Transcript 實證護理

實證營養報告
報告者：許啓松
報告日期：99年10月28日
Clinical Scenario
臨床劇本
• 肥胖容易造成各種代謝疾病的發生，如：糖尿
病、高血壓及心血管疾病。根據研究調查，青
少年約有百分之十罹患脂肪肝，其中肥胖者百
分之卅八至百分之七十七有脂肪肝，男孩比例
大於女孩，而青少年罹患脂肪肝，日後有較高
罹患肝臟疾病、糖尿病和心血管疾病等風險。
• 新聞曾經報導美國一項研究報告：婦女體內若
缺乏維生素D容易罹患肥胖症。肥胖者體內是
否也可能會有維生素D缺乏的情形呢？
Step 1: Ask an answerable
clinical question--P.I.C.O.
形成一個可以回覆的問題
PICO
Question:
•Patient / Problem : Healthy people 健康受試者
•Intervention / Exposure : Overweight or obesity
體重過重或肥胖
•Comparison : placebo or ideal body weight 安慰劑
組或理想體重
•Outcome : Vitamin D deficiency 維生素D缺乏
• Ex: In healthy people, do overweight or obesity increase
the risk of vitamin D deficiency? （在健康的受試者中，體
重過重或肥胖是否可能增加維生素D缺乏的發生危險？）
Step 2: Effective searches
for the best Evidence
搜尋最佳的證據
搜尋策略的設計表
SEARCH STRATEGY DESIGN TABLE
主要詞彙
Primary Term
同義字 Synonym 1
P
Healthy people
OR
E
Overweight
OR
C
Placebo
OR
O
Vitamin D
deficiency
OR
同義字 Synonym 2
OR
AND
Obesity
OR
AND
Ideal body
weight
OR
AND
OR
AND
•Etiology (病因)
•Level Ⅱ evidence research
A longitudinal cohort study
縱向世代研究
•Study population : A total of 3,890 Third Generation
participants (96% of attendees).
•Method :
Definitions for standard cardiovascular risk factors have
been detailed previously.
Physical activity was assessed using a physical activity
index, calculated from the number of hours spent each
day at various activity levels, weighted according to the
estimated oxygen consumption required for each activity.
Data regarding total vitamin D intake from supplements
and diet were obtained using a detailed food-frequency
questionnaire.
敘述性研究以時間面區分
• 橫斷性研究（Cross-sectional study）: 在某一時間
點進行的研究
• 縱向研究（Longitudinal studies）: 對某一群個體
追蹤一段時間觀察的研究。研究因時間而改變的題材
是最佳方式
–世代研究(cohort studies)~追蹤一群健康個體研
究他們暴露於危險因子之後的情形
研究的優缺點
• 橫斷性研究（Cross-sectional study）
優點：省錢、省時
缺點：無法說明因果關係
• 縱向研究（Longitudinal studies）
優點：具代表性，可探討因果關係
缺點：費時、費錢、耗資源
• 世代研究(cohort studies)
優點：具代表性，可探討因果關係
缺點：費時、費錢、追蹤時間受試者流失大
Introduction of The Framingham Heart Study
• The Framingham Heart Study was established in 1948, when
5,209 residents of Framingham, Massachusetts were enrolled
in a longitudinal cohort study designed to prospectively
identify risk factors for cardiovascular disease.
• In 1971, an additional 5,124 participants (offspring of the
original cohort subjects and their spouses) were enrolled in
the Framingham Offspring Study.
• Beginning in 2002, 4,095 Third Generation Study
participants, who had at least one parent in the Offspring
cohort, were also enrolled and underwent standardized clinic
examinations at the Heart Study between 2002 and 2005.
•Etiology (病因)
•Level Ⅱ evidence research
A longitudinal cohort study
縱向世代研究
•Study population : A total of 3,890 Third
Generation participants (96% of attendees).
• Method :
(1)Definitions for standard cardiovascular risk factors have
been detailed previously.
(2)Physical activity was assessed using a physical activity
index, calculated from the number of hours spent each
day at various activity levels, weighted according to the
estimated oxygen consumption required for each activity.
(3)Data regarding total vitamin D intake from supplements
and diet were obtained using a detailed food-frequency
questionnaire.
