***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 Few studies have evaluated the prevention of upper gastrointestinal complications ( UGIC ; bleeding or perforation ) in patients with uncomplicated peptic ulcer ( PU ) . We assessed the effect of proton pump inhibitors ( PPI ) in a non-r and omized setting . To maximize exchangeability of exposed and unexposed groups we restricted the study to patients with a new diagnosis of PU , i.e. , a clear indication . To minimize selection bias we mimicked an intention to treat approach by assessing the effect of PPI prescription after PU diagnosis . Methods Within a population of subjects aged 40–84 years from The Health Improvement Network data base , 1997–2006 , we identified 3,850 patients with incident PU . Among them , we confirmed 74 first UGIC episodes during a mean follow-up of 4 years . Exposure was prescription coverage during the month following PU diagnosis . We performed a nested case – control analysis and compared UGIC cases with 400 controls matched for age , sex , year and duration of follow-up . Relative risks ( RR ) and 95 % confidence intervals ( CI ) were estimated . Results The overall incidence of UGIC was 4.6 cases/1,000 person-years ; it was highest during the months after PU diagnosis , increased with age , and it was higher in men and subjects with Helicobacter pylori infection , anemia , and alcohol use at PU diagnosis . The RR for UGIC associated with PPI prescriptions during the month after PU diagnosis was 0.56 ( 95 % CI 0.31–1.0 ) . The RR for NSAIDs with and without a PPI was 1.72 ( 0.68–4.45 ) and 3.27 ( 0.85–12.67 ) , respectively . Conclusions Findings suggest that prescription of PPIs after a PU diagnosis is associated with a reduced risk of UGIC Background Emergency surgery or transarterial embolization ( TAE ) are options for the treatment of recurrent or refractory nonvariceal upper gastrointestinal bleeding . Surgery has the disadvantage of high rates of postoperative morbidity and mortality .  Embolization has become more available and has the advantage of avoiding laparotomy in this often unfit and elderly population . Objective To carry out a systematic review and meta- analysis of all studies that have directly compared TAE with emergency surgery in the treatment of major upper gastrointestinal bleeding that has failed therapeutic upper gastrointestinal endoscopy . Methods A literature search of Ovid MEDLINE , Embase , and Google Scholar was performed . The primary outcomes were all-cause mortality and rates of rebleeding . The secondary outcomes were length of stay and postoperative complications . Results A total of nine studies with 711 patients ( 347 who had embolization and 364 who had surgery ) were analyzed . Patients in the TAE group were more likely to have ischemic heart disease ( odds ratio [ OR ] = 1.99 ; 95 % confidence interval [ CI ] : 1.33 , 2.98 ; P=0.0008 ; I2=67 % [ r and om effects model ] ) and be coagulopathic ( pooled OR = 2.23 ; 95 % CI : 1.29 , 3.87 ; P=0.004 ; I2=33 % [ fixed effects model ] ) . Compared with TAE , surgery was associated with a lower risk of rebleeding ( OR = 0.41 ; 95 % CI : 0.22 , 0.77 ; P<0.0001 ; I2=55 % [ r and om effects ] ) . There was no difference in mortality ( OR = 0.70 ; 95 % CI : 0.48 , 1.02 ; P=0.06 ; I2=44 % [ fixed effects ] ) between TAE and surgery . Conclusion When compared with surgery , TAE had a significant increased risk of rebleeding rates after TAE ; however , there were no differences in mortality rates . These findings are subject to multiple sources of bias due to poor quality studies . These findings support the need for a well- design ed clinical trial to ascertain which technique is superior This is one of a series of statements discussing the use of GI endoscopy in common clinical situations . The St and ards of Practice Committee of the American Society for Gastrointestinal Endoscopy ( ASGE ) prepared this text . In preparing this guideline , a search of the medical literature was performed by using PubMed . Additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants . When few or no data exist from well- design ed prospect i ve trials , emphasis is placed on results from large series and reports from recognized experts . Guidelines for appropriate use of endoscopy are based on a critical review of the available data and expert consensus at the time the guidelines are drafted . Further controlled clinical studies may be needed to clarify aspects of this guideline . This guideline may be revised as necessary to account for changes in technology , new data , or other aspects of clinical practice . The recommendations are based on review ed studies and are grade d on the quality of the supporting evidence ( Table 1 ) . The strength of individual recommendations is based on both the aggregate evidence quality and an assessment of the anticipated benefits and harms . Weaker recommendations are indicated by phrases such as ‘ ‘ we suggest , ’ ’ whereas stronger recommendations are typically stated as ‘ ‘ we recommend . ’ ’ This guideline is intended to be an educational device to provide information that may assist endoscopists in providing care to patients . This guideline is not a rule and should not be construed as establishing a legal st and ard of care or as encouraging , advocating , requiring , or discouraging any particular treatment . Clinical decisions in any particular case involve a complex analysis of the patient ’s condition and available courses of action . Therefore , clinical considerations may lead an endoscopist to take a course of action that varies from this guideline . Upper GI endoscopy has largely replaced upper GI barium x-ray series for the evaluation of upper GI tract disease or symptoms because it allows direct visualization , tissue acquisition , and therapeutic interventions . This guideline is an up date of a previous ASGE document and defines the role of upper GI endoscopy in the OBJECTIVES Primary : to assess the necessity of a second endoscopy with a pathology study to confirm the healing of all gastric ulcers previously diagnosed through endoscopy in a population at intermediate risk for gastric cancer . Secondary : to assess correlation between endoscopic findings and pathology diagnosis . PATIENTS AND METHODS a prospect i ve analysis of patients diagnosed with gastric ulcer through endoscopy at Hospital General de Ciudad Real ( Spain ) over three years . We collected demographic , clinical , endoscopic , and pathological data for the first and subsequent endoscopies . We collected at least six biopsies obtained from ulcer margins , and assessed H. pylori infection . RESULTS Three hundred and two patients were included in this study .  