SPINE Volume 34, Number 3, pp 215–220 ©2009, Lippincott Williams & Wilkins

Effectiveness of a Lumbar Belt in Subacute Low Back Pain An Open, Multicentric, and Randomized Clinical Study Paul Calmels, PhD, MD,* Patrice Queneau, MD,† Claude Hamonet, PhD, MD,‡ Claude Le Pen, PhD,§ Frederique Maurel,§ Claire Lerouvreur,§ and Philippe Thoumie, MD, PhD¶

Study Design. Multicentric, randomized, and controlled study of clinical evaluation of medical device in subacute low back pain. Objective. To evaluate the effects of an elastic lumbar belt on functional capacity, pain intensity in low back pain treatment, and the benefice on medical cost. Summary of Background Data. There is limited evidence of efficiency of lumbar supports for treatment of low back pain. There is also a lack of the methodology in the studies reported on the efficiency of this device. Methods. This study is randomized, multicentric, and controlled with 2 groups: a patient group treated with a lumbar belt (BWG) and a control group (CG). The main criteria of clinical evaluation were the physical restoration assessed with the EIFEL scale, the pain assessed by a visual analogic scale, the main economical criteria was the overall cost of associated medical treatments. Results. One hundred ninety-seven patients have participated. The results show a higher decrease in EIFEL score in BWG than CG between days 0 and 90 (7.6 ⫾ 4.4 vs. de 6.1 ⫾ 4.7; P ⫽ 0.023). Respectively significant reduction in visual analogic scale was also noticed (41.5 ⫾ 21.4 vs. 32.0 ⫾ 20; P ⫽ 0.002). Pharmacologic consumption decreased at D90 (the proportion of patients who did not take any medication in BWG is 60.8% vs. 40% in CG; P ⫽ 0.029). Conclusion. Lumbar belt wearing is consequent in subacute low back pain to improve significantly the functional status, the pain level, and the pharmacologic consumption. This study may be useful to underline the interest of lumbar support as a complementary and nonpharmacologic treatment beside the classic medication use in low back pain treatment. Key words: low back pain, lumbar belt, pain, functional assessment, economical assessment. Spine 2009; 34:215–220

From *Service de Médecine Physique et Réadaptation, Université Jean Monnet, Hôpital Bellevue, Saint Etienne, France; †Centre Hospitalier de Saint Etienne, Saint-Etienne, France; ‡Service de Médecine Physique et Réadaptation, Hôtel-Dieu, Paris, France; §Aramis Consultants, Neuilly sur Seine, France; and ¶Service de Rééducation NeuroOrthopédique Hôpital Rothschild APHP, Paris, France. Acknowledgment date: January 4, 2008. First revision date: July 13, 2008. Second revision date: August 27, 2008. Acceptance date: August 27, 2008. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript. Address correspondence and reprint requests to Paul Calmels, PhD, MD, Service de Médecine Physique et Réadaptation, CHU SaintEtienne, Hôpital Bellevue, 42055 Saint Etienne Cedex 2, France. E-mail: [email protected]

Low back pain is a very frequent symptom in industrialized countries. Sixty percent to 90% of adults suffer or have suffered from low back pain during their life in industrialized countries,1–3 and the prevalence increase constantly in these countries. Back complaints accounted for 6.9%1 of consultations with physicians in cities. Although nonspecific low back pain accounts for a very large majority of low back pain, a distinction is made between acute (less than 4 weeks progression), subacute (between 4 weeks and 3 months), and chronic low back pain (more than 3 months).2 Low back pain evolution is frequently quickly favorable in few days, with or without treatment, with a frequent risk of recurrence.4 Indeed, for Coste et al,5 50% of episode last less than 1 week and 90% less than 2 weeks, but for von Korff,6 “the course of back pain is highly variable, occurring in transient, recurrent, and chronic phases.” The evolution must be evaluated at long-term follow-up. For von Korff and Saunders,7 after 1 year or more of an acute episode, “33% report intermittent or persistent pain of at least moderate intensity, 1 in 7 continue to report back pain of severe intensity, and 1 in 5 report substantial activity limitations.” More recently Enthoven et al8 reported after a 5-year follow-up that 52% of subjects have always pain and functional limitations. In these conditions, low back pain has a considerable impact in terms of medical costs (consultations, medical prescriptions, . . .) and repercussion on occupational activity.1,7–9 Many propositions of treatment, sometimes with combination, are reported. In acute or subacute low back pain, treatment tries to reduce or control the pain intensity to enable fast resumption of occupational and personal activities. Lumbar orthosis (corsets or belts) are proposed as a part of the wide range of therapeutic10 –12 and prevention13–15 options in practice. The antalgic effect is expected because of the control of lumbar mobility, the relative immobilization of the lumbar spine, and some subjective effects (heat, massage, continuous stimulation).12,16 These effects are still the subject of debate. Recent literature17,18 about the efficacy of lumbar belts in low back pain reported that their use as a mean of preventing low back pain is not proved and current knowledge does not allow a judgment of their interest in the treatment of low back pain. For van Tulder et al, there is some scientific information, which emphasizes 215

