The DOI matches its Crossref record; 46 of the 46 references it cites were found in a registry or an index; 2 of the 28 sources its claims cite were checked for support.
Gallstone Formation Prophylaxis After Gastric Restrictive Procedures for Weight Loss: A Randomized Double-Blind Placebo-Controlled Trial
Open accessAbstract
In Brief Object: To determine if a 6-month regimen of prophylactic ursodeoxycholic acid is effective in the prevention of gallstones. Summary Background Data: Rapid weight loss after surgery for the treatment of morbid obesity is associated with a high incidence of gallstone formation. Methods: Patients with vertical banded gastroplasty (VBG) and adjustable gastric banding (AGB) were enrolled in this study. A single-center, randomized, double-blind, prospective trial evaluated 500 mg of ursodeoxycholic acid versus placebo, beginning within 3 days after surgery and continuing for 6 months or until gallstone development, for patients with morbid obesity. Transabdominal sonography or abdominal CT scan was obtained preoperatively at 3, 6, 12, and 24 months after surgery or until gallstone formation. Results: From March 1997 to April 2000, 262 patients were submitted to surgery. Seventy-seven patients refused to participate in the study; 43 patients with previous gallstone operation or verified gallstones preoperatively were excluded. Of 152 patients, 76 were randomized to placebo and 76 to 500 mg of ursodeoxycholic acid daily. Preoperative age, sex, weight, BMI, and postoperative weight loss were not significantly different between groups. Gallstone formation was significantly less (P = 0.0018, Fisher exact test) frequent with ursodeoxycholic acid than with placebo at 12 months, 3% versus 22%, and 8% versus 30% (P = 0.0022) at 24 months, cholecystectomy in 4.7% versus 12%, respectively (P < 0,02, Fisher exact test). Conclusion: A daily dose of 500 mg of ursodeoxycholic acid for 6 months is effective prophylaxis for gallstone formation following gastric restrictive procedures. This long-term follow-up study was designed to determine if a 6-month regimen of prophylactic ursodeoxycholic acid is effective in the prevention of gallstones after restrictive bariatric surgery. Patients with vertical banded gastroplasty and adjustable gastric banding were enrolled in this study. A daily dose of 500 mg of ursodeoxycholic acid for 6 months is effective prophylaxis for gallstone formation after gastric restrictive procedures.
Overview
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Written from the paper’s full text.
TL;DR
A 6-month regimen of ursodeoxycholic acid 500 mg/d reduced gallstone formation after gastric restrictive bariatric surgery compared with placebo. The benefit persisted at 24 months and was accompanied by fewer cholecystectomies for symptomatic cholelithiasis.
Key findings
- Gallstone formation was significantly less frequent with ursodeoxycholic acid than placebo at 12 months (3% vs 22%; P = 0.0018, Fisher exact test) and at 24 months (8% vs 30%; P = 0.0022).
- Over 24 months, cholecystectomy for symptomatic cholelithiasis was performed in 3 ursodeoxycholic acid patients versus 12 placebo patients (4.7% vs 12%; P < 0.02), at a mean of 14.9 ± 4.3 months after bariatric surgery.
- Preoperative age, sex, weight, BMI, and postoperative weight loss did not differ significantly between groups. Compliance averaged 84% for ursodeoxycholic acid and 79% for placebo; mild/moderate side effects such as nausea and constipation were 9.3% vs 6.6%, with no severe side effects or serious adverse drug reaction withdrawals.
- The authors conclude that 500 mg/d ursodeoxycholic acid in divided doses for 6 months is effective prophylaxis for gallstone formation after gastric restrictive procedures.
Methods
- Single-center, randomized, double-blind, placebo-controlled trial in patients undergoing vertical banded gastroplasty (VBG) or adjustable gastric banding (AGB) for morbid obesity; eligibility included age >18 years and BMI ≥40 kg/m², or BMI ≥35 kg/m² with comorbidities. Exclusions included prior cholecystectomy, gallstones, pregnancy/inadequate contraception, and certain concomitant medications.
- 152 patients were randomized: 76 to placebo and 76 to ursodeoxycholic acid 500 mg/d, beginning within 3 days after surgery and continuing for 6 months or until gallstone development. Follow-up included transabdominal sonography or abdominal CT preoperatively and at 3, 6, 12, and 24 months after surgery or until gallstone formation.
