***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: CONTEXT Esophageal pH monitoring is considered to be the gold st and ard for the diagnosis of gastroesophageal acid reflux . However , this method is very troublesome and considerably limits the patient 's routine activities . Wireless pH monitoring was developed to avoid these restrictions . OBJECTIVE To compare the first 24 hours of the conventional and wireless pH monitoring , positioned 3 cm above the lower esophageal sphincter , in relation to : the occurrence of relevant technical failures , the ability to detect reflux and the ability to correlate the clinical symptoms to reflux . METHODS Twenty-five patients referred for esophageal pH monitoring and with typical symptoms of gastroesophageal reflux disease were studied prospect ively , underwent clinical interview , endoscopy , esophageal manometry and were su bmi tted , with a simultaneous initial period , to 24-hour catheter pH monitoring and 48-hour wireless pH monitoring . RESULTS Early capsule detachment occurred in one ( 4 % ) case and there were no technical failures with the catheter pH monitoring ( P = 0.463 ) . Percentages of reflux time ( total , upright and supine ) were higher with the wireless pH monitoring ( P < 0.05 ) . Pathological gastroesophageal reflux occurred in 16 ( 64 % ) patients su bmi tted to catheter and in 19 ( 76 % ) to the capsule ( P = 0.355 ) . The symptom index was positive in 12 ( 48 % ) patients with catheter pH monitoring and in 13 ( 52 % ) with wireless pH monitoring ( P = 0.777 ) . CONCLUSIONS 1 ) No significant differences were reported between the two methods of pH monitoring ( capsule vs catheter ) , in regard to relevant technical failures ; 2 ) Wireless pH monitoring detected higher percentages of reflux time than the conventional pH-metry ; 3 ) The two methods of pH monitoring were comparable in diagnosis of pathological gastroesophageal reflux and comparable in correlating the clinical symptoms with the gastroesophageal reflux Background Wireless capsule pH-metry ( WC ) is better tolerated than st and ard nasal pH catheter ( SC ) , but endoscopic placement is expensive . Aims : to confirm that non-endoscopic peroral manometric placement of WC is as effective and better tolerated than SC and to perform a cost analysis of the available esophageal pH-metry methods . Methods R and omized trial at 2 centers . Patients referred for esophageal pH testing were r and omly assigned to WC with unse date d peroral placement or SC after esophageal manometry ( ESM ) . Primary outcome was overall discomfort with pH-metry . Costs of 3 different pH-metry strategies were analyzed : 1 ) ESM + SC , 2 ) ESM + WC and 3 ) endoscopically placed WC ( EGD + WC ) using publicly funded health care system perspective . Results 86 patients ( mean age 51 ± 2 years , 71 % female ) were enrolled . Overall discomfort score was less in WC than in SC patients ( 26 ± 4 mm vs 39 ± 4 mm VAS , respectively , p = 0.012 ) but there were no significant group differences in throat , chest , or overall discomfort during placement . Overall failure rate was 7 % in the SC group vs 12 % in the WC group ( p = 0.71 ) . Per patient costs ( $ Canadian ) were $ 1475 for EGD + WC , $ 1014 for ESM + WC , and $ 906 for ESM + SC . Decreasing the failure rate of ESM + WC from 12 % to 5 % decreased the cost of ESM + WC to $ 991 . The ESM + SC and ESM + WC strategies became equivalent when the cost of the WC device was dropped from $ 292 to $ 193 . Conclusions Unse date d peroral WC insertion is better tolerated than SC pH-metry both overall and during placement . Although WC is more costly , the extra expense is partially offset when the higher patient and caregiver time costs of SC are considered . Trial registration Clinical trials.gov Identifier Objectives Oesophageal pH monitoring is the current st and ard for the diagnosis of gastro-oesophageal reflux disease . The Bravo capsule allows 48-h monitoring without the need for a naso-oesophageal catheter . Our aim was to assess the Bravo capsule in terms of patient discomfort and interference with daily activities , and to determine if 48-h Bravo pH studies facilitate the diagnosis of gastro-oesophageal reflux disease . Methods Ambulatory pH studies were performed at two hospitals using either the Bravo capsule ( n=100 ) or a conventional naso-oesophageal catheter ( n=100 ) . Participants were selected either for investigation of symptoms suggestive of gastro-oesophageal reflux disease , or to follow-up antireflux surgery . All participants completed question naires to assess discomfort and interference with daily activities . Results Eighty-nine Bravo studies recorded at least 48 h of data , and 95 were diagnostic . Bravo participants reported significantly less discomfort during insertion ( P<0.0001 ) and monitoring ( P<0.0001 ) , and less interference with daily activities ( P<0.0001 ) , eating ( P<0.005 ) , sleeping ( P<0.0001 ) and work ( P<0.0001 ) . No significant difference was observed between day 1 and 2 median total time pH<4 ( 4.0 and 4.3 % , P=0.64 ) , erect time pH<4 ( 5.0 and 5.0 % , P=0.56 ) , supine time pH<4 ( 0.5 and 0.5 % , P=0.23 ) , and Johnson – DeMeester scores ( 15.9 and 16.2 , P=0.90 ) . Ten Bravo participants ( 10 % ) were diagnosed with