valytics (version 0.4.1)

troponin_cardiac: Cardiac Troponin Method Comparison Dataset

Description

Synthetic dataset comparing high-sensitivity cardiac troponin I (hs-cTnI) measurements from two different immunoassay platforms. This dataset illustrates challenges in comparing troponin assays, which lack standardization across manufacturers.

Usage

troponin_cardiac

Format

A data frame with 50 observations and 3 variables:

sample_id

Character. Unique sample identifier.

platform_a

Numeric. Troponin I concentration (ng/L) measured by platform A.

platform_b

Numeric. Troponin I concentration (ng/L) measured by platform B.

Details

This synthetic dataset was designed to illustrate common patterns in cardiac troponin method comparisons:

• Concentration range: 2-5000 ng/L, from near the limit of detection to acute myocardial infarction levels

• Distribution: Log-normal (most values low, few very high), reflecting typical clinical populations

• Bias pattern: Systematic proportional difference between platforms (~15%), reflecting lack of troponin assay standardization

• Precision: Higher CV at low concentrations near the detection limit

Unlike many analytes, cardiac troponin assays are not standardized, meaning results from different manufacturers are not directly comparable. This has clinical implications for interpreting troponin values when patients are tested at different institutions.

References

Apple FS, et al. Cardiac Troponin Assays: Guide to Understanding Analytical Characteristics and Their Impact on Clinical Care. Clin Chem. 2017;63(1):73-81.

See Also

ba_analysis(), glucose_methods, creatinine_serum

Examples

# Bland-Altman analysis with percent differences
# (appropriate for proportional bias)
ba <- ba_analysis(platform_a ~ platform_b,
                  data = troponin_cardiac,
                  type = "percent")
summary(ba)
plot(ba)