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加拿大醫學協會期刊(Canadian Medical Association Journal)的一篇回溯式比較型安全世代研究結果，新舊避孕藥的膽囊疾病風險相當。

 The risk for gallbladder disease is virtually the same with newer and older types of birth control pills, according to the results of a retrospective, comparative safety cohort study reported online April 18 in the Canadian Medical Association Journal.

"Recent concerns have been raised about the risk of gallbladder disease associated with the use of drospirenone, a fourth generation progestin used in oral contraceptives," write Mahyar Etminan, PharmD, MSc, from the Faculty of Medicine, University of British Columbia in Vancouver, Canada, and colleagues. "We conducted a study to determine the magnitude of this risk compared with other formulations of oral contraceptives."

Using the IMS LifeLink Health Plan Claims Database, the investigators identified women who were using an oral contraceptive containing ethinyl estradiol combined with a progestin during 1997-2009 and who had been taking the oral contraceptive continuously for at least 6 months. A Cox proportional hazards model allowed calculation of adjusted rate ratios (RRs) for gallbladder disease, defined as cholecystectomy in the primary analysis, or as hospital admission secondary to gallbladder disease in a secondary analysis.

Of 2,721,014 women in the cohort, 27,087 underwent surgical or laparoscopic cholecystectomy during follow-up. There was a small but statistically significant increase in gallbladder disease risk with 3 of the newer oral contraceptives vs levonorgestrel, an older second-generation progestin. Adjusted RRs were 1.05 for desogestrel (95% confidence interval [CI], 1.01 - 1.09), 1.20 for drospirenone (95% CI, 1.16 - 1.26), and 1.10 for norethindrone (95% CI, 1.06 - 1.14). However, ethynodiol diacetate, norgestrel, and norgestimate were not associated with any statistically significant increase in risk vs levonorgestrel.

"In a large cohort of women using oral contraceptives, we found a small, statistically significant increase in the risk of gallbladder disease associated with desogestrel, drospirenone and norethindrone compared with levonorgestrel," the study authors write. "However, the small effect sizes compounded with the possibility of residual biases in this observational study make it unlikely that these differences are clinically significant."

Limitations of this study include lack of validation of the International Classification of Diseases, Ninth Revision(ICD-9), codes for gallbladder disease in most administrative databases, inability to control for body mass index and ethnicity, possible residual confounding with other known and unknown variables, and reporting bias as a possible reason for the apparent increase in gallbladder disease in people taking drospirenone.

"The surge in the number of reported cases of gallbladder disease facilitated through the media may have contributed in making drospirenone appear to be associated with a higher risk of gallbladder disease compared with older contraceptives," the study authors conclude.

The Fonds de la recherche en santé du Québec (FRSQ), the Ministère de la Santé et des Services sociaux, and the McGill University Health Center supported this study. Coauthor James Brophy, MD, PhD, is the recipient of a career award from the FRSQ. The remaining study authors have disclosed no relevant financial relationships.

　　
　　加拿大溫哥華英屬哥倫比亞大學醫學院Mahyar Etminan藥學博士等人寫道，近來對於使用drospirenone與膽囊疾病風險有關的顧慮日增，drospirenone是用於口服避孕藥的一種第四代黃體素；這項研究的目的在於比較並確認此藥與其他口服避孕藥的風險程度。
　　
　　研究人員使用IMS LifeLink Health Plan Claims Database這個資料庫，探討於1997至2009年間使用ethinyl estradiol加上一種黃體素的口服避孕藥、且持續服用口服避孕藥至少6個月的婦女。運用Cox部分風險模式計算膽囊疾病的校正率比(RRs)，定義是初步分析中有進行膽囊切除術、或者次級分析中有因為膽囊疾病而住院。
　　
　　這個世代共有2,721,014名婦女，27,087人在追蹤期間接受手術或腹腔鏡膽囊切除術；相較於舊的第二代黃體素levonorgestrel，有三種新的口服避孕藥之膽囊疾病風險都有小而顯著的增加。校正RR方面，desogestrel是1.05 (95%信心區間[CI]為1.01 - 1.09)，drospirenone是1.20(95% CI為1.16 -1.26)，norethindrone為1.10 (95% CI為1.06 - 1.14)，不過，ethynodiol diacetate、norgestrel以及norgestimate的風險並沒有比levonorgestrel顯著增加。
　　
　　研究作者寫道，使用口服避孕藥的大型婦女世代中發現，相較於levonorgestrel，desogestrel、drospirenone和norethindrone的膽囊疾病相關風險有小而顯著的增加；不過，影響程度小，加上這是篇觀察型研究的可能殘餘偏見，使得這些差異不太可能有臨床重要性。
　　
　　研究限制包括，缺乏以International Classification of Diseases, Ninth Revision (ICD-9)確認大多數住院資料庫中的膽囊疾病編碼，無法控制身體質量指數和種族，其他已知與未知變項可能有殘餘的干擾，報告時的偏見也可能是服用drospirenone者膽囊疾病明顯增加的一個可能原因。
　　
　　研究作者結論表示，在媒體推波助瀾之下，膽囊疾病的案例報告激增，可能會因此使drospirenone看來比其他較舊的避孕藥有更高的膽囊疾病風險。
　　
　　資料來源：http://www.24drs.com/professional/list/content.asp?x_idno=6504&x_classno=0&x_chkdelpoint=Y