Longitudinal impact of the Women’s Health Initiative study on hormone therapy use in Australia

Abstract

Purpose: This study aimed to examine the longitudinal impact of evidence changes on menopausal hormone therapy (MHT) use in Australia.

Methods: We analyzed two datasets of subsidized and total MHT use (2000–2016) using segmented regression analysis to explore the impact of the Women’s Health Initiative (WHI) 2002 and 2007 studies. Analyses were stratified by class, route, and strength. Use was measured in defined daily dose/1000 women/day (DDD/1000/day) or packs/1000 women/month (packs/1000/month).

Results: The drop in total MHT use after the WHI 2002 was substantial. The biggest decreases in class, route, and strength were estrogens (28.99 DDD/1000/day, 95% confidence interval [CI] 23.97, 34.01), oral (46.07 DDD/1000/day, 95% CI 41.13, 51.01), and medium strength (34.95 packs/1000/month, 95% CI 30.17, 39.73), respectively. However, vaginal use remained stable (−1.83 DDD/1000/day, 95% CI −3.83, 0.17). Profiles of total and subsidized use were similar over time. Utilization levels were relatively unchanged after 2007. Decreased utilization contributed to product discontinuation, with a lag of up to 4 years. Product discontinuation in 2009 further decreased utilization.

Discussion and conclusions: MHT use remained low after 2002 despite evidence favoring its use in women younger than 60 years or within 10 years postmenopause. Continued low use could relate to the WHI 2002 media coverage, therapy objectives, key stakeholder uncertainty, health policies, and medicine availability.

Chinese abstract

目的：本研究旨在探究澳大利亚女性绝经激素治疗（MHT）证据改变的纵向影响。

方法：我们使用分段回归分析方法分析了2000-2016年资助使用和总使用MHT的两个资料组, 以探讨2002年和2007年妇女健康倡议（WHI）研究的影响。按激素分类、途径和强度分析。使用的剂量单位为规定的每日剂量/1000女性/天（DDD/1000/天）或包/1000女性/月（包/1000/月）

结果：2002年世界大会之后, MHT总使用量有了显著下降。其分类、途径、强度下降最大的分别是雌激素（28.99DDD/1000/天, 95%的置信区间[CI]23.97, 34.01）、口服（46.07 DDD/1000/天, 95% CI 41.13, 51.01）和中等强度（34.95 包/1000/月, 95% CI 30.17, 39.73）。然而, 阴道使用保持稳定（1.83 DDD/1000/day, 95% CI 3.83, 0.17）。随着时间的延长总使用情况和资助使用情况是相似的。2007年之后, 利用水平保持相对不变。利用率的下降导致产品的停产, 滞后长达4年。2009年产品停产进一步降低了利用率。

讨论与结论：尽管有证据表现MHT在60岁以下或绝经后10年内的女性应用效果较好。但在2002年之后使用率依然很低。持续的使用率低可能与2002年WHI媒体报道、治疗目标、主要利益相关者的不确定, 卫生政策和药物的可获得性相关。

Keywords:

• Menopause
• estrogen replacement therapy
• drug utilization
• interrupted time series analysis
• Australia

Acknowledgements

RBN would like to acknowledge the Indonesia Endowment Fund for Education (LPDP) and Health World Limited for providing financial support. All authors would like to acknowledge IQVIA for providing access to the sales data.

Conflict of interest

RBN is financially supported by PhD scholarship from the Indonesia Endowment Fund for Education (LPDP) and a small research grant from Health World Limited, an Australian herbal medicine manufacturer. Neither sponsor was involved in designing, analyzing, writing, or reviewing the manuscript. The remaining authors declare no conflict of interest.

Source of funding

RBN is financially supported by PhD scholarship from Indonesia Endowment Fund for Education (LPDP) [grant number 20141022022034]; research grant (AU$5000) from Health World Limited.