Leon Piterman，周海鈴(譯)，黃文靜(譯)，楊 輝(譯)

·世界全科醫(yī)學工作瞭望·

《The Medical Republic》案例分享
——診斷：有意還是無意的偏差？

Leon Piterman1，周海鈴(譯)2，黃文靜(譯)2，楊 輝(譯)1

全科醫(yī)生；診斷；偏差

自古以來，我們的臨床方法就是病史采集、身體檢查和實驗室檢查這三件事。

做這三件事的目的，是為了獲得一個正確的診斷，并據(jù)此推斷出相應的預后，提出對治療或管理的建議。

老師教給我們的是，做診斷的關鍵是要“仔細(careful)” 地采集病史，僅通過病史采集就可以對70%的問題做出診斷。我們還知道，“仔細”這個詞， 對經驗豐富的醫(yī)生、專家、初級醫(yī)生和醫(yī)學生來說，是有不同的含義的。

經驗豐富的醫(yī)生(包括全科醫(yī)師和?？漆t(yī)師)，會把他們的疑問聚焦在關鍵的線索上。醫(yī)學生和初級醫(yī)生則采取系統(tǒng)的病史采集方法，也許他們還不能區(qū)分出每一種現(xiàn)有癥狀的相對重要程度。在這些情況下，依賴于實驗室檢查(往往這些實驗室檢查是不必要的)似乎主宰了診斷過程。

當我在門診做神經科學員的時候，我的導師習慣上先看所有的新患者，并采集病史。在他把這些患者轉給我之前，他不做體格檢查，也不安排實驗室檢查。

我的導師先寫下他的診斷，然后讓我做第2輪病史采集，并做體格檢查和實驗室檢查。然后，讓我把他事先寫的診斷與我的判斷做核對。我導師的診斷從來沒有錯誤！

閱歷，是對個人啟發(fā)的獎勵。導師以前聽過和看過所有這些病，這也就提高了他做的病史采集能做出陽性預測價值。在全科診療中，當我們想要走捷徑的時候，也會采取同樣的策略。我們也會從以往看過患者的知識中獲取信息，并受這些經驗的影響；我們還會考慮到當?shù)刂饕膊〉牧餍胁W，特別是疾病在不同季節(jié)的變化趨勢。

所以，診斷是個科學過程嗎？它沒有偏差嗎？

下面這些案例表明，診斷可以是任何東西，但不是科學?？茖W是無偏的，而我們不是在無偏的領域里工作。我們帶著自己的偏差，有的時候還帶著自己的偏見，登上診斷的舞臺。

比爾的故事

比爾，68歲，20多年來一直在我們診所看病。他多血質的面龐上，帶著幾處傷痕?？菔莸碾p手和肥胖的身軀，讓我們看到的是他與酒精的戰(zhàn)斗，而掩蓋了他曾在越南戰(zhàn)爭與惡魔戰(zhàn)斗時受到的傷害。

在過去的十年中，他患上了高血壓、2型糖尿病和脂肪肝，并遭受了幾次痛風發(fā)作。很久以前他的婚姻解體了，孩子們都不跟他聯(lián)系了。酒吧和老虎機成了他無聊的日常生活的唯一安慰。

在某個繁忙的星期一上午，接診員在已經預約好的患者之間把比爾加了進來。他一瘸一拐地走進我的診室，滿面胡須，表情痛苦。他一只腳上穿著松松垮垮的拖鞋，另一只腳上穿著破破爛爛的舊鞋子。

我感到沒有必要采集他的病史了。診斷看起來是顯而易見的。

“嗨，比爾，坐下?？磥砟愕耐达L又發(fā)作了”，我說。

“不是的，醫(yī)生”，他回答說，“是我修理燒烤爐的時候，把煤氣罐砸到腳上了。”

埃塞爾的故事

埃塞爾是一個58歲的脆弱的糖尿病患者。我接到了正在探望她的女兒(簡)的電話，請求緊急家庭訪視，理由是她母親出現(xiàn)了“低血糖”，而她喂不進任何糖或果汁。

我趕到埃塞爾家，發(fā)現(xiàn)她癱倒在廚房的椅子上，大汗淋漓和半昏迷狀態(tài)。我靜脈推注了葡萄糖和肌肉注射了胰高血糖素，同時安排急救車把埃塞爾送到當?shù)氐募痹\中心。

