***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: Background Supporting 21st century health care and the practice of evidence -based medicine ( EBM ) requires ubiquitous access to clinical information and to knowledge-based re sources to answer clinical questions . Many questions go unanswered , however , due to lack of skills in formulating questions , crafting effective search strategies , and accessing data bases to identify best levels of evidence . Methods This r and omized trial was design ed as a pilot study to measure the relevancy of search results using three different interfaces for the PubMed search system . Two of the search interfaces utilized a specific framework called PICO , which was design ed to focus clinical questions and to prompt for publication type or type of question asked . The third interface was the st and ard PubMed interface readily available on the Web . Study subjects were recruited from interns and residents on an inpatient general medicine rotation at an academic medical center in the US . Thirty-one subjects were r and omized to one of the three interfaces , given 3 clinical questions , and asked to search PubMed for a set of relevant articles that would provide an answer for each question . The success of the search results was determined by a precision score , which compared the number of relevant or gold st and ard articles retrieved in a result set to the total number of articles retrieved in that set . Results Participants using the PICO templates ( Protocol A or Protocol B ) had higher precision scores for each question than the participants who used Protocol C , the st and ard PubMed Web interface . ( Question 1 : A = 35 % , B = 28 % , C = 20 % ; Question 2 : A = 5 % , B = 6 % , C = 4 % ; Question 3 : A = 1 % , B = 0 % , C = 0 % ) 95 % confidence intervals were calculated for the precision for each question using a lower boundary of zero . However , the 95 % confidence limits were overlapping , suggesting no statistical difference between the groups . Conclusion Due to the small number of search es for each arm , this pilot study could not demonstrate a statistically significant difference between the search protocol s. However there was a trend towards higher precision that needs to be investigated in a larger study to determine if PICO can improve the relevancy of search results BACKGROUND AND STUDY AIMS Endoscopic ultrasound ( EUS ) in combination with fine-needle aspiration biopsy ( FNA ) is a highly accurate method for the preoperative staging of esophageal cancer . Its impact on medical decision-making and the cost of care is unknown . This prospect i ve case series was undertaken in order to determine the impact of EUS in combination with FNA on patients ' choice of therapy and on the cost of care . PATIENTS AND METHODS Sixty consecutive patients with esophageal cancer , referred for preoperative EUS staging in a large tertiary-care academic medical center , were enrolled . The accuracy of EUS , the impact of EUS-based staging on the patients ' choice of therapy , and costs were studied . RESULTS The accuracy rates for EUS combined with FNA in tumor and lymph-node staging were 83 % and 89 % , respectively . Twenty-five patients ( 42 % ) had EUS stage I and II and were c and i date s for curative surgery . Twenty-eight patients ( 47 % ) had stage III , and seven ( 12 % ) had stage IV . All patients with stage I had surgery , while all patients with stage IV had medical therapy . The majority ( 62 % ) of patients with stage II had surgery , while only a minority ( 25 % ) of patients with stage III had surgery . Thirty-six patients ( 60 % ) underwent medical therapy . Patients ' medical decisions in favor of surgical or medical therapy correlated strongly with the results of their EUS staging ( P = 0.005 ) , but not with age , sex , or referring physicians ( surgeons vs. nonsurgeons ) . EUS-guided therapy potentially decreased the cost of care by $ 740 424 ( $ 12 340/patient ) by reducing the number of thoracotomies . CONCLUSIONS Patients ' decisions regarding therapy correlated with their overall tumor staging , suggesting that the information provided by EUS played a significant role in patients ' decision-making . The use of EUS in combination with FNA reduces the cost of managing patients with esophageal cancer We compared the results of endoscopic sonography and CT in the preoperative staging of 46 patients with esophageal carcinoma studied prospect ively . All patients had surgery and 44 had pathologic examination of the mediastinal and celiac lymph nodes . The results of CT and endoscopic sonography were compared with surgical and pathologic findings . A total of 51 tumors were found in 46 patients . Sonographic estimation of tumor extension through the different layers of the esophagus was correct in 37 ( 73 % ) of all 51 tumors and in 22 ( 85 % ) of the 26 tumors in which the examination was complete . The echoendoscope ( 13-mm diameter ) could not pass through the tumor in 23 cases ( 50 % ) . Infiltration to adjacent organs was found in 15 cases at surgery . In four of these 15 , the extension was detected by CT ; in seven of the 15 cases , it was detected by sonography .  