Improving the reliability of total and high-density lipoprotein cholesterol measurements. Four testing strategies...

Area of Science:

• Clinical Chemistry
• Cardiovascular Disease Risk Assessment
• Biomarker Measurement

Background:

• Accurate measurement of total cholesterol and high-density lipoprotein (HDL) cholesterol is crucial for cardiovascular disease risk assessment.
• Existing testing strategies may vary in reliability, potentially impacting clinical decisions.

Purpose of the Study:

• To compare the reliability of four distinct testing strategies for total and HDL cholesterol.
• To identify the most effective strategy for clinical use in high-risk male outpatients.

Main Methods:

• Four testing strategies were evaluated: single measurement, duplicate measurements on one occasion, single measurements a week apart, and duplicate measurements over two occasions a week apart.
• Intraclass correlation coefficients and within-subject variance components were used to assess reliability.
• The study population comprised male outpatients at increased risk for cardiovascular disease.

Main Results:

• A single cholesterol measurement demonstrated the lowest reliability, indicated by lower intraclass correlation coefficients and higher within-subject variance.
• Averaging single measurements collected one week apart (strategy 3) reduced within-subject variance by 50% and improved the 95% confidence interval by 30% for both cholesterol types.
• Duplicate testing, whether on one or two occasions, offered only nominal improvements in reliability.

Conclusions:

• Averaging single measurements of total and HDL cholesterol collected one week apart is clinically advantageous.
• This strategy enhances accuracy, reduces misclassification risk, improves intervention monitoring, and supports national cholesterol guidelines.
• It also optimizes the use of HDL cholesterol as an independent cardiovascular risk factor.