Clemens J D, Chuong J J, Feinstein A R
JAMA. 1983 May 6;249(17):2362-9.
Because of the conflicting results of eight major controlled trials, BCG vaccination against tuberculosis remains controversial despite more than 50 years of use. Suspecting a methodological source for the controversy, we reviewed the scientific and statistical quality of each trial. The analysis showed that (1) although biased allocation of the vaccine appeared an unlikely explanation for the disparate results, adequate demonstration of unbiased detection of tuberculosis was available only for the three trials reporting 75% or greater protective efficacy; and (2) in most trials reporting low efficacy, the results had wide confidence intervals that could not exclude high efficacy, but the trials reporting high efficacy all had narrow confidence intervals that excluded low efficacy. Because the trials with the best methodological quality and greatest statistical precision reported high efficacy, the evidence suggests that BCG can confer a high degree of protection against tuberculosis and that bias or inadequate statistical power may have contributed to the conflicting data.
由于八项主要对照试验结果相互矛盾，尽管卡介苗已使用了五十多年，但针对结核病的卡介苗接种仍存在争议。我们怀疑争议源于方法学问题，因此对每项试验的科学和统计质量进行了审查。分析表明：（1）尽管疫苗分配有偏差似乎不太可能解释结果的差异，但仅在三项报告保护效力达75%或更高的试验中，才有足够证据证明结核病检测无偏差；（2）在大多数报告效力较低的试验中，结果的置信区间很宽，无法排除高效力，但报告高效力的试验其置信区间都很窄，排除了低效力。由于方法学质量最佳且统计精度最高的试验报告了高效力，因此有证据表明卡介苗可提供高度的结核病防护，而偏差或统计效力不足可能导致了数据冲突。
