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From |
"Ben Dwamena" <bdwamena@med.umich.edu> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
st: random-effects SROC model in gllamm |

Date |
Sun, 16 Dec 2007 03:12:17 -0500 |

I would appreciate assistance with a gllamm or xtmelogit code for the model described below for combining multiple 2 by 2 results of a binary diagnostic test with binary reference test outcome: The # of positive test results from the ith study in the disease grp is y_i1 and for the normal grp y_i0, follow binomial distributions such that y_ij ~bin(N_ij, eta_ij where N_ij is the # of test results in the group and eta_ij is the true rate of positive results. D_i and S_i are random-effects that describe how accuracy and implicit threshold , respectively, vary by studies such that: D_i = logit(eta_i1) - logit(eta_i0) S_i = logit(eta_i1) + logit(eta_i0) D_i is normally distributed with mean A+B*S_i and variance sigma_D^2 S_i is normally distributed with mean S and variance sigma_S^2 Thanks for your assisstance. Sincerely, Ben ********************************************************** Electronic Mail is not secure, may not be read every day, and should not be used for urgent or sensitive issues * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

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