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the therapeutic potential of lumbar belts for low back pain.18 Nevertheless, few studies have been carried out on the therapeutic efficacy of lumbar belts and, those that have been carried out are now outdated, contain contradictory results and/or are often not comparable. Furthermore, the methodologic weakness of most of these studies reported in the Cochrane review18 (low number of subjects included, cointervention not documented . . .) does not allow robust interpretation of their results. More recently, in a review, van Tulder et al19 conclude that there is limited evidence of efficiency of lumbar supports in comparison with no treatment and that they are more effective than other interventions for treatment of low back pain. Therefore, a controlled study is necessary, with randomization of the patients, exclusion of acute low back pain, and use of valid, reliable, and sensitive instruments for measuring efficacy. Objective The objective of the study was to assess the effectiveness of the lumbar belt in the treatment of patients suffering from subacute low back pain. Efficacy criteria—2 clinical effectiveness criteria and 1 economical criterion were defined and evaluated over the whole follow-up period: The functional recovery measured over 3 months using EIFEL scale (French version of the Roland-Morris scale). The change in pain intensity measured with a visual analogical scale (VAS) of 100 mm assessed. The medical consumption assessed by number of days with analgesic, anti-inflammatory, and/or myorelaxant agents. Materials and Methods The trial was a multicentric, open, prospective, and randomized clinical study of a lumbar belt and “control group” (CG) in the treatment of subacute low back pain with follow-up monitoring lasting 3 months. This study was approved by Ethic Committee (CCPPRB Rhoˆne Alpes–Loire N° 2004-13) and had received Centre National Informatique et Liberte´ authorization for data collection.

Population The studied population was made up of patients suffering from subacute low back pain treated by a family practitioner. Inclusion and exclusion criteria are presented in Table 1. The sample size had an estimated total of 210 patients. Two groups are randomized (the “wearing belt group” (WBG) and the CG with 105 patients in each group. The number of necessary subjects was estimated to highlight a significant difference in the level of score on the EIFEL scale between the 2 groups analyzed. A difference of 2 points on the EIFEL scale of a maximum score of 24 is considered to be clinically significant. Under these hypotheses, with an alpha risk of 0.05 and a beta risk of 0.1 (statistical power of 90%) the number of patients required is 84 per group, or 168 patients in total. To take into account patient compliance issues regarding wearing of the lumbar belt, a 25% increase in the number of persons involved was allowed.

Table 1. Inclusion and Exclusion Criteria Inclusion criteria Men or women between 20 and 60 yr of age Treatment for an initial episode or recurring nonspecific low back pain Episode lasting 1 to 3-mo No contraindications to step I or step II analgesics, NSAID, benzodiazepines and thiocolchicoside Signing the consent form, which was explained to them first Exclusion criteria Patients who have used a lumbar belt during the last 6 mo Patients who have low back pain irradiating beyond the knee and/or accompanied by neurological signs, including sciatica, Patients who have suffered from a low back pain episode during the 6 mo preceding inclusion Patients who had had a spinal operation during the 5 yr preceding inclusion Patients who have secondary low back pain due to an accident at work Patients who have a history of spinal arthrodesis Patients who have an unstabilized or symptomatic, chronic cardiac or respiratory complaint Patients who suffer from low back pain with an inflammatory, tumoural, or infectious cause Patients with a contraindication to step I or step II analgesics, NSAID, benzodiazepines, and thiocolchicoside Patients who are pregnant Patients whose higher functions do not enable them to properly comprehend the protocol or to reliably record the data Exclusion of patients with a chronic cardiac or respiratory complaint was justified by the theoretical warning of the potential effect of wearing a lumbar belt on the increase in cardio-respiratory load

