Table 1.

Psychometric Characteristics of the Three Scales

Scale Items (6-item scale)	Corrected Item Total Correlations
	Week 2	Week 4	Week 6	Week 8	Week 10	Week 12
1. Feeling too tired to do things	.28	.46	.38	.44	.43	.41
2. Having trouble going to sleep or staying asleep	.35	.27	.25	.20	.30	.38
3. Feeling unhappy, sad, or depressed	.58	.64	.63	.59	.64	.61
4. Feeling hopeless about the future	.56	.55	.58	.63	.66	.57
5. Feeling nervous or tense	.57	.63	.57	.59	.73	.45
6. Worrying too much about things	.62	.63	.64	.62	.62	.65
Scale Items (5-item scale)	Week 2	Week 4	Week 6	Week 8	Week 10	Week 12
1. Feeling too tired to do things	.26	.45	.36	.41	.43	.35
2. Feeling unhappy, sad, or depressed	.55	.66	.65	.61	.65	.60
3. Feeling hopeless about the future	.56	.56	.62	.63	.66	.56
4. Feeling nervous or tense	.59	.63	.59	.64	.72	.48
5. Worrying too much about things	.65	.66	.63	.63	.64	.69
Scale Items (4-item scale)	Week 2	Week 4	Week 6	Week 8	Week 10	Week 12
1. Feeling unhappy, sad, or depressed	.56	.66	.67	.62	.67	.60
2. Feeling hopeless about the future	.60	.57	59	.64	.63	.59
3. Feeling nervous or tense	.58	.63	.60	.63	.71	.48
4. Worrying too much about things	.66	.65	.64	.64	.66	.70

Scale	Cronbach’s alpha
	Week 2	Week 4	Week 6	Week 8	Week 10	Week 12
6-item scale	.75	.78	.76	.76	.80	.76
5-item scale	.75	.80	.79	.80	.82	.76
4-item scale	.79	.81	.81	.81	.84	.78

Note. Bold values reflect an ICC value of < .50.