Management of severe hypokalemia in hospitalized patients: A study of quality of care based on computerized databases

Background: While administrative databases are used to assess general indicators of quality of care, a detailed audit of the process of clinical care usually requires review of hospital medical records. Objective: To evaluate the feasibility of assessing the management of severe hypokalemia using computerized administrative and laboratory databases. Methods: The study included all patients hospitalized in 1997 who experienced serum potassium levels of less than 3.0 mmol/L at Hadassah University Hospital, Jerusalem, Israel, a tertiary care center. Using the computerized databases, we measured the following: (1) whether a subsequent serum potassium test was performed, (2) time to the subsequent test and to normalization of the serum potassium level, (3) achievement of normokalemia, and (4) in-hospital mortality. In a random subsample of 100 patients, these measures were compared with the blinded assessment of the quality of medical management of hypokalemia, as determined from medical records, using predetermined criteria for adequate management. Results: The computerized databases revealed that severe hypokalemia occurred in 866 patients (2.6% of the yearly hospitalizations): 55 patients (6.4%) had no subsequent serum potassium levels measured, and 260 (30.0%) were discharged from the hospital with a subnormal potassium level. The mean time to a subsequent test was 20 hours, and to normokalemia, 50 hours; both intervals varied by department. In-hospital mortality was 20.4%, or 10-fold that of the entire hospitalized population. A review of hospital medical records revealed inadequate clinical management of hypokalemia in 24%, which was associated with nonperformance of a subsequent test (likelihood ratio, 8.4), failure to normalize the serum potassium level (likelihood ratio, 4.2), discharge from the hospital with a subnormal potassium level (likelihood ratio, 2.1), and in-hospital death (likelihood ratio, 2.5), all of which could be determined by the computerized databases. Conclusions: The computerized laboratory database is useful in ascertaining the prevalence of severe hypokalemia and in assessing shortcomings in its management. Databases can be used to derive valid and efficient measures of the quality of the clinical management of electrolyte disorders.