***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: PURPOSE This in vitro study was performed to correlate the presence of discoloration on occlusal surfaces with its histological depth and assess its influence on Diagnodent measurements in a group of permanent and primary teeth . METHODS Ninty-five primary and 95 permanent third molars were r and omly selected from a pool of macroscopically intact teeth . One site of the fissure on each occlusal surface was selected and categorized according to its discoloration . Each site was measured 3 times with Diagnodent . The teeth were prepared histologically and evaluated according to their caries extent under a microscope ( final magnification x 12.8 ) . RESULTS In the group of permanent teeth with dark brown or black discoloration ( N=23 ) , 13 % showed dentinal caries , 57 % were sound or had an initial enamel lesion , and 30 % had a deep enamel lesion . In the group of primary teeth with dark brown and black discoloration ( N=19 ) , 42 % presented dentinal caries , 42 % showed deep enamel caries , and 16 % had an initial enamel lesion . The difference between permanent and primary teeth was statistically significant ( P<.05 ) . Discolored fissures showed higher Diagnodent values than nondiscolored or opaque fissures in both groups ( independent of their caries status ) . CONCLUSIONS The presence of brown or dark spots on fissures were not useful for the prediction of dentinal caries for permanent teeth . In primary teeth , however , a higher correlation between fissure discoloration and dentinal lesions was found . Diagnodent tends to overscore discolored surfaces Diagnosis is a critical component of health care , and clinicians , policymakers , and patients routinely face a range of questions regarding diagnostic tests . They want to know whether testing improves outcome ; what test to use , purchase , or recommend in practice guidelines ; and how to interpret test results . Well- design ed  diagnostic test accuracy studies can help in making these decisions , provided that they transparently and fully report their participants , tests , methods , and results as facilitated , for example , by the STARD ( St and ards for Reporting of Diagnostic Accuracy ) statement ( 1 ) . That 25-item checklist was published in many journals and is now adopted by more than 200 scientific journals worldwide . As in other areas of science , systematic review s and meta- analysis of accuracy studies can be used to obtain more precise estimates when small studies addressing the same test and patients in the same setting are available . Review s can also be useful to establish whether and how scientific findings vary by particular subgroups , and may provide summary estimates with a stronger generalizability than estimates from a single study . Systematic review s may help identify the risk for bias that may be present in the original studies and can be used to address questions that were not directly considered in the primary studies , such as comparisons between tests . The Cochrane Collaboration is the largest international organization preparing , maintaining , and promoting systematic review s to help people make well-informed decisions about health care ( 2 ) . The Collaboration decided in 2003 to make preparations for including systematic review s of diagnostic test accuracy in their Cochrane Data base of Systematic Review s. To enable this , a working group ( Appendix ) . was formed to develop methodology , software , and a h and book The first diagnostic test accuracy review was published in the Cochrane Data base in October 2008 . In this paper , we review recent method ological developments concerning problem formulation , location of literature , quality assessment , and meta- analysis of diagnostic accuracy studies by using our experience from the work on the Cochrane H and book . The information presented here is based on the recent literature and up date s previously published guidelines by Irwig and colleagues ( 3 ) . Definition of the Objectives of the Review Diagnostic test accuracy refers to the ability of a test to distinguish between patients with disease ( or more generally , a specified target condition ) and those without . In a study of test accuracy , the results of the test under evaluation , the index test , are compared with those of the reference st and ard determined in the same patients . The reference st and ard is an agreed-on and accurate method for identifying patients who have the target condition . Test results are typically categorized as positive or negative for the target condition . By using such binary test outcomes , the accuracy is most often expressed as the test 's sensitivity ( the proportion of patients with positive results on the reference st and ard that are also positive on the index test ) and specificity ( the proportion of patients with negative results on the reference st and ard that are also negative on the index test ) . Other measures have been proposed and are in use ( 46 ) . It has long been recognized that test accuracy is not a fixed property of a test . It can vary between patient subgroups , with their spectrum of disease , with the clinical setting , or with the test interpreters and may depend on the results of previous testing . For this