gastro-oesophageal reflux disease using day 2 data after a normal day 1 . Conclusions The Bravo capsule significantly reduces the patient discomfort and interference with normal daily activities during pH monitoring associated with a naso-oesophageal catheter . Moreover , 48-h Bravo studies offer an advantage over conventional 24-h studies in diagnosing gastro-oesophageal reflux disease OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity Background : The wireless pH is a new technique to monitor oesophageal acid exposure Goals To prospect ively evaluate the tolerability and clinical utility of the Bravo pH capsule  in children . Background Acid reflux is common in children , and pH testing can be used to correlate acid exposure with symptom expression . The tolerability and clinical utility of the Bravo capsule in children has not been prospect ively evaluated . Methods This was a prospect i ve , open-label trial conducted at an academic medical center . Patient demographics , symptoms , and medication use were recorded in an outpatient setting . After Bravo capsule placement , patients were followed to determine whether the results of the Bravo capsule study changed clinical management . Results Fifty children ( mean±SD=13±3 y ; 52 % female ) were studied ; no complications occurred . Reflux symptoms ( 40 % ) , abdominal pain ( 18 % ) , and nausea/vomiting ( 14 % ) were the 3 most common symptoms leading to Bravo capsule placement . Nearly all studies ( 96 % ) were performed off acid-suppressing medications . Results of the Bravo pH study changed clinical care in 88 % of children ; management changed more frequently in children with an abnormal study ( 94 % ) versus those with a normal study ( 78 % ; P<0.0001 ) . Conclusions The Bravo pH capsule is a safe , well-tolerated test to evaluate acid reflux symptoms in children , and the data obtained frequently changes patient management OBJECTIVES : Ambulatory esophageal pH monitoring has limited diagnostic accuracy in patients with gastroesophageal reflux disease ( GERD ) , especially in those with non-erosive reflux disease ( NERD ) . In addition , there is lack of symptom – reflux association in the majority of GERD patients . The aim of this study was to evaluate the impact of measuring acid exposure 1 cm above the gastroesophageal junction ( GEJ ) on diagnostic accuracy and symptom correlation in GERD patients compared with conventional pH measurements ( 6 cm above the GEJ ) using the wireless pH system . METHODS : GERD patients and controls as defined by two vali date d question naires ( Gastroesophageal Reflux Question naire and Reflux Disease Question naire ) were prospect ively enrolled . Under direct endoscopic vision , two wireless pH capsules ( BRAVO , Given Imaging , Yokneam , Israel ) were placed 6 and 1 cm , respectively , above the GEJ . Receiver operator characteristic curves were constructed , and symptom indexes were calculated separately for pH measurements at 6-cm ( proximal ) and 1-cm ( distal ) locations . RESULTS : A total of 40 GERD patients ( 20 erosive esophagitis ( EE ) and 20 NERD ) and 16 controls were analyzed .  Sensitivity and specificity of abnormal acid exposure times in GERD were as follows : proximal : 67 and 66 % , distal : 60 and 88 % ; in EE proximal : 75 and 81 % , distal : 84 and 92 % ; and in NERD proximal : 61 and 67 % , distal : 58 and 66 % , respectively . The proportion of patients with a positive symptom – reflux correlation in GERD was as follows : symptom index ( SI ) : proximal : 35 % , distal : 50 % ; symptom sensitivity index ( SSI ) : proximal : 25 % , distal : 5 % ; and symptom-associated probability ( SAP ) : proximal : 30 % and distal : 35 % . The higher proportion of patients with a positive SI distally was due to the EE group ( EE , proximal : 35 % and distal : 65 % ; NERD , proximal : 35 % and distal : 35 % ) . CONCLUSIONS : Compared with the traditional location , measurement of acid reflux 1 cm above the GEJ improved the diagnostic accuracy as well as symptom correlation in EE , but not in NERD patients . Thus , pH monitoring 1 cm above the GEJ for improving the diagnosis of NERD can not be recommended in clinical practice at this time OBJECTIVES : Esophageal pH monitoring using a wireless pH capsule has been suggested to generate less adverse symptoms result ing in improved patient acceptance compared with the catheter-based method although evidence to support this assumption is lacking . The aim of this study was to evaluate and compare the subjective experience of patients undergoing both techniques for esophageal pH monitoring . METHODS : Using a r and omized study design , patients referred for esophageal pH testing underwent both wireless and traditional catheter-based 24-h pH recording with a 7-day interval . The wireless pH capsule was placed during endoscopy and followed by 48-h pH recording . All patients answered a question naire , including a 10-cm visual analog scale ( VAS ) , which described the perceived severity of symptoms and the degree of interference with normal daily activities during the pH tests . RESULTS : Thirty-one patients , 16 women and 15 men , were included in the analysis . The 
    Output:
    
Discussion : WM is usually better tolerated than CBM but has more technical problems .