blandPowerCurve: Power Curve for Bland-Altman Limits of Agreement

In arcaldwell49/SimplyAgree: Flexible and Robust Agreement and Reliability Analyses

Power Curve for Bland-Altman Limits of Agreement

Description

This function calculates the power for the Bland-Altman method under varying parameter settings and for a range of sample sizes.

Usage

blandPowerCurve(
  samplesizes = seq(10, 100, 1),
  mu = 0,
  SD,
  delta,
  conf.level = 0.95,
  agree.level = 0.95
)

Arguments

samplesizes	vector of samples sizes at which to estimate power.
mu	mean of differences
SD	standard deviation of differences
delta	The threshold below which methods agree/can be considered equivalent, can be in any units. Equivalence Bound for Agreement. More than one delta can be provided.
conf.level	the confidence level(s) required. Default is 95%. More than one confidence level can be provided.
agree.level	the agreement level(s) required. Default is 95%. The proportion of data that should lie between the thresholds, for 95% limits of agreement this should be 0.95. More than one confidence level can be provided.

Value

A dataframe is returned containing the power analysis results. The results can then be plotted with the plot.powerCurve function.

References

Lu, M. J., et al. (2016). Sample Size for Assessing Agreement between Two Methods of Measurement by Bland-Altman Method. The international journal of biostatistics, 12(2), \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1515/ijb-2015-0039")}

Examples

powerCurve <- blandPowerCurve(samplesizes = seq(10, 200, 1),
mu = 0,
SD = 3.3,
delta = 8,
conf.level = .95,
agree.level = .95)
# Plot the power curve
plot(powerCurve, type = 1)
# Find at what N power of .8 is achieved
find_n(powerCurve, power = .8)

# If the desired power is not found then
## Sample size range must be expanded

arcaldwell49/SimplyAgree documentation built on Oct. 26, 2024, 4:15 p.m.