Testing the Interpersonal-Behavior model to explain intentions to use patient-delivered partner therapy

BACKGROUND: Patient-delivered partner therapy (PDPT) is an evidence-based method of partner treatment, but further research was needed to understand theoretical underpinnings of potential PDPT use. PURPOSE: We sought to develop and test a theoretical framework to understand PDPT intentions. METHODS: A Midwestern sample of sexually transmitted infection clinic patients were recruited to participate in a three-phase study incorporating semi-structured interviews (n = 20, total), cognitive interviews (n = 5), and surveys (n = 197; M(age) = 31.3, 61% male, 91% Black or African-American). Thematic analysis was conducted to identify major themes, which guided development and testing of a theoretical framework on PDPT intentions using structural equation modeling. RESULTS: We identified themes of information (knowledge); motivation (individual and partner protection beliefs, partner and provider motivation-to-comply); social support (sexual health and general); and behavioral skills (partner notification, medication delivery, and communication skills self-efficacy) in thematic analysis. The developed Interpersonal-Behavior model demonstrated good model fit in structural equation modeling [χ2(36) = 95.56, p<0.01; RMSEA = 0.09 (0.07–0.11, 90%C.I.); CFI = 0.94; SRMR = 0.05]. Information was associated with motivation (β = 0.37, p<0.001) and social support (β = 0.23, p = 0.002). Motivation was associated with social support (β = 0.64, p<0.001) and behavioral skills (β = 0.40, p<0.001), and social support was associated with behavioral skills (β = 0.23, p = 0.025). Behavioral skills were associated with higher PDPT intentions (β = 0.31, p<0.001), partially mediated the association of motivation with intentions (β(direct) = 0.53, p<0.001; β(indirect) = 0.12, 95%CI: 0.03–0.30), and fully mediated the association of social support with intentions (β(indirect) = 0.07, 95%CI: 0.00–0.21). CONCLUSIONS: The Interpersonal-Behavior model seems appropriate for PDPT intentions but should be tested longitudinally with PDPT outcomes and other interpersonal health behaviors.