L'impatto della non aderenza alla terapia immunosoppressiva sull’outcome del trapianto di fegato. Correlates and outcome of non adherence to immunosuppression after liver transplantation.

Using the integrative model of behavior prediction, we investigated the prevalence and outcome of self-reported non adherence (NA) to immunosuppression in 268 adult, de novo liver transplant (LT) recipients; the association between ‘non adherence’, ‘intention to adhere’ and ‘barriers to adhere’ (model 1), and the relationship between ‘intention to adhere’, ‘attitudes’, ‘norms’ and ‘self-efficacy’ (model 2). NA was measured by the Basel assessment of adherence to immunosuppressive medication scale (BAASIS) and patients were followed up for 5 years for evidence of the composite and components of efficacy failure (treated and/or biopsy proven acute rejection (t/BPAR), graft loss, and death). NA was reported by 32.4% patients (87/268) and included timing deviations >2 hours in 23.5% (63/268), dose omissions in 8.5% (23/268), and dose reduction in 0.4% (1/268). Non adherers were younger (p = 0.001), had a higher risk for t/BPAR (12.6% vs. 2.8%; OR = 4.95; 95% CI=1.6-14.7), and experienced more frequent episodes of lower immunosuppressant blood levels vs. adherers (22.9% vs. 9.6%; p = 0.0047; OR 2.79; 95% CI = 1.3-5.6). In model 1, NA was predicted by barriers (OR 2.79; 95% CI 1.19-6.53; p = 0.01) and lower intention to adhere (OR 0.62; 95% CI 0.454-0.86; p= 0.004). In model 2, intention to adhere was predicted by being in favor of immunosuppression (OR 0.14; 95% CI 0.06-0.03; p<0.0001) and higher self-efficacy (OR 1.28; 95% CI 1.03-1.59; p=0.02). NA is reported by one third of recipients and is associated with younger age and a higher risk for acute rejection. Intentions are influenced by cognitive factors (attitudes, self-efficacy), while NA is associated with barriers (forgetfulness) which can be targeted by interventions.