Data from: Non-industry sponsored preclinical studies on statins yield greater efficacy estimates than industry-sponsored studies: a meta-analysis

Industry-sponsored clinical drug studies are associated with publication of outcomes that favor the sponsor, even when controlling for potential bias in the methods used. However, the influence of sponsorship bias has not been examined in preclinical animal studies. We performed a meta-analysis of preclinical statin studies to determine whether industry sponsorship is associated with either increased effect sizes of efficacy outcomes and / or risks of bias in a cohort of published preclinical statin studies. We searched Medline (January 1966 - April 2012) and identified 63 studies evaluating the effects of statins on atherosclerosis outcomes in animals. Two coders independently extracted study design criteria aimed at reducing bias, results for all relevant outcomes, sponsorship source, and investigator financial ties. The I2 statistic was used to examine heterogeneity. We calculated the standardized mean difference (SMD) for each outcome and pooled data across studies to estimate the pooled average SMD using random effects models. In a priori subgroup analyses, we assessed statin efficacy by outcome measured, sponsorship source, presence or absence of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. The effect of statins was significantly larger for studies sponsored by non-industry sources (-1.99; 95% CI -2.68, -1.31) versus studies sponsored by industry (-0.73; 95% CI -1.00, -0.47) (p value < 0.001). Statin efficacy did not differ by disclosure of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. Possible reasons for the differences between non-industry and industry sponsored studies, such as selective reporting of outcomes, require further study.即便在控制所用方法中潜在偏倚的前提下，企业资助的临床药物研究仍更易发表有利于资助方的研究结果。然而，资助偏倚的影响尚未在临床前动物研究中得到考察。本研究针对已发表的他汀类药物（statin）临床前动物研究队列开展了一项荟萃分析，旨在明确企业资助是否与疗效结局的效应量增大及/或偏倚风险升高相关。我们检索了MEDLINE数据库（1966年1月-2012年4月），共纳入63项评估他汀类药物对动物动脉粥样硬化结局影响的研究。两名评阅员独立提取了旨在减少偏倚的研究设计标准、所有相关结局指标的结果、资助来源以及研究者的经济利益关联情况。采用I²统计量检验研究间异质性。我们计算了每项结局的标准化均数差（standardized mean difference, SMD），并整合各项研究的数据，使用随机效应模型估算合并后的平均标准化均数差。在预先设定的亚组分析中，我们根据所测量的结局指标、资助来源、是否披露利益冲突信息、是否使用结局评估的最优时间窗、是否纳入全部实验动物、纳入标准、盲法以及随机化情况，对他汀类药物的疗效进行了评估。结果显示，非企业资助的研究中他汀类药物的效应量显著更大（-1.99；95%置信区间[CI]：-2.68~-1.31），而企业资助的研究中该值为-0.73（95%CI：-1.00~-0.47），组间差异具有统计学意义（p<0.001）。他汀类药物的疗效在是否披露利益冲突信息、是否使用结局评估最优时间窗、是否纳入全部实验动物、纳入标准、盲法以及随机化情况方面均无显著差异。非企业资助与企业资助研究间的差异可能的原因（如结局指标的选择性报告）尚需进一步开展研究。