Prevalence and Outcomes of Pharmaceutical Industry-Sponsored Clinical Trials Involving Clozapine, Risperidone, or Olanzapine

Article excerpt

Objective: The literature continues to highlight the debate on the ethics and merits of trials sponsored by the pharmaceutical industry. This study attempts to determine the prevalence and outcomes of industry-sponsored trials involving clozapine, risperidone, or olanzapine.

Methods: We searched the literature from January 1, 1990, to December 31, 2001, to capture all eligible clinical trials involving clozapine, risperidone, or olanzapine. The primary outcome measured was the clinical outcome of industry-sponsored studies. Secondary outcome measures included the following parameters: disclosure of any sponsorship and financial support, author(s) employed by the industry, use of comparator drug(s) within the trial, sample size, blinding, and use of placebo.

Results: The database comprised 372 articles. Of these trials, 124 (33.3%) were sponsored by the pharmaceutical industry. In general, trials sponsored by Eli Lilly or Janssen had better research design than trials not funded by the pharmaceutical industry. With regard to authorship, more trials funded by Eli Lilly (74.6%) were coauthored by an employee of the company, compared with trials funded by either Janssen (23.3%) or Novartis/Sandoz (5.6%). Further, more trials sponsored by Eli Lilly reported positive outcomes (92.1%), compared with Janssen-sponsored trials (88.4%) and Sandoz/Novartis-sponsored trials (72.2%). No negative results were reported in any of the industry-funded trials.

Conclusions: One-third of the published clinical trials involving clozapine, risperidone, or olanzapine were funded by their respective manufacturer. The reported outcomes of the sponsored trials highly favour the manufacturer's product.

(Can J Psychiatry 2004;49:601-606)

Information on funding and support and author affiliations appears at the end of the article.

Clinical Implications

* More than ever, clinicians are developing partnerships with the pharmaceutical industry for the purpose of participating in clinical trials.

* Trials sponsored by the pharmaceutical industry are often of higher quality than publicly funded studies.

* Outcomes of pharmaceutical industry-sponsored trials highly favour their own product.

Limitations

* Although every effort was made to obtain all articles from the literature search, this was not possible.

* It is possible that disclosure of funding and conflicts of interest were underreported.

Key Words: clinical trials, conflict of interest, research support

Clinical trials are widely accepted as invaluable tools providing evidence-based guidance to practising clinicians. Ideally, when clinical trials are designed, investigators should pose scientific questions that primarily intend to make available better and safer treatments for a target population. When properly conducted, these clinical trials become the cornerstones for evidence-based medicine, which is the standard of care in most medical practices. Evidence-based medicine has been defined as "the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients" (1). Within this context, best evidence is derived from clinical trials (that is, external evidence) that have been critically appraised for validity and importance.

Since the introduction of the atypical antipsychotics into the clinical practice of psychiatry, clinical trials have increased in number, size, and of course, cost. With limited private funding available to conduct independent studies, it is not surprising that the number of clinical trials sponsored by the pharmaceutical industry continues to grow. It follows that there should also be an increase in the number of partnerships developed between the pharmaceutical industry and clinicians or academics. Although skepticism in regard to this alliance has been and continues to be expressed, the many benefits of the new reality have also been acknowledged. …