偱证医学作业Vc能预防感冒吗.docx
《偱证医学作业Vc能预防感冒吗.docx》由会员分享,可在线阅读,更多相关《偱证医学作业Vc能预防感冒吗.docx(19页珍藏版)》请在冰豆网上搜索。
偱证医学作业Vc能预防感冒吗
偱证医学作业
(远离感冒吃Vc有效吗?
Vc能预防感冒吗?
)
学院:
医学院
专业:
班级:
姓名:
学号:
背景问题:
远离感冒吃Vc有效吗?
一、首先,明确临床问题及类型,并将问题分解为若干要素
1、前景问题构建:
健康人,服用Vc与不服用Vc相比,能否预防感冒的发生?
(或者,服用Vc与不服用Vc相比能降低健康人的感冒发病率吗?
)
2、问题类型:
预防
3、前景问题通常包括三或四个基本成分,可按PICO原则确定:
(1)Patient/problem,P:
健康人,正常人,感冒
(2)Intervention,I:
服用Vc
(3)Comparison,C:
不服用Vc
(4)Outcome,O:
预防感冒的发生
二、然后,选择合适的数据库
(按照“4S”模型选择数据库,直接优先选择Systems即可,若Systems不能解决问题,再逐级选择Synopses,Sytheses,Studies)
1、首先检索经过评估或筛选的循证医学信息资源(二次文献数据库)
CochraneLibrary:
CochraneDatabaseofSystematicReviews(CDSR)
UpToDate
2、再考虑检索未经评估或筛选的信息资源(原始文献数据库)
EBSCO,
中国生物医学文献数据库(CBM)
CNKI中国期刊全文数据库
万方医学网
三、制定检索词和检索策略
(一)检索词的筛选
(首选P和I或两者之一作关键词,若结果太多再考虑O和C)
参考CNKI中国期刊全文数据库的“翻译助手”(
健康人healthysubjects,healthypeople,healthypersons(根据CNKI“翻译助手”提供的结果筛选出的可用词,下同)
正常人normal,normalsubjects,normalpersons,healthysubjects
感冒cold,commoncold
维生素Cvitaminc,ascorbicacid,vitaminec,vitc
发病率incidence,incidencerate,morbidity
预防prevention,prevent,preventing,preventive,prophylaxis
(2)检索策略的制定:
策略一:
(vitamincORascorbicacid)ANDprevent*AND(coldORcommoncold)
策略二:
(vitamincORascorbicacid)AND(prevent*ORprophylaxis)AND(coldORcommoncold)
策略三:
vitamincANDcommoncold
策略四:
维生素CAND感冒AND预防
(三)使用所选数据库检索偱证医学证据:
CochraneLibrary()
检索词(关键词):
感冒cold,commoncold;维生素Cvitaminc,ascorbicacid,vitaminec,vitc;发病率incidence,incidencerate,morbidity;预防prevention,prevent,preventing,preventive,prophylaxis
检索方式:
Title,Abstract,Keywords
检索策略:
(vitamincORascorbicacid)AND(coldORcommoncold)AND(incidenceORmorbidityORprevent*)
搜索结果:
CochraneDatabaseofSystematicReviews:
Issue6of12,June2013
Issueupdateddailythroughoutmonth
Thereis1resultfrom7941recordsforyoursearchon'(vitamincORascorbicacid)AND(coldORcommoncold)AND(incidenceORmorbidityORprevent*)intitleabstractkeywordsinCochraneReviews'
SortbyRelevanceAlphabeticalDate
option1VitaminCforpreventingandtreatingthecommoncold
HarriHemiläandElizabethChalker
January2013
CmReview
VitaminCforpreventingandtreatingthecommoncold
1HarriHemil
1,*,
2ElizabethChalker2
EditorialGroup:
CochraneAcuteRespiratoryInfectionsGroup
PublishedOnline:
31JAN2013
Assessedasup-to-date:
29NOV2012
DOI:
10.1002/14651858.CD000980.pub4
Copyright©2013TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
Abstract
1Topofpage
2Abstract
3Plainlanguagesummary
Background
VitaminC(ascorbicacid)forpreventingandtreatingthecommoncoldhasbeenasubjectofcontroversyfor70years.
Objectives
TofindoutwhethervitaminCreducestheincidence,thedurationorseverityofthecommoncoldwhenusedeitherasacontinuousregularsupplementationeverydayorasatherapyattheonsetofcoldsymptoms.