- Primary efficacy analysis was the proportion developing gallstones in the intent-to-treat for efficacy group (124 patients completed follow-up gallbladder sonography). Statistical testing used Fisher exact test, Wilcoxon-Mann-Whitney-U test, and χ² tests; power calculation assumed 76 patients per group to detect a 20% difference with beta 0.2 and two-sided alpha 0.05.
Limitations
- The authors report a high dropout rate of 28 patients (18%), possibly related to capsule size, and lower compliance in the VBG group (20 patients, 26%) than in the AGB group (8 patients, 10%). They also note uncertainty about how long ursodeoxycholic acid should be taken and about long-term effectiveness during weight loss.
- The text makes evident that only 124 of 152 randomized patients were eligible for the intent-to-treat efficacy analysis, and the reported screening/randomization numbers are inconsistent across the abstract and results. Surgical procedure type (VBG vs AGB) was not randomized, limiting subgroup comparisons.
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Claims the paper makes
10 Own method · 9 No full text of the sources · 9 Own result · 3 Own interpretation · 2 Not checked yet · 1 Partly supported · 1 Couldn’t confirm · accuracy not yet measured
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Ursodeoxycholic acid administered during VLCD and weight loss after bariatric surgery is effective in preventing gallstone formation19–23”
What the sources say
- Not checked — no full text of the sourcecites [19] Shiffman ML, Kaplan GD, Brinkman-Kaplan V, et al. Prophylaxis against gallstone formation with ursodeoxycholic acid in patients participating in a very-low-calorie diet program. Ann Intern Med. 1995;122:899–905. [DOI] [PubMed] [Google Scholar] source
- Partly supportedcites [20] Hood KA, Gleeson D, Ruppin DC, Dowling RH. Gall stone recurrence and its prevention: the British/Belgian Gall Stone Study Group’s post-dissolution trial. Gut. 1993;34:1277–1288. [DOI] [PMC free article] [PubMed] [Google Scholar] sourceExperimental — accuracy not yet measured
The post-dissolution trial studied gallstone recurrence, not new gallstone formation during very low-calorie dieting or after bariatric surgery. Its discussion of post-dissolution treatment says ursodeoxycholic acid may reduce or delay recurrence, but the reduction was not statistically significant and the authors say it did not prevent recurrence. The paper therefore offers limited support for a protective effect, not for the claimed effectiveness in the specified weight-loss settings. (LLM, conf=0.85)
- Not checked — no full text of the sourcecites [21] Sugerman HJ, Brewer WH, Shiffman ML, et al. A multicenter, placebo-controlled, randomized, double-blind, prospective trial of prophylactic ursodiol for the prevention of gallstone formation following gastric-bypass-induced rapid weight loss. Am J Surg. 1995;169:91–96. [DOI] [PubMed] [Google Scholar] source
- Not checked — no full text of the sourcecites [22] Wudel LJ Jr, Wright JK, Debelak JP, et al. Prevention of gallstone formation in morbidly obese patients undergoing rapid weight loss: results of a randomized controlled pilot study. J Surg Res. 2002;102:50–56. [DOI] [PubMed] [Google Scholar] source
- Not checked — no full text of the sourcecites [23] Williams C, Gowan R, Perey BJ. A double-blind placebo-controlled trial of ursodeoxycholic acid in the prevention of gallstones during weight loss after vertical banded gastroplasty. Obes Surg. 1993;3:257–259. [DOI] [PubMed] [Google Scholar] source
plaindirectn = 29- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Mild and moderate side effects such as nausea and constipation were equivalent in both groups: 4 patients in the placebo (6.6%) and 6 patients in the treatment group (9.3%).”
plainn = 6- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In our study, cholecystectomy was performed in symptomatic gallstone disease an average of 14.9 ± 4.3 months after bariatric surgery.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“No severe side effects from medication were observed.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“No patient was withdrawn from the study because of a serious adverse drug reaction.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“and 8% versus 30% (P = 0.0022) at 24 months”
- Also stated in: § RESULTS · plain
“and at 24 months, 8% versus 30% (P = 0,0022, Fisher exact test)”
- Also stated in: § DISCUSSION · boosted
“Our data from this study show a significantly reduced gallstone formation rate of 8% after 24 months compared with 30% in the placebo group.”
