Therapeutic alliance in dietetic practice for weight loss: Insights from health coaching

The psychological construct of 'therapeutic alliance' can be used to better understand the effectiveness of consultations, particularly goal setting for weight management. We analysed audio-recorded health coaching sessions during a weight loss trial to explore relationships between therapeutic alliance and various contextual factors.

Audio recordings of 50 health coaching sessions were analysed. After assessing fidelity to the protocol, therapeutic alliance was measured using an adapted Working Alliance Inventory Observer-rated Short Version (WAI-O-S), and examined by (i) identifying relationships between contextual factors and WAI-O-S scores (Spearman's coefficients); (ii) testing the impact of preparatory exercises and body mass index on WAI-O-S scores (one-way analysis of variance and least-squared differences tests) and (iii) comparing differences in WAI-O-S scores based on relationship status, gender and follow-up session completion (independent samples t-tests).

Fidelity was high (mean 88%). WAI-O-S total scores ranged from 55 to 70 (out of 84). Session duration was significantly correlated with WAI-O-S component of 'Bond' (r = 0.42, P = 0.002). Those who completed preparatory exercises had significantly higher total WAI-O-S scores, 'Goal' and 'Task' scores. Participants who completed the follow-up session scored significantly higher for 'Goal' compared to no follow-up.

Spending more time in a session appears related to increased bonding, a key component of therapeutic alliance. Preparatory work may help build therapeutic alliance and agreement on goals appears to influence follow-up completion. These exploratory findings provide directions for research addressing the professional relationship in dietetic consultations for weight loss.