***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: In a prospect i ve trial , 222 adults with low-back pain of at least 2 weeks ' duration in a Health Maintenance Organization ( HMO ) were r and omly assigned to usual care ( UC ) , a 4-hour back school psychoeducational session ( LBS ) , or the same back school plus a 1-year “ compliance package ” program design ed to encourage appropriate self-management for back pain ( CP ) . Sixty-four percent of LBS and CP subjects attended their back school sessions . Follow-up measurement of pain level ( using the Visual Analogue Scale ) , functional status ( using the Sickness Impact Profile ) , and various other indicators of health status showed no measurable effect of either treatment condition ( LBS or CP ) compared with UC at 3 , 6 , 12 , and 18 months after entry into the study . Initial disability resolved by 3 months in most patients , and a minority of subjects ( 10–15 % ) showed residual or recurrent functional Impairment 1 year after entry . Health care utilization tended to be slightly higher after intervention In the CP group . With or without follow-up encouragement , back school instructions given in a single 4-hour session had no measurable impact on the comfort or functional status of the majority of patients with new onset back pain in this HMO Design . R and omized prospect i ve study of the effects of three types of active therapy on back muscle function in chronic low back pain patients . Objectives . To quantify the effects of 3 months active therapy on strength , endurance , activation , and fatigability of the back entensor muscles . Summary of Background Data . Many studies have documented an association between chronic low back pain and diminished muscular performance capacity . Few studies have quantified the changes in these measures following interventions using objective measurement techniques or related them to changes in clinical outcome . Methods . A total of 148 individuals ( 57 % women ) with chronic low back pain ( age , 45.0 ± 10.0 years ; duration of low back pain , 10.9 ± 9.5 years ) were r and omized to a treatment that they attended for 3 months : active physiotherapy , muscle reconditioning on devices , or low-impact aerobics . Before and after therapy , assessment s were made of the following : trunk muscle strength ( in flexion , extension , lateral bending , and axial rotation ) , erector spinae activation ( maximal , and during forward bending movements ) , back extensor endurance ( Biering-S/orensen test ) , and erector spinae fatigability ( determined from changes in the median frequency of the surface electromyographic signal ) during isometric and dynamic tests . Results . A total of 132 of 148 patients ( 89 % ) completed the therapy . Isometric strength in each movement direction increased in all groups post-therapy ( P < 0.0008 ) , most notably in the devices group . Activation of the erector spinae during the extension tests also increased significantly in all groups and showed a weak , but significant , relationship with increased maximal strength ( P = 0.01 ) . Pretherapy 55 % of the subjects showed no relaxation of the back muscles at L5 when in the fully flexed position ; no changes were observed in any group post-therapy . Endurance time during the Biering-S/orensen test increased significantly post-therapy in all groups ( P = 0.0001 ) , but there were no significant changes in EMG-determined fatigability . Fatigability of the lumbar muscles at L5 ( EMG median frequency changes ) during the dynamic test increased post-therapy ( P = 0.0001 ) without group differences . Conclusion . Significant changes in muscle performance were observed in all three active therapy groups post-therapy , which appeared to be mainly due to changes in neural activation of the lumbar muscles and psychological changes concerning , for example , motivation or pain tolerance The purpose of this study was to assess the effects of two different treatment modalities on the rehabilitation process of chronic sacroiliac joint patients . The treatment modalities included spinal manipulative therapy given by a chiropractor and a program of back school therapy given by a physiotherapist . The rehabilitation process was assessed using clinical and biomechanical measures . It was found that back school therapy was a better treatment modality than the spinal manipulative therapy , according to the clinical measures of rehabilitation . Precisely the opposite result was found for the biomechanical measures This study investigated the effect of a back school rehabilitation program on lost work time , lost time cost , medical cost , and number of injuries in municipal employees . Seventy back-injured workers who participated in a 6-week back school  were compared on the dependent variables with 70 r and omly selected back-injured city employees who had not participated in a back school . Back school participants demonstrated a significant decrease on all dependent variables .  