Screening for clinical laboratory errors with Medicare claims data: results for digoxin

Area of Science:

• Clinical Chemistry
• Health Services Research
• Laboratory Medicine

Background:

• Clinical laboratory testing is crucial for patient care.
• Identifying laboratories with high rates of adverse events can indicate potential testing errors.
• Digoxin testing is a common diagnostic procedure with potential for adverse events if errors occur.

Purpose of the Study:

• To develop and demonstrate a statistical model for identifying outpatient clinical laboratories with high frequencies of adverse patient outcomes following digoxin testing.
• To investigate factors associated with adverse events, such as laboratory regulations, testing site, and testing volume.

Main Methods:

• Analysis of Medicare Part A and Part B claims data for 30,685 digoxin tests conducted between 1985 and 1987.
• Definition of "adverse events" as deaths or digoxin-related hospitalizations within 14 days of testing.
• Statistical modeling to assess the relationship between adverse events and laboratory characteristics.

Main Results:

• Approximately 3.3% of digoxin tests were followed by adverse events, with two-thirds leading to hospitalization or death.
• Adverse events were less frequent in states with stronger laboratory regulations.
• Adverse events were 15% higher when the testing site was switched.
• Adverse events were unrelated to testing volume in physician office laboratories or prior testing frequency.

Conclusions:

• The developed statistical model can identify clinical laboratories with potentially erroneous testing leading to adverse patient outcomes.
• Laboratory regulation stringency and testing site consistency are important factors in minimizing adverse events.
• Differences in findings compared to prothrombin testing suggest test-specific technical characteristics influence adverse event rates.