Use pattern for contraceptive implants in Norway

Knowledge about global use patterns of contraceptive implants is limited. This study aims to describe implant use patterns from a user and a prescriber perspective.

In a cross-sectional design, we estimated the annual number of users by calculating doses sold per 1000 women-years in the Norwegian Prescription Database for 2006-2012. For each contraceptive method, we calculated on an annual basis a proportion of defined daily doses of all hormonal contraceptives in five-year age groups. Data were analyzed in SPSS version 22, using chi-square test, t-test, and survival analysis.

Sales from pharmacies for contraceptive implants more than doubled over the study years and were consistently higher in the younger age groups. The collection rate was 9.3 per 1000 women in 2012, when implant sales amounted to 2.4% of all daily doses of hormonal contraceptives sold. General practitioners and doctors with no specialty were the major prescribers to those starting to use contraceptive implants (starters), whereas gynecologists prescribed nearly 12% of the volume, with a higher proportion to women >35 years of age than younger women. The cumulative proportions of continued users at 6, 12, 24, and 36 months were 96.1, 78.6, 51.9, and 34.9%, respectively, significantly lower for users who had prescribing doctors with no specialty. At end of the first expiration period, 21% of starters continued using implants.

Implants play a minor role in the overall use of hormonal contraception in Norway. One in five starters continue as long-term users.