False-negative determination of tumor extension occurred with endoscopic sonography in patients with stenotic tumor . There were no false-positive results with either CT or endoscopic sonography . For detection of mediastinal lymph-node involvement , the sensitivity of CT was 48 % . The sensitivity of sonography  was 50 % if metastatic nodes unexplored by sonography were included , or 84 % if only cases in which stenosis was passed were considered . Statistical comparison revealed that sonography was superior to CT for the detection of metastases to lymph nodes .  CT and endoscopic sonography provide complementary information . When the echoendoscope can be maneuvered past the tumor , sonography can be used accurately to define extension through the layers of the esophagus , extension to the adjacent organs , and involvement of the lymph nodes . When the tumor can not be passed by the echoendoscope , CT is superior to sonography for detection of mediastinal extension Introduction Improvement in esophageal cancer staging is needed . Positron emission tomography ( PET ) , computed tomography ( CT ) , and endoscopic ultrasound ( EUS ) in the staging of esophageal carcinoma were compared . Methods PET , CT , and EUS were performed and interpreted prospect ively in 75 patients with newly diagnosed esophageal cancer . Either tissue confirmation or fine needle aspiration ( FNA ) was used as the gold st and ard of disease . Sensitivity and specificity for tumor , nodal , and metastatic ( TNM ) disease for each test were determined . TNM categorizations from each test were used to assign patients to subgroups corresponding to the three treatment plans that patients could theoretically receive , and these were then compared . Results Local tumor staging ( T ) was done correctly by CT and PET in 42 % and by EUS in 71 % of patients ( P value > 0.14 ) . The sensitivity and specificity for nodal involvement ( N ) by modality were 84 % and 67 % for CT , 86 % and 67 % for EUS , and 82 % and 60 % for PET ( P value > 0.38 ) . The sensitivity and specificity for distant metastasis were 81 % and 82 % for CT , 73 % and 86 % for EUS , and 81 % and 91 % for PET ( P value > 0.25 ) . Treatment assignment was done correctly by CT in 65 % , by EUS in 75 % , and by PET in 70 % of patients ( P value > 0.34 ) . Conclusions EUS had superior T staging ability over PET and CT in our study group . The tests showed similar performance in nodal staging and there was a trend toward improved distant disease staging with CT or PET over EUS . Assignment to treatment groups in relation to TNM staging tended to be better by EUS . Each test contributed unique patient staging information on an individual basis BACKGROUND This study compares the health care costs and effectiveness of multiple staging options for patients with esophageal cancer . Techniques studied included computed tomographic ( CT ) scan , endoscopic ultrasound with fine-needle aspiration biopsy ( EUS-FNA ) , positron emission tomography ( PET ) , thoracoscopy/laparoscopy , and combinations of these . METHODS A decision- analysis model was constructed to compare different staging strategies . Costs were derived from the Surveillance , Epidemiology , and End Results (SEER)-Medicare linked data bases and from other Medicare reimbursement rates . Life expectancies were obtained from the 1973 - 1996 SEER data base and adjusted for quality of life . Cost and effectiveness measures were discounted at 0 % and 3 % per year . Sensitivity and specificity measures were obtained from the published literature and a parallel prospect i ve clinical trial , and all key variables were subjected to sensitivity analyses . RESULTS Under baseline assumptions , CT + EUS-FNA was the most inexpensive strategy and offered more quality -adjusted life-years , on average , than all other strategies with the exception of PET + EUS-FNA . The latter was slightly more effective but also more