***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 system has been constructed to evaluate the design , implementation , and analysis of  r and omized control trials ( RCT ) . The degree of quadruple blinding ( the r and omization process , the physicians and patients as to therapy , and the physicians as to ongoing results ) is considered to be the most important aspect of any trial . The analytic techniques are scored with the same emphasis as is placed on the control of bias in the planning and implementation of the studies . Description of the patient and treatment material s and the measurement of various controls of quality have less weight . An index of quality of a RCT is proposed with its pros and cons . If published papers were to approximate these principles , there would be a marked improvement in the quality of r and omized control trials . Finally , a reasonable st and ard design and conduct of trials will facilitate the interpretation of those with conflicting results and help in making valid combinations of undersized trials 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 ) In a r and omized , prospect i ve , multicenter trial , 227 children ranging in age from 3 to 17 years who had tonsillopharyngitis and a throat culture positive for group A beta-hemolytic streptococci ( GABHS ) were treated with erythromycin estolate ( 40 mg/kg/d in two divided doses for five days ) or penicillin V ( 30 mg/kg/d in three divided doses for ten days ) . Clinical signs and symptoms of tonsillopharyngitis were recorded , and throat cultures were obtained before treatment as well as one to three days and six weeks after treatment . Clinical success ( cure and improvement ) was observed on days 6 to 8 in 100 of 102 ( 98 % ) assessable children treated with erythromycin estolate and on days 11 to 13 in 97 of 99 ( 98 % ) assessable children treated with penicillin V. Of all patients showing clinical success , 11 were rated as improved , all of whom were treated with erythromycin estolate . There was a trend towards increased use of analgesic treatment in the erythromycin estolate group ( 41 % vs 33 % ) . On completion of treatment , the rate of eradication of GABHS was 83.3 % in the erythromycin estolate group compared with 87.9 % in the penicillin V group . The difference is not significant but does not take into account patients excluded because of erythromycin resistance ( 3.7 % ) . Clinical recurrence was observed in 11 ( 10.8 % ) patients treated with erythromycin estolate and in 6 ( 6.1 % ) patients treated with penicillin V ( non-significant difference ) . Compliance in the erythromycin estolate group was statistically superior to that in the penicillin V group . The incidence and nature of adverse events were similar in both treatment groups Objective . To compare a 3-day azithromycin vs. a 10-day penicillin V regimen for treatment of acute group A streptococcal ( GAS ) pharyngitis in children and to determine whether viral infection and /or pharyngeal GAS carriage in patients and adult contacts affect clinical and bacteriologic efficacy . Methods . This multicenter , r and omized , comparative , open label study compared 3-day , once daily 10 mg/kg azithromycin oral suspension with a 10-day regimen of 100 000 IU/kg/day penicillin V oral suspension in three divided doses in children with acute GAS pharyngitis .  Clinical and bacteriologic efficacy and tolerability of the antibiotics were evaluated . Recurrence of symptoms and infection was monitored for 6 months . Results . In total , 292 children ( age range , 2 to 12 years ) received at least one dose of study medication . Clinical success ( cure/improvement ) with either antibiotic was similar at the end of therapy ( Day 14 ; azithromycin , 95 % ; penicillin V , 97 % ) and at Day 28 ( azithromycin , 94 % ; penicillin V , 95 % ) . Bacteriologic eradication was significantly less with azithromycin than with penicillin V at Day 14 ( azithromycin , 38 % ; penicillin V , 81%;P < 0.001 ) and at Day 28 ( azithromycin , 31 % ; penicillin V , 68%;P < 0.001 ) . There was no associated increase in GAS-related sequelae . The lower incidence of bacteriologic eradication with azithromycin was not the result of possible concomitant viral infections in the patients , GAS carriage in one parent/guardian or any reduced susceptibility in pretreatment GAS isolates . Both antibiotics were equally well-tolerated . Conclusions . Treatment with 3-day , once daily 10 mg/kg azithromycin for GAS pharyngitis is associated with similar high levels of clinical efficacy , but lower levels of bacteriologic eradication , than with 10-day 100 000 IU/kg/day penicillin OBJECTIVE To estimate the incidence and risk factors of group A streptococcus ( GAS ) sore throat among school-aged children living in a periurban slum area of Ch and igarh , North India . METHODS A total of 536 children aged 5 - 15 years from 261 families identified by a 
    Output:
    
Three to six days of oral antibiotics had comparable efficacy compared to the st and ard duration 10-day course of oral penicillin in treating children with acute GABHS pharyngitis .
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