Table 3.

Estimated marginal means and linear mixed models results and effect sizes for health anxiety, depression and psychological distress from pre-to post-treatment in the COVID-19 sample.

	Pre-treatment EMM (SD)	Post-treatment EMM (SD)	df for the time effect	F	r	Hedge’s g [95% CI]
SHAIa	29.15 (11.13)	20.54 (10.18)	463.52	36.23*	.731	0.89 [0.74; 1.04]
PHQ-9b	9.54 (7.50)	6.09 (5.74)	323.80	73.59*	.680	0.55 [0.40; 0.70]
K-10c	25.14 (7.78)	19.40 (5.95)	1114.51	75.83*	.652	0.91 [0.76; 1.06]

Note. SHAI = Short Health Anxiety Inventory; PHQ-9 = Patient Health Questionnaire-9 Item; K-10 = Kessler Distress Scale-10 item; r = Pearson correlation between Lesson 1 and Lesson 6 scores for calculation of within-group effect sizes; EMM = estimated marginal mean; SD = standard deviation; *p < .001; a = Adjusted model with measurement occasion (time), age, gender and time by age interaction as fixed effects in the model; b = Adjusted model with measurement occasion (time), rural status and age as fixed effects in the model; c = Adjusted model with measurement occasion (time) and age as fixed effects in the model.