human
***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 The effects of two different prevention programmes on : ( 1 ) reported neck , shoulder and back pain , ( 2 ) perceived physical exertion at work and perceived work-related psychosocial factors , were evaluated by question naires after 12 and 18 months . Female nursing aides and assistant nurses ( n = 282 ) working in the home-care services , were r and omly assigned to one of three groups for : ( 1 ) individually design ed physical training programme , ( 2 ) work-place stress management , ( 3 ) control group . Results revealed no significant differences between the three groups . However , improvements in low back pain were registered within both intervention groups for up to 18 months . Perceived physical exertion at work was reduced in the physical training group . Improvements in neck and shoulder pain did not differ within the three groups . Dissatisfaction with work-related , psychosocial factors was generally increased in all groups . As the aetiology of neck , shoulder and back disorders is multifactorial , a combination of the two intervention programmes might be preferable and should be further studied CONTEXT Low back pain is a frequent and costly health problem . Prevention of low back pain is important both for the individual patient and from an economic perspective . OBJECTIVE To assess the efficacy of lumbar supports and education in the prevention of low back pain in industry . DESIGN A r and omized controlled trial with a factorial design . SETTING The cargo department of an airline company in the Netherl and s. PARTICIPANTS A total of 312 workers were r and omized , of whom 282 were available for the 6-month follow-up . INTERVENTIONS Subjects were r and omly assigned to 4 groups : ( 1 ) education ( lifting instructions ) and lumbar support , ( 2 ) education , ( 3 ) lumbar support , and ( 4 ) no intervention . Education consisted of 3 group sessions on lifting techniques with a total duration of 5 hours . Lumbar supports were recommended to be used during working hours for 6 months . MAIN OUTCOME MEASURES Low back pain incidence and sick leave because of back pain during the 6-month intervention period . RESULTS Compliance with wearing the lumbar support at least half the time was 43 % . In the 282 subjects for whom data were available , no statistically significant differences in back pain incidence ( 48 [ 36 % ] of 134 with lumbar support vs 51 [ 34 % ] of 148 without , P=.81 ) or in sick leave because of low back pain ( mean , 0.4 days per month with lumbar support vs 0.4 days without , P=.52 ) were found among the intervention groups . In a subgroup of subjects with low back pain at baseline , lumbar supports reduced the number of days with low back pain per month ( median , 1.2 vs 6.5 days per month ; P=.03 ) . CONCLUSIONS Overall , lumbar supports or education did not lead to a reduction in low back pain incidence or sick leave . The results of the subgroup analysis need to be confirmed by future research . Based on our results , the use of education or lumbar supports can not be recommended in the prevention of low back pain in industry STUDY DESIGN A systematic review of r and omized and nonr and omized controlled trials . SUMMARY OF BACKGROUND DATA Lumbar supports are used in the treatment of low back pain , but also to prevent the onset ( primary prevention ) or recurrences of a low back pain episode ( secondary prevention ) . OBJECTIVES To assess the effects of lumbar sup-ports for prevention and treatment of nonspecific low back pain .  METHODS The Medline , Cinahl , and Current Contents data bases ; the Cochrane Controlled Trials Register up to September 1999 ; and the Embase data base up to September 1998 were all search ed . References of identified trials and systematic review s were review ed and the Science Citation Index used to identify additional trials . Method ologic quality assessment and data extraction were performed by two review ers independently . A quantitative analysis was performed in which the strength of evidence was classified as strong , moderate , limited or conflicting , and no evidence . RESULTS Five r and omized and two nonr and omized preventive trials and six r and omized therapeutic trials were included in the review . Only 4 of the 13 studies were of high quality . There was moderate evidence that lumbar supports are not effective for primary prevention . No evidence was found on the effectiveness of lumbar supports for secondary prevention . The systematic review of therapeutic trials showed that there is limited evidence that lumbar supports are more effective than no treatment , whereas it is still unclear whether lumbar supports are more effective than other interventions for treatment of low back pain . CONCLUSIONS There continues to be a need for high quality r and omized trials on the effectiveness of lumbar supports . One of the most essential issues to tackle in these future trials seems to be the realization of adequate compliance This study was funded in part by NIH grant AR36308 The authors thank the employees of the United States Postal Service and the American Postal Workers Union ( APWU ) , Boston Metro Area Local , and Maith and lers Local 301 for their help and cooperation ; therapists from the Department of Rehabilitation Services , Bngham and Women 's Hospital for help in training