expensive . The marginal cost-effectiveness ratio for PET + EUS-FNA was $ 60,544 per quality -adjusted life-year . These findings were robust and changed very little in all of the sensitivity analyses . CONCLUSIONS The combination of PET + EUS-FNA should be the recommended staging procedure for patients with esophageal cancer , unless re sources are scarce or PET is unavailable . In these instances , CT + EUS-FNA can be considered the preferred strategy To assess the accuracy and limitations of endoscopic ultrasonography ( EUS ) in the preoperative staging of esophageal and gastric carcinoma , we performed a prospect i ve controlled study over a five year period . Data from 63 patients with esophageal cancer and 147 patients with gastric cancer who underwent surgery were available for comparison of the endosonographic TNM classification to the histophathological findings of the resected specimens . The overall accuracy of EUS  in the assessment of tumor infiltration depth was 85.7 % and 78 % in esophageal and gastric cancer , respectively . The sensitivity of EUS in the detection of regional lymph node metastases was 90 % in esophageal and 87 % in gastric carcinoma . The most frequent causes of misdiagnoses by endosonography were microscopic tumor invasion and peritumorous inflammatory changes . The inability to traverse a tumor stenosis restricted the endosonographic evaluation in 31.6 and 14 % of the cases with esophageal and gastric cancer , respectively BACKGROUND AND AIM Endoscopic ultrasonography ( EUS ) is established as a st and ard approach for locoregional staging of esophageal cancer . However , only a few published studies have attempted to correlate the station of the abnormal lymph nodes detected by EUS with the definitive histology . We compared EUS and computed tomography ( CT ) in the initial staging of esophageal squamous cell carcinoma . METHODS Consecutive patients with esophageal cancer undergoing EUS were evaluated .  EUS findings and patient data including histopatology were collected prospect ively and analyzed retrospectively . Lymph node locations were divided into three groups ; abdominal ( A ) , paraesophageal ( B ) , and thoracic paratracheal ( C ) . RESULTS A total of 365 consecutive patients underwent EUS and 159 patients underwent esophagectomy without neoadjuvant chemotherapy . Thirty-eight patients were excluded ( insufficient EUS , etc . ) , and 121 patients were enrolled . The overall accuracy of EUS was 64 % ( sensitivity 68 % , specificity 58 % , positive predictive value [ PPV ] 68 % ) , CT was 51 % ( sensitivity 33 % , specificity 75 % , PPV 64 % ) , and CT + EUS was 64 % ( sensitivity 74 % , specificity 50 % , PPV 66 % ) . The accuracy of EUS was higher than CT in Groups A and C. Sensitivity of CT was lower than that of EUS alone and CT + EUS . CONCLUSIONS This study has demonstrated that EUS is a more accurate technique than contrast-enhanced CT for detecting abnormal lymph nodes . Sensitivity of CT was lower than that of EUS alone and CT + EUS . But some metastatic lymph nodes in neck and abdominal fields are only detectable by CT . Therefore , both EUS and CT should be undertaken for routine examination prior to treatment of esophageal cancer BACKGROUND Endoscopic ultrasonography is recommended for staging gastro-oesophageal cancers , but has never been evaluated . OBJECTIVE COGNATE ( Cancer of Oesophagus or Gastricus - New Assessment of Technology of Endosonography ) therefore aim ed to evaluate whether adding ' endoscopic ultrasound ' ( EUS ) to the usual staging algorithm changes treatment , improves ( quality -adjusted ) survival , and uses re sources cost-effectively . DESIGN Pragmatic parallel-group trial . Patients with gastro-oesophageal cancer received st and ard staging algorithms .  Multidisciplinary teams chose provisional management plans from endoscopic mucosal resection , immediate surgery , surgery after chemotherapy , or chemotherapy and radiotherapy . We used dynamic r and omisation to allocate consenting patients remotely by telephone in equal proportions between EUS and not . Thereafter we recorded changes in management plan , use of health-care re sources , and three aspects of participant-reported quality of life : generic [ measured by European Quality of Life - 5 Dimensions ( EQ-5D ) ] , cancer related [ Functional Assessment of Cancer Therapy - General scale 
    Output:
    
Conclusions The data available suggest use of EUS as a complementary staging technique to other staging techniques for GOCs appears to be cost saving and offers greater QALYs .