STRATHCLYDE INVENTORY Development of a psychotherapy outcome measure based on Rogers’ theory of therapy change

BACKGROUND Comparative outcome studies suggest general equivalence of psychotherapies (‘Dodo bird’ hypothesis) Possible explanation: different outcomes do occur but are not detected by current research tools

Most psychotherapy outcome measures are pathology-oriented: assessing ‘symptom’ intensity Need to develop an outcome measure assessing change as conceptualised/ promoted by person-centred therapy

Person-centred therapists and clients may feel more comfortable using nonpathology- oriented instrument

AIMS To develop and test the validity of a psychotherapy outcome measure based on Rogers’s theory of therapy change: The “Strathclyde Inventory”

METHOD ITEM PREPARATION Sentences picked up from Rogers’ writings where he described the person after therapy or the fully functioning person

51 items were developed, covering six dimensions of therapeutic change: Locus of Evaluation Openness to Experience Self-Liking Existential Living Acceptance of Others Psychological Adjustment

Examples of items: I trust in my own feelings and reactions to situations (Openness to Experience) I look to others for approval or disapproval (Locus of Evaluation) I am able to understand those with whom I have personal contact (Acceptance of Others) I express myself in my own unique way (Existential Living) I feel that the ‘core’ of myself is something positive (Self-Liking) Sometimes I do things that are not myself, which I cannot control (Psychological Adjustment)

Four-point rating scale used: –‘Fits me pretty much’ –‘Fits me fairly well, but not totally accurate’ –‘Might be true for me, but I’m not sure’ –‘Clearly doesn’t fit me’ 21 items were ‘negatively’framed with reversed scores

PROCEDURE Pilot phase: –Strathclyde Inventory responded to by 121 partcipants –alongside range of other instruments to test validity of the measure

Convergent validity assessed through comparisons with ‘Scales for Experiencing Emotions’ (SEE) and ‘Rosenberg Self- Esteem Scale’ Discriminant validity assessed through comparison with CORE-OM (Clinical Outcome and Routine Evaluation Outcome Measure) Social desirability bias assessed through ‘Marlowe-Crowne Social Desirability Scale’

RESULTS Four-point rating scale was inadequate: produced a ceiling effect Feedback given by some participants indicates that this rating scale was problematic

REFINEMENT OF THE MEASURE Initially, 11 items dropped out: 2 with a high inter-correlation 8 items with high correlation with CORE 1 item with poor face validity (“I often feel anxious”)

EXPLORATORY FACTOR ANALYSIS Two factors were identified: Congruence/Experiential Fluidity Incongruence/Experiential Constriction

The instrument had too many items for its two factors: 9 more items were dropped out (items that loaded less than 0.5 on its factor)

CONGRUENCE/EXPERIENTIAL FLUIDITY FACTOR (20 items) Examples: –I feel truly myself –I am aware of my feelings –I am able to be spontaneous and genuine –I live fully in each new moment –I am a person of worth

INCONGRUENCE/EXPERIENTIAL CONSTRICTION FACTOR (11 items ) Examples: –I look to others for approval or disapproval –I frequently conform to what others think or want –I feel afraid of my emotional reactions –I hide some elements of myself behind a “mask” –I frequently find myself "on guard" when relating with others

INTERNAL CONSISTENCY (After dropping out the 20 unneccessary items) The intrument showed good overall internal reliability: Cronbach’s alpha = 0.94 The two factors each also showed good internal reliability: Cronbach’s alpha for the first and two factors were 0.92 and 0.90 respectively

CONVERGENT VALIDITY The instrument after the ‘cleaning’ showed good convergent validity: Congruency Factor Incongruency Factor (R) All items Self Esteem Accepting own emotions Experiencing lack of emotions

DISCRIMINANT VALIDITY: SOCIAL DESIRABILITY BIAS The instrument showed only a modest degree of social desirability bias: Correlation with Marlowe-Crowne Social Desirability Scale = 0.27

CONFOUNDING WITH CLINICAL DISTRESS Discriminant validity in relation to the CORE measure was poor: Correlation = But correlation with the risk domain was lower: Correlation =

Congruency Factor Incongruency Factor All items CORE All items Well-being Problems/ Symptoms Life Functioning Risk

CONCLUSIONS The Strathclyde Inventory was found to have excellent item-reliability and showed good convergence with related measures It was not substantially associated with social desirability, but showed greater than desired overlap with clinical distress A revised version of the measure has been developed and is currently being tested