CMS SOM App. C, Tag D5777

(b) The laboratory must have a system to identify and assess patient test results that

appear inconsistent with the following relevant criteria, when available:

(b)(1) Patient age.

(b)(2) Sex.

(b)(3) Diagnosis or pertinent clinical data.

(b)(4) Distribution of patient test results.

(b)(5) Relationship with other test parameters.

Interpretive Guidelines §493.1281(b)

The laboratory must have a system in place to monitor and evaluate test results for

inconsistencies with patient information, and for correlation between test results. For

example, a laboratory could multiply the hemoglobin result by a factor of 3, to see if the

result is equal to the hematocrit.

If the laboratory has auto-validation in its Laboratory Information System (LIS), they

must take steps to reduce the likelihood of sample-switching errors. For example, when

the creatinine result is significantly different from the patient’s previous creatinine test

results, or if the MCV is significantly different from the patient’s previous test results and

the patient did not receive a blood transfusion.

For automated laboratories, inconsistent patient results may be evaluated through the use

of verified LIS supported logic, patient distribution test results, verified automated test

comparison logic programs and individual test repeat criteria.

Probes §493.1281(b)

How does the laboratory obtain sufficient information to enable an evaluation of test

results with clinically relevant patient information?

Does the laboratory have procedures to assess and evaluate patient test results for

inconsistencies?

For example:

• Hemoglobin and Hematocrit (MCHC value exceeds reference range);

• BUN and Creatinine comparison;

• Albumin and Total Protein;

• Correlation of urine culture with urine microscopic; and

• Alkaline phosphatase with orthopedic surgical patients and/or pediatric patients;

and

• Correlation of microscopic sediment findings with macroscopic results, such as,

the presence of protein with casts, positive occults blood with red cells, and

positive leukocyte esterase with white cells.

§493.1281 Standard: Comparison of test results.

(c) The laboratory must document all test result comparison activities.

Interpretive Guidelines §493.1281(c)

The actual measurement(s) of test results and comparison activities must be recorded.

Acceptable formats for documentation may vary. Cite documentation deficiencies at

§493.1281(a) or §493.1281(b). Use D5775 or D5777, as appropriate.