Hello everyone

I am investigating the factors that influence Adherence Pre-Exposure Prophylaxis (PrEP) 1. Education level(No education , Primary, Secondary, Tertiary. 2 - Age group(Adolescents, Adults, Elderly). 3 - Experienced Side effects(Yes. No). **Note text in bold is reference category**
Array

1. Help me in interpreting these odds ratios
2. I have a total of 245 obs but why did Stata not include the 5 obs from the "Elderly Age group" as incicated by "empty" with odds ratio of 1

Thank you
Abraham