Recruitment of the patients was proposed by the practitioners to all subjects consulting for subacute low back pain and had to stop after all the 210 patients had been recruited. For the WBG the practitioners gave the belt (which was provided and delivered to the practitioners) to the eligible randomized patients. The instructions were to wear it during the whole day and over the whole duration of the trial and to explain how to adjust it. A call center was set up to answer all the questions asked by the patients regarding the belt. For the CG the patients did not receive the belt. The practitioners asked them not to purchase the belt or to wear a lumbar belt for the whole duration of the study. At the end of the 3 months of the study, if the practitioner considered it to be necessary, prescription of a belt could be suggested to the patient. For each group the other treatments were left to the discretion of the investigating practitioner. Randomized assignment was carried out initially with a block of 6 patients for each practitioner. During the study, to compensate for the insufficient number of patients recruited by certain practitioners, the block was increased from 6 to 8, just for them who had already included 6 patients and able to include 2 more. After the inclusion of each patient (satisfying the eligibility criteria and consent form), the practitioner connected with a vocal server (AREMIS Consultants) to find out which group the patients were included. Recruitment of the investigating practitioners was carried out randomly from a database of practitioners developed by CEGEDIM Company (Boulogne-Billancourt, France). On a list of 757 practitioners solicited, 61 had accepted to participle and 44 were active for patient’s recruitment. Participation of the investigating practitioners required that they accept the protocol, agree the remuneration, the quality control process, be capable of fulfilling the recruitment.

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Medical Device Experimented It was an elastic textile lumbar belt Combitex with crossed bands and posterior metallic reinforcement (Lomba-Cross Activity, Thuasne, France). It is a class 1 medical device “CE marked” in conformity with n° 93/42/CEE directive.

Outline of the Study The total duration of the study was 24 months (09/2004-09/ 2006), with an inclusion phase of 12 months. The patients were examined 3 times, on D0 inclusion, on D30 ⫾ 3 days, on D90 ⫾ 3 days, and an intermediate contact was realized at D60 ⫾ 3 days (D60) by a phone survey. The collected informations during the follow-up were: At inclusion (D0), questionnaire with: complete sociodemography data of the patient (age, sex, height, weight); general clinical state and clinical conditions of the low back pain, history, and previous treatments; measurement of the EIFEL scale and pain VAS; and current treatment and prescribed treatment. At the visits (D30, D90) and phone survey (D60), questionnaire with: assessment of wearing the belt since the last visit (patient compliance for WBG); measurement of the EIFEL scale and pain VAS; and use of medical treatments since the last visit (pharmaceutical intake) and just for the visits, treatments prescribed. The data were collected at D0, D30, D60, and D90, and the analysis was carried out in an anonymous way by ARAMIS Consultants.

Instrument The EIFEL scale is a valid and reliable self-questionnaire for assessing functional capacity in low back pain.20,21 It consists of 24 questions. The patient must answer each question in function of the difficulty applicable on the day the questionnaire is completed. Each question equals 1 point and the total EIFEL score corresponds to the sum. Thus, a score of 24 corresponds to the most unfavorable situation (total functional incapacity associated with their low back pain). The pain VAS was measured with a horizontal scale from 0 (no pain) to 100 (maximal pain).

Statistical Analysis The statistical analyses had been carried out on: the intention to treat population (ITTP) corresponds to all randomized patients fulfilling the inclusion and noninclusion criteria without regard they complied with the lumbar belt wearing recommendations or not; the per protocol population (PPP) corresponds all the patients in the ITT whose efficacy criteria (EIFEL and VAS) were measured at D0 and D90 and who wore a lumbar belt at least once a week during the whole duration of the follow-up for the WBG and those who never wore a belt for CG. A descriptive analysis of the population was carried out on the 2 groups at D0 to compare them. The efficacy analyses were carried out on the various treatment groups by means of a variance analysis with recurring measurements for comparing the main and secondary efficacy criteria (variations in the EIFEL and VAS scores, days of analgesic intake). In addition, a comparison was carried out on the rate of patients responding (i.e., showing an improvement in EIFEL score of at least 2 points from 24). The qualitative variables were presented with the persons involved and frequency of representation for each modality. The quantitative variables were presented with their average, standard deviation, median, and extreme values. All the descriptive analyses were carried out according to the randomization group (WBG and CG) and for the whole population. For each variable, a comparison test was carried out between the 2 groups studied, and was presented in the table of results: t test for the quantitative variables; ␹2 for the qualitative variables. The missing data (no answer) for the main clinical criteria (EIFEL score and VAS score) was taken into account by applying the imputation method to the average data. For an individual, the missing data of a variable were replaced with the average of the calculated values based on the individuals in the same subpopulation. Analysis of the variance of the repeated data enables the existing correlation between different measurements (over time) for the same individual to be taken into account. ANOVA, with repeated data were carried out using the

Figure 1. Population and number of persons in each group for each of the visits (D0, D30, and D90) or telephone contact (D60).