reason , inclusion of these elements in the study question is essential . In order to make a policy decision to promote use of a new index test , evidence is required that using the new test increases test accuracy over other testing options , including current practice , or that the new test has equivalent accuracy but offers other advantages ( 79 ) . As with the evaluation of interventions , systematic review s need to include comparative analyses between alternative testing strategies and should not focus solely on evaluating the performance of a test in isolation . In relation to the existing situation , 3 possible roles for a new test can be defined : replacement , triage , and add-on ( 7 ) . If a new test is to replace an existing test , then comparing the accuracy of both tests on the same population and with the same reference st and ard provides the most direct evidence . In triage , the new test is used before the existing test or testing pathway , and only patients with a particular result on the triage test continue the testing pathway . When a test is needed to rule out disease in patients who then need no further testing , a test that gives a minimal proportion of falsenegative results and thus a relatively high sensitivity should be used . Triage tests may be less accurate than existing ones , but they have other advantages , such as simplicity or low cost . A third possible role of a new test is add-on . The new test is then positioned after the existing testing pathway to identify false-positive or false-negative results after the existing pathway . The review should provide data to assess the incremental change in accuracy made by adding the new test . An example of a replacement question can be found in a systematic review of the diagnostic accuracy of urinary markers for primary bladder cancer ( 10 ) . Clinicians may use cytology to triage patients before they undergo invasive cystoscopy  , the reference st and ard for bladder cancer . Because cytology combines high specificity with low sensitivity ( 11 ) , the goal of the review was to identify a tumor marker with sufficient accuracy to either replace cytology or be used in addition to cytology . For a marker to replace cytology , it has to achieve equally high specificity with improved sensitivity . New markers that are sensitive but not specific may have roles as adjuncts to conventional testing . The review included studies in which the test under evaluation ( several different tumor markers and cytology ) was evaluated against cystoscopy or histopathology . Included studies compared 1 or more of the markers , cytology only , or a combination of markers and cytology . Although information on accuracy can help clinicians make decisions about tests , good diagnostic accuracy is a desirable but not sufficient condition for the effectiveness of a test ( 8) . To demonstrate that using a new test does more good than harm to patients tested , r and omized trials of test- and -treatment strategies and review s of such trials may be necessary . However , with the possible exception of screening , in most cases , such r and omized trials are not available and systematic review s of test accuracy may provide the most useful evidence available to guide clinical and health policy decision making and use as input for decision and cost-effectiveness analysis ( 12 ) . Identification and Selection of Studies Identifying test accuracy studies is more difficult than search ing for r and omized trials ( 13 ) . There is not a clear , unequivocal keyword or indexing term for an accuracy study in literature data bases comparable with the term r and omized , controlled trial . The Medical Subject Heading sensitivity and specificity may look suitable but is inconsistently applied in most electronic bibliographic data bases . Furthermore , data on diagnostic test accuracy may be hidden in studies that did not have test accuracy estimation as their primary objective . This complicates the efficient identification of diagnostic test accuracy studies in electronic data bases , such as MEDLINE . Until indexing systems properly code studies of test accuracy , search ing for them will remain challenging and may require additional manual search es , such as screening reference lists . In the development of a comprehensive search strategy , review authors can use search strings that refer to the test(s ) under evaluation , the target condition , and the patient description or a subset of these . For tests with a clear name that are used for a single purpose , search ing for publications in which those tests are mentioned may suffice . For other review s , adding the patient description may be necessary , although this is also often poorly indexed . A search strategy in MEDLINE should contain both Medical Subject Headings and free text words . A search strategy for articles about tests for bladder cancer , for example , should include as many synonyms for bladder cancer as possible in the search strategy , including neoplasm , carcinoma , transitional cell , and hematuria . Several method ological electronic search filters for diagnostic test accuracy studies have been developed , each attempting to restrict the search to articles that are most likely to be test accuracy studies ( 1316 ) . These filters