(4)Serum 25(OH)D
(5)Abdominal adipose tissue imaging
Step 3: Critically appraise that
evidence for its validity and
importance
嚴格評讀文獻是否令人信服及其重要性
A.此一有害原因的研究結果能令人信服嗎?
Are the results of this harm/etiology
study valid?
1.實驗組與對照組除了對治療的曝露有別外, 其他方
面是否皆相似?
Were there clearly defined groups of patients,
similar in all important ways other than
exposure to the treatment or other cause?
• Yes
• 本研究為一個縱向性世代研究，單純只觀察受試
者BMI、體脂肪與維生素D缺乏的相關性。
Introduction of The Framingham Heart Study
• The Framingham Heart Study was established in 1948, when
5,209 residents of Framingham, Massachusetts were enrolled
in a longitudinal cohort study designed to prospectively
identify risk factors for cardiovascular disease.
• In 1971, an additional 5,124 participants (offspring of the
original cohort subjects and their spouses) were enrolled in
the Framingham Offspring Study.
• Beginning in 2002, 4,095 Third Generation Study
participants, who had at least one parent in the Offspring
cohort, were also enrolled and underwent standardized clinic
examinations at the Heart Study between 2002 and 2005.
Study sample
Inclusion criteria
• participants who resided in the greater New England area.
• weighed ＜350 pounds (189kg)
• men ≧35 years of age or women ≧40 years of age and not
pregnant
＊22% of participants
were obese
(BMI≧30 kg/m2)
＊35% were overweight
(BMI≧25kg/m2 and
＜30 kg/m2)
2.實驗組與對照組的評量方法是否相同?
Were treatments/ exposures and clinical
outcomes measured in the same ways in both
groups (Was the assessment of outcomes either
objective or blinded to exposure?)
• Yes
• P.243
Participants were eligible if they weighed < 350 pounds
and were men ≧35 years of age or women ≧40 years of
age and not pregnant. Of the participants who underwent
CT scans, 1,882 (90%) had abdominal subcutaneous
adipose tissue (SAT) and visceral adipose tissue (VAT)
volumes measured, were free of cardiovascular disease
and diabetes, and had measurement of 25(OH)D.
3.追蹤夠久、夠完整嗎?
Was the follow-up of the study patients
sufficiently long (for the outcome to occur)
and complete?
• Yes.
• Contemporaneous with serum 25(OH)D measurements, a
subset of 2,111. Third Generation participants also
underwent multidetector CT imaging between 2002 and
2005.
• 1,882 (90%) had abdominal subcutaneous adipose tissue
(SAT) and visceral adipose tissue (VAT) volumes
measured, were free of cardiovascular disease and
diabetes, and had measurement of 25(OH)D.
4.因果關係夠明確嗎?
Do the results of the harm study satisfy some of the
diagnostic tests for causation?
• a.曝露在發作之前嗎?
Is it clear that the exposure
preceded the onset of the
outcome?
• b.與劑量具有相關反應嗎?
Is there a dose-response
gradient?
• c.從”去曝露--再曝露”的研究上
有正面證據嗎?
Is there any positive evidence
from a “dechallengerechallenge” study?
• d.因果關係具有生物學上的意義嗎?
Does the association make
biological sense?
• a. unclear.
This article didn’t
mention about it.
• b. Yes.
P.245
Fig 1
Fig 2
＊The prevalence of vitamin D deficiency rose with
increasing VAT tertile, even among lean individuals.
threefold prevalence
15.8%
5.1%
Individuals with both high SAT and high VAT had an
approximately threefold prevalence of vitamin D deficiency
compared with those with both low SAT and low VAT (15.8
vs. 5.1%, P＜ 0.001)
4.因果關係夠明確嗎?
Do the results of the harm study satisfy some of the
diagnostic tests for causation?
• a.曝露在發作之前嗎?
Is it clear that the
exposure preceded the onset
of the outcome?
• b.與劑量具有相關反應嗎?
Is there a dose-response
gradient?
• c.從”去曝露--再曝露”的研究
上有正面證據嗎?
Is there any positive
evidence from a
“dechallenge-rechallenge”
study?