Back school participants had significantly fewer injuries in the 6-month postintervention period . No statistically significant differences were found between groups on the time and cost variables . Actual dollars saved in lost time and medical costs between groups was of practical value to the city . Study findings offer support for the back school as a cost-effective measure A clinical trial , aim ed at secondary prevention of low-back pain , was performed in 142 hospital employees reporting at least three annual episodes of this condition . Participants were r and omly assigned to one of three groups : a calisthenics program ( CAL ) for 3 months with biweekly sessions of flexion exercises , a back school program ( 5 sessions ) , and a control group . The effectiveness of the two intervention programs was evaluated over a 1-year period . Baseline preintervention data and evaluation at the end of 3 months of intervention and after an additional 6 months were collected . A monthly surveillance for the whole year showed a mean of 4.5 “ painful months ” in the CAL group versus 7.3 and 7.4 months in the back school and control groups , respectively ( P < 0.0001 ) . The superiority of the CAL group was achieved partly because of the significant increase in trunk forward flexion and to initial increment in abdominal muscle strength . The increased trunk flexion was associated with the rate of participation in the CAL sessions . Further research is needed to answer the question of “ intensity versus type of exercise ” by comparing different intervention programs , with similar intensity OBJECTIVE To evaluate a progressive fitness programme for patients with chronic low back pain . DESIGN Single blind r and omised controlled trial . Assessment s were carried out before and after treatment by an observer blinded to the study and included a battery of vali date d measures . All patients were followed up by postal question naire six months after treatment . SETTING Physiotherapy department of orthopaedic hospital . SUBJECTS 81 patients with chronic low back pain referred from orthopaedic consultants for physiotherapy . The patients were r and omly allocated to a fitness programme or control group . INTERVENTION Both groups were taught specific exercises to carry out at home and referred to a back-school for education in back care . Patients allocated to the fitness class attended eight exercise classes over four weeks in addition to the home programme and backschool . RESULTS Significant differences between the groups were shown in the changes before and after treatment in scores on the Oswestry low back pain disability index ( P < 0.005 ) , pain reports ( sensory P < 0.05 and affective P < 0.005 ) , self efficacy reports ( P < 0.05 ) , and walking distance ( P < 0.005 ) . No significant differences between the groups were found by the general health question naire or question naire on pain locus of control . A benefit of about 6 percentage points on the disability index was maintained by patients in the fitness group at six months . CONCLUSION There is a role for supervised fitness programmes in the management of moderately disabled patients with chronic low back pain . Further clinical trials , however , need to be established in other centres to confirm these findings We analysed 113 reports published in 1980 in a sample of medical journals to relate features of study design to the magnitude of gains attributed to new therapies over old . Overall we rated 87 per cent of new therapies as improvements over st and ard therapies . The mean gain ( measured by the Mann-Whitney statistic ) was relatively constant across study design s , except for non-r and omized controlled trials with sequential assignment to therapy , which showed a significantly higher likelihood that a patient would do better on the innovation than on st and ard therapy ( p = 0.004 ) . R and omized controlled trials that did not use a double-blind design had a higher likelihood of showing a gain for the innovation than did double-blind trials ( p = 0.02 ) . Any evaluation of an innovation may include both bias and the true efficacy of the new therapy , therefore we may consider making adjustments for the average bias associated with a study design . When interpreting an evaluation of a new therapy , readers should consider the impact of the following average adjustments to the Mann-Whitney statistic : for trials with non-r and om sequential assignment a decrease of 0.15 , for non-double-blind r and omized controlled trials a decrease of 0.11 Inpatient and outpatient treatments were compared with a control intervention in 288 men and 168 women , aged 35 - 54 , who were at work , but suffered from chronic or recurrent low back pain .  