rely on indexing terms for research methodology and text words used in reporting results , but they often miss relevant studies and are unlikely to decrease the number of articles one needs to screen . Therefore , they are not recommended for systematic review s ( 17 , 18 ) . The incremental value of search ing in language s other than English and in the gray literature has not yet been fully investigated . In systematic review s of intervention studies , publication bias is an important and well-studied form of bias in which the decision to report and publish studies is linked to their findings . For clinical trials , the magnitude and determinants of publication bias have been identified by tracing the publication history of cohorts of trials review ed by ethics committees and research boards ( 19 ) . A consistent observation has been that studies with significant results are more likely to be published than studies with nonsignificant findings ( 19 ) . Investigating publication bias for diagnostic tests is problematic , because many studies are done without ethical review or study registration ; therefore , identification of cohorts of studies from registration to final publication status OBJECTIVE The objective of this study was to assess trends in dental caries prevalence and severity in 1- to 4 year-old children living in Diadema , Brazil , over a 11-year period , from 1997 to 2008 . METHODS In 2008 an epidemiological oral health survey was carried out and the results on caries were compared with five cross-sectional studies carried out using the same methods and criteria in 1997 , 1999 , 2002 , 2004 , and 2006 in the same city . In all surveys , children were r and omly selected from those attending a National Day of Children 's Vaccination . Calibrated dentists carried out the clinical examination using WHO criteria . Caries trends were assessed by time-lag analysis . In total , 5348 children were examined in the six surveys over the 11-year period . RESULTS Time-lag analysis showed a marked and statistically significant decline in the prevalence ( chi(2 ) for trends : P < 0.001 ) and severity ( Kruskal-Wallis : P < 0.001 ) of dental caries between 1997 and 2008 . CONCLUSION In conclusion , the last cohort of preschool children in Diadema had much better dental caries status than those in 1997 The aim of this in vitro study was to investigate the intra- and interdevice reproducibility of the DIAGNOdent 2095 ( DD2095 ) and the new DIAGNOdent Pen ( DDPen ) on non-cavitated occlusal caries sites . Altogether , 241 sites on 90 molars were inspected twice with both devices and by four examiners . The intra/interdevice reproducibilities were assessed by means of the intraclass correlation coefficient ( ICC ) as well as by the range of the 95 % limits of agreement of Bl and & Altman . Additionally , a linear mixed-effects model was fitted with fixed effects for the visual scores and the devices used and r and om effects for occlusal sites and examiners within each measurement site . In result , the following values were determined for the intradevice reproducibility : DD2095 : ICC 0.89 , range 42.3 ; and DDPen : ICC 0.88 , range 49.3 . The interdevice reproducibility was found to be in the same order of magnitude ( ICC 0.82 , range 53.7 ) . The comparison between both devices indicated significantly lower mean values for the DDPen . The estimates of the linear model show that there is a high variation between the sites that can not be explained by the fixed effects . In conclusion , both devices showed an imperfect reproducibility , which indicate the usage as adjunct tool only in clinical practice Children and adolescents must be examined often for occlusal caries . Diagnosis of fissure caries is difficult especially when the tooth surface appears seemingly intact . It has been shown that using traditional clinical methods , as little as 20 % of teeth with fissure caries under intact surfaces were correctly recognised as such . Therefore , new methods for increasing the accuracy of diagnosis have been sought for years . Recently , a new device , based on fluorescence measurements , was introduced . The purpose of this study was to test the device under in vivo conditions in order to provide recommendations for its use in the dental office . Seven general dental practitioners examined a total of 332 occlusal surfaces in 240 patients .  Caries extent was determined for each site after operative intervention ( = ' gold st and ard ' ) . Clinical inspection and analysis of bitewing radiographs exhibited statistically significant lower sensitivities ( 31 - 63 % ) than did the DIAGNOdent device ( sensitivity > or = 92 % ) . It is recommended that the laser device is used in the decision-making process in relation to the diagnosis of occlusal caries as a second opinion in cases of doubt after visual inspection 
    Output:
    
In general , the analysis demonstrated that the fluorescence-based method tend to have similar accuracy for all types of teeth , dental surfaces or setting s. There was a trend of better performance of fluorescence methods in detecting more advanced caries lesions .
CONCLUSIONS Fluorescence-based devices have similar overall performance ; however , better accuracy in detecting more advanced caries lesions has been observed