當我走進她狹小而且單一朝向的小木屋時，起居室和廚房的雜亂情形把我嚇了一跳。房間里到處堆著盛滿樹葉和樹枝的箱子。這就像埃塞爾一直在收集花園垃圾，并儲藏在她家里。

相對于解開埃塞爾家里的亂麻而言，把她的血糖恢復正?？雌饋硪菀椎亩?。我不得不向她的女兒表達我對埃塞爾的總體生活、身體和心理狀況，以及她自我照顧能力的擔心。

簡很禮貌地告訴我，埃塞爾是一位藝術家。她用樹葉、樹枝和其他植物作為她作品的一部分。然后她遞給我一個請柬，那是埃塞爾3周后在一個當?shù)禺嬂鹊膫€人藝術展，簡問我是否認為埃塞爾的健康能容許她完成藝術展 。

通過這2個例子，我很快認識到，事情并不總是他們看起來的樣子。

醫(yī)學是一個觀察性科學，不過，上面這兩種觀察都帶有偏差。

在比爾的例子中，我受到他既往史的影響，還沒采集一點點病史就快速下診斷了。

通常的情形是，患者走進診室沒多久，我們就已經有了對患者臆測的診斷假設。畢竟，我們使用了自己全部的觀察能力；但是，在沒有進一步證據(jù)提高假設存在的可能性之前，診斷假設會持續(xù)存在的。

在埃塞爾的例子中，我對她生活環(huán)境的偏性看法，讓我過快地跳躍到給她下一個社會診斷。

觀察是重要的，但是，觀察的同時要有細心的傾聽和謹慎的反應。

我從我的教訓中得到了學習。

譯者注：多血質面容：在全科醫(yī)學看病過程中，首先觀察到的是患者的面容。面容或表情，是與特定疾病或健康問題有關系的。多血質面容，常見于Cushing綜合征、單純紅細胞增多癥、長期酗酒、慢性肺心病、類癌綜合征、上腔靜脈綜合征。

志謝：特別感謝原文出版者《The Medical Republic》同意將此文編譯后刊登于《中國全科醫(yī)學》。

Our time-honoured clinical method consists of history taking,physical examination and investigation.

The purpose of undertaking this exercise is to achieve a correct diagnosis to which we attach a prognosis and advise treatment or management.

We are taught that "careful" history taking is key to diagnosis and that 70% of diagnoses can be based on history alone.We also know that "careful" has a different meaning to experienced practitioners,specialists,junior doctors and medical students.

Experienced practitioners,both GPs and specialists,focus their questioning on highly critical cues.Medical students and junior doctors take a systematic approach to history taking and may not differentiate the weight of each presenting symptom.Reliance on investigations(often unnecessary) seems to dominate the diagnostic process in these circumstances.

When I was a neurology registrar in outpatients my boss was in the habit of seeing all new patients first and taking a history,but not undertaking a physical examination or arranging tests before he had passed them over to me.

He then wrote down the diagnosis and asked me to check once I had completed a second round of history-taking as well as physical examination and investigations.He was never wrong.

Past experience,an appreciation of personal heuristics-he had heard and seen it all before-enhanced the positive predictive value of his history taking.In general practice,while we may appear to take shortcuts,we adopt similar practices.We are also informed and influenced by our past knowledge of the patient and the prevailing local epidemiology of diseases,particularly seasonal variations.

So is the diagnostic process scientific? Is it free of bias?

The following cases tend to suggest that it is anything but scientific.We do not operate in a bias-free zone.We bring our biases,and occasionally our prejudices,into the diagnostic arena.

BILL′S STORY

Bill,aged 68,had been attending our clinic for more than 20 years.His plethoric facial appearance,complemented by a number of scars,his knobbly hands and truncal obesity bore witness to his battles with alcohol,not to mention battles with the demons that his service in Vietnam had inflicted on him.

Over the past decade he had developed hypertension,type 2 diabetes and fatty liver and suffered several attacks of gout.His marriage had failed long ago,his children were estranged,and the pub and the pokies provided the only relief from the boredom of the daily routine.

On this occasion Bill was squeezed in as an extra on a busy Monday morning.He limped into my consulting room,unshaven and distressed.He wore a loose fitting slipper on one foot and a worn-out shoe on the other.

I didn′t feel the need to take history.The diagnosis seemed quite obvious.

"Hi Bill,take a seat.So you have another attack of gout," I remarked.

"No doc," he replied,"I dropped a full gas bottle on my foot when I was trying to fix the BBQ."

ETHEL′S STORY

Ethel was a 58-year-old brittle diabetic.I had a call from her visiting daughter,Jane,requesting an urgent home visit as her mother was having a "hypo" and she could not get any sweets or juice into her.

I rushed to Ethel′s home to find her slumped in a chair in the kitchen,sweaty and semiconscious.I administered some IV glucose and IM glucagon and arranged an ambulance to take Ethel to the local ED.

