# Odd ratio in subgroups for a continuos outcome variable.

#### fedegf

##### New Member
I'm stuck in this.
I have a population divided as follow.
Population as been randomised among Standard or Sperimental procedure.
Surgical access was Laparoscopy or Laparotomy.
Objective is to decrease Day of recovery.
Data example as follow:
HTML:
<table><tr><td>Intervention group</td><td>Surgery Type</td><td>Day of recovery</td></tr>
<tr><td>Standard</td><Td>Laparoscopy</td><td>3</td></tr>
<tr><td>Standard</td><Td>Laparoscopy</td><td>4</td></tr>
<tr><td>Standard</td><Td>Laparotomy</td><td>5</td></tr>
<tr><td>Standard</td><Td>Laparotomy</td><td>6</td></tr>

<tr><td>Sperimental</td><Td>Laparoscopy</td><td>2</td></tr>
<tr><td>Sperimental</td><Td>Laparoscopy</td><td>2</td></tr>
<tr><td>Sperimental</td><Td>Laparotomy</td><td>3</td></tr>
<tr><td>Sperimental</td><Td>Laparotomy</td><td>3</td></tr>
</table>
My question regards how can i calculate the odd ratio of the subgroup Surgery type to see if there is an innreased or decreased risk to have a smaller outcome?
I ve used Mann Witney to assess difference among Sperimental and Standard and it's significative using SPSS.
Many thanks for your precious suggestions.
Feder