COCHRANE ROB 2 · 偏誤風險評讀
UAS7 蕁麻疹活動度
← 回到「慢性蕁麻疹」的圖表
總體判斷 OVERALL-High(高風險)
Domain 與 overall 判斷由程式依 Cochrane RoB 2 官方演算法計算;AI 只負責回答下方各訊號問題。符號:+ 低風險、? 有些疑慮、- 高風險(不只靠顏色)。
風險偏誤紅綠燈
- +Domain 1 隨機化過程:Low(低風險)
- +Domain 2 偏離預定介入:Low(低風險)
- -Domain 3 缺失結局資料:High(高風險)
- +Domain 4 結局測量:Low(低風險)
- ?Domain 5 選擇性報告:Some concerns(有些疑慮)
- -總體(Overall):High(高風險)
中文摘要(給一般讀者)
這篇論文的偏誤風險與 limitation
本試驗為三臂多中心隨機假針對照試驗(發表於 Annals of Internal Medicine),此處評的是針灸 vs 假針灸在第 4 週 UAS7 變化量。隨機化由獨立中央線上系統產生並隱匿,基線相近,隨機化偏誤低。患者以 Park 非穿透假針設盲,施針者知情,但未見因試驗情境造成的介入偏離,且三組各 110 人全數納入 ITT 分析,偏離介入的偏誤低。缺失資料是主要疑慮:第 4 週假針組缺失約 12%、針灸組約 6%,缺失比例相差近一倍且多為原因不明的失聯,多重插補與 PPS 分析都不能排除缺失與症狀真值相關,此面向偏誤風險偏高。結局為病人自填的 UAS7,病人盲化檢測兩組猜對率無顯著差異,測量偏誤大致可接受,但假針組猜對者較多,盲性並非無懈可擊。選擇性報告方面,主要結局與時點事先指定,但主分析方法與插補方法相對計畫書有更動,且無法確認更動在解盲前完成,有一些疑慮。整體而言,本結局的偏誤主要來自組間不均的缺失資料,其次為分析計畫的更動。
詳細評讀(給專業讀者)
Domain 1:隨機化過程 — 判斷:Low
偏誤來源:隨機分組的過程——分配序列是否隨機產生、是否隱蔽到分組為止、基線(第一期開始時)是否平衡。
1.1 Was the allocation sequence random?
分配序列是否隨機產生?
- 回答:是(Yes — 有明確證據支持)
- 原文引述:the random sequence was generated and masked by an online response system maintained by the Clinical Evaluation Center of the China Academy of Chinese Medical Sciences ... Randomization was stratified by site and defined with a block size of 6隨機序列由中國中醫科學院臨床評價中心維護的線上應答系統產生並隱藏……隨機化依研究中心分層,區組大小為 6。
- 理由:由獨立機構的線上系統產生分層區塊隨機序列,含隨機成分,答 Y。
1.2 Was the allocation sequence concealed until participants were enrolled and assigned to interventions?
分配是否隱蔽到分組為止?
- 回答:是(Yes — 有明確證據支持)
- 原文引述:block size of 6, which was masked to the investigators ... The clinical research assistant at each hospital requested the randomization sequence and group assignments via the online system or mobile phone message.區組大小 6 對研究者保密……各醫院的臨床研究助理透過線上系統或手機簡訊取得隨機序列與分組。
- 理由:分組由遠端中央線上系統在納入後才發放,屬典型的中央隨機分配,區組大小也對研究者保密,分配隱匿適當,答 Y。
1.3 Did baseline differences between intervention groups suggest a problem with the randomization process?
(第一期開始時)基線差異是否暗示隨機化有問題?