What struck me as I walked into the small,single-fronted timber home was the chaotic nature of the living room and the kitchen.There were boxes of leaves and tree branches strewn everywhere.It was as if Ethel had been collecting garden refuse and storing it in her home.

Restoring her blood sugar to normal seemed easy compared with unravelling the mess in her home.I felt compelled to express my concern to her daughter about Ethel′s general wellbeing,physical and mental,and her ability to cope on her own.

Jane politely informed me that Ethel was an artist and used leaves,branches and other plants as part of her artwork.She then handed me an invitation to an exhibition that Ethel was having at a local gallery in three weeks′ time and asked if I thought Ethel would be fit enough to make it.

In both cases I very quickly learned that things are not always what they seem.

Medicine is an observational science but observations in both instances were coloured by bias.

In Bill′s case his past history drew me to a rapid fire diagnosis in the absence of taking a skerrick of history.

It is not uncommon to postulate diagnostic hypotheses as soon as the patient walks in the room.After all we use all of our powers of observation.But hypotheses should remain as such until further evidence raises their level of probability.

In Ethel′s case I jumped too quickly to a social diagnosis informed by a biased view of her environment.

Observation is important but looking should be accompanied by careful listening and cautious responding.

I learned my lesson.

(本文編輯：崔沙沙)

Diagnosis:Unconscious or Conscious Bias?

General practitioners;Diagnosis;Uncertainty

注：本文首次刊登于《The Medical Republic》

R 197

A

10.3969/j.issn.1007-9572.2017.16.002

Leon Piterman教授，醫(yī)學學士，醫(yī)學博士，教育學碩士，英國醫(yī)生學會會員，澳大利亞全科醫(yī)生學會會員，Monash大學貝里克和半島校區(qū)校長。全科醫(yī)學教授，曾任初級保健學院院長，醫(yī)學部副部長。研究興趣是慢性病管理、心理健康、醫(yī)學教育。曾獲澳大利亞勛章，醫(yī)學部醫(yī)學教育獎，澳大利亞全科醫(yī)生學會研究獎，香港全科醫(yī)生學會研究獎，以表彰其在醫(yī)學研究和教育上的成就。獲多項澳大利亞衛(wèi)生和醫(yī)學研究理事會等大型研究項目，發(fā)表120多篇科學文章和著作章節(jié)，《全科醫(yī)學中的精神病學》的合作著者。主持建立了澳大利亞最成功的家庭醫(yī)學碩士項目，是澳大利亞醫(yī)學理事會的考官，并在大學和各種專業(yè)機構擔任要職。他在繁忙的行政和研究工作之中，堅持在全科醫(yī)學診所給病人看病。

2017-05-02)

1.3168 Monash University,Melbourne,Australia 2.518003 廣東省深圳市，羅湖醫(yī)院集團黃貝嶺社區(qū)健康服務中心

【編者按】 澳大利亞的全科醫(yī)生具有行業(yè)自律性，體現(xiàn)在其自行制定行業(yè)標準、自主進行資質考核及自主執(zhí)業(yè)等方面，也體現(xiàn)在《The Medical Republic》這一共享平臺上。Leon Piterman是Monash University的副校長、全科醫(yī)學教授，從事全科醫(yī)學臨床服務近40年，其建議我國的全科醫(yī)生應培養(yǎng)“共和”思想，以為全科醫(yī)學領域提供更多的平等交流機會。目前Piterman教授定期為《The Medical Republic》撰寫文章，本刊深受“醫(yī)學共和”思想的啟發(fā)，特邀本刊編委Monash University楊輝教授對Piterman教授的文章進行編譯，并將進行連載刊登，希望對我國的全科醫(yī)生有所幫助和啟發(fā)！本期Piterman教授和大家分享了其對診斷的看法，眾所周知診斷是治療疾病的首要前提，那診斷到底有沒有偏差呢？本文從兩個案例的教訓中得出醫(yī)學是一個觀察性科學，不過觀察會帶有偏差。對于全科醫(yī)生而言，通過觀察得到的臆測診斷假設，在沒有進一步證據(jù)提高假設存在的可能性之前，診斷假設會持續(xù)存在；另外觀察的同時要有細心的傾聽和謹慎的反應，敬請關注!

PITERMAN L.診斷：有意還是無意的偏差？[J]. 周海鈴，黃文靜，楊輝，譯.中國全科醫(yī)學，2017，20(16)：1918-1920.[www.chinagp.net]

PITERMAN L.Diagnosis: unconscious or conscious bias?[J]. ZHOU H L，HUANG W J，YANG H，translators.Chinese General Practice，2017，20(16)：1918-1920.