boosteddirectn = 152 ·- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Also stated in: § RESULTS · plain
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“However, among patients with restrictive procedures, those in the VBG group had markedly lower compliance (20 patients, 26%) than those in the AGB Group (8 patients, 10%).”
plaincorrelationaln = 20- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Gallstone formation was significantly less (P = 0.0018, Fisher exact test) frequent with ursodeoxycholic acid than with placebo at 12 months, 3% versus 22%”
- Also stated in: § RESULTS · plain
“gallstone formation was significantly less (P = 0.0018, Fisher exact test) frequent with ursodeoxycholic acid than with placebo at 12 months: 3% versus 22%, respectively”
plaindirectn = 152 ·- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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- Also stated in: § RESULTS · plain
In the paper
“Shiffman et al could show that bile cholesterol normalized when the weight stabilized27 24 months after gastric bypass.”
What the sources say
- Not checked — no full text of the sourcecites [27] Shiffman ML, Shamburek RD, Schwartz CC, et al. Gallbladder mucin, arachidonic acid, and bile lipids in patients who develop gallstones during weight reduction. Gastroenterology. 1993;105:1200–1208. [DOI] [PubMed] [Google Scholar] source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
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In the paper
“Ursodeoxycholic acid administered during VLCD seems to inhibit the development of biliary cholesterol crystals.8”
What the sources say
- Not checked — no full text of the sourcecites [8] Festi D, Colecchia A, Larocca A, et al. Review: low caloric intake and gall-bladder motor function. Aliment Pharmacol Ther. 2000;14(Suppl 2):51–53. [DOI] [PubMed] [Google Scholar] source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“In obese subjects, the risk of developing gallstones is increased due to a higher cholesterol saturation of gallbladder bile.8”
What the sources say
- Not checked — no full text of the sourcecites [8] Festi D, Colecchia A, Larocca A, et al. Review: low caloric intake and gall-bladder motor function. Aliment Pharmacol Ther. 2000;14(Suppl 2):51–53. [DOI] [PubMed] [Google Scholar] source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Ursodeoxycholic acid (600 mg/d) is highly effective in preventing gallstone formation in patients undergoing dietary-induced weight reduction.19”
What the sources say
- Not checked — no full text of the sourcecites [19] Shiffman ML, Kaplan GD, Brinkman-Kaplan V, et al. Prophylaxis against gallstone formation with ursodeoxycholic acid in patients participating in a very-low-calorie diet program. Ann Intern Med. 1995;122:899–905. [DOI] [PubMed] [Google Scholar] source
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“A daily dose of 500 mg of ursodeoxycholic acid for 6 months is effective prophylaxis for gallstone formation following gastric restrictive procedures.”
- Also stated in: § DISCUSSION · plain
“In conclusion, a daily dose of 500 mg of ursodeoxycholic acid in divided doses semi-daily for 6 months is an effective prophylaxis for gallstone formation after gastric restrictive procedures”
- Also stated in: § DISCUSSION · plain
“The results of the present study show an effective prophylaxis with a dosage of 500 mg/d.”
plaindirectn = 152 ·- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Also stated in: § DISCUSSION · plain
None of the sources cited for this claim have been checked yet.
In the paper
“Rapid weight loss after surgery for the treatment of morbid obesity is associated with a high incidence of gallstone formation.”
