# Is it possible to calculate odds ratio(95% CI) for only control group?

The original data contains scores of case/control group. The score is the number of risk alleles multiplied by the regression coefficient for SNP. So in the data, case samples have higher score than control samples.

 ID   disease     Score
001      case      5.93
002      case      6.12
003      case      6.54
004   control      3.67
005   control      2.33
006   control      1.24


Now I grouping control samples in decile, and I want to calculate odds ratio for each decile. Finally output a plot like below. Can anyone please tell me how can I calculate this in R or other software?

• If I understood correctly your question, the answer should be $1$ because the OR of a group $j$ is defined as $OR_j = \frac{odds(group_j)}{odds(control)}$. – Ertxiem - reinstate Monica Nov 18 '19 at 11:29