Saliva sample analysis
In order to evaluate cortisol levels (CL), saliva samples were collected at each STAI completion phase. Prior to the collection of saliva, subjects were asked to rinse their mouths with plain water to clear away any debris or food. Care was taken to ensure the non-contamination of saliva with blood.Salivary cortisol was estimated by solid phase enzyme-linked immunosorbent assay (ELISA) (DiaMetra, Boldon, UK) in ng/ml. The procedure was done as per the manufacturer guidelines on saliva samples.