***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: OBJECTIVE To determine whether presenting test performance characteristics influences clinical management . DESIGN Two question naire-based , r and omized controlled trials . SETTING Mailed surveys with 2 clinical vignettes . PARTICIPANTS R and omly selected US pediatricians ( N=1502 ) . INTERVENTION Vignette-specific , r and omly assigned test information : no additional information ( control ) , test characteristics ( TC ) , or TC defined . In the pertussis vignette , the TC group received the direct fluorescent antibody test 's sensitivity and specificity , and the TC defined group received the same information with definitions . In the urinalysis vignette , the TC group received the false-positive rate of persistent microhematuria in predicting renal disease , and the TC defined group received a definition of this information . MAIN OUTCOME MEASURES In the pertussis vignette , diagnostic test choice and management of erythromycin therapy and hospital discharge plans . In the urinalysis vignette , serum laboratory testing and nephrology referral plans . RESULTS Six hundred fifty-three participants ( 49.5 % of those eligible ) returned completed surveys . In the pertussis vignette , significantly more of the TC ( 73 % ) and TC defined ( 71 % ) groups ordered the best-performing test than did controls ( 21 % ) ( P<.001 for both comparisons ) . Receiving test characteristics did not significantly affect erythromycin therapy or hospital discharge plans ( P > or=.40 ) . In the urinalysis vignette , the TC defined group referred to nephrology ( 30 % ) and checked laboratory tests ( 88 % ) significantly more often than did controls ( 19 % , P=.01 ; 78 % , P=.01 , respectively ) , but the TC and control groups ' testing and referral plans did not differ significantly ( 22 % vs 19 % , P=.36 ; 75 % vs 78 % , P=.48 , respectively ) . CONCLUSION Providing test performance characteristics influenced certain clinical decisions , sometimes in unexpected ways Abstract Objective : To assess the extent to which different forms of summarising diagnostic test information influence general practitioners ' ability to estimate disease probabilities . Design : Controlled question naire study . Setting : Three Swiss conferences in continuous medical education . Participants : 263 general practitioners . Intervention : Question naire with multiple choice questions about terms of test accuracy and a clinical vignette with the results of a diagnostic test described in three different ways ( test result only , test result plus test sensitivity and specificity , test result plus the positive likelihood ratio presented in plain language ) . Main outcome measures : Doctors ' knowledge and application of terms of test accuracy and estimation of disease probability in the clinical vignette . Results : The correct definitions for sensitivity and predictive value were chosen by 76 % and 61 % of the doctors respectively , but only 22 % chose the correct answer for the post-test probability of a positive screening test . In the clinical vignette doctors given the test result only overestimated its diagnostic value ( median attributed likelihood ratio (aLR)=9.0 , against 2.54 reported in the literature ) . Providing the scan 's sensitivity and specificity reduced the overestimation ( median aLR=6.0 ) but to a lesser extent than simple wording of the likelihood ratio ( median aLR=3.0 ) . Conclusion : Most general practitioners recognised the correct definitions for sensitivity and positive predictive value but did not apply them correctly . Conveying test accuracy information in simple , non-technical language improved their ability to estimate disease probabilities accurately . What is already known on this topic Many doctors confuse the sensitivity of clinical tests and their positive predictive value Doctors tend to overestimate information derived from such tests and underestimate information from a patient 's clinical history Most primary research on diagnostic accuracy is reported using sensitivity and specificity or likelihood ratios What this study adds In a cohort of experienced Swiss general practitioners most were unable to interpret correctly numerical information on the diagnostic accuracy of a screening test When presented with a positive result alone they grossly overestimated its value Adding information on the test 's sensitivity and specificity moderated these overestimates , and expressing the same numerical information as a positive likelihood ratio in simple , non-technical language brought the estimates still closer to their true Abstract Objective To investigate the accuracy of interpretation of  probabilistic screening information  by different stakeholder groups and whether presentation as frequencies improves accuracy . Design Between participants experimental design ; participants responded to screening information embedded in a scenario . Setting Regional maternity service and national conferences and training days . Participants 43 pregnant women attending their first antenatal appointment in a regional maternity service ; 40 companions accompanying the women to their appointments ; 42 midwives ; 41 obstetricians . Participation rates were 56 % , 48 % , 89 % , and 71 % respectively . Measures Participants estimated the probability that a positive screening test result meant that a baby actually had Down 's syndrome on the basis of all the relevant information , which was presented in a scenario . They were r and omly assigned to scenarios that presented the information in percentage ( n = 86 ) or frequency ( n = 83 ) format . They also gave basic demographic information and rated their confidence in their estimate . Results Most responses ( 86 % ) were incorrect . Obstetricians gave significantly more correct answers ( although still only 43 % ) than either midwives ( 0 % ) or pregnant women ( 9 % ) . Overall , the proportion of correct answers was higher for presentation as frequencies ( 24 % ) than for presentation as percentages ( 6 % ) , but further analysis showed that this difference occurred only in responses from obstetricians . Many health professionals were confident in their incorrect responses . Conclusions Most stakeholders in pregnancy screening draw incorrect inferences from probabilistic information , and health professionals need to be aware of the difficulties that both they and their patients have with such information . Moreover , they should be aware that different people make different mistakes and that ways of conveying information that help some people will not help others BACKGROUND Underst and ing pre-test probability and baseline risks helps to interpret the results of diagnostic tests and the benefits of treatment , but how good is the underst and ing of these concepts ? OBJECTIVES Our aim was to assess the ability of GPs and consultant physicians to make accurate estimates and underst and the application of pre-test probability and baseline risk for two common clinical conditions . METHODS A two-stage question naire survey based on case scenarios of patients with angina and congestive heart failure was carried out of 202 physicians , r and omly selected from the members of the Royal College of Physicians in the NW of Engl and , 205 GPs r and omly chosen from the practice list of the NW Health Authorities and 128 MRCGP examiners attending an examiners meeting . A total of 115 , 106 and 81 members of these groups , respectively , responded to the first stage , and 44 , 46 and 64 to the second . The main outcome measures were the stated likelihood of true ischaemic heart disease ( IHD ) being present and the predicted 1-year mortality ; the impact of changing prevalence and baseline risk on these results ; and interpretation of different methods of risk presentation . RESULTS Estimates of pre-test probability of IHD being present ranged from 5 to 100 % and of baseline risk of 1-year mortality from 0 to 86 % . More GP examiners and consultant physicians understood the impact of increasing age on the test result than did the r and om sample of GPs . A majority of each group correctly said that increasing age would reduce the number needed to treat ( NNT ) . Presentation of benefit as relative risk reduction was a greater stimulus to starting treatment than the NNT or measures of population impact . CONCLUSION Clinicians should collect data to allow a better knowledge of the likelihood of disease and of baseline risk in their patient population s. Methods to increase the underst and ing of the influence of pre-test probability on diagnostic test results and of how to quantify and demonstrate the impact of the benefit of interventions should be explored Abstract Objectives : To determine how medical students apply research evidence that varies in validity of methods and importance of results to a clinical decision . Design : Students examined a st and ardised patient with a whiplash injury , decided whether to order a cervical spine radiograph , and rated their confidence in their decision . They then read one of four r and omly assigned variants of a structured abstract from a study of a decision rule that argued against such a procedure in this patient . Variants factorially combined two levels of validity of methods ( prospect i ve cohort or chart review ) with two levels of importance of results ( high sensitivity or high specificity rule ) . After reading the abstract , students repeated their choice and rated their confidence . Setting : Academic medical centre in the United States . Participants : 164 graduating medical students . Main outcome measures : Proportion of students in each group whose beliefs shifted or stayed the same . Results : When abstract s were of low importance students were more likely to shift their beliefs in favour of radiography  , which was not supported by the evidence ( odds ratio 3.42 , 95 % confidence interval 1.10 to 10.66 ) . Neither method ological validity nor the interaction between validity and importance influenced decision shift . Few students acquired all necessary clinical data from the patient . Conclusions : Although the students could apply concepts of diagnostic testing , greater focus is needed on appraisal of validity and application of evidence to a particular patient . What is already known on this topic Evidence based medicine is increasingly emphasised and taught in medical schools Few studies have assessed the ability of physicians to apply literature findings to clinical decisions What this paper adds In making decisions about ordering investigations during a st and ardised patient exam students were sensitive to the importance of results This effect was not moderated by validity of the study that produced the results or whether the students had collected enough information to apply the Context There are several ways to present information about the accuracy of diagnostic tests . Contribution In this vignette-based study , 183 physicians read 6 scenarios that included patients ' presenting symptoms , risk profiles , and test results . Physicians were r and omly assigned to view information about test accuracy as sensitivity and specificity , a likelihood ratio , or an inexact graphic of the likelihood ratio . In general , the groups estimated similar post-test probabilities of disease regardless of how diagnostic accuracy was presented . Implication s This preliminary work suggests some