Negative pressure wound therapy: Potential publication bias caused by lack of access to unpublished study results data

<p>Abstract</p> <p>Background</p> <p>Negative pressure wound therapy (NPWT) is widely applied, although the evidence base is weak. Previous reviews on medical interventions have shown that conclusions based on published data alone may no longer hold after consideration of unpublished data. The main objective of this study was to identify unpublished randomised controlled trials (RCTs) on NPWT within the framework of a systematic review.</p> <p>Methods</p> <p>RCTs comparing NPWT with conventional wound therapy were identified using MEDLINE, EMBASE, CINAHL and The Cochrane Library. Every database was searched from inception to May 2005. The search was updated in December 2006. Reference lists of original articles and systematic reviews, as well as congress proceedings and online trial registers, were screened for clues to unpublished RCTs. Manufacturers of NPWT devices and authors of conference abstracts were contacted and asked to provide study information. Trials were considered nonrandomised if concealment of allocation to treatment groups was classified as "inadequate". The study status was classified as "completed", "discontinued", "ongoing" or "unclear". The publication status of completed or discontinued RCTs was classified as "published" if a full-text paper on final study results (completed trials) or interim results (discontinued trials) was available, and "unpublished" if this was not the case. The type of sponsorship was also noted for all trials.</p> <p>Results</p> <p>A total of 28 RCTs referring to at least 2755 planned or analysed patients met the inclusion criteria: 13 RCTs had been completed, 6 had been discontinued, 6 were ongoing, and the status of 3 RCTs was unclear. Full-text papers were available on 30% of patients in the 19 completed or discontinued RCTs (495 analysed patients in 10 published RCTs vs. 1154 planned patients in 9 unpublished RCTs). Most information about conference abstracts and unpublished study information referring to trials that were unpublished at the time these documents were generated was obtained from the manufacturer Kinetic Concepts Inc. (KCI) (19 RCTs), followed by The Cochrane Library (18) and a systematic review (15). We were able to obtain some information on the methods of unpublished RCTs, but results data were either not available or requests for results data were not answered; the results of unpublished RCTs could therefore not be considered in the review. One manufacturer, KCI, sponsored the majority of RCTs (19/28; 68%). The sponsorship of the remaining trials was unclear.</p> <p>Conclusion</p> <p>Multi-source comprehensive searches identify unpublished RCTs. However, lack of access to unpublished study results data raises doubts about the completeness of the evidence base on NPWT.</p

Antithyroid drug-induced aplastic anemia

Background: Antithyroid drugs have been used for more than 50 years for the management of hyperthyroidism. Most patients tolerate treatment well but some may develop life threatening side effects such as agranulocytosis and aplastic anemia (AA). We review all cases of antithyroid drug induced AA and describe, as illustrative cases, two women with Graves&apos; disease who developed AA after 8 and 24 weeks of carbimazole (CBM) and methimazole (MMI) treatment respectively. Patient findings and summary: To date, at least 34 cases of aplastic anemia (AA) due to antithyroid drugs [(1 with CMZ, 31 with MMI, and 2 with propylthiouracil (PTU)] have been published, not including the two patients described here. In addition, at least another 14 patients in whom AA developed after treatment with antithyroid drugs (11 with CMZ, and 3 with MMI) have been reported in Yellow Card Scheme data analysis. Patients with AA usually exhibit sudden onset of symptoms after a relative short time of exposure to the drugs, and all have concomitant agranulocytosis. Most have a rapid recovery following discontinuation of the drug and supportive treatment. Although only two antithyroid drug induced AA deaths have been published, the mortality rate was higher in the Yellow Card Scheme data analysis. Conclusions: Aplastic anemia associated with antithyroid drug treatment is rarer than antithyroid drug associated agranulocytosis. The prognosis of patients with antithyroid drug induced AA is good overall, but may not be as favorable as that of antithyroid drug induced isolated agranulocytosis. © Copyright 2008, Mary Ann Liebert, Inc