Quality system essentials $($QSEs$)$ form the foundation $o{\displaystyle \underset{\phantom{}}{\overset{f}{}}}$ a quality management system. QSEs are also:

Mandated by regulatory, standard$-$setting and accrediting agencies.

The management infrastructure that supports the workflow of the laboratory.

A part of providing quality patient care.

Maintained by specifically trained supervisory personnel.

Required to have input from patient advocates.

$2,3$ and $4.$

$2,3$ and $5.$

$1$ and $4.$

$1,2$ and $3.$