Skin patch and vaginal ring versus combined oral contraceptives for contraception

 

Abstract

Background

The delivery of combination contraceptive steroids from a skin patch or vaginal ring offers potential advantages over the traditional oral route. The skin patch and vaginal ring could require a lower dose due to increased bioavailability and improved user compliance.

Objectives

To compare the contraceptive effectiveness, cycle control, adherence (compliance), and safety of the skin patch or the vaginal ring versus combination oral contraceptives (COCs).

Search methods

For trials of the contraceptive patch or the vaginal ring, we searched MEDLINE, POPLINE, CENTRAL, EMBASE, LILACS, ClinicalTrials.gov, and ICTRP. We contacted manufacturers and researchers to identify other trials.

Selection criteria

All randomized controlled trials comparing the skin patch or vaginal ring with a COC.

Data collection and analysis

Data were abstracted by two authors and entered into RevMan. For dichotomous variables, the Peto odds ratio (OR) with 95% confidence intervals (CI) was calculated. For continuous variables, the mean difference was computed.

Main results

We found 5 trials of the skin patch and 10 of the vaginal ring. Contraceptive effectiveness was similar for the patch or ring versus the comparison COC. More patch users discontinued early than COC users: ORs were 1.59 (95% CI 1.26 to 2.00), 1.56 (95% CI 1.18 to 2.06), and 2.57 (95% CI 0.99 to 6.64). Patch users also had more discontinuation due to adverse events. Compared to COC users, patch users reported more breast discomfort, dysmenorrhea, nausea, and vomiting. Patch users reported more compliant cycles than the COC users in two trials: ORs were 2.05 (95% CI 1.83 to 2.29) and 2.76 (95% CI 2.35 to 3.24). The ring trials generally showed similar discontinuation for ring and COC users. Ring users reported less nausea, acne, irritability, and depression than COC users. Ring users had more vaginitis and leukorrhea but less vaginal dryness. Ring users had similar adherence to COC users in two trials but less adherence in one. Cycle control was generally similar for the patch and COC, and was similar or better for the ring versus COC.

Authors' conclusions

Effectiveness was similar for the methods compared. The patch could lead to more discontinuation while the vaginal ring showed little difference. The patch group had better compliance than the COC group but more side effects. Ring users generally had fewer adverse events than COC users but more vaginal irritation and discharge. High losses to follow up can affect the validity of the results.

 

Plain language summary

Skin patch or vaginal ring compared to pills for birth control

The skin patch and the vaginal (birth canal) ring are two methods of birth control. Both methods contain the hormones estrogen and progestin. The patch is a small, thin, adhesive square that is applied to the skin. The contraceptive vaginal ring is a flexible, lightweight device that is inserted into the vagina. Both methods release drugs like those in birth control pills. These methods could be used more consistently than pills because they do not require a daily dose. Little is known about how these methods compare to birth control pills. This review looked at how well the methods worked to prevent pregnancy, how safe they were, if they caused bleeding problems, and if women used them as prescribed.

We did a computer search for randomized controlled trials of the skin patch or vaginal ring compared to pills for birth control. Pills included types with both estrogen and progestin. We wrote to researchers to find other trials.

We found 15 trials; 5 compared the patch to birth control pills and 10 looked at the ring and pills. The methods compared had similar pregnancy rates. Patch users were more likely than pill users to drop out early from the trial. Ring users were not more likely to drop out early. Compared to pill users, patch users had more breast discomfort, painful periods, nausea, and vomiting. Ring users had less nausea, acne, irritability, and depression than pill users. Ring users often had fewer bleeding problems but more vaginal irritation and discharge. Patch users reported using their method more consistently than the pill group did.

Compared to pill users, the patch group had more side effects while ring group had fewer. The patch might lead to stopping the birth control method early. High losses to follow up can lower the value of the results. Studies of the skin patch and vaginal ring should provide more detail on whether women used the method correctly.

 

摘要

背景

皮膚貼片及陰道環與口服避孕藥之避孕效果的比較

經由皮膚貼片或陰道環來投予避孕用的類固醇，比起傳統的口服路徑擁有潛在優勢。皮膚貼片或陰道環因為藥物生物獲得性較高所以使用劑量較低，且皮膚貼片或陰道環的使用者配合度較高。

目標

為比較皮膚貼片、陰道環與口服避孕藥之避孕效果、控制經期、病患配合度及安全性。

搜尋策略

我們搜尋了MEDLINE, POPLINE, CENTRAL, EMBASE, 以及 LILACS 裡面關於避孕貼片或陰道環的試驗。並連絡製造商與研究者以找出其他的試驗。

選擇標準

所有皮膚貼片或陰道環與口服避孕藥隨機相比較的隨機對照試驗。

資料收集與分析

由兩位作者將資料篩出，並輸入 RevMan。如資料為二分變項，則計算 Peto 勝算比及百分之九十五信賴區間。連續變項則計算加權平均差。

主要結論

我們找到三個皮膚貼片及八個陰道環的試驗。貼片或陰道環與口服避孕藥的避孕效果相當。貼片的使用者比起口服避孕藥回報說使用的配合度較高，在兩個試驗中，勝算比分別為2.05(百分之95的信賴區間為1.83到2.29)以及2.76(百分之95的信賴區間為2.35到3.24)。而一項陰道環的交叉試驗顯示使用者的配合度較低。有兩個試驗顯示使用者，比起口服避孕藥，對陰道環較感滿意。在兩個試驗中發現，貼片的使用者比起口服避孕藥，較容易提早停止用藥：勝算比分別為1.58(百分之95的信賴區間為1.25到1.99)以及1.45(百分之95的信賴區間為1.11到1.90)。這是因為貼片的不良反應引起使用者提早停藥。陰道環的試驗則顯示和口服避孕藥有相同的停藥比例。與口服避孕藥相比，貼片的使用者表示有乳房不適、經痛、嘔心及噁吐。有單一個試驗顯示，陰道環的使用者和口服避孕藥相比，有較少的噁心、躁動和憂鬱。然而陰道環的使用者較常發生陰道炎以及白帶。陰道環出血的問題與口服避孕藥相當或較少發生。

作者結論

各種方式的有效率都相近。貼片的配合度比口服避孕藥好，但有較多的副作用。陰道環的副作用比口服避孕藥少，但較易產生陰道刺激及分泌物。貼片較容易停藥而陰道環的停藥率則沒有差別。高比率的失去追蹤率會影響這些結果的效度。

翻譯人

本摘要由臺灣大學附設醫院陳俊葦翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

皮膚貼片與陰道環是兩種新的避孕方式。避孕貼片是一種小、薄、有黏性的方塊，黏著在皮膚上。陰道環是一個具有彈性而輕的裝置，塞在陰道中使用。這兩種方式皆釋放類似口服避孕藥的成份。因為不必像口服避孕藥需要天天服用，新的避孕方法的使用配合度較高。我們搜尋到三個隨機分派對照的試驗，研究皮膚貼片與口服避孕藥。這些試驗發現兩者的懷孕率相同。其中一個試驗發現貼片組的提早停藥率較高，但另一個試驗沒有相同的發現。使用貼片的女性較常回報乳房不適。其他的頭痛、噁心、經痛以及腹痛等不良反應，兩組的發生率相同。