Computes the analytic noncentrality parameter (NCP) for the likelihood-ratio test allowing for error (LRTae) in a prospective case-control design. The calculation incorporates fallible measurements and validation subsamples for phenotype, genotype, or both. It does not analyze observed study data.

lrtae_ncp(
  true_control_genotype_frequencies,
  true_case_genotype_frequencies,
  true_sampling_proportions,
  phenotype_misclassification_matrix,
  genotype_misclassification_matrix,
  n_fallible,
  n_pheno_validated,
  n_geno_validated,
  n_both_validated
)

Arguments

true_control_genotype_frequencies

Numeric vector of true genotype frequencies among controls.

true_case_genotype_frequencies

Numeric vector of true genotype frequencies among cases, in the same category order as true_control_genotype_frequencies.

true_sampling_proportions

Numeric vector of length two containing the true control and case sampling proportions, in that order.

phenotype_misclassification_matrix

Numeric two-by-two matrix whose rows are true phenotype categories (control, case) and whose columns are observed phenotype categories (control, case).

genotype_misclassification_matrix

Numeric square matrix whose rows are true genotype categories and whose columns are observed genotype categories, in the genotype-frequency order.

n_fallible

Number sampled with fallible phenotype and genotype measurements only.

n_pheno_validated

Number whose phenotype is validated while genotype is measured fallibly.

n_geno_validated

Number whose genotype is validated while phenotype is measured fallibly.

n_both_validated

Number whose phenotype and genotype are both validated.

Value

A single nonnegative numeric value: the LRTae NCP.

References

Ji, F., Yang, Y., Haynes, C., Finch, S. J., & Gordon, D. (2005). Computing asymptotic power and sample size for case-control genetic association studies in the presence of phenotype and/or genotype misclassification errors. Statistical Applications in Genetics and Molecular Biology, 4(1), Article 37. doi:10.2202/1544-6115.1184

Barral, S., Haynes, C., Stone, M., & Gordon, D. (2006). LRTae: improving statistical power for genetic association with case/control data when phenotype and/or genotype misclassification errors are present. BMC Genetics, 7, 24. doi:10.1186/1471-2156-7-24

Gordon, D., Finch, S. J., & Kim, W. (2020). Heterogeneity in Statistical Genetics: How to Assess, Address, and Account for Mixtures in Association Studies. Springer. doi:10.1007/978-3-030-61121-7

Examples

lrtae_ncp(
  true_control_genotype_frequencies = c(0.81, 0.18, 0.01),
  true_case_genotype_frequencies = c(0.64, 0.32, 0.04),
  true_sampling_proportions = c(0.5, 0.5),
  phenotype_misclassification_matrix = matrix(
    c(0.95, 0.05, 0.05, 0.95), nrow = 2, byrow = TRUE
  ),
  genotype_misclassification_matrix = matrix(
    c(0.950, 0.050, 0.000,
      0.025, 0.950, 0.025,
      0.000, 0.050, 0.950),
    nrow = 3, byrow = TRUE
  ),
  n_fallible = 700,
  n_pheno_validated = 100,
  n_geno_validated = 100,
  n_both_validated = 100
)
#> [1] 29.17305