I need to calculate 95% confidence intervals or predicted probabilities from a logistic mixed effects model, created using the glmer function from lme4 R package. The model includes a stabilized probability weighting to correct for the selecttion bias on the analized data.
I've read that bootMer function (lme4 package) perform a Model-based semi-parametric bootstraping that makes staighforward to get the CI's as the quantiles of the distribution (quantile approach).
Nevertheless, when I apply the function bootMer, the following error is generated:
"Error in sfun(object, nsim = 1, ftd = rep_len(musim, n * nsim), wts = weights): cannot simulate from non-integer prior.weights"
I must use a non-integer weights, so my question is ¿How can I solve this problem using bootMer function? Or if it's impossible, ¿Are anny alternatives?
#The model
M1s = glmer(plab ~ 1 + edad2_c + I(edad2_c^2) + periodo_c + cohorte + nocu_c + tipoocu2 + sector + educ + benef + genero + ecivil + area + generojh + edadjh2_c + nhogar_c + nhogar05_c + nhogar0614_c + nhogar66_c + (1 | periodo_c), weights = ipw,
data = seriecasen,family = binomial(link=logit),nAGQ = 10,glmerControl(optimizer = "bobyqa", optCtrl = list(maxfun = 2e5)))
#Model-based semi-parametric bootstrap for mixed models - CI's predicted probabilites
merBoot <- bootMer(M1s, predict, nsim = 1000, use.u = TRUE, type = c("parametric"), seed = 1959)
CI.lower = apply(merBoot$t, 2, function(x) as.numeric(quantile(x, probs=.025, na.rm=TRUE)))
CI.upper = apply(merBoot$t, 2, function(x) as.numeric(quantile(x, probs=.975, na.rm=TRUE)))
Error in sfun(object, nsim = 1, ftd = rep_len(musim, n * nsim), wts = weights): cannot simulate from non-integer prior.weights