workers ; and Ms Nancy Tanner for BACKGROUND Low back injuries are common and costly , accounting for 15 to 25 percent of injuries covered by workers ' compensation and 30 to 40 percent of the payments made under that program . The high costs of injury , the lack of effective treatment . and the evidence that there are behavioral risk factors have led to widespread use of employee education programs that teach safe lifting and h and ling . The effectiveness of those programs , however , has received little rigorous evaluation . METHODS We evaluated an educational program design ed to prevent low back injury in a r and omized , controlled trial involving about 4000 postal workers . The program , similar to that in wide use in so-called back schools , was taught by experienced physical therapists . Work units of workers and supervisors were trained in a two-session back school ( three hours of training ) , followed by three to four reinforcement sessions over the succeeding few years . Injured subjects ( from both the intervention and the control groups ) were r and omized a second time to receive either training or no training after their return to work . RESULTS Physical therapists trained 2534 postal workers and 134 supervisors . Over 5.5 years of follow-up , 360 workers reported low back injuries , for a rate of 21.2 injuries per 1000 worker-years of risk . The median time off from work per injury was 14 days ( range , 0 to 1717 ) ; the median cost was $ 204 ( range , zero to $ 190,380 ) . After their return to work , 75 workers were injured again . Our comparison of the intervention and control groups found that the education program did not reduce the rate of low back injury , the median cost per injury , the time off from work per injury , the rate of related musculoskeletal injuries , or the rate of repeated injury after return to work ; only the subjects ' knowledge of safe behavior was increased by the training . CONCLUSIONS A large-scale , r and omized , controlled trial of an educational program to prevent work-associated low back injury found no long-term benefits associated with training This study was design ed to determine the effect of multimodal intervention and the prevention of back injury , and to evaluate the adverse side effects of using a lumbosacral corset in the workplace . Subjects were 90 male warehouse workers r and omly selected from over 800 employees at a grocery distribution center . Subjects were assigned to three groups : true controls , no back school , no brace orthoses ; back school only ; and back school plus wearing a custom molded lumbosacral orthosis . Comparisons of pre-testing and 6-month follow-up posttesting for abdominal strength , cognitive data , work injury incidence and productivity and use of health care services were evaluated . Controls and training-only group showed no changes in strength productivity or lost time . Orthoses and training-group showed no changes in strength productivity or accident rate ; however , they showed substantially less lost time . This study supports the concept of using education and prophylactic bracing to prevent back injury and reduce time loss . It appears that the use of intermittent prophylactic bracing has no adverse affects on abdominal muscle strength and may contribute to decreased lost time from work injuries The personnel at a geriatric hospital were r and omized into two groups . One group was allowed to exercise during working hours to improve back muscle strength , endurance , and coordination . The other group did not participate in the exercise program and received no further advice or information . After 13 months , the training group had increased back muscle strength . One subject had been absent from work 28 days in the training group whereas 12 subjects had been absent 155 days from work because of low back pain in the control group ( P<0.004 ) . The back pain complaints and intensity of back pain in the training group also decreased in a statistically significant way . Every hour spent by the physiotherapist on the training group reduced the work absence among the participants by 1.3 days , result ing in a cost/benefit ratio greater than 10 To define the cost-effectiveness of a back school program in industry , a controlled longitudinal field study was carried out in a Dutch bus company . The experimental group received a program consisting of information on back care , physical fitness , nutrition , stress , and relaxation . Objective data on absenteeism were collected and compared during a 6-year period for the control and experimental groups . Results showed that a tailor-made back school program reduced absenteeism by at least 5 days per year per employee , therefore being cost-effective to industry . A reduction was not observed in incidence , but in mean length of absenteeism . This effect turned out to be persistent during a 2-year period following the program The purpose s of this study were to evaluate the effect of a weekly exercise program on  short-term sick leave ( less than 50 days ) attributable to back pain and to determine whether changes in absenteeism were related to changes in cardiovascular fitness . Subjects were r and omly assigned to an exercise group ( n = 58 ) and a control group ( n = 53 ) .  