Qualitative evaluation of a novel contingency management-related intervention for patients receiving supervised injectable opioid treatment.

Aim: To evaluate a novel contingency management (CM)-related intervention for people experiencing complex drug problems, thereby increasing understanding of CM implementation in real-world settings. Objectives are to provide new insights into (i) how context influences intervention delivery; (ii) aspects of intervention delivery that influence outcomes; and (iii) intervention outcomes.

Design: Qualitative realist evaluation of a novel CM-related intervention: conditional budgets (CB).

Setting: Supervised injectable opioid treatment (IOT) clinic in England (May 2014-March 2015).

Participants: Twenty IOT clinic patients (14 men; six women); 10 IOT clinic staff (seven men; three women).

Measurements: Semi-structured interviews systematically coded relating to knowledge and views of the intervention, experiences of delivering/receiving the intervention, and effectiveness of the intervention.

Intervention: Personal budgets provided to patients who reduced their supervised IOT while demonstrating ongoing stability.

Findings: (i) Contextual factors influencing intervention delivery included patient motivation; clarity of intervention information; prior trust in the treatment system; patient and staff involvement in intervention design; stability of the treatment setting. (ii) Aspects of delivery influencing outcomes included transparency of the eligibility criteria, rules and operating processes; rule enforcement; continued verbal information about the intervention; speed of incentive processing and receipt. (iii) Reduced drug use was difficult to attribute to CBs, as patients who did well were those most motivated to change before the intervention started. Unintended outcomes were positive (improved patient psychological wellbeing, staff job satisfaction, staff/patient relationships) and negative (patient relapse, increased staff work-load, tensions in clinic relationships).

Conclusions: A 'qualitative realist' evaluation of a contingency management intervention to help address complex substance use disorder problems suggests that the programmes need to have stakeholder input, implement consistent eligibility criteria, rules and processes and be introduced into stable treatment settings where relationships are trusting and patients and staff feel secure.