Calculate the coefficient of detection ratio for two variants

This function calculates the coefficient of detection ratio \(C_{V_1}/C_{V_2}\) for two variants. This function assumes that variant 1 is the variant of concern. This function is specific to the two-variant system. Parameters not provided are assumed to be equivalent between the two variants.

vartrack_cod_ratio(
  phi_v1 = 1,
  phi_v2 = 1,
  gamma_v1 = 1,
  gamma_v2 = 1,
  psi_v1 = 1,
  psi_v2 = 1,
  tau_a = 1,
  tau_s = 1
)

Arguments

phi_v1

probability that a tested infection caused by variant 1 results in a positive test (sensitivity)

phi_v2

probability that a tested infection caused by variant 2 results in a positive test (sensitivity)

gamma_v1

probability that a detected infection caused by variant 1 meets some quality threshold

gamma_v2

probability that a detected infection caused by variant 2 meets some quality threshold

psi_v1

probability that an infection caused by variant 1 is asymptomatic

psi_v2

probability that an infection caused by variant 2 is asymptomatic

tau_a

probability of testing an asymptomatic infection (any variant); note that this parameter is not required if psi_v1==psi_v2

tau_s

probability of testing a symptomatic infection (any variant); note that this parameter is not required if psi_v1==psi_v2

Value

scalar giving the multiplicative bias of variant 1

See also

Other variant tracking functions: vartrack_prob_detect_cont(), vartrack_prob_detect_xsect(), vartrack_prob_detect(), vartrack_prob_prev_xsect(), vartrack_prob_prev(), vartrack_samplesize_detect_cont(), vartrack_samplesize_detect_xsect(), vartrack_samplesize_detect(), vartrack_samplesize_prev_xsect(), vartrack_samplesize_prev()

Author

Shirlee Wohl, Elizabeth C. Lee, Bethany L. DiPrete, and Justin Lessler

Examples

vartrack_cod_ratio(phi_v1=0.975, phi_v2=0.95, gamma_v1=0.8, gamma_v2=0.6)
#> [1] 1.368421