- Also stated in: § DISCUSSION · boosted
“Gallstone formation is a well-recognized complication of rapid weight loss.1–4”
What the sources say
- Not checked yetcites [1] Bennion LJ, Grundy SM. Risk factors for the development of cholelithiasis in man (second of two parts). N Engl J Med. 1992;307:798–800. [DOI] [PubMed] [Google Scholar]
- Not checked yetcites [2] Diehl AK. Epidemiology and natural history of gallstone disease. Gastroenterol Clin North Am. 1991;20:1–19. [PubMed] [Google Scholar]
- Not checked yetcites [3] Jorgensen T. Gallstones in a Danish population. Relation to weight, physical activity, smoking, coffee consumption, and diabetes mellitus. Gut. 1989;30:528–534. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Not checked — no full text of the sourcecites [4] Kodama H, Kono S, Todoroki I, et al. Gallstone disease risk in relation to body mass index and waist-to-hip ratio in Japanese men. Int J Obes Relat Metab Disord. 1999;23:211–216. [DOI] [PubMed] [Google Scholar] source
boostedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Also stated in: § DISCUSSION · boosted
In the paper
“The authors of the present study could demonstrate in another prospective study on more than 1000 restrictive procedures that a weight stabilization phase is reached not before 24 months.43”
What the sources say
- Not checked yetcites [43] Miller K, Höller E, Hell E. Restrictive procedures in the treatment of morbid obesity – vertical banded gastroplasty vs. adjustable gastric banding. Zentralbl Chir. 2002;127:1038–1043. [DOI] [PubMed] [Google Scholar]
boosted- Asserted: passes — The authors put it forward as true.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“and avoids simultaneous cholecystectomy in morbid obese patients.”
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“A small Canadian double-blind study on 29 patients reported that 6 (43%) of the 14 subjects on placebo developed stones 3 months after the operation.23”
What the sources say
- Not checked — no full text of the sourcecites [23] Williams C, Gowan R, Perey BJ. A double-blind placebo-controlled trial of ursodeoxycholic acid in the prevention of gallstones during weight loss after vertical banded gastroplasty. Obes Surg. 1993;3:257–259. [DOI] [PubMed] [Google Scholar] source
plainn = 14- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Weight loss was equivalent between the placebo and the ursodeoxycholic acid group (Table 2).”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- It may state two separate claims as one. 11
- Probably not a substantial claim. 8
The cited sources that could be checked couldn’t confirm or dispute this claim.
In the paper
“In prospective randomized studies, the prophylactic administration of ursodeoxycholic acid has been shown to be effective in gastric bypass procedures20–22, as well as in a small series with vertical banded gastroplasty.23”
What the sources say
- Could not verifycites [20] Hood KA, Gleeson D, Ruppin DC, Dowling RH. Gall stone recurrence and its prevention: the British/Belgian Gall Stone Study Group’s post-dissolution trial. Gut. 1993;34:1277–1288. [DOI] [PMC free article] [PubMed] [Google Scholar] sourceExperimental — accuracy not yet measured
The Abstract describes a randomized trial of ursodeoxycholic acid to prevent gallstone recurrence after complete stone dissolution, not after bariatric surgery. Searches for vertical banded gastroplasty and gastric bypass found no passage addressing either procedure, so our copy cannot verify the claim attached to citation 23. (LLM, conf=0.76)
- Not checked — no full text of the sourcecites [21] Sugerman HJ, Brewer WH, Shiffman ML, et al. A multicenter, placebo-controlled, randomized, double-blind, prospective trial of prophylactic ursodiol for the prevention of gallstone formation following gastric-bypass-induced rapid weight loss. Am J Surg. 1995;169:91–96. [DOI] [PubMed] [Google Scholar] source
- Not checked — no full text of the sourcecites [22] Wudel LJ Jr, Wright JK, Debelak JP, et al. Prevention of gallstone formation in morbidly obese patients undergoing rapid weight loss: results of a randomized controlled pilot study. J Surg Res. 2002;102:50–56. [DOI] [PubMed] [Google Scholar] source
- Not checked — no full text of the sourcecites [23] Williams C, Gowan R, Perey BJ. A double-blind placebo-controlled trial of ursodeoxycholic acid in the prevention of gallstones during weight loss after vertical banded gastroplasty. Obes Surg. 1993;3:257–259. [DOI] [PubMed] [Google Scholar] source
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Could not verify
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In the VBG group, patients showed a noticeably more rapid weight loss, but no significant incident development of gallstone formation was noticed.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In the 24-month follow-up period, 15 cholecystectomies were performed (mean 14.9 ± 4.3 months after bariatric surgery) in patients with symptomatic cholelithiasis: 3 patients in the ursodeoxycholic group and 12 patients in the placebo group, 12% versus 4.7%, respectively (P < 0,02, Fisher exact test).”