• d.因果關係具有生物學上的意義
嗎?
Does the association make
biological sense?
•c. No.
This article didn’t
mention about it.
•d. Yes.
Fig 2
threefold prevalence
15.8%
5.1%
Individuals with both high SAT and high VAT had an
approximately threefold prevalence of vitamin D deficiency
compared with those with both low SAT and low VAT (15.8
vs. 5.1%, P＜ 0.001)
B.此一有害原因的研究結果夠重要嗎?
Are the valid results of this harm study
important?
1.暴露與結果之間的相關性有多強？
What is the magnitude of the association between the
exposure and outcome?
維生素D缺乏
總計
發生
沒有
是
High SAT,
High VAT
VS
Low SAT,
Low VAT
(OR) = ad/bc
NNH=1/[a/(a+b)−c/(c+d)]
否
總
計
?理論上無法計算
15.8%
14%
9%
5.1%
Low SAT,
Low VAT
High SAT,
Low VAT
Low SAT,
High VAT
High SAT,
High VAT
Vit D def.
5.1%
9%
14%
15.8%
No Vit D
def.
94.9%
91%
86%
84.2%
Vit D def.
5.1
9
14
15.8
No Vit D
def.
94.9
91
86
84.2
1.暴露與結果之間的相關性有多強？
What is the magnitude of the association between the
exposure and outcome?
維生素D缺乏
總計
High SAT,
High VAT
VS
Low SAT,
Low VAT
(OR) = ad/bc
NNH=1/[a/(a+b)−c/(c+d)]
發生
沒有
是
15.8
84.2
100
否
5.1
94.9
100
總
計
20.9
179.1
維生素D缺乏
High SAT,
High VAT
VS
Low SAT, Low
VAT
總計
發生
沒有
是
15.8
84.2
100
否
5.1
94.9
100
總計
20.9
179.1
(OR) = ad/bc
=15.8*94.9/84.2*5.1
=3.49
NNH=1/[a/(a+b)−c/(c+d)]
=1/[15.8/(15.8+85.2)-5.1/(5.1+94.9)]
=1/[0.158-0.051]
=1/0.107
=9.3
※如果只比較High SAT、 High VAT與Low
SAT、Low VAT兩組，每增加9.3個高皮下脂
肪、高內臟脂肪的人，有可能會增加一個人
發生維生素D缺乏的情形???
2.暴露與結果之相關性的估計有多精準？
What is the precision of the estimate of the
association between the exposure and the outcome?
threefold prevalence
高皮下脂肪、高內臟脂肪組之體內維生素D缺乏
情形較低皮下脂肪、低內臟脂肪組高出3倍。
P<0.001。結果具有統計上顯著性差異。
Individuals with both high SAT and high VAT had an
approximately threefold prevalence of vitamin D deficiency
compared with those with both low SAT and low VAT (15.8
vs. 5.1%, P＜ 0.001)
C.此一令人信服且結果重要的研究的會改變我們對
病患的治療嗎?
Can this valid and important evidence about
harm be applied to our patient?
1.我們的病患與研究中收錄的病患有明顯不同，以致於無法應
用該研究的結果？
Is our patient so different from those included in the
study that its results cannot apply?
• No.
• 研究對象與平常我們接觸需要減重的個案條件類似
2.此項治療對我們的病患潛在的益處為何?潛在的危害為何?
What is our patient’s risk of benefit and harm from
the agent?
• 由本研究可以得知：肥胖者體內容易有維生素D缺乏的
情形發生，未來可能增加罹患骨質疏鬆症的危險。
3.我們的病人對治療的偏好、關心與期待為何?
What are our patient’s preferences, concerns, and
expectations from this treatment?
• 對於需要減重的個案，可以用這個研究結果鼓勵民眾
減重，以避免未來發生體內維生素D缺乏的情形。
4.有哪些替代治療?
What alternative treatments are available?
• 本研究僅為一世代觀察型研究，並未針對個案進行介
入性研究，所以，文章中並未提及有何替代性治療方
式。不過，針對體重過重及肥胖的個案，臨床上仍建
議以飲食控制搭配運動來達到控制體重的目的。
感謝您的聆聽