Utilization pattern of hormone therapy in UK general practice between 1996 and 2015: a descriptive study

To describe the long-term trends in hormone therapy (HT) use in UK general practice after evidence of associated increased risks of cardiovascular disease (CVD) and breast cancer, subsequent guideline changes in 2003/2004 advising individualized HT prescribing, and halving of HT use between 2002 and 2005.

We conducted a descriptive study to quantify annual proportions of overall and new HT use in women aged 40 to 79 years, using the UK-based Clinical Practice Research Datalink (1996-2015). We further described HT utilization patterns (drug type, administration route, dose) within 2-year blocks overall and within subpopulations with pre-existing CVD or breast cancer.

Overall HT use continued to decline from 9.4% in 2006 to 7.5% in 2015. Between 1998 and 2001, the proportion of HT initiation was around 1.7%, which halved by 2005 (0.8%), and increased again up until 2015 (1.0%). The mean age of HT users increased from 54.7 in 1996/1997 to 56.6 in 2002/2003, and leveled off at 57 to 58 years in 2014/2015. The prevalence of CVD in HT users decreased from a peak of 5.8% in 2002/2003 to 4.5% in 2014/2015, whereas breast cancer prevalence continuously increased from 0.9% in 1996/1997 to 1.9% in 2014/2015. Overall, we observed trends towards use of estrogen therapy, vaginal HT, and lower HT dose after 2002/2003, which were stronger among subpopulations with pre-existing CVD or breast cancer.

Our study suggests that the HT guideline changes implemented in UK clinical practice resulted in safer HT use, particularly in women with pre-existing CVD or breast cancer.