Short Abstract

Despite strong quantitative evidence, ethical concerns prevent adopting Contingency Management in addiction services. This qualitative Realist Evaluation reveals new relational, symbolic, and temporal mechanisms directly addressing these concerns—bridging the implementation gap for the NHS.

Description

Background: Low attendance remains a critical challenge in delivering psychosocial interventions for alcohol use disorders (AUDs), compromising outcomes. Contingency Management (CM), using financial incentives, has a robust quantitative evidence base. However, adoption in UK practice is limited by professional concerns that CM is coercive and undermines intrinsic motivation. Qualitative research exploring lived experiences is essential to inform implementation.

Aims: This study sought to explain how, why, for whom, and under what circumstances CM improves treatment engagement. Using a qualitative Realist Evaluation approach, the research examined CM’s effectiveness within the Alcohol Dependence and Adherence to Medication (ADAM) trial. In this intervention, cumulative shopping vouchers (maximum £120) were provided for attending a 24-week, pharmacist-led psychosocial programme supporting acamprosate adherence. The study aimed to uncover the mechanisms of change to directly address the ethical concerns limiting CM adoption.

Methods: Semi-structured interviews were conducted with 31 users of NHS specialist alcohol services randomised to receive CM within the ADAM trial, and 3 frontline pharmacists who delivered the telephone-based psychosocial intervention. Purposive sampling ensured variation across attendance trajectories. Interviews explored experiences, reasoning processes, and perceived outcomes. Data were analysed using retroductive reasoning to identify Context-Mechanism-Outcome (CMO) configurations.

Findings: The analysis reconceptualises CM as a multifaceted therapeutic process, not just operant conditioning. Three key mechanisms emerged: 1. Symbolic: Vouchers functioned as tangible progress markers restoring dignity.

2. Relational: Vouchers were often given to family, enabling participants to “pay back their kindness”.

3. Temporal: A dual-delivery system (immediate SMS + delayed voucher) provided instant validation and future-oriented motivation ("something to look forward to"). Rather than undermining intrinsic motivation, incentives facilitated psychological stability, *enabling* intrinsic motivation to emerge. A 2–4-week post-detox "readiness window" was optimal for CM initiation. Strong therapeutic relationships were supportive, while trauma and housing instability were constraints for CM effectiveness.

Implications for practice and policy: The findings offer a direct, patient-level refutation of the ethical concerns, demonstrating CM’s compatibility with therapeutic values in harm reduction settings. Six evidence-based implementation strategies emerged: (1) Incentives framed as "recognition awards"; (2) Target the 2-4 week readiness window; (3) Ensure therapeutic continuity; (4) Provide immediate feedback via SMS or other systems; (5) Avoid excluding patients with comorbidities; (6) Allow voucher flexibility for family use.

This research demonstrates the essential complementarity of evaluation methods. While RCTs establish treatment effectiveness, Realist Evaluation reveals the mechanisms* necessary to address professional resistance and translate evidence into practice. When barriers are philosophical (HOW it works), mechanistic understanding from qualitative evaluation is essential, not supplementary.