***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: Systematic Review Series Series Editors : Cynthia Mulrow , MD , MSc Deborah Cook , MD , MSc The last article in this series outlined methods with which to search the literature for studies on the clinical question that generates a systematic review [ 1 ] . Herein , we discuss the subsequent steps of selecting and appraising  studies  for a review . Both of these steps involve important judgments that can influence the results of a review . In selecting studies , review ers judge the relevance of the studies to the review question . In appraising studies , review ers judge numerous features of design and analysis . Some of these judgments are easy to make ; others are more difficult and prone to error . To be confident in their decisions , review ers should use methods that are reliable ( the results do not change if the procedure is repeated ) , impartial ( not influenced by the study results ) , and explicit ( unambiguous ) [ 2 ] . These strategies for selection and appraisal are sensible , and they distinguish most systematic review s from most narrative review s. However , evidence to support the importance of some of the methods we suggest is either scant or conflicting ; readers are referred to the original research on these approaches for more details . Selecting Studies for Systematic Review s If review ers perform a comprehensive search of the literature using the methods described previously in this series [ 1 ] , they will probably have assembled a large sample of articles . This sample will include most ( ideally , all ) studies that are relevant to the review question ( that is , the sensitivity of the search will be high ) . Inevitably , because such a wide net is cast , articles not pertinent to the clinical question will be retrieved ( that is , the specificity of the search will be modest ) . Thus , the review ers ' next task is to sort through all of the potentially relevant articles and select those that will be included in the review . To do so , review ers adopt several of the tactics listed in Table 1 and Table 2 for planning and executing the selection process ( in effect , improving the specificity of the search ) ; these tactics are described below . Table 1 . Planning Study Selection Table 2 . Strategies for Selecting and Appraising Studies Begin with a Well-Built Clinical Question Review ers should ensure that the question for review includes the four elements of a well-built clinical question [ 3 , 4 ] : the patients of interest , the main interventions under investigation , the comparison interventions , and the clinical outcomes of interest . By including these four elements , review ers can better focus the selection process . Choose Selection Criteria That Fit the Clinical Question Consider a systematic review of the effectiveness of a drug treatment ( for example , a proton-pump inhibitor ) for patients with a particular disorder ( such as esophageal reflux ) . Review ers need to decide whether to include studies of patients with any symptoms of reflux , only those with classic symptoms , or only those in whom definitive diagnostic tests have confirmed the presence of reflux . In addition , review ers might choose to include studies of patients with different comorbid conditions ; patients from different demographic or geographic or cultural background s ; or patients from different health systems , such as inpatient or community population s. Similarly , review ers should use selection criteria that reflect the main and comparison interventions of interest . In our esophageal reflux example , review ers would need to decide whether to include studies of a particular drug or studies of all agents in that drug 's class and whether to include studies of any dose and regimen or only studies with a specific regimen . For the comparison interventions , the review ers would decide whether to include studies that compare the experimental drug with alternate treatments ( such as antacids or histamine-2-receptor antagonists ) , with placebo , or with both . For the clinical outcomes , review ers have analogous tasks of defining the outcomes and translating them into criteria . In our example , the review ers would start by listing each clinical outcome ( for example , whether the outcome was endoscopic or clinical and whether it focused on cure or persistence ) and then decide whether to include studies that reported any outcome or only those with certain clinical ly important outcomes ( such as improvement in symptoms at 1 year ) . After thoroughly considering each element of the review question , review ers compile a set of explicit selection criteria . When these criteria are not explicit , the results of the review are more prone to error [ 5 , 6 ] . Reporting the selection criteria used in a review is extremely important to readers because the criteria indicate the relevance of the review to the readers ' clinical practice . Specify the Types of Study Design To Be Included After creating selection criteria that appropriately reflect the review question , review ers should consider which study design s to include . Ideally , review ers choose study design s that are most likely to produce valid results . For example , to answer questions about therapy or harm , review ers may want to include r and omized trials [ 7 ] because they provide more accurate estimates of benefit or harm than do cohort studies , casecontrol studies , and case series [ 8 ] . In reality , however , r and