*3.4. Athens Insomnia Scale (AIS)*

For our study, the Cronbach's Alpha for the total group was 0.87. A total score equal or greater than 6 was considered as indicative of insomnia for AIS. Our analysis of data showed a total score of 11.37 ± 3.45, meaning that our respondents showed a high level on this scale. Results ranged from a minimum score of 8 (19.3%, *n* = 16) to a maximum of 24 points (1.2%, *n* = 1). Detailed results are presented in Table 3.

**Table 3.** Results for items of Athens Insomnia Scale (AIS) 1.


<sup>1</sup> Means and standard deviations (M ± SD).

The comparative analysis showed that dentists suffering from chronic diseases (Mdn = 17) had insomnia (z = −2.892, *p* = 0.004) more often than healthy dentists (Mdn = 10). Results of the Mann Whitney test (z = −3.583, *p* < 0.001) showed that dentists with a higher level of fear (Mdn = 14) had a higher score on the questionnaire assessing the severity of insomnia than the dentists who had lower levels for FCV-19S (Mdn = 10). Dentists with a higher level of fear (Mdn = 6) had had fewer working weeks since the outbreak of the pandemic compared (z = −2.900, *p* = 0.004) to dentists with a lower level of fear (Mdn = 9).

There were significant gender differences in terms of symptoms during the night, namely sleep induction, sleep quality and total sleep duration (z = −2.090, *p* = 0.037) in the sense that men (Mdn = 4) scored higher at this subscale and had more problems with night-time symptoms, as opposed to women (Mdn = 3).

The comparative analysis also showed that dentists who had a family member infected with COVID-19 (Mdn = 13) had a higher score on the questionnaire assessing the severity of insomnia (z = −2.529, *p* = 0.011) than dentists who did not have a family member infected with COVID-19 (Mdn =10).

A significant positive correlation was identified between the total score of AIS and the total score for the FCV-19S questionnaire (r = 0.42 \*\*, *p* < 0.001), indicated by the correlation coefficient which proved a medium effect size. This means that the more the dentists were afraid of COVID-19, the more they would suffer from insomnia.

Our results showed that there was a positive correlation between the total score of AIS and variables which refer to some of the doctors' fears. Thus, we identified that the more the dentists were afraid of the fact that the patients did not declare the truth about their health, the more their insomnia would be severe (r = 0.29 \*\*, *p* = 0.007). The more the dentists were afraid of the fact that they might be infected by their co-workers (r = 0.33 \*\*, *p* = 0.002) or while taking off their protective suit (r = 0.26 \*, *p* = 0.016), the more severe their insomnia would be. A negative correlation was identified between the total score of AIS and the fact that the patients respected COVID-19 preventive measures. We found that the more the patients respected these measures, the less the dentists suffered from insomnia (r =−0.26 \*, *p* = 0.016).

For some dentists, wearing a protective suit became a difficult task because it prevented visibility and medical procedures. Thus, the more the dentists were concerned about the fact that wearing a protective suit would impede them from carrying out medical procedures *(r =* 0.40 \*\*, *p* = 0.002) or about the fact that wearing a protective suit impeded visibility (r = 0.30 \*, *p* = 0.020), the more they would have severe insomnia.

The statistical analysis proved that there were strong correlations between the anxiety state when dentists watched the news about the pandemic and both scores for fear and AIS. The results showed that the more anxious the dentists were when they followed news related to COVID-19, the higher both scores were (0.43 \*\*, *p* < 0.001 for AIS, and: r = 0.79 \*\*, *p* < 0.001 for FCV-19S). Positive correlations were also identified between AIS and other variables. Results are detailed in Table 4.


**Table 4.** Correlation analysis between Fear of Covid-19 Scale, Athens Insomnia Scale and self-rated items.

\* *p* < 0.05; \*\* *p* < 0.001.
