* p <.001
Mediation Analyses
Mediation analyses were conducted for each anxiety disorder measure
using Baron and Kenny’s (1986) method. All assumptions of multiple
regression were met, with linearity between variables and no evidence of
multicollinearity, apart from OCI-R scores which demonstrated evidence
of substantial positive skewness and were transformed using logarithmic
transformation (Log10). Additionally, SMSP scores showed evidence of
moderate positive skewness and were transformed using the square-root
method, as suggested by Tabachnick and Fidell (2007) and Howell (2007).
GAD
Using GAD-7 scores as the IV in Step One of the mediation model, GAD
scores significantly predicted AQ scores, β =.20, SE =.09,t (358)=3.77, p <.001, accounting for 3.6% of the
variance, F (1,358)=14.27, p <0.001. Step Two
showed that GAD was also a significant predictor of the mediator IU
(measured by IUS-12) β =.38, SE =.10 t (358)=7.86,p <.001, and accounted for 14.5% of the varianceF (1,358)=61.70, p <0.001. Step Three showed that
IU was a significant predictor of AQ, β =.49, SE =.04t (358)=10.65, p <.001, predicting 23.8% of the
variance, F (1,358)=113.34, p <0.001. Step Four
showed that when controlling for IU, the model accounted for 23.6% of
the variance F (2,357)=56.54, p <0.001, and GAD
scores were no longer a significant predictor of AQ β =.01,SE =.009 t (358)=.18, p =.856, while IU remained
significant, β =.49, SE =.04 t (358)=9.75,p <.001, thus IU is a partial mediator of the
relationship between GAD and AQ, as demonstrated in Figure 1a.
The second part of the GAD model aimed to establish if SOR was a
mediator in the relationship between GAD and AQ. Step One describing GAD
as a significant predictor of AQ has been described above. Step Two
demonstrated that SOR (as measured by ASPQ) could be significantly
predicted by GAD, β =.30, SE =.25, t (358)=5.93,p <.001, and predicted 8.7% of the variance in SOR
scores, F (1,358)=35.21, p <0.001. In Step Three,
SOR was also a significant predictor of AQ scores, β =.53,SE =.02 t (358)=11.85, p <.001, predicting
28% of the variance F (1,358)=140.38, p <0.001.
Step Four demonstrated that when both GAD and SOR were used to predict
AQ scores, GAD was no longer significant, β =.04, SE =.04,t (358)=.87, p =.388, while SOR remained a significant
predictor, β =.520, SE =.52, t (358)=11.04,p <.001, thus SOR was a partial mediator in the
relationship between GAD and AQ, with both variables explaining 27.9%
of the variance in AQ scoresF (2,357)=70.51, p <0.001, as illustrated in
Figure 1b.