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Multi‐level modelling of conception in artificial insemination by donor
Author(s) -
Ecochard Rene,
Clayton David G.
Publication year - 1998
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/(sici)1097-0258(19980530)17:10<1137::aid-sim822>3.0.co;2-1
Subject(s) - artificial insemination , covariate , insemination , hierarchy , donor insemination , random effects model , logistic regression , statistics , pregnancy , computer science , biology , mathematics , medicine , economics , genetics , meta analysis , market economy
Data on insemination with donor's sperm have a crossed hierarchical structure due to the coexistence of female factors (ovulatory cycles within pregnancy attempt within women) and male factors (inseminations within donations within donors). A crossed random multi‐level logistic model, taking account of this structure, permits an improved estimation of the fixed effects and provides insights into their influence at each level in the hierarchy. We present an efficient algorithm for fitting such models using alternating EM steps. We further discuss the inclusion of compositional covariates to determine what information the quality of a donation conveys regarding the donor basal fecundability and on the specific sperm donation. © 1998 John Wiley & Sons, Ltd.