H. pylori infection was diagnosed in 173 ( 57 % ) , and 113 ( 37 % ) patients had used NSAIDs . The positive and negative predictive value for malignancy of endoscopic diagnosis regarding ulcer fold , base , and margins were 34 and 97 % , respectively . Only one patient was diagnosed with a tumor during the second endoscopy . At the end of follow-up , the etiology of the ulcer was considered as peptic in 276 patients ; Crohn s disease-related in one , and neoplastic in 25 patients ( 21 adenocarcinomas , 4 lymphomas ) . CONCLUSIONS in an intermediate-risk population for gastric cancer a second endoscopy is not justified for gastric ulcer patients when endoscopy and biopsy results do not suggest malignancy Methods for combining data from several studies exist and appear to be quite useful . None satisfactorily addresses the question of what studies should be combined . This issue is the most serious method ological limitation . Even studies with statistically significant interaction might still be combined if the effect were in the same direction . Thus , substantial scientific input is required as to what criteria must be met by each potential study . Much can be learned from combining or pooling data but it must be done cautiously . Pooling exercises do not replace well design ed prospect i ve clinical trials . Efforts for establishing basic design criteria to allow for multicentre and multicountry trials to be more easily combined might be useful . Abstract Objective . Morbidity and mortality following perforated peptic ulcer ( PPU ) remain substantial . In the recently published PULP trial , 30-day mortality in patients surgically treated for PPU decreased from 27 % to 17 % following the implementation of a perioperative care protocol based on The Surviving Sepsis Guidelines . The objective of the present study was to evaluate long-term mortality in the PULP trial intervention and control cohort . Material and methods . Design : nationwide follow-up study of a multicenter , non-r and omized , clinical trial with external controls . Setting : Danish patients surgically treated for PPU between 1 January 2008 and 31 December 2009 . Patients : 117 patients in the intervention group and 512 in the control group . Intervention : a perioperative care protocol based on The Surviving Sepsis Guidelines . Outcome measures : 60-day , 90-day , 180-day , 1-year , and 2-year mortality rates . Statistical analysis : survival statistics . Results . Baseline characteristics , clinical , and perioperative data were in general , similar in the intervention and control group . Sixty days postoperatively , the originally observed difference in 30-day mortality had diminished ( 25 % vs. 30 % , p = 0.268 ) . After 180 days , the mortality difference was reduced additionally ( 31 % vs. 33 % , p = 0.645 ) , and one year postoperatively , a mortality difference was no longer present ( 36 % in both groups , p = 0.993 ) . Two years postoperatively , the mortality rate in the intervention group was 44 % , as compared to 40 % in the control group ( p = 0.472 ) . Conclusions . The survival benefit associated with a perioperative care protocol in patients treated for PPU decreases progressively after 30 days and is no longer present after one year . Registration number : NCT00624169 ( http://www . clinical trials.gov ) BACKGROUND AND AIM This prospect i ve cohort observational study , set in a district hospital , presents our experience ( 1976 - 1993 ) of duodenal ulcer refractory to histamine H2 receptor antagonists ( defined as not healed after 3 months ' treatment ) and comments on onset , outcome and spontaneous decline . METHODS Patients were treated mainly with cimetidine , the dose being titrated ( up to 3.2 g daily ) according to response , and followed by serial check endoscopy and clinical assessment . RESULTS A total of 782 of the 4032 duodenal ulcer patients seen ( 19 % ) were refractory ; the incidence declined over time : 1976 - 1978 : 124/379 ( 33 % ) ; 1979 - 1983 : 390/1240 ( 31 % ) ; 1984 - 1988 : 190/1295 ( 15 % ) ; 1989 - 1993 : 78/1118 ( 7 % ) . A total of 344 were refractory for the first time on their first healing course and 174 on their second . Healing was achieved in two-thirds after a mean of 7 months ' treatment with cimetidine 1 g ; treatment for 12 - 18 months with higher doses was needed in the remainder . Relapse occurred in up to three-quarters of patients despite maintenance cimetidine up to 3 g daily . Eventually 47 patients were operated upon but good results ( i.e. , no ulcer , no symptoms ) were achieved in only 11 . CONCLUSION Refractoriness was common until recently . Its incidence has declined dramatically , the fall preceding the newer more powerful treatment with proton pump inhibitors and with Helicobacter pylori eradication . We suggest this phenomenon is a modern example of a spontaneous change in the natural history of the disease In a prospect i ve controlled trial 86 duodenal ulcer patients with symptoms severe enough to indicate surgery were r and omized to a full-dose cimetidine course followed by maintenance therapy for 1 year or parietal cell vagotomy ( PCV ) . The average follow-up period was 57 months . In the group assigned to medical therapy 62 % of the patients were free of symptoms during maintenance therapy , and 12 % remained well during the follow-up period . Operation was later performed in 35 % , whereas 53 % had symptomatic recurrence dem and ing medical treatment regularly . After PCV no patient died , and there were no serious sequelae . The overall recurrence rate was 17 % ; after treatment of failures 9 % continued to have dyspepsia . Since nearly 3/4 of the patients were free of symptoms after PCV , operation seems to be the method of choice in patients with a severe history and fast recurrence after medical therapy . However , the aged and those at high risk of surgery may benefit from cimetidine maintenance therapy 
    Output:
    
It appears that the participants did not have previous complications such as bleeding or perforation .
We found no studies that provide the relative benefits and harms of medical versus surgical treatment for recurrent or refractory peptic ulcers .