Sick leave attributable to back pain was determined in the intervention period of 1 1/2 years and a comparable 1 1/2-year period prior to the study . In the exercise group , the number of episodes of back pain and the number of sick-leave days attributable to back pain in the intervention period decreased by over 50 % . Absenteeism attributable to back pain increased in the control group . The decrease in sick leave in the exercise group was not accompanied by any change in cardiovascular fitness . Suggestions for establishing exercise programs are given CONTEXT Despite scientific uncertainties about effectiveness , wearing back belts in the hopes of preventing costly and disabling low back injury in employees is becoming common in the workplace . OBJECTIVE To evaluate the effectiveness of using back belts in reducing back injury cl aims and low back pain . DESIGN AND SETTING Prospect i ve cohort study . From April 1996 through April 1998 , we identified  material -h and ling employees in 160 new retail merch and ise stores ( 89 required back belt use ; 71 had voluntary back belt use ) in 30 states ( from New Hampshire to Michigan in the north and from Florida to Texas in the south ) ; data collection ended December 1998 , median follow-up was 6(1/2 ) months . PARTICIPANTS A referred sample of 13,873 material h and ling employees provided 9377 baseline interviews and 6311 ( 67 % ) follow-up interviews ; 206 ( 1.4 % ) refused baseline interview . MAIN OUTCOME MEASURES Incidence rate of material -h and ling back injury workers ' compensation cl aims and 6-month incidence rate of self-reported low back pain . RESULTS Neither frequent back belt use nor a belt-requirement store policy was significantly associated with back injury cl aim rates or self-reported back pain . Rate ratios comparing back injury cl aims of those who reported wearing back belts usually every day and once or twice a week vs those who reported wearing belts never or once or twice a month were 1.22 ( 95 % confidence interval [ CI ] , 0.87 - 1.70 ) and 0.95 ( 95 % CI , 0.56 - 1.59 ) , respectively . The respective odds ratios for low back pain incidence were 0.97 ( 95 % CI , 0.83 - 1.13 ) and 0.92 ( 95 % CI , 0.73 - 1.16 ) . CONCLUSIONS In the largest prospect i ve cohort study of back belt use , adjusted for multiple individual risk factors , neither frequent back belt use nor a store policy that required belt use was associated with reduced incidence of back injury cl aims or low back pain . JAMA . 2000;284:2727 - 273 
    Output:
    
agent
Since three of four RCTs on lumbar supports reported no effect , there is no evidence for the effectiveness of lumbar supports .
The four RCTs on exercise consistently reported a positive effect , indicating limited evidence for the effectiveness of exercise .
CONCLUSION There is no evidence for the effectiveness of lumbar supports or education in the primary prevention of low back pain at the workplace .
There is limited evidence for the efficacy of exercise , and the effect that can be obtained is moderate .
***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 The effects of two different prevention programmes on : ( 1 ) reported neck , shoulder and back pain , ( 2 ) perceived physical exertion at work and perceived work-related psychosocial factors , were evaluated by question naires after 12 and 18 months . Female nursing aides and assistant nurses ( n = 282 ) working in the home-care services , were r and omly assigned to one of three groups for : ( 1 ) individually design ed physical training programme , ( 2 ) work-place stress management , ( 3 ) control group . Results revealed no significant differences between the three groups . However , improvements in low back pain were registered within both intervention groups for up to 18 months . Perceived physical exertion at work was reduced in the physical training group . Improvements in neck and shoulder pain did not differ within the three groups . Dissatisfaction with work-related , psychosocial factors was generally increased in all groups . As the aetiology of neck , shoulder and back disorders is multifactorial , a combination of the two intervention programmes might be preferable and should be further studied CONTEXT Low back pain is a frequent and costly health problem . Prevention of low back pain is important both for the individual patient and from an economic perspective . OBJECTIVE To assess the efficacy of lumbar supports and education in the prevention of low back pain in industry . DESIGN A r and omized controlled trial with a factorial design . SETTING The cargo department of an airline company in the Netherl and s. PARTICIPANTS A total of 312 workers were r and omized , of whom 282 were available for the 6-month follow-up . INTERVENTIONS Subjects were r and omly assigned to 4 groups : ( 1 ) education ( lifting instructions ) and lumbar support , ( 2 ) education , ( 3 ) lumbar support , and ( 4 ) no intervention . Education consisted of 3 group sessions on lifting techniques with a total duration of 5 hours . Lumbar supports were recommended to be used during working hours for 6 months . MAIN OUTCOME MEASURES Low back pain incidence and sick leave because of back pain during the 6-month intervention period . RESULTS Compliance with wearing the lumbar support at least half the time was 43 % . In the 282 subjects for whom data were available , no statistically significant differences in back pain incidence ( 48 [ 36 % ] of 134 with lumbar