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Fits Zou's (2004) modified-Poisson working model for binary incidence outcomes under a KK matching-on-the-fly design: a log-link Poisson model \(\log E[Y_i \mid w_i, x_i] = \beta_0 + \beta_T w_i + x_i^\top \gamma\) is fit to the binary (0/1) response by ordinary Poisson maximum likelihood (a working, misspecified likelihood — the true response is Bernoulli, not Poisson), and the coefficient standard errors are corrected by a cluster-robust sandwich covariance rather than the (invalid, for a misspecified likelihood) model-based Poisson information. Matched pairs are treated as clusters (2 members) and reservoir subjects as singleton clusters when computing the sandwich covariance, so the matched-pair correlation induced by the design is accounted for even though the modified-Poisson working model itself does not encode it directly. \(\exp(\hat\beta_T)\) is the estimated risk ratio, directly interpretable unlike a logistic regression's odds ratio (which only approximates the risk ratio when the outcome is rare). likelihood_tier = "none" (the sandwich-corrected inference is not a normalized model likelihood): only Wald inference is exposed. See InferenceAbstractKKMarginalIncid for the shared marginal-incidence fitting contract.

References

Zou, G. (2004). "A Modified Poisson Regression Approach to Prospective Studies with Binary Data." American Journal of Epidemiology, 159(7), 702-706, doi:10.1093/aje/kwh090 ; Kapelner, A. and Krieger, A. M. (2014). "Matching on-the-fly: Sequential allocation with higher power and efficiency." Biometrics, 70(2), 378-388, doi:10.1111/biom.12148 , for the KK matching-on-the-fly design this class is built for.

See also

InferenceIncidModifiedPoisson for the non-KK analog.

Super classes

Inference -> InferenceAbstractKKMarginalIncid -> InferenceAbstractKKModifiedPoisson -> InferenceIncidKKModifiedPoisson

Methods

+ inherited public methods from InferenceAbstractKKModifiedPoisson
+ inherited public methods from InferenceAbstractKKMarginalIncid
+ inherited public methods from Inference


InferenceIncidKKModifiedPoisson$clone()

The objects of this class are cloneable with this method.

Usage

InferenceIncidKKModifiedPoisson$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

# \donttest{
seq_des = DesignSeqOneByOneKK14$new(n = 10, response_type = 'incidence')
for (i in 1:10) {
  seq_des$add_one_subject_to_experiment_and_assign(data.frame(x1 = rnorm(1), x2 = rnorm(1)))
}
seq_des$add_all_subject_responses(rbinom(10, 1, 0.5))
inf = InferenceIncidKKModifiedPoisson$new(seq_des)
inf$compute_estimate()
#> [1] 0.4658296
# }