Physical measurements and back pain assessment s  were carried out before the intervention and at a 3-month follow-up . Physical fitness improved most in the in patients , but the out patients did not differ from the controls . Correlations between back pain and physical measurements indicated that increase of lumbar and hip mobility was more important than increase of trunk strength for subjective progress in these patients . Increased trunk extension strength correlated significantly with subjective progress in women , who also had higher correlations between improved physical fitness and progress than men Ninety-two chronic low back pain patients were r and omly allocated to two groups to evaluate the effectiveness of a back school compared with an exercise-only regimen according to specified outcome variables . The data from 78 patients with 7 years mean duration of symptoms was analyzed . Three assessment s were made : before treatment and 6 and 16 weeks after treatment . Changes in patients ' levels of pain , functional disability , and other related variables were compared in the two groups . Almost all variables showed an improvement at 6 weeks . At 16 weeks , functional disability and pain levels showed a significant difference . Back school patients continued to make an improvement . This method of managing low back pain makes maximal use of limited re sources and appears to be effective , especially in the longer term Controlled clinical trials of the treatment of acute myocardial infa rct ion offer a unique opportunity for the study of the potential influence on outcome of bias in treatment assignment . A group of 145 papers was divided into those in which the r and omization process was blinded ( 57 papers ) , those in which it may have been unblinded ( 45 papers ) , and those in which the controls were selected by a nonr and om process ( 43 papers ) . At least one prognostic variable was maldistributed ( P less than 0.05 ) in 14.0 per cent of the blinded-r and omization studies , in 26.7 per cent of the unblinded-r and omization studies , and in 58.1 per cent of the nonr and omized studies . Differences in case-fatality rates between treatment and control groups ( P less than 0.05 ) were found in 8.8 per cent of the blinded-r and omization studies , 24.4 per cent of the unblinded-r and omization studies , and 58.1 per cent of the nonr and omized studies . These data emphasize the importance of keeping those who recruit patients for clinical trials from suspecting which treatment will be assigned to the patient under consideration OBJECTIVE To assess the efficacy of a back school program for patients with a first episode of acute work-related low back pain requiring compensation . DESIGN A r and omized single-blind controlled trial . SETTING A private physiatrics outpatient clinic . PATIENTS The mean duration of low back pain was 15 days . INTERVENTION Eligible patients were r and omized to a st and ard treatment program that included daily physiotherapy ( n = 86 ) or the same program with the addition of back school ( n = 82 ) . The back school program consisted of three 90-minute sessions given by a single trained instructor at 0 , 1 , and 8 weeks . MAIN OUTCOME MEASURES The primary outcomes were the time off work for the presenting episode of back pain and the number and duration of recurrences in the year following the study onset . Secondary outcomes included the level of pain , spinal mobility , active straight-leg raising , and functional disability assessed by the Oswestry and Rol and -Morris scales . RESULTS Those r and omized to the back school group gained significantly more knowledge , based on the multiple choice examination ( p = .0001 ) and performed the exercise program significantly better ( p = .0001 ) than the st and ard care group . There were no differences between the two treatment groups for either of the primary outcomes . The median time to return to work from r and omization was 33 days for both the back school and the st and ard care groups ( p = .48 ) . The number of compensated recurrences of low back pain over 1 year was similar ( back school = 14 , st and ard care = 10 , p = .16 ) , as was the median duration of these episodes ( back school = 25 days , st and ard care = 70 days , p = .21 ) . There were no significant differences favoring the back school group for any of the secondary outcomes at the posttreatment , 6-month , or 12-month assessment s. CONCLUSION A back school intervention in addition to st and ard care result ed in no reduction in the time to return to work or the number or duration of recurrences of low back pain requiring compensation over a period of one year The long-term outcome results of  inpatient and outpatient treatment  of low back pain ( LBP ) were studied in 476 subjects ( aged 35 - 54 , 63 % men ) r and omly assigned to three study groups : in patients ( n = 157 ) , out patients ( n = 159 ) , and controls ( n = 160 ) . The study included changes in 
    Output:
    
The results indicate that there is moderate evidence that back schools have better short-term effects than other treatments for chronic low back pain , and that there is moderate evidence that back schools in an occupational setting are more effective compared to ' placebo ' or waiting list controls .
REVIEW ER 'S CONCLUSIONS Back schools may be effective for  patients with recurrent and chronic low back pain  in occupational setting s , but little is known about the cost-effectiveness of back schools