It is also very important to corroborative evidence from their family.是什么意思？

It is also very important to corroborative evidence from their family.

当然,家属对于病人认知能力下降的察觉也是诊断此症状的关键.

it

pron. 它，他，正好是所需的，事实[情况]；n. <美俚>傻瓜，笨蛋，<俚>绝妙的人，理想的东西，登峰造极；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

is

vt.& vi. 是（be的三单形式；n. 存在；

例句
Bollinger 'RD' is a rare, highly prized wine.
博林格RD香槟是一种名贵的备受推崇的葡萄酒。

also

adv. 也，同样，并且；conj. 另外；

例句
The media have also abetted the feeling of unreality.
媒体也在一旁对这种非现实感推波助澜。

very

adj. 很，非常，恰好是，正是，十足的，特有的；adv. 很，非常，充分，完全；

例句
Most people have very little difficulty in seeing why a Van Gogh is a work of genius.
多数人不难理解为什么凡·高的作品是天才之作。

important

adj. 重要的，权威的，有势力的，有地位的；

例句
The presence or absence of clouds can have an important impact on heat transfer...
有无云层对热量的传递会产生重要的影响。

to

prep. 向，朝着，到，关于，属于；adv. 朝一个方向的，到某种状态，关闭；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

corroborative

adj. 确证（性）的，确凿的；

例句
...a written statement supported by other corroborative evidence.
由其他证据支持的书面陈述

evidence

n. 证词，证据，迹象，明显；vt. 使明显，显示，表明，证实；

例句
...scientific evidence that did not fully accord with the facts uncovered by the police.
与警方所掌握的情况不完全一致的科学证据

from

prep. （表示时间）从…，（表示原因）因为，（表示来源）来自…，（表示分离）与…分离[隔开]；

例句
...an abortive attempt to prevent the current President from taking office.
企图阻止现任总统连任的失败尝试

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

family

n. 家庭，家族，孩子，祖先；adj. 家庭的，一家所有的，属于家庭的，适合全家人的；

例句
Almost like an accident of nature, this family has produced more talent than seems possible.
就像是天缘巧合，这个家族不可思议地人才辈出。