- 回答:否(No — 有明確證據支持)
- 原文引述:Table 1 shows the baseline characteristics, which were similar between groups.表 1 列出基線特徵,各組相近。
- 理由:表 1 顯示針灸組與假針組基線 UAS7(23.5 vs 21.9)、年齡、性別、病程等差異小、信賴區間重疊,屬機會可解釋的範圍,未見隨機化出問題的跡象,答 N。
Domain 2:偏離預定介入 — 判斷:Low
偏誤來源:實際執行時偏離預定的介入——盲性如何、是否依「隨機分到的組別」分析(ITT)。
2.1 Were participants aware of their assigned intervention during the trial?
參與者是否(在每一期)知道自己的分組?
- 回答:可能否(Probably no — 綜合判斷後傾向「否」)
- 原文引述:Patients, outcome assessors, and the statistician were blinded to group allocation. ... The credibility assessment of blinding showed no statistically significant difference in the correct guess rate between the acupuncture and sham acupuncture groups, although more participants guessed correctly in the sham acupuncture group患者、結局評估者與統計師皆不知分組……盲化可信度評估顯示針灸組與假針組的猜對率無顯著差異,但假針組猜對的人較多。
- 理由:假針組使用 Park 非穿透假針,患者設計上是盲的;治療結束時的盲化檢測兩組猜對率無顯著差異,但假針組猜對者較多,作者也自承盲化不完全,故答 PN(可能不知分組)。
2.2 Were carers and people delivering the interventions aware of participants' assigned intervention during the trial?
照護/執行者是否(在每一期)知道分組?
- 回答:是(Yes — 有明確證據支持)
- 原文引述:The acupuncturists were not blinded to treatment.施針者並未對治療分組設盲。
- 理由:施針者知道自己施的是真針或假針(針灸試驗的先天限制),答 Y。
2.3 Were there deviations from the intended intervention that arose because of the trial context?
是否因試驗情境造成偏離?
- 回答:可能否(Probably no — 綜合判斷後傾向「否」)
- 原文引述:Participants in the acupuncture and sham acupuncture groups received the same instructions for antihistamine use as the waitlist control group.針灸組與假針組接受與等待對照組相同的抗組織胺使用指示。
- 理由:兩組療程次數相同、救急用藥規則相同;停止治療者(針灸 7 人、假針 13 人)屬一般不遵從,未見因試驗情境(施針者知情)而改變介入或加用違規治療的證據,答 PN。
2.4 Were these deviations likely to have affected the outcome?
這些偏離是否可能影響結局?
- 回答:不需評估(NA)
- 原因:條件題:依 2.3 的答案,本題依 RoB 2 官方路由不需評估(NA)。
2.5 Were these deviations from intended intervention balanced between groups?
這些偏離在兩組間是否平衡?
- 回答:不需評估(NA)
- 原因:條件題:依 2.4 的答案,本題依 RoB 2 官方路由不需評估(NA)。
2.6 Was an appropriate analysis used to estimate the effect of assignment to intervention?
是否用了適當分析(ITT)?
- 回答:是(Yes — 有明確證據支持)
- 原文引述:The primary analysis set included the participants who had at least 1 assessment of the primary outcome. Missing values were imputed using multiple imputation by chained equations主要分析集納入至少有一次主要結局評估的受試者,缺失值以鏈式方程多重插補補齊。
- 理由:流程圖顯示三組各 110 人全部納入 ITT 分析、依原分組分析,屬估計指派效果的適當分析,答 Y。
2.7 Was there potential for a substantial impact (on the result) of the failure to analyse participants in the group to which they were randomized?
未依隨機分組分析,是否可能對結果造成重大影響?
- 回答:不需評估(NA)
- 原因:條件題:依 2.6 的答案,本題依 RoB 2 官方路由不需評估(NA)。
Domain 3:缺失結局資料 — 判斷:High
偏誤來源:結局資料缺失——是否幾乎所有人都有資料、缺失是否可能與病情(結局真實值)相關。
3.1 Were data for this outcome available for all, or nearly all, participants randomized?
是否幾乎所有受試者都有此結局的資料?
