Searching for inaccuracy in clinical laboratory testing using Medicare data. Evidence for prothrombin time

Area of Science:

• Clinical laboratory science
• Health services research
• Quality assurance

Background:

• Clinical laboratory testing is crucial for patient care.
• Identifying laboratories with potential error rates is essential for quality assurance.
• Previous methods for identifying laboratory errors have limitations.

Purpose of the Study:

• To investigate if adverse health outcomes following clinical laboratory testing can identify laboratories with elevated error rates.
• To compare error rates between physician office laboratories and commercial laboratories.
• To assess the impact of laboratory switching and regulatory oversight on patient outcomes.

Main Methods:

• Retrospective case-control study analyzing Medicare Part A and B claims, and death records (1985-1987).
• Focused on 14,755 Medicare patients undergoing prothrombin time testing.
• Examined outcomes like stroke, myocardial infarction, or death within 6 days of testing.

Main Results:

• Physician office laboratories with <40 prothrombin time tests/month showed higher odds of stroke (1.96x) and myocardial infarction (3.43x) compared to commercial labs.
• Switching laboratories increased odds of stroke (1.57x) and myocardial infarction (1.32x).
• States with strong laboratory regulation had fewer adverse outcomes.

Conclusions:

• Patient health outcomes following clinical laboratory testing can serve as a valuable tool for quality assurance.
• Physician office laboratories with low test volumes may warrant closer monitoring.
• Regulatory oversight plays a significant role in minimizing laboratory-associated adverse events.