02-28-2018 05:38 PM
I am trying to build a hierarchical model for a large survey dataset and I keep getting the error "WARNING: Obtaining minimum variance quadratic unbiased estimates as starting values for the covariance parameters failed" when fitting the following model:
proc glimmix data = arrlib.data pconv = 1e-4; class hospid flag_chf(ref = '0'); model flag_ihca(event = '1') = flag_chf / cl dist = binary oddsratio solution; random intercept / sub = hospid type = chol; nloptions maxiter = 100 gconv = 1e-4; weight discwt; by flag_cancer; title 'small data'; run;
However, when I fit the model using a subset of this data, I am able to get the OR with no problems. I'm not sure if this is arising from the number of observations and whether I need to allow more iterations, or what.
Thanks for y'all's consideration.