- 回答:可能否(Probably no — 綜合判斷後傾向「否」)
- 原文引述:A total of 299 participants (90.6%) completed the intervention共 299 位受試者(90.6%)完成介入。
- 理由:第 4 週實際有 UAS7 資料者:針灸組 103/110(93.6%)、假針組 97/110(88.2%,見圖 2 各時間點評估人數);假針組缺失約 12%,未達連續結局常用的約 95% 門檻,插補值依規則視為缺失,答 PN。
3.2 Is there evidence that the result was not biased by missing outcome data?
是否有證據顯示結果未受缺失資料偏誤?
- 回答:否(No — 有明確證據支持)
- 原文引述:Missing values were imputed using multiple imputation by chained equations ... We did a secondary analysis by replicating the analyses in the per protocol data set (PPS).缺失值以鏈式方程多重插補……我們另以符合計畫書的資料集(PPS)重做分析作為次要分析。
- 理由:多重插補(隨機缺失假設)不能視為校正了缺失偏誤;PPS 分析只是剔除更多人,並非針對「缺失與真值相關」不同假設的敏感度分析,故無證據顯示結果未受缺失影響,答 N。
3.3 Could missingness in the outcome depend on its true value?
缺失是否可能取決於結局真實值?
- 回答:可能是(Probably yes — 綜合判斷後傾向「是」)
- 原文引述:Participants who could not be contacted and whose reasons for dropping out were unknown were marked as lost to follow-up.無法聯絡且退出原因不明的受試者標記為失去追蹤。
- 理由:缺失者多為原因不明的失聯;UAS7 是病人自填症狀,覺得沒改善的人較可能不再回診填日誌,缺失可能與結局真值有關,答 PY。
3.4 Is it likely that missingness in the outcome depended on its true value?
缺失是否很可能取決於結局真實值?
- 回答:可能是(Probably yes — 綜合判斷後傾向「是」)
- 原文引述:Thirty-four participants (10.3%) dropped out during the study period (7 in the acupuncture group, 15 in the sham acupuncture group, and 12 in the waitlist group).研究期間共 34 人(10.3%)退出(針灸組 7 人、假針組 15 人、等待組 12 人)。
- 理由:兩組缺失比例明顯不同(第 4 週缺失針灸 7 人 vs 假針 13 人,約一倍),且原因多為不明失聯;官方指引將「組間缺失比例不同」列為答 Yes 的理由。假針組症狀未改善者較可能流失,會使假針組的平均改善看起來較好或較差都有可能,但缺失與真值相關的可能性高,答 PY。此題屬邊界判斷(缺失人數差 6 人),若視為差異不大可改 PN。
Domain 4:結局測量 — 判斷:Low
偏誤來源:結局的測量——測量工具是否恰當、評估者是否盲化、評估是否可能受分組知情影響。
4.1 Was the method of measuring the outcome inappropriate?
結局測量方法是否不適當?
- 回答:否(No — 有明確證據支持)
- 原文引述:The UAS7 scale is widely used to quantify urticaria symptomsUAS7 量表被廣泛用於量化蕁麻疹症狀。
- 理由:UAS7 是國際指引建議、藥物試驗通用的蕁麻疹活動度量表,測量方法適當,答 N。
4.2 Could measurement or ascertainment of the outcome have differed between intervention groups?
(每一序列內)結局測量是否可能因介入而異?
- 回答:否(No — 有明確證據支持)
- 原文引述:All of the participants were asked to keep daily urticaria diaries recording CSU symptoms and concomitant medication use.所有受試者都被要求每天記錄蕁麻疹日誌,記下症狀與併用藥物。
- 理由:三組都用相同的每日日誌、相同時間點計算 UAS7,組間測量方式一致,答 N。
4.3 Were outcome assessors aware of the intervention received by study participants?
結局評估者是否知道受試者接受的介入?
