Hello, I'm trying to predict preterm birth (yes/no) from weight gain during pregnancy, controlling for race/ethnicity, bmi at entry to prenatal care, and parity (number of previous births). I've run a logistic regression with the following model statement: preterm=wtgaincat ethnicity bmicat parity; wtgaincat has 4 levels (ethnicity has 3, bmicat has 4) In my output, the p-value for the Wald Chi-Square in Type 3 Analysis of Effects table is .0292 - so less than .05, so significant. In the Maximum Likelihood parameter estimates table, the p-value for one of the levels of wtgaincat is .0130, so significant. The OR is for that level of wtgaincat 0.332. BUT the CI is 0.082 -1.345 - so not significant? Are there some situations where the p-value for the ML estimate is better, and other situations where you'd favor the 95% CI around the OR???? I'm not sure what to think or to report. Any help would be much appreciated! Thanks, Patricia
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