The placebo group developed 30 cases over a 3-year period, about 10 cases per year
安慰剂组3年内出现了30例,大约每年10例
The vitamin D treated group developed only 9 cases
而维生素D服用组只有9例
That's a striking difference and highly statistically significant
差异明显,在统计学上有非常显著的意义
The problem with this kind of effect is that
这类现象的问题在于
unless you're in a study of this where you were carefully following the subjects from month to month and visit to visit
如果不是专门研究、仔细跟踪被试者,月复一月,一次又一次
you never would notice this, because the patients who don't get influenza don't come back to the doctor
是注意不到这个的,因为没有患流感的人是不会回头看医生的
I mean such obvious thing could make sense when you think about it that you wonder why didn't I think about that
想想这显然是说得通的
Much more recently, published just this year, this interesting study of Japanese school children
更近的研究,这是今年发表的关于日本学龄儿童的有趣研究
that was published in the American Journal of Clinical Nutrition
发表于美国临床营养学杂志
This is the relative risk of serologically proved influenza
这是血清上证明患流感的相对风险
with a relative risk of any individuals who were assigned to placebo being assigned one point zero
安慰剂服用者的相对风险设为1.0
Those who got vitamin D a very substantial reduction nearly 50% and those who had no other supplemental vitamin D even greater reduction
维生素D服用者显著减少近50%,而维生素D(没有其它补充)者减少更多
So clearly a protective effect in the double-blind placebo-controlled randomized trial under the circumstances
显然,双盲安慰剂对照随机试验显示了这种保护效果
One more piece of level one evidence showing protection
又一个一级证据证明了这个效果