proc genmod data=NIS.nis_2019_septicemia_ipexcmicat;
class pay1recat (ref = "3") amonth (ref = "1") aweekend (ref = "0") died (ref = "0") elective (ref = "0") female (ref = "0") zipinc_qrtl (ref = "4") hosp_bedsize (ref = "3") hosp_locteach (ref = "1") hosp_region (ref = "1") aprdrg_risk_mortality (ref = "0") aprdrg_severity (ref = "0") pl_nchsrecat (ref = "1") racerecat (ref = "4") cmr_index_mortalitycat (ref = "1") / param=ref;
model los = pay1recat age pay1recat*age amonth pay1recat*amonth aweekend died pay1recat*died elective pay1recat*elective female pay1recat*female i10_ndx pay1recat*i10_ndx i10_npr pay1recat*i10_npr zipinc_qrtl pay1recat*zipinc_qrtl hosp_bedsize pay1recat*hosp_bedsize hosp_locteach pay1recat*hosp_locteach hosp_region pay1recat*hosp_region aprdrg_risk_mortality pay1recat*aprdrg_risk_mortality aprdrg_severity pay1recat*aprdrg_severity pl_nchsrecat pay1recat*pl_nchsrecat racerecat pay1recat*racerecat cmr_index_mortalitycat pay1recat*cmr_index_mortalitycat totchg pay1recat*totchg / dist=negbin link=log;
run;
Log
WARNING: The negative of the Hessian is not positive definite. The convergence is questionable.
WARNING: The procedure is continuing but the validity of the model fit is questionable.
WARNING: The specified model did not converge.
WARNING: Negative of Hessian not positive definite.
