*2.2. Instruments*

A questionnaire was used to collect the data for the present research, and contained three parts:


experienced any sleep difficulty described in each question at least three times a week during the previous month. A maximum total score of 24 indicated the most severe symptoms of insomnia. For this scale, the cut-off point of ≥6 represented a minimum criterion for the confirmation of insomnia symptoms in our respondents.
