Collection devices for obtaining cervical cytology samples

 

Abstract

Background

This review is no longer appropriate for update as liquid based cytology has superceded smear technology.

The large variation in disease detection rated with cervical smears may be partly due to differences in the sampling devices and the techniques of sampling.

Objectives

To assess whether the design of the cervical smear device affects rates of inadequate smears and the detection of disease; and whether the presence of endocervical cells in the smear affects disease detection.

Search methods

We searched the Cochrane Gynaecological Cancer Group
trials register and MEDLINE up to July 1997. We also handsearched 16
journals.

Selection criteria

Randomised and quasi-randomised trials and non-randomised comparative studies comparing cervical smear collection devices in women attending for primary screening, colposcopy following an abnormal smear or colposcopy after treatment.

Data collection and analysis

Two reviewers independently abstracted data. Study quality was assessed.

Main results

Thirty-six trials and six observational comparative studies were included. The Ayre spatula was shown to be less effective compared with extended tip spatulas for collecting endocervical cells in eight trials (odds ratio 2.25, 95% confidence interval 2.06 to 2.44).
Use of a spatula with the cytobrush was more effective than spatula alone at collecting endocervical cells (odds ratio 3.33, 95% confidence interval 3.05 to 3.63) and the same effect was present for adequate smear rates (odds ratio 1.51 95% confidence interval 1.19-1.92). Extended tip spatulas were also superior for the detection of dyskaryosis in seven trials (odds ratio 1.21, 95% confidence interval 1.10 to 1.33). Based on data from two trials and three observational studies, smears that contained endocervical cells were more likely to detect dyskaryosis, particularly in severe disease. The proportion of smears with endocervical cells present increased with increasing severity of the disease.

Authors' conclusions

Extended tip spatulas of various designs appear to be better for collecting endocervical cells than the commonly used Ayre spatula. The most effective combination appears to be the cytobrush with an extended tip spatula. The rate of detection of endocervical cells appears to be a valid and convenient surrogate for the ability to detect dyskaryosis and for adequate smear rates. The ability of the extended tip spatula with the cytobrush compared with the extended tip spatula alone to detect disease, needs to be evaluated in a trial.

 

Plain language summary

This review is no longer appropriate for update as liquid based cytology has superceded smear technology.

Commonly used spatula not the most effective for cervical screening.

Cervical screening (pap smear) is an effective way of detecting pre-cancerous abnormalities of the cervix (cervical intraepithelial neoplasia). Tests can be affected by the tester's skill and the design of the device used. Inadequate smears can produce incorrect results, causing stress and inconvenience to women having to undergo repeat screening. This review of trials found that the commonly used Ayre spatula is not as effective in collecting cells as the extended tip spatula. The most effective appears to be a combination of the cytobrush with an extended tip spatula.

 

摘要

背景

用於取得子宮頸細胞學樣本之收集裝置

以子宮頸抹片評估偵測疾病所存在的大量差異，部分是因為取樣裝置以及取樣技術的不同。

目標

評估子宮頸抹片裝置之設計是否會影響不適當抹片之比率及疾病之偵測；以及抹片中存在子宮頸內頸細胞是否或影響疾病之偵測。

搜尋策略

我們搜尋了直到1997年7月之Cochrane Gynaecological Cancer Grouptrials register以及MEDLINE。我們亦以人工搜尋16份期刊。

選擇標準

針對求診進行初步篩選、在異常抹片後進行子宮鏡檢、或是在治療後進行子宮鏡檢之女性，比較子宮頸抹片收集裝置之隨機及半隨機試驗以及非隨機比較性研究。

資料收集與分析

由2名回顧作者獨立摘錄數據。亦評估研究品質。

主要結論

共收錄36項試驗及6項觀察性比較研究。在8項試驗中，相較於前端延伸匙，Ayre匙較無法有效收集子宮內頸膜細胞 (勝算比2.25, 95% 信賴區間2.06 to 2.44) 。使用具有細胞刷之匙可較僅使用匙而更有效的收集子宮內頸細胞 (勝算比3.33, 95% 信賴區間3.05 to 3.63) ，而其對適當抹片率則有相同作用 (勝算比1.51 95% 信賴區間1.19 – 1.92) 。在7項試驗中，前端延伸匙亦可較佳偵測核異常 (勝算比1.21, 95% 信賴區間1.10 to 1.33) 。根據取自2項試驗及3項觀察性研究之數據，含有子宮內頸細胞之抹片較可能偵測到核異常，特別是在嚴重疾病之情形下。含有子宮內頸細胞之抹片比率會隨著疾病的嚴重性而增加。

作者結論

就收集子宮內頸細胞而言，各種不同設計之前端延伸匙似乎優於常用之Ayre匙。最為有效之組合似乎為細胞刷加上前端延伸匙。子宮內頸細胞之偵測率似乎可有效且便利的代表為偵測核異常之能力以及適當抹片率。前端延伸匙加細胞刷相較於單獨使用前端延伸匙之疾病偵測能力仍需要在試驗中進行評估。

翻譯人

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

總結

本回顧已不再適合進行更新，因液態基礎性細胞學技術已取代了抹片技術。常用之匙並非為最有效進行子宮頸篩選者。子宮頸篩選 (子宮頸抹片檢查) 是一種可用於偵測子宮頸癌前病變 (子宮頸上皮病變) 的有效方式。試驗會受到試驗者之技巧以及所用裝置之設計影響。不適當之抹片可產生不正確之結果，並對必須重複進行篩選之女性造成壓力及不便。本試驗回顧發現，就收集細胞而言，常用之Ayre匙並不如前端延伸匙般有效。最為有效者似乎為細胞刷與前端延伸匙之組合。