I performed a logistic regression with stepwise selection, and a variable that was retained has on OR point estimate of 1.000, with 95% Wald CLs of 1.000-1.001. Is this likely a glitch, or are the "true" point estimate and lower CL just a titch above 1 and victims of rounding (e.g., lower CL 1.00001, point estimate 1.00008)?
The code:
PROC LOGISTIC DATA=train;
CLASS landcover (REF='11') / PARAM=REF;
MODEL case (EVENT='1')=landcover water_pct temperature precipitation / SELECTION=STEPWISE;
RUN;
Because the variable was selected, I would guess the CI is [1 + epsilon, 1.001]. You can use the ODS OUTPUT statement to see the full precision of the estimates:
ods output OddsRatios=OR;
PROC LOGISTIC ...;
RUN;
proc print data=OR;
format LowerCL UpperCL 16.14;
run;
Because the variable was selected, I would guess the CI is [1 + epsilon, 1.001]. You can use the ODS OUTPUT statement to see the full precision of the estimates:
ods output OddsRatios=OR;
PROC LOGISTIC ...;
RUN;
proc print data=OR;
format LowerCL UpperCL 16.14;
run;
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