support vs 51 [ 34 % ] of 148 without , P=.81 ) or in sick leave because of low back pain ( mean , 0.4 days per month with lumbar support vs 0.4 days without , P=.52 ) were found among the intervention groups . In a subgroup of subjects with low back pain at baseline , lumbar supports reduced the number of days with low back pain per month ( median , 1.2 vs 6.5 days per month ; P=.03 ) . CONCLUSIONS Overall , lumbar supports or education did not lead to a reduction in low back pain incidence or sick leave . The results of the subgroup analysis need to be confirmed by future research . Based on our results , the use of education or lumbar supports can not be recommended in the prevention of low back pain in industry STUDY DESIGN A systematic review of r and omized and nonr and omized controlled trials . SUMMARY OF BACKGROUND DATA Lumbar supports are used in the treatment of low back pain , but also to prevent the onset ( primary prevention ) or recurrences of a low back pain episode ( secondary prevention ) . OBJECTIVES To assess the effects of lumbar sup-ports for prevention and treatment of nonspecific low back pain .  METHODS The Medline , Cinahl , and Current Contents data bases ; the Cochrane Controlled Trials Register up to September 1999 ; and the Embase data base up to September 1998 were all search ed . References of identified trials and systematic review s were review ed and the Science Citation Index used to identify additional trials . Method ologic quality assessment and data extraction were performed by two review ers independently . A quantitative analysis was performed in which the strength of evidence was classified as strong , moderate , limited or conflicting , and no evidence . RESULTS Five r and omized and two nonr and omized preventive trials and six r and omized therapeutic trials were included in the review . Only 4 of the 13 studies were of high quality . There was moderate evidence that lumbar supports are not effective for primary prevention . No evidence was found on the effectiveness of lumbar supports for secondary prevention . The systematic review of therapeutic trials showed that there is limited evidence that lumbar supports are more effective than no treatment , whereas it is still unclear whether lumbar supports are more effective than other interventions for treatment of low back pain . CONCLUSIONS There continues to be a need for high quality r and omized trials on the effectiveness of lumbar supports . One of the most essential issues to tackle in these future trials seems to be the realization of adequate compliance This study was funded in part by NIH grant AR36308 The authors thank the employees of the United States Postal Service and the American Postal Workers Union ( APWU ) , Boston Metro Area Local , and Maith and lers Local 301 for their help and cooperation ; therapists from the Department of Rehabilitation Services , Bngham and Women 's Hospital for help in training workers ; and Ms Nancy Tanner for BACKGROUND Low back injuries are common and costly , accounting for 15 to 25 percent of injuries covered by workers ' compensation and 30 to 40 percent of the payments made under that program . The high costs of injury , the lack of effective treatment . and the evidence that there are behavioral risk factors have led to widespread use of employee education programs that teach safe lifting and h and ling . The effectiveness of those programs , however , has received little rigorous evaluation . METHODS We evaluated an educational program design ed to prevent low back injury in a r and omized , controlled trial involving about 4000 postal workers . The program , similar to that in wide use in so-called back schools , was taught by experienced physical therapists . Work units of workers and supervisors were trained in a two-session back school ( three hours of training ) , followed by three to four reinforcement sessions over the succeeding few years . Injured subjects ( from both the intervention and the control groups ) were r and omized a second time to receive either training or no training after their return to work . RESULTS Physical therapists trained 2534 postal workers and 134 supervisors . Over 5.5 years of follow-up , 360 workers reported low back injuries , for a rate of 21.2 injuries per 1000 worker-years of risk . The median time off from work per injury was 14 days ( range , 0 to 1717 ) ; the median cost was $ 204 ( range , zero to $ 190,380 ) . After their return to work , 75 workers were injured again . Our comparison of the intervention and control groups found that the education program did not reduce the rate of low back injury , the median cost per injury , the time off from work per injury , the rate of related musculoskeletal injuries , or the rate of repeated injury after return to work ; only the subjects ' knowledge of safe behavior was increased by the training . CONCLUSIONS A large-scale , r and omized , controlled trial of an educational program to prevent work-associated low back injury found no long-term benefits associated with training This study was design ed to determine the effect of multimodal intervention and the prevention of back injury , and to evaluate the adverse side effects of using a lumbosacral corset in the workplace . Subjects were 90 male warehouse workers r and omly selected from over 800 employees at a grocery distribution