calculate_lob: Limit of Blank (LoB) calculations

In njjms/nicks: Basic Functions for Biostatistics

Limit of Blank (LoB) calculations

Description

These calculations are based on CLSI EP17-A2 (section 5.3.3.1 covers both calculations and when to use each)

Usage

calculate_lob(x, k, alpha = 0.05)

Arguments

x	Vector of blank sample data
k	Number of unique blank samples
alpha	defaults to .05

Details

According to EP17, the minimal experimental design is: - 2 reagent lots - 1 instrument system - 3 days - 4 blank samples - 2 replicates per sample

Note that multiplying all of this together gives us 48 samples. According to EP17, the minimum number of replicates for blank samples is 60, so at least one of these factors will have to be increased.

For the nonparametric approach, the number of reagent lots used in the experimental design is important. For 2 or 3 lots, LoB is calculated for each of the lots and the overall LoB is the maximum of those values. For 4 or more lots, the data is pooled together and a single LoB is calculated.

Value

a list containing parametric and nonparametric LoB, sample mean, sample standard deviation, sample size, corrected quantile (parametric), and rank (nonparametric)

Examples

x <- data.frame(x = rnorm(20, mean = 1, sd = .2))
calculate_lob(x = x, k = 4)

njjms/nicks documentation built on May 4, 2022, 8:10 a.m.