Indices of change in exposure and response prevention for contamination-based OCD

Few studies have examined indices of change in treatment for obsessive compulsive disorder (OCD). The current study evaluated within- and between-session trajectories of fear, disgust, and urge to wash in exposure and response prevention (ERP) for contamination-based OCD and tested whether change in these indices were associated with treatment outcomes. Forty-one participants (75.6% female) engaged in three sessions of ERP for contamination OCD. Participants provided ratings of fear, disgust, and urge to wash during each session, and contamination symptoms were assessed at pre- and post-treatment and two-week follow-up. Fear, disgust, and urge to wash all significantly decreased both within and between sessions. Both fear and disgust declined significantly faster than urge to wash within session, though declines in fear and disgust did not significantly differ from each other. Within-session changes in fear were significantly associated with reduced symptoms at post-treatment, whereas within-session changes in disgust were associated with symptoms at two-week follow-up. The current study highlights the roles of fear and disgust in the context of ERP as unique indicators of treatment outcome for contamination-based OCD. Only within-session fear was uniquely associated with treatment outcome at post, while within-session disgust predicted outcome at follow-up. Theoretical and clinical implications are discussed.

Comparison of indices of clinically meaningful change in child and adolescent mental health services: difference scores, reliable change, crossing clinical thresholds and 'added value' - an exploration using parent rated scores on the SDQ

BACKGROUND

Establishing what constitutes clinically significant change is important both for reviewing the function of services and for reflecting on individual clinical practice. A range of methods for assessing change exist, but it remains unclear which are best to use and under which circumstances.

METHOD

This paper reviews four indices of change [difference scores (DS), crossing clinical threshold (CCT), reliable change index (RCI) and added value scores (AVS)] drawing on outcome data for 9764 young people from child and adolescent mental health services across England.

RESULTS

Looking at DS, the t-test for time one to time two scores indicated a significant difference between baseline and follow up scores, with a standardised effect size of d = 0.40. AVS analysis resulted in a smaller effect size of 0.12. Analysis of those crossing the clinical threshold showed 21.2% of cases were classified as recovered, while 5.5% were classified as deteriorated. RCI identified 16.5% of cases as showing reliable improvement and 2.3% of cases as showing reliable deterioration. Across RCI and CCT 80.5% of the pairings were exact (i.e., identified in the same category using each method).

CONCLUSIONS

Findings indicate that the level of agreement across approaches is at least moderate; however, the estimated extent of change varied to some extent based on the index used. Each index may be appropriate for different contexts: CCT and RCI may be best suited to use for individual case review; whereas DS and AVS may be more appropriate for case-mix adjusted national reporting.