# Interpreting odds ratios less than 1 with 3-category outcome

I have a 3-category ordered outcome (food consumption: 1=no food, 2=less food, 3=more food) and a 3-category ordered predictor (food exposure: 3=no time, 2= less time, 1= more time- whereby 3=no time is taken as reference category in the ordinal regression model). I want to explore hypothesis that more food exposure is associated to more food consumption.

I want to know how I can interpret odds ratios less than 1. For example, I have OR= 0.62 for predictor category 2= less time. I have calculated OR as exp(coeff) in Excel, whereby OR of reference category no time is exp(0)=1.

• So you ran an ordinal logistic regression & exp(coeff) is <1? What software did you use to get these? Can you provide the model output? Usually, you would get a coefficient for your predictor + a set of threshold values. Which coef is this? Dec 2, 2013 at 16:15
• I used SPSS 19. I can't add a photo or file as it seems, but the coefficients I calculate OR for are those for the predictor categories (the one I gave here is for predictor category 2 (less time spent), which is -0.474, so OR=exp(-0.474)=0.622). The coeff for category 1 (more time) is 0.111 (so OR = 1.117), and that for category 3 (no time=reference category) is coeff=0, so OR=1. This model is adjusted for gender, ethnicity, age. Outcome (food consumption) is from 1= lowest to 3= highest consumption, so that I can interpret it as moving to higher levels of consumption Dec 2, 2013 at 16:39