The continuation rates of long-acting reversible contraceptives in UK general practice using data from The Health...

The purpose of this study was to determine the continuation rates of new users of long-acting reversible contraceptive (LARC) methods in the UK, using data from general practice.

We conducted an observational study using a general practitioner (GP) database, The Health Improvement Network (THIN). The methods studied were copper intrauterine devices (Cu-IUDs), levonorgestrel-releasing intrauterine system (LNG-IUS), progestogen-only implants and progestogen-only injections. The study population comprised women in THIN aged 18-44 years during the period 2004-2009 who had been registered with their GP for at least 5 years, with a computerized prescription history of at least 1 year. Using computer algorithms, the database was searched for the Read and Multilex codes for each LARC method. New LARC users were identified and followed until there was a record indicating termination of use or the study period ended.

The proportion of women who discontinued use during the same year of administration was 7.5% for Cu-IUDs, 10.6% for LNG-IUS, 13.2% for progestogen-only implants and 54.4% for progestogen-only injections. By the end of the study, a higher proportion of Cu-IUD and LNG-IUS users (21.1 and 18.6%, respectively) undertook consecutive use of the same method than progestogen-only implant users (10.7%). Manual review of computerized profiles demonstrated the validity of this approach.

In the UK, the continuation rates of LARCs are high, and approximately one fifth of women chose to have a second intrauterine device fitted after expiry of the first device. A validation step demonstrated the reliability of the methodology and computer algorithms used.