- 回答:可能否(Probably no — 綜合判斷後傾向「否」)
- 原文引述:Patients, outcome assessors, and the statistician were blinded to group allocation. ... The credibility assessment of blinding showed no statistically significant difference in the correct guess rate between the acupuncture and sham acupuncture groups患者、結局評估者與統計師皆不知分組……盲化可信度評估顯示針灸組與假針組的猜對率無顯著差異。
- 理由:UAS7 是病人自填,評估者就是病人本身;病人以非穿透假針設盲,盲化檢測兩組猜對率無顯著差異,故答 PN。但假針組猜對者較多,作者也承認盲化不完全,盲性並非無懈可擊。
4.4 Could assessment of the outcome have been influenced by knowledge of intervention received?
結局評估是否可能受介入知情影響?
- 回答:不需評估(NA)
- 原因:條件題:依 4.3 的答案,本題依 RoB 2 官方路由不需評估(NA)。
4.5 Is it likely that assessment of the outcome was influenced by knowledge of intervention received?
結局評估是否很可能受介入知情影響?
- 回答:不需評估(NA)
- 原因:條件題:依 4.4 的答案,本題依 RoB 2 官方路由不需評估(NA)。
Domain 5:選擇性報告 — 判斷:Some concerns
偏誤來源:選擇性報告結果——是否依事前訂定的分析計畫分析、有無從多個結果中挑選有利者報告(交叉另含:是否因偵測到殘留而只報第一期)。
5.1 Were the data that produced this result analysed in accordance with a pre-specified analysis plan that was finalized before unblinded outcome data were available for analysis?
是否依事前訂定(取得未盲化資料前定版)的分析計畫分析?
- 回答:可能否(Probably no — 綜合判斷後傾向「否」)
- 原文引述:The study protocol and statistical analysis plan were previously published (16). Details of deviations from the protocol (exclusion of participants with regular antihistamine use or hormone treatment, change of the method for missing value imputation, and change of the analysis from analysis of covariance to linear regression) are provided in the supplemental material.研究計畫書與統計分析計畫已先行發表。與計畫書的偏離(排除規則使用抗組織胺或荷爾蒙者、更換缺失值插補方法、分析由共變數分析改為線性迴歸)詳見補充資料。
- 理由:有事先登錄與發表的計畫書及統計分析計畫,但主要分析方法(ANCOVA 改為線性迴歸)與插補方法都改過,正文未說明更動是在解盲前完成,無法確認分析依照事前定案的計畫進行,答 PN。
5.2 Is the numerical result being assessed likely to have been selected, on the basis of the results, from multiple eligible outcome measurements (e.g. scales, definitions, time points) within the outcome domain?
此數值結果是否可能依結果,從多個量表/定義/時間點中選出?
- 回答:否(No — 有明確證據支持)
- 原文引述:The primary outcome was the reduction in the Weekly Urticaria Activity Score (UAS7) at 4 weeks.主要結局為第 4 週 UAS7 的下降量。
- 理由:主要結局 UAS7 與第 4 週時間點在計畫書與登錄中即已指定,報告的就是這個量表與時點,看不出從多種測量中挑選,答 N。
5.3 Is the numerical result being assessed likely to have been selected, on the basis of the results, from multiple eligible analyses of the data?
此數值結果是否可能依結果,從多種分析中選出?
- 回答:可能否(Probably no — 綜合判斷後傾向「否」)
- 原文引述:The primary analysis used a linear regression model to test whether acupuncture improved UAS7 more than sham acupuncture or waitlist control.主要分析以線性迴歸模型檢驗針灸改善 UAS7 是否多於假針與等待對照。
- 理由:論文只報一種主分析,PPS 與盲化可信次群組結果方向一致;不過分析由 ANCOVA 改為以變化量為依變項、未調整基線的線性迴歸,而針灸組基線 UAS7 略高(23.5 vs 21.9),此改動可能對針灸有利。無直接證據顯示是依結果挑選,答 PN。