Impact of Modified System of Objectified Judgement Analysis (SOJA) methodology on prescribing costs of ACE inhibitors

Abstract

Background and objectives: System of Objectified Judgement Analysis (SOJA) is a structured approach to the selection of drugs for formulary inclusion. How- ever, while SOJA is a very important advance in drug selection for formulary purposes, it is hospital based and can only be applied to one indication at a time. In SOJA, cost has been given a primary role in the selection process as it has been included as a selection criterion from the start. Cost may therefore drive the selection of a particular drug product at the expense of other basic criteria such as safety or efficacy. The aims of this study were to use a modified SOJA approach in the selection of ACE inhibitors (ACEIs) for use in a joint formulary that bridges primary and secondary care within a health board in Northern Ireland, and to investigate the potential impact of the joint formulary on prescribing costs of ACEIs in that health board.

Methods: The modified SOJA approach involved four phases in sequence: an evidence-based pharmacotherapeutic evaluation of all available ACEI drug entities, a separate safety/risk assessment analysis of products containing agents that exceeded the pharmacotherapeutic threshold, a budget-impact analysis and, finally, the selection of product lines. A comprehensive literature review and expert panel judgement informed the selection of criteria (and their relative weighting) for the pharmacotherapeutic evaluation. The resultant criteria/scoring system was circulated (in questionnaire format) to prescribers and stakeholders for comment. Based on statistical analysis of the latter survey results, the final scoring system was developed. Drug entities that exceeded the evidence threshold were sequentially entered into the second and third phases of the process.

Results: Five drug entities (11 currently available in the UK) exceeded the evidence threshold and 22 of 26 submitted product lines containing these drug entities satisfied the safety/risk assessment criteria. Three product lines, each containing a different drug entity, were selected for formulary inclusion after budget impact analysis was performed. The estimated potential annual cost savings for ACEIs (based on estimated annual usage in defined daily doses) for this particular health board was 42%.

Conclusion: The modified SOJA approach has a significant contribution to make in containing the costs of ACEIs. Applying modified SOJA as a practical method for all indications will allow the development of a unified formulary that bridges secondary and primary care.