plainn = 12 ·- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“The study was approved by the ethical committee of the Landesregierung Salzburg, Austria, a government institution. Informed consent was obtained from each patient before the procedure and before initiation of the study.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Concomitant cholecystectomy in bariatric surgery can be a very difficult procedure with a higher incidence of complications.17,18”
- Also stated in: § DISCUSSION · plain
“Synchronous cholecystectomy in bariatric surgery can be a very difficult procedure with a higher incidence of complications, especially in the field of laparoscopic surgery.17,18”
What the sources say
- Not checked — no full text of the sourcecites [17] Ammori BJ, Vezakis A, Davides D, et al. Laparoscopic cholecystectomy in morbidly obese patients. Surg Endosc. 2001;15:1336–1339. [DOI] [PubMed] [Google Scholar] source
- Not checked — no full text of the sourcecites [18] Angrisani L, Lorenzo M, De Palma G, et al. Laparoscopic cholecystectomy in obese patients compared with nonobese patients. Surg Laparosc Endosc. 1995;5:197–201. [PubMed] [Google Scholar]
plaindirect- Asserted: passes — The authors put it forward as true.
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- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Also stated in: § DISCUSSION · plain
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“One hundred twenty-four patients completed follow-up gallbladder sonography and were eligible for inclusion in the intent-to-treat for efficacy group.”
plainn = 4- Asserted: passes — The authors put it forward as true.
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- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Investigation site was blinded from Falk Corporation, FRG to the drug codes, except in case of emergency.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Preoperative age, sex, weight, BMI, and postoperative weight loss were not significantly different between groups.”
- Also stated in: § RESULTS · plain
“There were no significant differences with respect to age, sex, preoperative weight, or BMI between those receiving medication or placebo in any of the patient groups.”
plainn = 152- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
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- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Also stated in: § RESULTS · plain
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“The optimum dose for gallstone prophylaxis appears to be 600 mg/d, or 4 to 5 mg/kg.19,21”
What the sources say
- Not checked — no full text of the sourcecites [19] Shiffman ML, Kaplan GD, Brinkman-Kaplan V, et al. Prophylaxis against gallstone formation with ursodeoxycholic acid in patients participating in a very-low-calorie diet program. Ann Intern Med. 1995;122:899–905. [DOI] [PubMed] [Google Scholar] source
- Not checked — no full text of the sourcecites [21] Sugerman HJ, Brewer WH, Shiffman ML, et al. A multicenter, placebo-controlled, randomized, double-blind, prospective trial of prophylactic ursodiol for the prevention of gallstone formation following gastric-bypass-induced rapid weight loss. Am J Surg. 1995;169:91–96. [DOI] [PubMed] [Google Scholar] source
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Between 10% and 25% of persons having lost weight through very low-calorie dieting (VLCD) develop gallstones.12,13”
What the sources say
- Not checked — no full text of the sourcecites [12] Yang H., Peterson GM., Roth MP, et al. Risk factors for gallstone formation during rapid weight loss. Dig Dis Sci. 1992;37:912–918. [DOI] [PubMed] [Google Scholar] source
- Not checked — no full text of the sourcecites [13] Zapata R, Severin C, Manriquez M, et al. Gallbladder motility and lithogenesis in obese patients during diet-induced weight loss. Dig Dis Sci. 2000;45:421–428. [DOI] [PubMed] [Google Scholar] source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“In addition, 35–38% of patients with morbid obesity develop gallstones as they lose weight after bariatric surgery.5,14,15”
What the sources say
- Not checked — no full text of the sourcecites [5] Amaral JF, Thompson WR. Gallbladder disease in morbidly obese. Am J Surg. 1985;149:551–557. [DOI] [PubMed] [Google Scholar] source
- Not checked — no full text of the sourcecites [14] Deitel M, Petrov I. Incidence of symptomatic gallstones after bariatric operations. Surg Gynecol Obstet. 1987;164:549–552. [PubMed] [Google Scholar]
- Not checked — no full text of the sourcecites [15] Shiffman ML, Sugerman HJ, Kellum JM, et al. Changes in gallbladder bile composition following gallstone formation and weight reduction. Gastroenterology. 1992;103:214–221. [DOI] [PubMed] [Google Scholar] source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“With 76 patients in each treatment group, a difference in proportions of -0.2 (20%) is required to achieve a beta of 0.2 and a sigma of 0.52 on the basis of a two-sided test with a significance level of 0.05.”
plainn = 76- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Summarizing the available data on gallstone prevention at the time of rapid weight loss, it is clear that UDCA is effective and has few adverse drug reactions, but its use has not been very common yet.”
