Henry D A, Evans D B, Robertson J
Faculty of Medicine, Royal Newcastle Hospital, NSW.
Med J Aust. 1991 Jun 3;154(11):766-72.
To estimate the reduction in mortality associated with a reduced adverse reaction rate following the substitution of older high osmolar radiocontrast media (HOCM) by the newer and more expensive low osmolar contrast media (LOCM), and to assess the cost-effectiveness of switching from HOCM to LOCM in patients with and without underlying risk factors for adverse reactions from radiocontrast agents.
Data from large prospective studies of adverse reactions to HOCM and LOCM were used to estimate the expected number of deaths and severe non-fatal reactions in a hypothetical population receiving one million intravenous radiocontrast injections with HOCM, and the expected reduction in the frequency of these outcomes after substitution by LOCM in high-risk and low-risk groups respectively. Life-years lost with each radiocontrast-related death were estimated from an audit of fatal adverse reaction reports submitted to the Adverse Drug Reactions Advisory Committee. The direct costs considered in the study were the increased costs of LOCM and the hospital costs of treating radiocontrast reactions which were estimated from an audit of cases admitted to public hospitals in Newcastle.
The literature search included Medline (1966-1989) and bibliographies of original and review articles. We included only studies which were prospective, monitored patients in a formal way, described a mechanism for the recording of adverse events and were of sufficient size to have been capable of detecting severe reactions to radiocontrast agents.
Data were extracted independently by two investigators, unblinded, with disagreements resolved by consensus.
Mortality data from individual reports were pooled and exact confidence intervals were calculated on the assumption of a Poisson distribution. In the case of comparative studies the relative risks of severe reactions in low-risk versus high-risk patients and with LOCM compared with HOCM were treated for homogeneity, and pooled odds ratios and 95% confidence intervals (CI) were calculated by combining the logarithms of the odds ratios weighted by their variances.
The mortality after intravenous administration of HOCM was estimated from all studies to be 23.3 (95% CI, 2.4-33.1) per million injections. However, the mortality was 11.7 per million (95% CI, 2.4-34.1) in studies published since 1986. The mortality after the use of LOCM was estimated as 3.9 per million (95% CI, 0.1-21.7).(ABSTRACT TRUNCATED AT 400 WORDS)
评估用更新且更昂贵的低渗性造影剂（LOCM）替代旧的高渗性造影剂（HOCM）后，因不良反应率降低所带来的死亡率下降情况，并评估在有和没有造影剂不良反应潜在危险因素的患者中，从HOCM转换为LOCM的成本效益。
来自对HOCM和LOCM不良反应的大型前瞻性研究的数据，用于估计在接受100万次静脉注射HOCM的假设人群中预期的死亡和严重非致命反应数量，以及分别在高风险和低风险组中用LOCM替代后这些结果发生频率的预期降低情况。通过对提交给药物不良反应咨询委员会的致命不良反应报告进行审核，估计每次与造影剂相关死亡所损失的生命年数。研究中考虑的直接成本是LOCM增加的成本以及治疗造影剂反应的医院成本，这些成本是根据对纽卡斯尔公立医院收治病例的审核估算得出的。
文献检索包括Medline（1966 - 1989年）以及原始文章和综述文章的参考文献目录。我们仅纳入前瞻性研究、以正规方式监测患者、描述了不良事件记录机制且规模足够大能够检测到造影剂严重反应的研究。
由两名研究人员独立提取数据，不设盲，分歧通过协商解决。
汇总来自个体报告的死亡率数据，并在泊松分布假设下计算精确的置信区间。对于比较研究，低风险与高风险患者以及LOCM与HOCM相比严重反应的相对风险进行同质性处理，并通过合并以方差加权的比值比的对数来计算合并比值比和95%置信区间（CI）。
所有研究估计静脉注射HOCM后的死亡率为每百万次注射23.3（95%CI，2.4 - 33.1）。然而，1986年以后发表的研究中死亡率为每百万次11.7（95%CI，2.4 - 34.1）。使用LOCM后的死亡率估计为每百万次3.9（95%CI，0.1 - 21.7）。（摘要截断于400字）
