Subdermal implantable contraceptives versus other forms of reversible contraceptives or other implants as effective methods for preventing pregnancy

 

Abstract

Background

Implantable methods of contraception offer long-acting reversible contraception. Their uptake rate in comparison to other contraceptive methods, particularly in developed countries, has historically been low.

Objectives

To assess the contraceptive effectiveness, tolerability and acceptability of subdermal implants in comparison to other reversible contraceptive methods.

Search methods

Literature were identified through database searches, reference lists and individuals/organisations working in the contraceptive field.

Selection criteria

All randomised and controlled trials comparing subdermal implants with other forms of reversible contraceptives and reporting on pre-determined outcomes in women of reproductive years. Primary outcomes were pregnancy and continuation.

Data collection and analysis

Quality assessment of studies and data extraction were completed independently by two reviewers. A quality checklist was designed to identify general methodological and contraceptive specific factors. Study authors and pharmaceutical companies were contacted to provide additional data.
Data were collected on pregnancy rates, continuation, side effects and adverse events.

Main results

All nine identified trials compared different types of contraceptive implant. Eight, involving 1578 women, compared Implanon with Norplant , and one, involving 1198 women, compared Jadelle with Norplant. There was no difference between Implanon and Norplant for contraceptive effectiveness rates or continuation over 4 years. Both were highly effective methods of contraception with no pregnancies occurring in any of the trials during 26,972 and 28,108 women months of follow up respectively. The most common side-effect with Implanon and Norplant was changes in bleeding pattern. The pattern with Implanon was initially more variable, bleeding with both implants became less frequent with duration of use. After two years use the amenorrhoea rate was significantly higher with Implanon. The trials reported no significant difference in hormonal side-effects or adverse events. Implanon was significantly quicker to insert and remove than Norplant.
There was no difference in contraceptive effectiveness and in continuation rates between Jadelle and Norplant. Jadelle was significantly quicker to remove than Norplant.

Authors' conclusions

Implanon, Norplant and Jadelle are highly effective contraceptive methods. No significant differences were found in contraceptive effectiveness or continuation. The most common side-effect with all implants was unpredictable vaginal bleeding. Time taken for removal of Implanon and Jadelle was less than that for Norplant.
Although this systematic review was unable to provide a definitive answer on relative effectiveness, tolerability and acceptability of contraceptive implants in comparison to other contraceptive methods, it has raised issues around the conduct of contraceptive research.

 

Plain language summary

This review aimed to assess how effective contraceptive implants were at preventing pregnancy and how acceptable women found them compared to other methods of contraception.

All the trials identified compared different types of contraceptive implant. No trials were found that compared implants to other contraceptive methods. All the implants were highly effective methods of contraception in the selected women. The majority of women using contraceptive implants chose to continue with the method long term, over 80% of women were still using their implant at two years. Women in developed country studies were less likely to continue with these methods when compared to women in developing country studies. The most common reported side -effect was of irregular vaginal bleeding. Bleeding with all implants became less frequent with time. Removal was quicker for Implanon and Jadelle than for Norplant. Insertion problems were rare with any of the implants. Problems at removal were uncommon but were significantly more likely to occur in Norplant users than Implanon users.

 

摘要

背景

皮下植入式避孕藥與其他型式的可逆避孕或其他植入式避孕，作為預防懷孕的有效方法之比較

植入式避孕藥提供了長效且可逆性的避孕，然而它們的接受比率比起其他避孕方式向來比較低，特別是在已開發國家。

目標

比較皮下植入避孕藥和其他可逆的避孕方式，其避孕之有效性 (effectiveness)、容忍度 (tolerability)、和接受度 (acceptability)。

搜尋策略

文獻來自於搜尋資料庫，參考資料列表，和在避孕研究領域工作的個人或組織。

選擇標準

所有比較皮下植入式避孕和其他可逆性避孕的隨機對照試驗，以及在生育年齡婦女身上的預定研究結果 (predetermined outcomes) 。初步結果包括懷孕和持續度。

資料收集與分析

試驗的品質評估和資料選取由兩個審查者各自獨立完成。有一份設計好的品管清單用來檢視方法學上的因子和避孕相關的特殊因子 (contraceptive specific factors)。連絡文獻作者和藥廠去獲得額外的資訊。收集的資料包括懷孕率、持續度、副作用和不良事件。

主要結論

總共有九個試驗比較了不同種類的植入式避孕。八個試驗 (囊括1578個婦女) 比較Implanon和Norplant，一個試驗 (囊括1198個婦女) 比較Jadelle和Norplant。Implanon和Norplant兩者在四年內的避孕有效機率或者持續度上沒有顯著差異。兩者都是極為有效的避孕方法，在各自追蹤達26972人月 (women months) 和28108人月的過程中沒有發生任何懷孕。最常出現的副作用是出血型態的改變。Implanon使用早期的出血型態變化較大。出血的頻率隨著植入式避孕藥的使用時間越長而降低。使用兩年後無月經的機率以Implanon顯著較高。荷爾蒙副作用或者不良事件在這些試驗中並沒有顯著差異。Implanon比起Norplant在植入或者移除所需的時間上明顯較為快速。Jadelle和Norplant兩者在避孕有效機率或者持續度上沒有顯著差異。Jadelle移除的速度比起Norplant明顯較為快速。

作者結論

Implanon, Norplant和Jadelle都是極為有效的避孕方式，在避孕有效性和持續度上均無顯著差異。在所有植入式避孕最常見的副作用是非預期的陰道出血。Implanon和Jadelle移除所需的時間比起Norplant顯著較短。雖然比較植入式避孕和其他避孕方法之間相對的有效性、容忍度和接受度，這篇系統性的評論還無法提供一個最確切的答案，但是它提供了日後研究的方向。

翻譯人

本摘要由臺灣大學附設醫院黃楚珺翻譯。

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

總結

這篇評論目的是評估植入式避孕和其他避孕方式相較之下的有效性和接受度。所有被採用的文獻都是針對不同的植入式避孕藥做比較，沒有文獻是將植入式避孕和其他避孕方式做比較。結論顯示所有植入式避孕藥都是高度有效的的避孕方法，大多數選擇使用植入式避孕的婦女會選擇繼續長期使用，超過80%的婦女使用超過兩年以上。已開發國家的婦女比起開發中國家的婦女持續使用的機率較低。最常見的副作用是不規則陰道出血，每種植入式避孕藥的出血頻率均會隨者使用時間越長而降低。移除植入式避孕藥的時間以Implanon和Jadelle比Norplant較快速。植入產生的問題相當罕見。移除產生的問題同樣罕見，但Norplant使用者比起Implanon使用者顯著較常發生問題。