Establishing, harmonizing and analyzing critical values in a large academic health center

Background: No report on establishing critical values (CVs) lists has described a process for harmonizing different lists in a large academic health center or validation on follow-up after 5 years. Methods: A definition of a critical value was adopted. CVs in use and reporting times for chemistry, hematology and coagulation (CH&C) tests during a 1-week period at one hospital were analyzed prior to the revision and again 5 years later. Results: CVs lists in use by the different campus hospital laboratories were reviewed for compliance with the definition for a critical value. Lists were harmonized with a total of 37 CH&C tests, five of these included adult and either cord blood or neonatal values. Overall, 26 tests were eliminated, 61 individual values were changed and two tests were added. The revised CVs list reduced the number of calls at one primary teaching hospital by 33%. In the next 5-year period, value thresholds changed (n=2) and one value was re-instated (n=1). When retrospectively examined for impact, one value change was considered appropriate. Conclusions: CVs lists were harmonized among campus hospitals. Tests not considered critical were removed and values adjusted for uniformity. Changes in CVs lists should be evaluated for appropriateness. A process is now in place for periodic review and considerations related to CVs lists.