ASCP Laboratory Operations 2

Question 1

In Westgard rules for quality control, the 1:3s rule means:

Accepted Answer

One QC result exceeds 3 standard deviations from the mean — reject the run

Answer

The 1:3s rule is a rejection rule: if any single QC result falls outside mean plus or minus 3 SD, the run is rejected. This primarily detects random error with high probability of error detection and a low false rejection rate.

Question 2

Reference interval verification in a new laboratory minimally requires:

Accepted Answer

At least 20 healthy subjects when adopting manufacturer or published reference intervals

Answer

CLSI EP28-A3c allows reference interval verification (not full establishment) with a minimum of 20 healthy reference individuals. If 2 or fewer of 20 results fall outside the claimed reference interval, the interval is considered verified for that population.

Question 3

The delta check in laboratory medicine is designed to detect:

Accepted Answer

Significant changes in a patient's results that may indicate specimen mislabeling or acute clinical change

Answer

A delta check compares a patient's current result to a previous result within a defined time window. An unexpected delta (change greater than established limits) triggers investigation for specimen mislabeling (most common cause) or a true rapid clinical change.

Question 4

Which ISO standard is specifically designed for medical laboratory quality management?

Accepted Answer

ISO 15189

Answer

ISO 15189 is the international standard specifically for medical laboratories, addressing quality management and technical competence. It is based on ISO 17025 (testing laboratories) but adapted for the unique requirements of clinical laboratory medicine.

Question 5

When a critical (panic) value is generated for a patient, what is the immediate required action?

Accepted Answer

Immediately notify the responsible healthcare provider and document the communication

Answer

CLIA requires immediate notification of responsible clinical personnel when critical values are obtained. The laboratory must notify the provider or designee, document the date, time, result, and name of person notified. Documentation is mandatory.

ASCP Practice Test

ASCP Practice Test

ASCP Laboratory Operations 2