1.17 to -0.36). Very low-quality evidence (four RCTs, N = 154) suggests no significant differences between supervised and home exercise programmes for short-term pain relief (SMD -0.76;  95% CI -2.04 to 0.53) or functional status (four RCTs, N = 154; SMD -0.36; 95% CI -0.88 to 0.15). AUTHORS' CONCLUSIONS: Considerable variation was noted in the content, duration and intensity of the rehabilitation programmes included in this review, and for none of them was high- or moderate-quality evidence identified. Exercise programmes starting four to six weeks postsurgery seem to lead to a faster decrease in pain and disability than no treatment, with small to medium effect sizes, and high-intensity exercise programmes seem to lead to a slightly faster decrease in pain and disability than is seen with low-intensity programmes, but the overall quality of the evidence is only low to very low. No significant differences were noted between supervised and home exercise programmes for pain relief, disability or global perceived effect. None of the trials reported an increase in reoperation rate after first-time lumbar surgery. High-quality randomised controlled trials are strongly needed.

Effectiveness and cost-effectiveness of rehabilitation after lumbar disc surgery (REALISE): design of a randomised controlled trial.

BACKGROUND: Patients who undergo lumbar disc surgery for herniated discs, are advocated two different postoperative management strategies: a watchful waiting policy, or referral for rehabilitation immediately after discharge from the hospital. A direct comparison of the effectiveness and cost-effectiveness of these two strategies is lacking. METHODS/DESIGN: A randomised controlled trial will be conducted with an economic evaluation alongside to assess the (cost-) effectiveness of rehabilitation after lumbar disc surgery. Two hundred patients aged 18-70 years with a clear indication for lumbar disc surgery of a single level herniated disc will be recruited and randomly assigned to either a watchful waiting policy for first six weeks or exercise therapy starting immediately after discharge from the hospital. Exercise therapy will focus on resumption of activities of daily living and return to work. Therapists will tailor the intervention to the individual patient's needs. All patients will be followed up by the neurosurgeon six weeks postoperatively. Main outcome measures are: functional status, pain intensity and global perceived recovery. Questionnaires will be completed preoperatively and at 3, 6, 9, 12 and 26 weeks after surgery. Data will be analysed according to the intention-to-treat principle, using a linear mixed model for continuous outcomes and a generalised mixed model for dichotomous outcomes. The economic evaluation will be performed from a societal perspective. DISCUSSION: The results of this trial may lead to a more consistent postoperative strategy for patients who will undergo lumbar disc surgery. TRIAL REGISTRATION: Netherlands Trial Register: NTR3156.