center . Subjects were assigned to three groups : true controls , no back school , no brace orthoses ; back school only ; and back school plus wearing a custom molded lumbosacral orthosis . Comparisons of pre-testing and 6-month follow-up posttesting for abdominal strength , cognitive data , work injury incidence and productivity and use of health care services were evaluated . Controls and training-only group showed no changes in strength productivity or lost time . Orthoses and training-group showed no changes in strength productivity or accident rate ; however , they showed substantially less lost time . This study supports the concept of using education and prophylactic bracing to prevent back injury and reduce time loss . It appears that the use of intermittent prophylactic bracing has no adverse affects on abdominal muscle strength and may contribute to decreased lost time from work injuries The personnel at a geriatric hospital were r and omized into two groups . One group was allowed to exercise during working hours to improve back muscle strength , endurance , and coordination . The other group did not participate in the exercise program and received no further advice or information . After 13 months , the training group had increased back muscle strength . One subject had been absent from work 28 days in the training group whereas 12 subjects had been absent 155 days from work because of low back pain in the control group ( P<0.004 ) . The back pain complaints and intensity of back pain in the training group also decreased in a statistically significant way . Every hour spent by the physiotherapist on the training group reduced the work absence among the participants by 1.3 days , result ing in a cost/benefit ratio greater than 10 To define the cost-effectiveness of a back school program in industry , a controlled longitudinal field study was carried out in a Dutch bus company . The experimental group received a program consisting of information on back care , physical fitness , nutrition , stress , and relaxation . Objective data on absenteeism were collected and compared during a 6-year period for the control and experimental groups . Results showed that a tailor-made back school program reduced absenteeism by at least 5 days per year per employee , therefore being cost-effective to industry . A reduction was not observed in incidence , but in mean length of absenteeism . This effect turned out to be persistent during a 2-year period following the program The purpose s of this study were to evaluate the effect of a weekly exercise program on  short-term sick leave ( less than 50 days ) attributable to back pain and to determine whether changes in absenteeism were related to changes in cardiovascular fitness . Subjects were r and omly assigned to an exercise group ( n = 58 ) and a control group ( n = 53 ) .  Sick leave attributable to back pain was determined in the intervention period of 1 1/2 years and a comparable 1 1/2-year period prior to the study . In the exercise group , the number of episodes of back pain and the number of sick-leave days attributable to back pain in the intervention period decreased by over 50 % . Absenteeism attributable to back pain increased in the control group . The decrease in sick leave in the exercise group was not accompanied by any change in cardiovascular fitness . Suggestions for establishing exercise programs are given CONTEXT Despite scientific uncertainties about effectiveness , wearing back belts in the hopes of preventing costly and disabling low back injury in employees is becoming common in the workplace . OBJECTIVE To evaluate the effectiveness of using back belts in reducing back injury cl aims and low back pain . DESIGN AND SETTING Prospect i ve cohort study . From April 1996 through April 1998 , we identified  material -h and ling employees in 160 new retail merch and ise stores ( 89 required back belt use ; 71 had voluntary back belt use ) in 30 states ( from New Hampshire to Michigan in the north and from Florida to Texas in the south ) ; data collection ended December 1998 , median follow-up was 6(1/2 ) months . PARTICIPANTS A referred sample of 13,873 material h and ling employees provided 9377 baseline interviews and 6311 ( 67 % ) follow-up interviews ; 206 ( 1.4 % ) refused baseline interview . MAIN OUTCOME MEASURES Incidence rate of material -h and ling back injury workers ' compensation cl aims and 6-month incidence rate of self-reported low back pain . RESULTS Neither frequent back belt use nor a belt-requirement store policy was significantly associated with back injury cl aim rates or self-reported back pain . Rate ratios comparing back injury cl aims of those who reported wearing back belts usually every day and once or twice a week vs those who reported wearing belts never or once or twice a month were 1.22 ( 95 % confidence interval [ CI ] , 0.87 - 1.70 ) and 0.95 ( 95 % CI , 0.56 - 1.59 ) , respectively . The respective odds ratios for low back pain incidence were 0.97 ( 95 % CI , 0.83 - 1.13 ) and 0.92 ( 95 % CI , 0.73 - 1.16 ) . CONCLUSIONS In the largest prospect i ve cohort study of back belt use , adjusted for multiple individual risk factors , neither frequent back belt use nor a store policy that required belt use was associated with reduced incidence of back injury cl aims or low back pain . JAMA . 2000;284:2727 - 273 
    Output:
    