| pA2 online © Copyright 2004 The British Pharmacological Society |
190P
GKT, University of London Winter Meeting December 2003 |
|
Effect of
the women's health initiative trial on hormone replacement therapy
prescribing |
|
Print abstractHormone Replacement Therapy (HRT) has been used for many years to manage menopausal symptoms and for the prevention of osteoporosis. Although previously thought to confer protection against cardiovascular disease (CVD), recently published randomised controlled trials have reported an increased risk of CVD with certain forms of combination HRT.
This study assessed the effect of the publication of one such study, the Women's Health Initiative (WHI) study1 in July 2002 (which was widely covered in the popular media) on HRT prescribing patterns in Ireland. The General Medical Services (GMS) prescription database was used to identify women aged 45-69 years who were prescribed HRT from Jan. 2001 - April 2003. Prescription rates were calculated at 3-monthly intervals for the following preparations: oestrogen only (EST) combined (i.e. oestrogen / progesterone) continuous HRT (cHRT), combined sequential HRT (sHRT) and tibolone. Age-adjusted rates were calculated per 1,000 GMS population. Linear and quadratic trends were calculated to evaluate prescription patterns over time. Results showed statistically significant reduction in prescription rates for all HRT preparations during the study (Table 1). Oestrogen, the most commonly prescribed preparation showed similar rates of reduction compared with cHRT and sHRT, while tibolone, the least commonly prescribed preparation, showed a lower but still statistically significant reduction.
Table 1: Prescribing patterns of HRT Jan, 2001-April 2003
| Age-adjusted prescribing rate / 1000 GMS population | |||||
| Month |
Total
on HRT (n)
|
Tibolone
|
EST
only
|
cHRT
|
sHRT
|
| Jan 01 |
5963
|
24.3
|
150.5
|
88
|
132.9
|
| Apr 01 |
5604
|
23.4
|
140.3
|
86.4
|
121.7
|
| Jul 01 |
5733
|
24.3
|
140.4
|
92
|
123.6
|
| Oct 01 |
5821
|
23.7
|
146.1
|
94.9
|
122.2
|
| Jan 02 |
6012
|
26.2
|
152.2
|
100.7
|
120.5
|
| Apr 02 |
5924
|
26.5
|
144.1
|
106.2
|
116.5
|
| Jul 02 |
5851
|
28.1
|
146.0
|
104.2
|
111.6
|
| Oct 02 |
5215
|
26
|
132.6
|
93.1
|
94.8
|
| Jan 03 |
4887
|
24.8
|
126.6
|
84.8
|
88.7
|
| Apr 03 |
4593
|
24.0
|
118.4
|
79.9
|
82.9
|
|
Test
forlinear trend
|
P=0.025
|
P<0.001
|
P<0.001
|
P<0.001
|
|
|
Test
for quadratic trend
|
P=0.032
|
P<0.001
|
P<0.001
|
||
The decline in prescribing rates was particularly evident from July 2002 onwards for EST, cHRT and sHRT. Since the results show a reduced prescribing rate of all HRT, although the WHI trial results related to combination preparations only, the findings suggest that the media coverage and prescriber uncertainty has had a negative impact on overall HRT prescribing.
1WHI study, JAMA 2002;288:321-333.