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Figure 2. Change in EIFEL score between D0 and D90. MIXED procedure of SAS, with retention of the repeated option for the individuals. The statistical analyses were carried out using the SAS software V8.02 in the Windows environment.

Results Population Two hundred seven patients were randomized (106 WBG and 101 CG)(Fig. 1). After checking and validating the data, 197 patients correspond to the ITTP, 102 WBG, and 95 CG (6 patients did not observe the inclusion criteria and for 4 patients we never received the inclusion questionnaires, 2 in WBG and 2 CG). The PPP contained 171 persons (90 WBG and 81 CG) (Fig. 1). The characteristics of ITTP were a ratio of 54.8% men, an age average of 43 ⫾ 10.7 years, weight of 73 ⫾ 15.4 kg, and height of 170 ⫾ 8.7 cm. The PPP characteristics were comparable. There were no significant differences between the 2 groups regarding their socio-demographic characteris-

tics, way of life, physical activities and occupation, health status at the beginning of the study, medical history on the spine, previous medical treatment for low back pain, and characteristics of this low back pain episode (duration, responsible factors, . . .). There was also no significant difference regarding the efficacy criteria at the beginning of the study: EIFEL score: 10.3 ⫾ 4.3 WBG and 10.1 ⫾ 4.3 CG; VAS score: 60.9 ⫾ 17.7 WBG, and 59.7 ⫾ 18.1 CG; drugs consummation: 66% of patients don’t use medication at the inclusion, with 64.7% WBG and 67.4% CG. In WBG, the patients wore the belt, on average and per week, 5 days at D30, 4 days at D60, and 3 days at D90. In addition, the number of daily hours on which the belt was worn was 8 hours at D30, 6 hours at D60, and finally 5 hours at D90. Change in EIFEL Score There was a significant difference of change of EIFEL score between WBC and CG: from D0 to D30, respec-

Figure 3. Change in VAS score between D0 and D90.

Lumbar Belt in Subacute Low Back Pain • Calmels et al 219

tively, reduction in the average EIFEL score by 5.4 ⫾ 4.1 and 4.0 ⫾ 4.3 for CG (P ⫽ 0.022); from D0 to D90 reduction by 7.6 ⫾ 4.4 and 6.1 ⫾ 4.73 (P ⫽ 0.023) (Fig. 2). Change in Pain Intensity There was a significant difference of change of VAS pain intensity between WBG and CG: from D0 to D30, respectively, reduction in the average VAS score by 26.8 ⫾ 18.2 and 21.3 ⫾ 18.7 (P ⫽ 0.038); from D0 to D90 reduction in the average VAS score by 41.5 ⫾ 21.49 and 32.0 ⫾ 20.0 (P ⫽ 0.002) (Fig.3). Medication Consumption There was a significant difference of the medication consumption between WBG and CG: at D90, the proportion of patients who did not take any medication in WBG is 60.8% versus 40% in CG (P ⫽ 0.029). The proportion of patients who took at least 1 medication at the time of inclusion was identical for both groups (33% WBG and 32.6% CG), increased during the first month of follow-up (D30: 66.7% WBG and 78.9% CG; P ⫽ 0.039), and fall after (D90: 34.3% WBG and 56.8% CG; P ⫽ 0.002), so that WBG consumed far fewer medication treatments than CG. Discussion The results of this study show that wearing a lumbar belt in the subacute low back pain is benefic for functional recovery, pain intensity control, and medication consumption. At our knowledge there is no comparable study in low back pain with a so large population, a CG, and a randomization, with a multicentric participation, and taking into account antalgic, functional, and medication consumption benefices during a so long-phase of treatment. Some methodologic characteristics of this study are in agreement with the recommendations of the just 3 studies can be considered for the effects reported on pain intensity. Penrose et al22 reported the results of wearing a pneumatic belt during 6 weeks in low back pain. This was a randomized study with a CG but without any precision about the low back pain history, the duration of the episode, and the complementary treatment. The evaluation was made on pain, muscle strength, and mobility of the back. Each subject has been evaluated after 1 hour, 3, and 6 weeks of wearing the belt. The results show a significant decrease of pain intensity for BWG respectively with 18%, 46%, and 73% at 1 hour, 3, and 6 weeks. The results were significantly less for the CG. It was the same for muscle strength and mobility. The compliance to the wearing of the belt was not evaluated. Valle-Jones et al11 have analyzed the benefices of wearing a back support in the treatment of acute non specific low back pain, at 10 to 12 days. This randomized, controlled, parallel-group clinical trial was carried out in general practice. Two hundred sixteen patients have been included (111 wearing corset and 105 controls). All the patients had also paracetamol from 1 to 4 g

