There is much debate about the effect on interpretation of results caused by the funding of studies by the pharmaceutical industry. This paper attempts to look for objective differences in results depending on the source of funding for studies on the adverse effects of inhaled corticosteroids.

A Medline search identified original articles on inhaled corticosteroids containing data on adverse effects between 1993 and 2002. The studies were analysed, blinded to funding source, by two authors who categorised side effects and authors’ conclusions on drug safety. If there was a discrepancy a third author had a casting vote. Comparison was then made between pharmaceutical industry funded (PF) and non-pharmaceutical industry funded (non-PF) studies.

Non-PF studies were more likely to report significant adverse effects than PF studies. However, the results became non-significant when confounders such as study design were taken into account. However, PF studies were more likely than non-PF studies to conclude a drug was safe when a statistically significant adverse event had occurred in the study. The current authors contacted the authors of non-PF papers (where the authors had not stated a funding source) and, of those who responded, 8.1% reported pharmaceutical funding and were reallocated in the current study.

This study indicates that authors’ conclusions may be influenced by funding sources and reiterates the importance of assessing funding and conflicts of interest when evaluating studies.

Nieto A, Mazon A, Pamies R, et al. Adverse effects of inhaled corticosteroids in funded and nonfunded studies. Arch Intern Med 2007;167:2047–53