physicians may interpret sensitivity and specificity and likelihood ratio information in a similar manner . The Editors Diagnostic tests are used to reduce uncertainty about the presence or absence of an illness . The informativeness of a diagnostic test , usually expressed as its sensitivity and specificity or as a likelihood ratio , determines how much the illness probability changes from the pretest to the post-test situation . The change in illness probability can be calculated using the Bayes theorem , which combines the illness probability before testing with the information derived from the test ( 1 ) . Few physicians use this formal approach to weigh the informativeness of diagnostic test results ( 2 ) and , perhaps as a result , make mistakes when asked to use it ( 3 , 4 ) . Many investigators advocate the use of likelihood ratios ( 5 - 8 ) . However , the effect of different presentation formats for diagnostic accuracy on post-test probability estimates has not been rigorously tested . We conducted a r and omized study to see if physicians ' estimates about illness probability more closely reflect estimates determined by the Bayes theorem when diagnostic information is presented as sensitivity and specificity estimates , a likelihood ratio , or an inexact numerical graphic . Methods We r and omly assigned experienced specialists in family and internal medicine attending a continuing medical education conference to complete 1 of 3 self-administered question naires that presented vignettes representative of scenarios commonly encountered early in the diagnostic work-up . The vignettes differed only in how diagnostic test accuracy was presented . The question naires were sealed within 576 envelopes that had been r and omized in 32 blocks of 18 to avoid order effects ( 6 different vignette orders for each of the 3 test accuracy presentation formats ) . We distributed the envelopes before participants entered the lecture hall so that we could not predict which participant received which envelope , thus concealing the r and omization . The moderator of the lecture ( which was unrelated to material presented in the vignettes ) advised those present to complete the question naire during small breaks or at the end of the lecture . We collected 183 question naires 15 minutes after the lecture and excluded 5 question naires that were sent to us later . The question naires asked participants to assess 6 clinical patient profiles and to estimate the probability of illness , specifying a percentage between 0 % and 100 % , for each scenario . With the exception of the chronic obstructive pulmonary disease vignette , all patient vignettes consisted of a description of presenting symptoms , additional clinical facts , and a risk profile ( Appendix Table ) . In the chronic obstructive pulmonary disease vignette , no presenting symptom but only the risk profile was given . For each vignette , we then gave the result of a diagnostic test commonly used in clinical practice and the test 's accuracy derived from the literature , presented as sensitivities and specificities ( group 1 ) , as a positive or negative likelihood ratio ( group 2 ) , or as an inexact numerical graphical format ( group 3 ) . Using the test result and its diagnostic accuracy , participants were then invited to estimate the post-test probability . As shown in the Appendix Table , we varied the informativeness of the diagnostic tests for both negative and positive results by presenting examples of weak ( vignettes 1 and 4 ) , intermediate ( vignettes 2 and 5 ) , and strong ( vignettes 3 and 6 ) test accuracies . Sensitivities and specificities were given as percentages to group 1 . In group 2 , the positive or negative likelihood ratios were presented as a numerical value and described in nontechnical language . For example , the description of the  d-dimer test  's positive likelihood ratio of 1.7 in patients with high probability of pulmonary embolism ( 9 ) was additionally described as in patients with pulmonary embolism , a positive test result is found almost twice as often as in patients without pulmonary embolism . For group 3 , we depicted an inexact numerical presentation with a simple graphic of 5 circles ( ) . We darkened an increasing number of circles to correspond with increasing positive likelihood ratios or 
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Results Participants unfamiliar with the design and methodology of DTARs found the review s largely inaccessible and experienced a range of difficulties stemming mainly from the mismatch between background knowledge and level of explanation provided in the text .
Experience with systematic review s of interventions did not guarantee better underst and ing and , in some cases , led to confusion and misinterpretation .
These difficulties were further exacerbated by poor layout and presentation , which affected even those with relatively good knowledge of DTARs and had a negative impact not only on their underst and ing of the review s but also on their motivation to engage with the text .
Comparison between the readings of the three review s showed that more accessible presentation , such as presenting the results as natural frequencies , significantly increased participants ’ underst and ing .
Conclusions The study demonstrates that authors and editors should pay more attention to the presentation as well as the content of Cochrane DTARs , especially if the reports are aim ed at readers with various levels of background knowledge and experience .
It also raises the question as to the anticipated target audience of the reports and suggests that different groups of healthcare decision-makers may require different modes of presentation