In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: RESULTS : A total of 210 patients were enrolled in the study ; 203 patients ( 143 men , 60 women ) completed the study while 7 were lost to follow - up ( 4 patients in the T + A group and 3 in the A group ) and considered with - drawn .
### Output Text:
RESULTS : A total of 210 patients were enrolled in the study ; 203 patients ( 143 men , 60 women ) completed the study while 7 were lost to follow - up ( 4 patients in the T + A group and 3 in the A group ) and considered with - drawn . 