Publication bias in the medical literature: A review by a Canadian research ethics board

BACKGROUND: We reviewed the publication record of all protocols submitted to the Capital District Health Authority Research Ethics Board (REB) in Halifax, Nova Scotia, for the period 1995-1996. Because of a heightened awareness of the issue, we hypothesized that there would be less publication bias (a failure to report negative results) and a higher publication rate from completed studies, than previously reported. METHODS: Closed studies were identified from the REB database. Publications were identified by the investigators, requests from sponsors, and a literature review. For each publication, we identified authors, title, journal, number of subjects enrolled, and whether or not the publication was a report of a randomized clinical trial. Comparisons were done using a Student's t test, the Chi-square statistic, or Fisher's exact test as appropriate. RESULTS: From the database of closed studies, 106 remained unpublished, while completed investigations resulted in 84 publications (44% publication rate). The median time to publication was 32.5 months. Publication of statistically significant results occurred in 71/84 trials. Publication of protocols submitted by departments ranged from 91% (anesthesia; 10/11) to 25% [nursing; 2/8 (P<0.05)]. Trials investigating new drugs in Phase 3 or 4 studies were more likely to be published than trials investigating agents in Phase 1 or 2 (P<0.05), and were less likely to be published if sponsored by a pharmaceutical company (P<0.05). CONCLUSIONS: Publication bias continues to be a problem, particularly for early phase investigative studies. Our results suggest that a different approach is required to reduce publication bias. The role that REBs and peer-reviewed journals might play requires further exploration.     

Influenza A pneumonia presenting as progressive focal infiltrates in a stem cell transplant recipient.

BACKGROUND: Stem cell transplant recipients are susceptible to pulmonary infections, including influenza A. Typically, isolated influenza pneumonia has a diffuse, interstitial infiltrate pattern. OBJECTIVES: To describe the unusual clinical and radiographic course of influenza A pneumonia in a stem cell transplant recipient. STUDY DESIGN: Case report in which microbiologic assays, bronchoscopic and pathologic specimens are obtained. RESULTS: We describe a patient with influenza A pneumonia 8 months following a peripheral blood stem cell transplant who presented with minimal respiratory symptoms and rapidly progressing, focal pulmonary infiltrates. The large size and appearance of the masses have not been reported before in a patient with isolated influenza. CONCLUSION: This case highlights the differences of presentation and importance of early diagnosis and treatment of immunocompromised patients infected with influenza.     

Detection and localization of single-base sequence differences in foot-and-mouth disease virus genomes by the RNase mismatch cleavage method.

The RNase mismatch cleavage method was examined for its efficiency of indicating single-base sequence differences in the capsid protein-coding regions of different foot-and-mouth disease virus subtype O1 strains. The method was found suitable for indicating such differences. RNase A as well as RNase T1 contributed to substrate conversion. Examples for the cleavage of eleven different single-base mismatches in RNA double-strands are now known. All virus genomes found to differ from each other exhibited three or more non-neighboured single-base sequence differences. Other genomes found to be indistinguishable by this method were those of a recent field isolate adapted to cell culture, and those of a vaccine production strain; its progeny was transmitted to pig and cow and then analyzed. The results suggest that host change does not necessarily select for antigenic variant virus, and that virus submitted to some kind of selection pressure is changed at more than one position.     

The incidence of gout in patients with Dupuytren's disease.

In a retrospective study we found that the incidence of gout in patients with Dupuytren's disease is 3.5%. The mean serum uric acid was 330 mumol/l. (5.5 mg./100 ml.) in men and 240 mumol./l. (4.0 mg./100 ml.) in women. The rate of hyperuricaemia was 7%. These are not significantly higher than the expected figures in Britain.     

Phase mapping from left ventricular radionuclide ventriculograms: interobserver reliability and accuracy of the programme

Phase analysis of data from radionuclide ventriculograms is known to provide space-time information on the mechanical emptying of pixels located in the ventricular regions. It could therefore perhaps be useful for detecting abnormal sequences of contraction of the ventricles as well as to localize sites of premature electromechanical action. The phase programme used in this investigation is designed to trace the electromechanical action of the ventricles from colour-coded phase images (first harmonic Fourier transform), not only visually from a cinematic representation, but particularly from a data output of x, y coordinates and phase angles of sites chosen as they empty in the ventricular regions. Six healthy baboons were subjected to conventional radionuclide ventriculography, performed hourly for the duration of 11 h under anaesthesia. The programme was used by two independent observers to map the progression of emptying for each of the thus acquired 66 left ventricular phase images. The interobserver reliability and the accuracy achieved in mapping normal contraction patterns was found to be good. Abnormalities which appeared during the prolonged anaesthesia and which were confirmed with 12 lead electrocardiography were likewise detected consistently.