omized trials may not be conducted to address questions of harm [ 9 ] . Therefore , review ers need to consider which study design s are likely to be available to answer their question ; this information may necessitate modification of originally conceptualized selection criteria to incorporate observational ( nonexperimental ) studies . Specify Criteria Related to Type and Form of Publication Review ers also need to consider issues related to type and form of publication . Ideally , all of the relevant studies would be published as peer- review ed journal articles . However , some completed studies may be published only as abstract s , in non-peer- review ed form , or not at all . Review ers decide whether to include these incompletely reported studies when planning their literature search . By including all articles in various stages of publication and subjecting them to rigorous critical appraisal , review ers minimize the threat of publication bias ( the preferential reporting of studies with positive results ) [ 10 - 12 ] , which could generate misleading review s. Other studies may be reported more than once . To avoid over-representing duplicate studies in the review , investigators should plan to look for and exclude duplicate publications [ 13 ] . Finally , because studies may be published in different language s and because excluding studies published in different language s may bias the results of review s [ 14 , 15 ] , articles should be included , as appropriate , regardless of the language of publication ( translating as necessary ) . Limited time and re sources , however , may preclude such an approach . Construct and Pretest Selection Forms After deciding on selection criteria , review ers can prepare customized forms that contain checklists of the selection criteria ( Figure 1 ) . Using these forms can simplify the selection process , increase reliability , and provide a record of the judgments made about each study . After drafting form prototypes , review ers pretest these forms for clarity , ease of application , and reliability . To pretest the forms , two or more independent review ers typically apply them to a r and om sample of studies identified by the literature search . Review ers compare their results to identify sources of ambiguity and then revise the forms accordingly . If the revisions are substantial , this process may need to be repeated before the forms can be used . Figure 1 . Example of a form that might be developed for the selection of studies for a systematic review evaluating the efficacy of -blockers for secondary prevention of variceal bleeding .  Write a Detailed Protocol Having a selection protocol as part of a larger protocol for the entire review helps review ers in two ways . First , it provides a document that explicitly states the review question and the selection criteria , making the process accountable . Review ers can later return to the protocol for guidance in resolving disagreements about article selection . Second , the selection protocol identifies what work will be done , by whom , in what manner , when , and for what reason ; thus , it provides a mode of communication within the review team . When review ers have a very large sample of studies from which to select , they can simplify this task by review ing all of the titles , then the abstract s , and then the full articles , excluding studies that do not meet one or more selection criteria at each step . In doing so , review ers should record ( on the selection forms ) the reasons for exclusion . After review ers have selected studies for the systematic review , they will move to the next task of critical appraisal . This procedure also requires careful planning . Appraising Studies for Systematic Review s Review ers appraise the studies selected for review with three objectives in mind : 1 ) to underst and the validity of the studies , 2 ) to uncover reasons for differences among study results other than chance , and 3 ) to provide readers with sufficient information with which to judge for themselves the applicability of the systematic review to their clinical practice . To achieve these goals , review ers use the strategies outlined in Table 2 and Table 3 to carefully reexamine many important features of the primary studies . Table 3 . Planning Study Appraisal Examine Important Clinical Features Although the selection criteria for a systematic review define the population , interventions , and outcomes of interest , the appraisal process involves a detailed assessment of the patients ( for example , high , medium , or low risk ) , the study interventions ( for example , frequency , degree , and duration ) , and the outcome measurements ( for example , definitions and degree of surveillance ) Background Most patients in the secondary care sector consulting for low back pain ( LBP ) seem to have a more or less constant course of pain during the ensuing year . Fewer patients with LBP in the primary care sector report continual pain over a one-year period . However , not much is known about the long-term course of LBP in the general population . A systematic critical literature review was undertaken in order to study the natural course of LBP over time in the general population . Methods A search of articles was performed in Pubmed , Cinahl and Psychinfo using the search terms ‘ epidemiology ’ ; ‘ low back pain ’ or ‘ back pain ’ ; ‘ prospect i ve study ’ or ‘ longitudinal study ’ ; ‘ follow-up ’ , ‘ natural course ’ , ‘ course ’ or ‘ natural history ’ ; ‘ general population ’ or ‘ working population ’ . Inclusion criteria were that one of the objectives was to study the course of (L)BP in the adult population , that the period of follow-up was at least 3 months , and that there were three points of observation or more . The review was undertaken by two independent review ers using three checklists relating to description of studies , quality and outcomes . The course of LBP was established in relation to those who , at baseline , were reported not to have LBP or to have LBP . Would this course be stable , fluctuating , worsening , or improving over time ? A synthesis of results in relation to common patterns was presented in a table and interpreted in a narrative form . Results Eight articles were included . Articles were different on time span , the number of surveys , and the definition of LBP . In six of the seven relevant studies , for those with no LBP at baseline , relatively substantial stable subgroups of people who continued to be LBP free were identified . In six of the seven relevant studies , definite stable subgroups of continued LBP were noted and improvement ( becoming pain free ) was never reported to be a common finding . Conclusion The status of LBP in individuals of the general population appears to be relatively stable over time , perhaps particularly so for those without LBP at baseline Background Back pain represents a substantial burden globally , ranking first in a recent assessment among causes of years lived with disability . Though back pain is widely studied among working age adults , there are gaps with respect to basic descriptive epidemiology among seniors , especially in the United States . Our goal was to describe how pain , function and health-related quality of life vary by demographic and geographic factors among seniors presenting to primary care providers with new episodes of care for back pain . Methods We examined baseline data from the  Back pain Outcomes using Longitudinal Data ( BOLD ) registry , the largest inception cohort to date of seniors presenting to a primary care provider for back pain . The sample included 5,239 patients ≥ 65 years old with a new primary care visit for back pain at three integrated health systems ( Northern California Kaiser-Permanente , Henry Ford Health System [ Detroit ] , and Harvard Vanguard Medical Associates [ Boston ] ) . We examined differences in patient characteristics across healthcare sites and associations of patient sociodemographic and clinical characteristics with baseline patient-reported measures of pain , function , and health-related quality of life . Results Patients differed across sites in demographic and other characteristics . The Detroit site had more African-American patients ( 50 % ) compared with the other sites ( 7 - 8 % ) . The Boston site had more college graduates ( 68 % ) compared with Detroit ( 20 % ) . Female sex , lower educational status , African-American race , and older age were associated with worse functional disability as measured by the Rol and -Morris Disability Question naire . Except for age , these factors were also associated with worse pain . Conclusions Baseline pain and functional impairment varied substantially with a number of factors in the BOLD cohort . Healthcare site was an important factor . After controlling for healthcare site , lower education , female sex , African-American race , and older age were associated with worse physical disability and all of these factors except age were associated with worse pain . Trial registration Clinical Trials.gov NCT01776242 ; Registration date : June 13 , 2012 OBJECTIVE The purpose of the study was to compare the effects of thrust manipulation ( TM ) and non-TM ( NTM ) on a sample of older subjects with low back pain . METHODS This is a secondary data analysis of a r and omized control trial . Forty-nine subjects aged 55 to 88 years participated in the trial , who received either a TM or NTM on at least 2 occasions during the course of care , and were extracted from the larger data set . The treatment program included a st and ardized home exercise program for the first 2 sessions , which could be modified by the therapist after those 2 sessions . Numeric pain rating scale and Oswestry Disability Index ( ODI ) were the outcomes for this study . RESULTS Multivariate analysis revealed no significant between-group differences for treatment group ( P=.99 ) without group × time interaction ( P=.90 ) . Significant within-group changes were observed for both groups for ODI and numeric pain rating scale ( P<.001 ) ; the average self-report of recovery was 78.0 % ( SD , 19.8 % ) . Age stratification of the older subset revealed between-group differences in ODI change scores for the oldest subjects ( > 70 years ) compared with 60 to 69 years ( P=.02 ) . CONCLUSIONS This study showed that outcomes for both TM and NTM improved in older adults with low back pain OBJECTIVES To investigate the effects of Swedish massage with aromatic ginger oil ( SMGO ) on  chronic low back pain and disability in older adults compared with traditional Thai massage ( TTM ) . DESIGN R and omized controlled trial . SETTING Massage clinic in Ratchaburi province , Thail and . 
    Output:
    
The included studies provided moderate evidence supporting the use of manual therapy to reduce pain levels and alleviate disability .
Conclusions A limited number of studies have investigated the effectiveness and safety of manual therapy in the management of older people with chronic LBP .