However, when mutually exclusive interventions are compared, it is essential to use incremental cost-effectiveness ratios.

For the complete intervention, we also calculated the incremental cost-effectiveness ratios, which compare the complete intervention to the condom use skills component.

The incremental cost-effectiveness ratio (ICER) is an equation used commonly in health economics to provide a practical approach to decision making regarding health interventions.

Incremental cost-effectiveness ratio (ICER):

The incremental cost-effectiveness ratio (ICER) is the ratio between the difference in costs and the difference in benefits of two interventions.

Cost-effectiveness is typically expressed as an incremental cost-effectiveness ratio (ICER), the ratio of change in costs to the change in effects.

Calculations suggest a base-case incremental cost-effectiveness ratio (ICER) of £19,870 per incremental quality-adjusted life years (QALYs) for patients with DMARD resistance.

When combined with the relative cost of treatment this information can be used to form an Incremental Cost-Effectiveness Ratio (ICER) to allow comparison of suggested expenditure against current resource use at the margin (the cost effectiveness threshold).