醫生有可能殺了你嗎？

BMJ 英國醫學出版集團做為英國醫學會的下屬機構，一直本著為其會員，即英國醫生群體服務，『創造一個更健康的世界』這一原則，為其提供最新的臨床決策支持工具，幫助醫務工作者的臨床實踐和醫療質量的改善。

BMJ的醫療總監Kieran Walsh醫生近期發布了關於如何避免誤診的討論文章，以一個模擬病例為情景，討論了臨床中可能誤診的原因和解決方法。全文翻譯如下：

如何避免誤診

一個40歲的中年男性因為咳嗽就診，但是他的全科醫生找不到病因。最終，這名患者被轉診至當地醫院，並在那裡被診斷為哮喘。醫生給他開了吸入劑，但是沒有控制病情，於是患者又回去複診。下一名接診的醫生增加了吸入劑的計量，但是仍然沒起作用，於是患者開始口服激素治療——仍未見效。後來，患者又接受了更多的檢查，並被診斷為胃食管反流。他接受了相關的治療，停用了吸入劑治療，並且開始好轉。

這是一個虛擬的場景，但是像這樣的故事每天都在發生。我們可以從多個角度來看待這個故事——但是其中一個角度是認知偏差。在這個案例里，認知偏差很可能可以定位在下診斷的瞬間。一旦患者接受了某個診斷的標籤，那麼這個診斷就很難被移除或替代了。在這個場景中，醫生認為患者得了哮喘，於是其他的醫生也就順著這個診斷和治療步驟走下去，直到他們走到了死胡同里。雖然他們最終得到了正確的診斷，但是顯然可以診斷得更快些。這個故事最終有個相對圓滿的結局，畢竟這是一個良性的，可以治療的疾病。但是如果患者得的是肺癌，那結局就不那麼美好了。

所以，我們可以做些什麼避免這種情況的發生呢？也許我們可以教育醫生關於認知偏差的概念，那麼他們就更有可能認識到自己的錯誤，並由此減少誤診的發生。事實果真如此嗎？並不是。證據顯示，減少認知偏差的教育幾乎不能降低誤診的發生率。Norman等人剛剛發表的研究開啟了我們在2017年中對這一領域的思考。那麼，如果相關的培訓不能停止認知偏差的發生，有什麼手段可以呢？這個問題很複雜，其答案同樣複雜，微妙並且需要視情況而定。

我們再來看看這個故事－這次以臨床知識策略為基礎的角度出發。假設醫生髮現患者對吸入劑不敏感後就停葯了。假設醫生們停葯後分析了已有的信息，考慮了其他診斷的可能性，並且檢索了可能幫助他們的新臨床知識。接著，他們考慮了哮喘的鑒別診斷，並找到了正確的診斷。證據顯示，新的策略有更好的效果。因此，認識到臨床知識的欠缺十分關鍵。

我們如何幫助臨床知識增長又是一個全然不同的故事了。醫務工作者們需要最新，最可靠，基於循證的，同時能夠幫助他們即時回答具體臨床問題的知識庫。但是在大部分情況下，他們卻缺乏這樣的臨床知識庫。在現實中，他們獲得了太多不靈活實用，也並不循證的臨床知識來回答其他人、而不是他們患者的問題。

這一領域往往比想像的更複雜，因為存在著太多的細枝末節和注意事項。醫務工作者時間太少，而且更沒有時間去停下來查閱資料。這點是必須被強調的。但此同時，臨床知識必須能在醫務工作者觸手可及的地方能被隨時獲取。這也取決於環境－但這也許意味著在移動設備，app或者其他設備上更更方便地獲取臨床知識。

這篇文章中指出，獲取臨床知識對於減少醫療差錯，改善醫療質量至關重要。臨床知識的提供者可以改變傳遞信息的方式，並保障這些信息不僅僅是正確的，並且是高質量的。就這一點而言，臨床知識的即時性，實用性和循證背景都非常重要。

原文地址：Kieran Walsh: Finding your way back from the wrong diagnosis

A 40 year old man has a cough—but his GP cannot find out the cause. Eventually the patient is referred to the local hospital where he is diagnosed with asthma. The doctor who sees him starts inhalers. But the inhalers don』t work and so he goes back for another appointment. The next doctor that he sees increases the dose of the inhalers. But this doesn』t work either so eventually the patient starts on oral steroids. These don』t help either. Finally the patient has some further tests and is diagnosed with gastro-esophageal reflux. He receives treatment for this, stops his inhalers, and gets better.

This is a fictional scenario, but stories like this happen all the time in real life. We can look at the story from a number of perspectives—but one way of looking at it is from the perspective of cognitive bias. In this case the cognitive bias is likely one of anchoring or diagnosis momentum. Once a patient receives a diagnostic label, it is difficult to remove and replace it. In this scenario the doctor thought the patient had asthma and more doctors continued down this diagnostic and treatment pathway until they ran out of road. They eventually got to the correct diagnosis but clearly could have got there faster. This story ended fairly happily with a delayed diagnosis of a benign and treatable condition. But the patient could just as easily have had lung cancer and then the lesson learned would have had a bitter aftertaste.

So what can we do to stop this happening? Maybe if we educate doctors about cognitive biases, then they would be more likely to recognise their own cognitive biases and less likely to make mistakes. Right? Wrong. The evidence shows that education to reduce cognitive biases has little or no effect on diagnostic errors. This paper by Norman et alhas just been published and so opens up thinking in this area for the rest of 2017. So if education to stop cognitive biases won』t help, what will? This is a complex problem and the answer to it is complex, nuanced and dependent on circumstances.

Let』s look at the story again—this time from the perspective of knowledge based strategies. Let』s say that the doctor stopped when the patient didn』t respond to the inhalers. Let』s say that they stopped and analysed the information that they had and thought about what else the diagnosis could be and maybe identified new knowledge that would help them. And then they thought about the differential diagnosis of asthma and came up with the correct diagnosis. The evidence shows that this strategy is more likely to work. So knowledge deficits are important.

How we help with knowledge is a whole different story. Healthcare professionals need knowledge that is current, reliable, and evidence based and at the same time will help them quickly answer the specific clinical question that they have. But too often they don』t get this type of knowledge. Rather they get too much knowledge that is unwieldy, that answers other people』s questions rather than those of their patients and that is sometimes not evidence based.

However the area is even more complex than this—there are a range of nuances and caveats. Healthcare professionals are short of time and sometimes don』t have time to stop and think and look things up. This must be addressed. But in the meantime knowledge must be available at the point of care and in a format that healthcare professionals can use. This in turn depends on circumstances—but is likely to mean on a mobile or app or whatever device is being used.

The literature is currently pointing back to knowledge as a vital resource that can reduce error and improve the quality of care. Providers of knowledge can help by changing how they deliver knowledge and ensuring that they work to high standards and, as importantly, to the right standards. In this regard, currency, evidence base and applicability are all important.

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