Table 2.

Internal consistency for both waves

Internal consistency	DAS Item 1	DAS Item 2	DAS Item 3	DAS Item 4	Cronbach’s Alpha	McDonald’s Omega
Wave 27: 2013/2014 ( N  = 329)					0.93	0.93
- Mean ± SEM	2.64 ± 0.06	2.03 ± 0.06	2.63 ± 0.06	2.23 ± 0.06
- Skewness	0.80	0.98	0.53	0.70
- Kurtosis	0.15	0.36	-0.32	-0.07
- Alpha if Item deleted	0.92	0.90	0.89	0.91
- Corrected item total correlation	0.80	0.86	0.87	0.81
Wave 31: 2019/2020 ( N  = 323)					0.93	0.93
- Mean ± SEM	2.57 ± 0.06	2.00 ± 0.06	2.56 ± 0.06	2.16 ± 0.06
- Skewness	0.95	1.04	0.58	0.79
- Kurtosis	0.47	0.55	-0.29	>-0.01
- Alpha if Item deleted	0.92	0.90	0.90	0.92
- Corrected item total correlation	0.80	0.88	0.87	080

Internal consistency for DAS items 1–4 (1. “If you had to go to the dentist tomorrow, how would you feel about it?“, 2. “When you are waiting in the dentist’s office for your turn in the chair, how do you feel?“, 3: “When you are in the dentist’s chair waiting while he gets the drill ready to begin working on your teeth, how do you feel? And 4. “You are in the dentist’s chair to get your teeth cleaned. While you are waiting and the dentist is getting out the instrument which he will use to scrape your teeth around the gums, how do you feel?”): in waves 27 (2013/2014) and 31 (2019/2020). Mean ± SEM, skewness, kurtosis, alpha if item deleted and corrected item total correlation for DAS item 1–4 are reported. Cronhach’s Alpha and McDonald’s Omega are reported for the DAS-Score.