Next SectionBackground Scientific papers are retracted for many reasons including fraud (data fabrication or falsification) or error (plagiarism, scientific mistake, ethical problems). Growing attention to fraud in the lay press suggests that the incidence of fraud is increasing. Methods The reasons for retracting 742 English language research papers retracted from the PubMed database between 2000 and 2010 were evaluated. Reasons for retraction were initially dichotomised as fraud or error and then analysed to determine specific reasons for retraction. Results Error was (...) more common than fraud (73.5% of papers were retracted for error (or an undisclosed reason) vs 26.6% retracted for fraud). Eight reasons for retraction were identified; the most common reason was scientific mistake in 234 papers (31.5%), but 134 papers (18.1%) were retracted for ambiguous reasons. Fabrication (including data plagiarism) was more common than text plagiarism. Total papers retracted per year have increased sharply over the decade (r=0.96; p<0.001), as have retractions specifically for fraud (r=0.89; p<0.001). Journals now reach farther back in time to retract, both for fraud (r=0.87; p<0.001) and for scientific mistakes (r=0.95; p<0.001). Journals often fail to alert the naïve reader; 31.8% of retracted papers were not noted as retracted in any way. Conclusions Levels of misconduct appear to be higher than in the past. This may reflect either a real increase in the incidence of fraud or a greater effort on the part of journals to police the literature. However, research bias is rarely cited as a reason for retraction. (shrink)

Background Papers retracted for fraud (data fabrication or data falsification) may represent a deliberate effort to deceive, a motivation fundamentally different from papers retracted for error. It is hypothesised that fraudulent authors target journals with a high impact factor (IF), have other fraudulent publications, diffuse responsibility across many co-authors, delay retracting fraudulent papers and publish from countries with a weak research infrastructure. Methods All 788 English language research papers retracted from the PubMed database between 2000 and 2010 were evaluated. Data (...) pertinent to each retracted paper were abstracted from the paper and the reasons for retraction were derived from the retraction notice and dichotomised as fraud or error. Data for each retracted article were entered in an Excel spreadsheet for analysis. Results Journal IF was higher for fraudulent papers (p<0.001). Roughly 53% of fraudulent papers were written by a first author who had written other retracted papers (‘repeat offender’), whereas only 18% of erroneous papers were written by a repeat offender (χ=88.40; p<0.0001). Fraudulent papers had more authors (p<0.001) and were retracted more slowly than erroneous papers (p<0.005). Surprisingly, there was significantly more fraud than error among retracted papers from the USA (χ2=8.71; p<0.05) compared with the rest of the world. Conclusions This study reports evidence consistent with the ‘deliberate fraud’ hypothesis. The results suggest that papers retracted because of data fabrication or falsification represent a calculated effort to deceive. It is inferred that such behaviour is neither naïve, feckless nor inadvertent. (shrink)

Background Clinical papers so flawed that they are eventually retracted may put patients at risk. Patient risk could arise in a retracted primary study or in any secondary study that draws ideas or inspiration from a primary study. Methods To determine how many patients were put at risk, we evaluated 788 retracted English-language papers published from 2000 to 2010, describing new research with humans or freshly derived human material. These primary papers—together with all secondary studies citing them—were evaluated using ISI (...) Web of Knowledge. Excluded from study were 468 basic science papers not studying fresh human material; 88 reviews presenting older data; 22 case reports; 7 papers retracted for journal error and 23 papers unavailable on Web of Knowledge. Overall, 180 retracted primary papers (22.8%) met the inclusion criteria. Subjects enrolled and patients treated in 180 primary studies and 851 secondary studies were combined. Results Retracted papers were cited over 5000 times, with 93% of citations being research related, suggesting that ideas promulgated in retracted papers can influence subsequent research. Over 28 000 subjects were enrolled—and 9189 patients were treated—in 180 retracted primary studies. Over 400 000 subjects were enrolled—and 70 501 patients were treated—in 851 secondary studies which cited a retracted paper. Papers retracted for fraud (n=70) treated more patients per study (p<0.01) than papers retracted for error (n=110). Conclusions Many patients are put at risk by retracted studies. These are conservative estimates, as only patients enrolled in published clinical studies were tallied. (shrink)

Background Medical research so flawed as to be retracted may put patients at risk by influencing treatments. Objective To explore hypotheses that more patients are put at risk if a retracted paper appears in a journal with a high impact factor (IF) so that the paper is widely read; is written by a ‘repeat offender’ author who has produced other retracted research; or is a clinical trial. Methods English language papers (n=788) retracted from the PubMed database between 2000 and 2010 (...) were evaluated. Only those papers retracting research with humans or freshly derived human material were included; 180 retracted primary papers (22.8%) met inclusion criteria. Subjects enrolled and patients treated were tallied, both in the retracted primary studies and in 851 secondary studies that cited a retracted primary paper. Results Retracted papers published in high-IF journals were cited more often (p=0.0004) than those in low-IF journals, but there was no difference between high- and low-IF papers in subjects enrolled or patients treated. Retracted papers published by ‘repeat offender’ authors did not enrol more subjects or treat more patients than papers by one-time offenders, nor was there a difference in number of citations. However, retracted clinical trials treated more patients (p=0.0002) and inspired secondary studies that put more patients at risk (p=0.0019) than did other kinds of medical research. Conclusions If the goal is to minimise risk to patients, the appropriate focus is on clinical trials. Clinical trials form the foundation of evidence-based medicine; hence, the integrity of clinical trials must be protected. (shrink)

Media attention to retracted research suggests that a substantial number of papers are corrupted by misinformation. In reality, every paper contains misinformation; at issue is whether the balance of correct versus incorrect information is acceptable. This paper postulates that analysis of retracted research papers can provide insight into medical misinformation, although retracted papers are not a random sample of incorrect papers. Error is the most common reason for retraction and error may be the principal cause of misinformation as well. Still, (...) one-quarter of retracted papers are fraudulent, and misinformation may also arise through fraud. This paper hypothesises that error and fraud are the main sources of misinformation and that error is more common than fraud. Retraction removes misinformation from the literature; bias is non-retracted misinformation. Bias arises when scientific impropriety results in false research findings. Impropriety can involve experimental design, data collection, data analysis, or data presentation. Yet impropriety also arises through earnest error or statistical naiveté; not all bias is fraud. Several measures are proposed to minimise misinformation in the medical literature, including: greater detail in the clinical trial registry, with rigorous definition of inclusion and exclusion criteria and primary endpoints; clear statistical criteria for every aspect of clinical trials, especially sample size; responsibility for data integrity that accrues to all named authors; increased transparency as to how the costs of research were paid; and greater clarity as to the reasons for retraction. Misinformation can arise without malicious intent; authors of incorrect papers are owed a presumption of incompetence, not malice. (shrink)