The women's health initiative study: impact on the prescribing of hormone replacement therapy in a defined South African population

• Main Author: Hanly, Teia
• Format: Others
• Language: English
• Published: Nelson Mandela Metropolitan University 2006
• Subjects: Women > Health and hygiene > South Africa; Women's health services > South Africa; Menopause > Hormone therapy > South Africa
• Online Access: http://hdl.handle.net/10948/519; http://hdl.handle.net/10948/d1011713

Context: The Women’s Health Initiative (WHI) study, published in July 2002, had a significant impact on the prescribing of hormone replacement therapy (HRT). The controversy surrounding the findings, however, has led to much uncertainty regarding the prescription of HRT. Aims and Objectives: The aim of this study is to determine both the initial and the continued impact of the WHI study on the prescribing of HRT in a defined South African population and to determine whether HRT was appropriately individualised based on recommendations published subsequent to the WHI study. Setting: Claims data from a Managed Healthcare Organisation (MHO) that administers for a number of medical aid schemes in South Africa. Method: A retrospective drug utilisation review (DUR) was conducted to identify HRT-related prescribing patterns in the defined populations. The time-frame of the dataset included January 2002, to assess prescribing patterns prior to the publication of the WHI study, January 2003 to determine the initial impact of the WHI study, and January 2005 to assess the continued impact. An extensive, additional dataset of all the HRT users in the defined populations was utilised to conduct a sub-group analysis and determine whether HRT had been appropriately individualised. Key Findings: The percentage of patients in the dataset using HRT decreased from 30.05 percent in January 2002 to 28.30 percent in January 2003 and to 23.24 percent in January 2005, with the latter decrease reaching statistical significance. Although sex hormones and modulators (G03) of the genital system were the most frequently prescribed drug class in all three years of the study period, the prescribing frequency decreased significantly from 10.40 percent in January 2002 to 9.32 percent in January 2003 and 7.44 percent in January 2005. The most noteworthy change in the prescribing of HRT was a 3.95 percent decrease in the prescribing of conjugated equine estrogen (CEE), with a corresponding 2.53 percent increase in the prescribing of estradiol between January 2002 and January 2003. However, less pronounced changes were observed in the prescribing frequencies of other types of HRT, including medroxyprogesterone and estrogen (the HRT type investigated in the estrogen plus progestin phase of the WHI study). Patients initiating HRT post-WHI publication were generally found to be in the younger menopausal age categories (40 to 49 years). These patients were more likely to have been initiated on HRT types other than those investigated in the WHI study and were at a higher risk for disease states for which HRT use is beneficial, such as osteoporosis. Patients discontinuing HRT post-WHI publication were generally found to be in the older menopausal age categories (60 to 69 years), were more likely to have been combined HRT users (although not necessarily the type investigated in the WHI study) and were at a higher risk for disease states for which HRT use is considered harmful or has an uncertain effect, such as diseases affecting the cardiovascular system. Conclusion: It can be concluded that the WHI study did have an impact on the prescribing of HRT in the defined South African population of this study, but that the impact was considerably less than the impact reported in global studies. It was also determined that HRT was appropriately individualised according to recommendations made subsequent to publication of the WHI study.