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Compliance with the trial drug regimen was similar across the operated subsets and averaged 79% (60 of 76) for placebo and 84% (64 of 76) for ursodeoxycholic acid.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Patients in the placebo and treatment groups dropped out for same reasons at similar rates.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“No financial support, grant, or donation was submitted by the Falk Corporation.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“A single-center, randomized, double-blind, prospective trial evaluated 250 mg of ursodeoxycholic acid twice a day (total dosage of 500 mg/d) versus placebo”
- Also stated in: § Abstract · plain
“A single-center, randomized, double-blind, prospective trial evaluated 500 mg of ursodeoxycholic acid versus placebo”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
- Also stated in: § Abstract · plain
The paper relies on this without support.
Gallstone formation is correlated with weight loss.
“It is generally accepted that gallstone formation is correlated with weight loss.”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“indicating that patients undergoing bariatric surgery experienced difficulty in tolerating either the size or structure of the tablet, rather than the content.8,37,38”
From Ursodeoxycholic acid for the prevention of symptomatic gallstone disease after bariatric surgery (UPGRADE): a multicentre, double-blind, randomised, placebo-controlled superiority trial (2021) · cites this paper as [37]
Experimental — accuracy not yet measured
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Rated major: it would touch a result — a value a result rests on, reported and recomputed p-values on opposite sides of the significance level, two passages that conflict with no sign which is right, or a cited work retracted before this paper was published.
In the paper
“From March 1997 to April 2000, 262 patients were submitted to surgery. In the study, 76 were randomized to placebo and 76 to 500 mg/d ursodeoxycholic acid. One hundred twenty-four patients completed follow-up gallbladder sonography and were eligible for inclusion in the intent-to-treat for efficacy group. One hundred thirty patients refused to participate in the study or did not meet the inclusion criteria.”
Reported 262 · recomputed 282
Rated minor: it would not touch a result — a value no result rests on, a p-value that stays on the same side of the significance level, or a conflict that is clerical, resolved elsewhere in the paper, or outside its own findings.
In the paper
§ RESULTS
“3 patients in the ursodeoxycholic group and 12 patients in the placebo group, 12% versus 4.7%, respectively”
§ Abstract
“cholecystectomy in 4.7% versus 12%, respectively”
Citations
Cites
Gastrointestinal Surgery for Severe Obesity
Panel, C. D. C. (1991) · Annals of Internal Medicine · doi:10.7326/0003-4819-115-12-956 · Cited by 2,163
Gastrointestinal surgery for severe obesity
Brolin, R. E. (1996) · Nutrition · doi:10.1016/s0899-9007(96)00154-2 · Cited by 641
The Natural History of Silent Gallstones
Gracie, W. A., & Ransohoff, D. F. (1982) · New England Journal of Medicine · doi:10.1056/nejm198209233071305 · Cited by 589
Bariatric Analysis and Reporting Outcome System (BAROS)
Oria, H. E., & Moorehead, M. K. (1998) · Obesity Surgery · doi:10.1381/096089298765554043 · Cited by 540
Risk Factors for the Development of Cholelithiasis in Man
Bennion, L. J., & Grundy, S. M. (1978) · New England Journal of Medicine · doi:10.1056/nejm197811232992104 · Cited by 376
Sugerman, H. J., Brewer, W. H., Shiffman, M. L., Brolin, R. E., Fobi, M. A. L., Linner, J. H., MacDonald, K. G., MacGregor, A. M., Martin, L. F., Oram-Smith, J. C., et al. (1995) · The American Journal of Surgery · doi:10.1016/s0002-9610(99)80115-9 · Cited by 336
