getParkesZones {ega}

Assign Parkes (Consensus) error grid zones to paired glucose values

Description

referenceVals and testVals are assumed to contain paired glucose values from a reference method and a test method, respectively. The discrepancy between the two values, as well as the type of error grid desired (Type 1 or Type 2 diabetes), is used to place the pair into a Parkes (Consensus) error grid zone, according to the criteria described in the second reference below. unit contains info on the unit of measurement. Two options exist: "gram" for mg/dL and "mol" for mmol/l with "gram" applied by default.

Usage

getParkesZones(referenceVals, testVals, type = 1, unit = "gram")

Arguments

referenceVals

A vector of glucose values obtained via the reference method.

testVals

A vector of glucose values obtained via a non-reference method (e.g. a new meter). The values in this vector are paired with those in referenceVals, so the length should be the same.

type

An integer (1 or 2) specifying whether to obtain zones for Type 1 or Type 2 diabetes. Defaults to 1.

unit

A string specifying the units of measurement. This should be either "gram" (the default) for mg/dl or "mol" for mmol/l.

Value

A character vector is returned, with each element being one of "A", "B", "C", "D", or "E".

References

Parkes, J. L., S. L. Slatin, S. Pardo, and B.H. Ginsberg. "A New Consensus Error Grid to Evaluate the Clinical Significance of Inaccuracies in the Measurement of Blood Glucose." Diabetes Care 23, no. 8 (August 2000): 1143-48

Pfutzner, Andreas, David C. Klonoff, Scott Pardo, and Joan L. Parkes. "Technical Aspects of the Parkes Error Grid." Journal of Diabetes Science and Technology 7, no. 5 (September 2013): 1275-81

Examples

zones <- getParkesZones(glucose_data$ref, glucose_data$test)

# counts
table(zones)

# percentages
round (table (zones) / length (zones) * 100, digits=2)