Economic analysis of long-term reversible contraceptives. Focus on Implanon

To examine the economic impact of a new implantable contraceptive, Implanon, in comparison with other available contraceptive methods.

This was a modelling study using cost data derived from national published sources and effectiveness data from either controlled clinical trials (Implanon) or reports in the literature (other contraceptives). In the baseline analysis, Implanon was compared with 2 long term reversible contraceptives, Norplant and Mirena. Further analyses were then carried out comparing Implanon with Depo-Provera and with combined oral contraceptives.

The study concentrated on the UK, but also made reference to several other European countries.

The baseline analysis showed that all 3 long term reversible contraceptives produce very good rates of return, with Implanon providing the best rate of return (both average and internal) of the 3 methods. The payback period for Implanon was calculated as 146 days, compared with 339 and 368 days for Norplant and Mirena, respectively. In terms of cost effectiveness, the cost per protected year for Implanon was 95 Pounds, compared with 146 Pounds and 168 Pounds for Norplant and Mirena, respectively. In comparison with Depo-Provera (an injectable contraceptive), Implanon was both less costly and more effective, the cost per protected year for Depo-Provera being 131 Pounds. The threshold beyond which Implanon delivers cost savings compared with combined oral contraceptives was at a failure rate of 4.9% for the combined pill.

Reversible long term approaches to contraception provide an effective and efficient use of healthcare resources and generate an excellent return on public investment. Implanon produces better rates of return than both Norplant and Mirena, and is also more cost effective in terms of cost per pregnancy avoided and cost per protected year than Norplant, Mirena, Depo-Provera and oral contraceptives.