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Biomedical subjects

B Scherrer

Publications and source records attributed to B Scherrer.

8 recordsLinked to original sources
PubMed2000

Fraud in medical research: an international survey of biostatisticians. ISCB Subcommittee on Fraud.

The characteristics of scientific fraud and its impact on medical research are in general not well known. However, the interest in the phenomenon has increased steadily during the last decade. Biostatisticians routinely work closely with physicians and scientists in many branches of medical research and have therefore unique insight into data. In addition, they have methodological competence to detect fraud and could be expected to have a professional interest in valid results. Biostatisticians therefore are likely to provide reliable information on the characteristics of fraud in medical research. The objective of this survey of biostatisticians, who were members of the International Society for Clinical Biostatistics, was to assess the characteristics of fraud in medical research. The survey was performed between April and July 1998. The participation rate was only 37%. We report the results because a majority (51%) of the participants knew about fraudulent projects, and many did not know whether the organization they work for has a formal system for handling suspected fraud or not. Different forms of fraud (e.g., fabrication and falsification of data, deceptive reporting of results, suppression of data, and deceptive design or analysis) had been observed in fairly similar numbers. We conclude that fraud is not a negligible phenomenon in medical research, and that increased awareness of the forms in which it is expressed seems appropriate. Further research, however, is needed to assess the prevalence of different types of fraud, as well as its impact on the validity of results published in the medical literature.

Biometry↗
PubMed1999

The role of biostatistics in the prevention, detection and treatment of fraud in clinical trials.

Recent cases of fraud in clinical trials have attracted considerable media attention, but relatively little reaction from the biostatistical community. In this paper we argue that biostatisticians should be involved in preventing fraud (as well as unintentional errors), detecting it, and quantifying its impact on the outcome of clinical trials. We use the term 'fraud' specifically to refer to data fabrication (making up data values) and falsification (changing data values). Reported cases of such fraud involve cheating on inclusion criteria so that ineligible patients can enter the trial, and fabricating data so that no requested data are missing. Such types of fraud are partially preventable through a simplification of the eligibility criteria and through a reduction in the amount of data requested. These two measures are feasible and desirable in a surprisingly large number of clinical trials, and neither of them in any way jeopardizes the validity of the trial results. With regards to detection of fraud, a brute force approach has traditionally been used, whereby the participating centres undergo extensive monitoring involving up to 100 per cent verification of their case records. The cost-effectiveness of this approach seems highly debatable, since one could implement quality control through random sampling schemes, as is done in fields other than clinical medicine. Moreover, there are statistical techniques available (but insufficiently used) to detect 'strange' patterns in the data including, but no limited to, techniques for studying outliers, inliers, overdispersion, underdispersion and correlations or lack thereof. These techniques all rest upon the premise that it is quite difficult to invent plausible data, particularly highly dimensional multivariate data. The multicentric nature of clinical trials also offers an opportunity to check the plausibility of the data submitted by one centre by comparing them with the data from all other centres. Finally, with fraud detected, it is essential to quantify its likely impact upon the outcome of the clinical trial. Many instances of fraud in clinical trials, although morally reprehensible, have a negligible impact on the trial's scientific conclusions.

Biometry↗
PubMed1999

Preface

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Journal Article↗
PubMed1999

The kappa agonist fedotozine relieves hypersensitivity to colonic distention in patients with irritable bowel syndrome.

BACKGROUND & AIMS: Visceral hypersensitivity plays a major role in the pathophysiology of inflammatory bowel syndrome (IBS). Opioid kappa receptors on afferent nerves may modulate it and may be the target of new IBS treatments. The aim of this study was to evaluate the effects of fedotozine, a potent and selective kappa agonist, on responses to colonic distention and colonic compliance in patients with IBS. METHODS: Fourteen patients with IBS (Rome criteria; 50 +/- 12 years; 6 men and 8 women) were included in a randomized double-blind, crossover trial comparing the effect of an intravenous infusion of 100 mg fedotozine or saline on sensory thresholds elicited by left colon phasic distention (4-mm Hg steps for 5 minutes) up to a sensation of abdominal pain. Colonic compliance was compared by the slope of the pressure-volume curves built on placebo and on fedotozine. RESULTS: In the fedotozine group, thresholds of first perception (28.7 +/- 5.9 mm Hg) and pain (34.7 +/- 5.5 mm Hg) were significantly greater than with placebo (23.3 +/- 4.5 and 29.0 +/- 3.5 mm Hg, respectively; P = 0.0078). Colonic compliance was 9. 20 +/- 3.87 mL. mm Hg-1 with placebo and 8.73 +/- 3.18 mL. mm Hg-1 with fedotozine (not significant). CONCLUSIONS: Fedotozine increases thresholds of perception of colonic distention in patients with IBS without modifying colonic compliance. Fedotozine seems capable of reversing visceral hypersensitivity observed in these patients and could have some beneficial action on their symptoms.

Adult↗
PubMed1999

Validation of a specific quality of life questionnaire for functional digestive disorders.

BACKGROUND: Dyspepsia and irritable bowel syndrome are suitable conditions for assessment of quality of life. Their similarities justify the elaboration of a single specific questionnaire for the two conditions. AIMS: To examine the process leading to the validation of the psychometric properties of the functional digestive disorders quality of life questionnaire (FDDQL). METHODS: Initially, the questionnaire was given to 154 patients, to assess its acceptability and reproducibility, analyse its content, and reduce the number of items. Its responsiveness was tested during two therapeutic trials which included 428 patients. The questionnaire has been translated into French, English, and German. The psychometric validation study was conducted in France, United Kingdom, and Germany by 187 practitioners. A total of 401 patients with dyspepsia or irritable bowel syndrome, defined by the Rome criteria, filled in the FDDQL and generic SF-36 questionnaires. RESULTS: The structure of the FDDQL scales was checked by factorial analysis. Its reliability was expressed by a Cronbach's alpha coefficient of 0.94. Assessment of its discriminant validity showed that the more severe the functional digestive disorders, the more impaired the quality of life (p<0.05). Concurrent validity was supported by the correlation found between the FDDQL and SF-36 questionnaire scales. The final version of the questionnaire contains 43 items belonging to eight domains. CONCLUSIONS: The properties of the FDDQL questionnaire, available in French, English, and German, make it appropriate for use in clinical trials designed to evaluate its responsiveness to treatment among patients with dyspepsia and irritable bowel syndrome.

Adult↗