Season drives the outcome and drives who gets treated. Putting a Fourier basis into the propensity as well as the outcome model stops calendar time from masquerading as a treatment effect; a basis rather than month dummies keeps January and December neighbours.
Details
Formula: augment with cos(2 pi j t/p), sin(2 pi j t/p) for
j = 1..n_fourier, then target with
H = D/g - (1 - D)/(1 - g).
References
Westreich, D. & Cole, S. R. (2010). Am J Epidemiol 171:674-677; van der Laan & Rubin (2006) IJB 2(1):11.
Examples
Tmlper(y = c(1, 2, 3, 4, 5, 6, 7, 8), D = 5L, X = c(1, 2, 3, 4, 5, 6, 7, 8),
period = c(1, 2, 3, 4, 5, 6, 7, 8))
#> $estimate
#> [1] -3.426309e+77
#>
#> $se
#> [1] 0
#>
#> $eps
#> [1] -4.162806e+75
#>
#> $n_basis
#> [1] 4
#>
#> $n
#> [1] 8
#>
#> $method
#> [1] "TMLE with a Fourier seasonal basis"
#>
#> attr(,"class")
#> [1] "morie_rich_result" "list"