a day if necessary to control pain. A self evaluation was made daily during 3 weeks, with pain intensity level (at rest, at night, and during activity), limitation activity level, antalgic consumption, and ability to work. A clinical examination of back mobility was realized at the beginning and end of the period. After 21 days, all the patients were ameliorated for pain intensity, limitation activity level, but this amelioration was significant greater for wearing group than CG. A significantly higher proportion of patients in the wearing group could work normally respectively 85% vs. 67% (P ⬍ 0.02) and for the wearing group the analgesic consumption was significantly lower (P ⬍ 0.0001). Clinical assessment scores were significantly superior in the wearing group (P ⬍ 0.002). Calmels et al23 have conducted a randomized and multicentric study with a CG on the effects of the wearing of a tissue belt during 3 weeks after acute low back pain. The results showed, after 8 days, a significant decrease of pain intensity evaluated by VAS for wearing belt group (P ⫽ 0.029) and of the mobility (outdistance hand-ground) (P ⫽ 0.05); after 21 days a significant increase of functional capacities (0.028 ⬍ P ⬍ 0.032) and medical consumption (P ⫽ 0.028). For this study as this of Valle-Jones et al, the limitations are a too small population and a too short period of assessment. First, our study reports a clinical efficiency of lumbar belt wearing for the subacute low back pain as a complementary treatment to medication. The use of belts, corsets, or orthoses is frequently reported as an alternative therapeutic associated in low back pain but without strong evidence. The benefice can be explained by some mechanical effects in regard with all the components of low back pain: limitation of the back mobility,24,25 and more specifically the limitation of the flexion in subjects daily activities, which is reported as an important factor of disc constraint26,27 and back pain intensity28; increase of intra-abdominal pressure,26,29 which is an other factor to decrease disc pressure,26 limit disc compression, and disc pain; postural control with an educative effect by belt to maintain spine in a relative extension as proposed to prevent back problems30; spine stability and adaptation of muscle activity.29,31–33 In the case of belt, the limitation of the mobility and pressure are less than for rigid orthoses but the effect on postural control can explain the clinical benefice reported by recent studies on the benefices of belt wearing.34 –37 The second important aspect and never analyzed in this clinical situation is the global benefice on medical consumption. This constitute an important argument, because of the economic impact and the potentially decrease of iatrogenic effects of some antalgic or antiinflammatory drugs used to treat low back pain. If this result is interesting, it must be discussed. There is a more important and significant decrease of medication use for WBG than CG at the end of the study, but in each group it is also reported an increase in the first month; this was due that, at inclusion, the practitioners can prescribe

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medication with belt to reduce pain intensity for this patients who consulted for the first time for this back pain episode. It is also reported no difference between the number of medication use at the beginning and at the end of the study for WBG; this must be considered in this study as “wearing belt” decreases medication consumption comparatively with “no wearing,” but does not suppresses all medications; wearing belt is a complementary and not the primary treatment of back pain. In regards with different treatments proposed for low back pain, it is also interesting to underline that lumbar belt wearing does not induce secondary or iatrogenic effects and that there is no contraindication, which can induce some preferences to a belt wearing than more aggressive therapy. In conclusion, this study reports significant results of the clinical and functional benefices to wearing a tissue belt as a complementary treatment of subacute low back pain, with a significant decrease of medication consumption. Key Points ● It is a multicentric, randomized, and controlled study of clinical evaluation of a lumbar belt in subacute low back pain. ● The clinical criteria were the physical restoration assessed with the EIFEL scale, the pain assessed by a VAS, the economical criteria was the overall cost of associated medical treatments. ● One hundred ninety-seven patients have participated. The results show a higher decrease in EIFEL score, VAS score, and pharmacologic consumption in wearing belt group than CG.

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