Epidemiology and Natural History of Gallstone Disease
Diehl, A. K. (1991) · Gastroenterology Clinics of North America · doi:10.1016/s0889-8553(21)00531-8 · Cited by 326
SERUM-SICKNESS-LIKE SYNDROME WITH MEMBRANOUS GLOMERULOPATHY IN PATIENT ON CAPTOPRIL
Hoorntje, S., Weening, J. J., Kallenberg, C. M., Prins, E. L., & Donker, A. M. (1979) · The Lancet · doi:10.1016/s0140-6736(79)92303-1 · Cited by 225
Gallstones in obesity and weight loss
Erlinger, S. (2000) · European Journal of Gastroenterology & Hepatology · doi:10.1097/00042737-200012120-00015 · Cited by 215
URSODEOXYCHOLIC ACID TREATMENT OF GALLSTONES
Maton, P. N., Murphy, G. M., & Dowling, R. H. (1977) · The Lancet · doi:10.1016/s0140-6736(77)90358-0 · Cited by 210
Research works printed but not linked: 1
- Hell, 1998, Long term results with vertical banded gastroplasty in the treatment of morbid obesity., Obes Surg, 8, 373
Cited by
Sorted by citations
Garvey, W. T., Mechanick, J. I., Brett, E. M., Garber, A. J., Hurley, D. L., Jastreboff, A. M., Nadolsky, K., Pessah-Pollack, R., & Plodkowski, R. (2016) · Endocrine Practice · doi:10.4158/ep161365.gl · Cited by 1,914
Picot, J., Jones, J., Colquitt, J., Gospodarevskaya, E., Loveman, E., Baxter, L., & Clegg, A. (2009) · Health Technology Assessment · doi:10.3310/hta13410 · Cited by 1,066
Guidelines on the management of common bile duct stones (CBDS)
Williams, E., Green, J., Beckingham, I. J., Parks, R. W., Martin, D. F., & Lombard, M. (2008) · Gut · doi:10.1136/gut.2007.121657 · Cited by 595
EASL Clinical Practice Guidelines on the prevention, diagnosis and treatment of gallstones
(2016) · Journal of Hepatology · doi:10.1016/j.jhep.2016.03.005 · Cited by 576
Stenberg, E., Falcão, L. F. D. R., O’Kane, M. P. M., Liem, R. S. L., Pournaras, D. J., Salminen, P. T. P., Urman, R. D., Wadhwa, A. N., Gustafsson, U. O., & Thorell, A. (2022) · World Journal of Surgery · doi:10.1007/s00268-021-06394-9 · Cited by 551
Metadata
- Authors
- Miller, K., Hell, E., Lang, B., & Lengauer, E.
- ORCID
- Miller, Karl
- Venue
- Annals of Surgery
- Published
- 2003-11
- Volume
- 238
- Issue
- 5
- Pages
- 697-702
- ISSN
- 0003-4932 (ISSN-L)
- PMC
- PMC1356148
- OpenAlex
- W1983687527
- Semantic Scholar
- 8cacff0f9a128f781bfc31ff01cc72506e45fdaa
- Cited by
- 200
- References
- 45
- Citations by year
- 2026: 9 · 2025: 5 · 2024: 2 · 2023: 15 · 2022: 12 · 2021: 7 · 2020: 19 · 2019: 10 · 2018: 9 · 2017: 7 · 2016: 13 · 2015: 8 · 2014: 12 · 2013: 4 · 2012: 10
- FWCI
- 6.76
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Annals of Surgery (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Surgery › Bariatric Surgery and Outcomes
- Health Sciences › Medicine › Gastroenterology › Gallbladder and Bile Duct Disorders
- Health Sciences › Medicine › Gastroenterology › Biliary and Gastrointestinal Fistulas
- Keywords
- ursodeoxycholic acid, prophylaxis, bariatric surgery, morbid obesity, vertical banded gastroplasty, gastric banding, rapid weight loss, cholecystectomy, gallstone prevention
- MeSH terms
- Adolescent, Adult, Cholagogues and Choleretics, Double-Blind Method, Female, Humans, Male, Middle Aged, Obesity, Morbid, Postoperative Complications, Prospective Studies, Ursodeoxycholic Acid, Gastroplasty, Cholecystolithiasis, Gallstones
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-11-08, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-11-08 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Cited sources are checked with a language model’s help (gpt-6-sol).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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