A probabilistic cost-effectiveness analysis of escitalopram, generic citalopram and venlafaxine as a first-line treatment of major depressive disorder in the UK

Objectives: To determine if escitalopram is cost-effective in the UK when compared with venlafaxine and generic citalopram in primary care treatment of Major Depressive Disorder (MDD). Methods: A pre-existing cost-effectiveness model was adapted to reflect the practice in the UK. Adult patients (> 18 years) with MDD [baseline scores >= 18 and <= 40 on the Montgomery-Asberg Depression Rating Scale (MADRS)] were accepted into the decision model. Success rates were derived from a meta-analysis of RCTs and other clinical and cost data from the General Practice Research Database, published literature and expert opinion. Patients were considered to be in remission when their MADRS score was <= 12. Failures were referred to consultant psychiatrists for secondary care. Analytic perspectives included those of society and of the National Health Service (NHS). Indirect costs were calculated using a Human Capital approach based on the average wage. Results: Expected costs were lower (465 pound vs. 544) pound and successes were higher (63.5% vs. 58.2%) with escitalopram than citalopram. Expected costs/successfully treated patient for escitalopram and citalopram were 732 pound and 933 pound, respectively, from the NHS perspective and 3635 pound and 4519 pound, respectively, from the societal perspective. In both cases, escitalopram dominated citalopram. Escitalopram's success rate was similar to that of venlafaxine, but at lower costs (range of savings with escitalopram: 53- pound 61) pound, just dominating venlafaxine. Robustness of findings was assessed in multivariate sensitivity analyses. Conclusion: In primary care in the UK, escitalopram is cost-effective compared with citalopram and quite similar to venlafaxine in treating MDD.