Searchmethods
WesearchedCENTRAL2012,Issue11,MEDLINE(1966toNovemberweek3,2012),EMBASE(1990toNovember2012),CINAHL(January2010toNovember2012),LILACS(January2010toNovember2012)andWebofScience(January2010toNovember2012).WealsosearchedtheU.S.NationalInstitutesofHealthtrialsregisterandWHOICTRPon29November2012.
Selectioncriteria
Weexcludedtrialswhichusedlessthan0.2gperdayofvitaminCandtrialswithoutaplacebocomparison.Werestrictedourreviewtoplacebo-controlledtrials.
Datacollectionandanalysis
Tworeviewauthorsindependentlyextracteddata.Weassessed'incidence'ofcoldsduringregularsupplementationastheproportionofparticipantsexperiencingoneormorecoldsduringthestudyperiod.'Duration'wasthemeannumberofdaysofillnessofcoldepisodes.
Mainresults
Twenty-ninetrialcomparisonsinvolving11,306participantscontributedtothemeta-analysisontheriskratio(RR)ofdevelopingacoldwhilsttakingvitaminCregularlyoverthestudyperiod.Inthegeneralcommunitytrialsinvolving10,708participants,thepooledRRwas0.97(95%confidenceinterval(CI)0.94to1.00).Fivetrialsinvolvingatotalof598marathonrunners,skiersandsoldiersonsubarcticexercisesyieldedapooledRRof0.48(95%CI0.35to0.64).
Thirty-onecomparisonsexaminedtheeffectofregularvitaminConcommoncoldduration(9745episodes).Inadultsthedurationofcoldswasreducedby8%(3%to12%)andinchildrenby14%(7%to21%).Inchildren,1to2g/dayvitaminCshortenedcoldsby18%.TheseverityofcoldswasalsoreducedbyregularvitaminCadministration.
SevencomparisonsexaminedtheeffectoftherapeuticvitaminC(3249episodes).NoconsistenteffectofvitaminCwasseenonthedurationorseverityofcoldsinthetherapeutictrials.
Themajorityofincludedtrialswererandomised,double-blindtrials.Theexclusionoftrialsthatwereeithernotrandomisedornotdouble-blindhadnoeffectontheconclusions.
Authors'conclusions
ThefailureofvitaminCsupplementationtoreducetheincidenceofcoldsinthegeneralpopulationindicatesthatroutinevitaminCsupplementationisnotjustified,yetvitaminCmaybeusefulforpeopleexposedtobriefperiodsofseverephysicalexercise.RegularsupplementationtrialshaveshownthatvitaminCreducesthedurationofcolds,butthiswasnotreplicatedinthefewtherapeutictrialsthathavebeencarriedout.Nevertheless,giventheconsistenteffectofvitaminConthedurationandseverityofcoldsintheregularsupplementationstudies,andthelowcostandsafety,itmaybeworthwhileforcommoncoldpatientstotestonanindividualbasiswhethertherapeuticvitaminCisbeneficialforthem.FurthertherapeuticRCTsarewarranted.
Plainlanguagesummary
VitaminCforpreventingandtreatingthecommoncold
Thecommoncoldisamajorcauseofvisitstoadoctorinhigh-incomecountriesandofabsenteeismfromworkandschool.Thereareover200viruseswhichcancausethecommoncoldsymptomsincludingrunnynose,congestion,sneezing,sorethroat,cough,andsometimesheadache,feverandredeyes.Symptomsvaryfrompersontopersonandcoldtocold.Sincethecommoncoldisusuallycausedbyoneoftherespiratoryviruses,antibioticsareuselessandthereforeotherpotentialtreatmentoptionsareofsubstantialpublichealthinterest.
VitaminChasbeenproposedfortreatingrespiratoryinfectionssinceitwasisolatedinthe1930s.Itbecameparticularlypopularinthe1970swhenNobellaureateLinusPaulingconcludedfromearlierplacebo-controlledtrialsthatvitaminCwouldpreventandalleviatethecommoncold.Overtwodozennewtrialswereundertakenthereafter.VitaminChasbeenwidelysoldandusedasapreventiveandtherapeuticagent.
Thisreviewisrestrictedtoplacebo-controlledtrialstesting0.2g/dayormoreofvitaminC.本综述限于采用维生素C的量为0.2克/天或更多的安慰剂对照试验。
RegularingestionofvitaminChadnoeffectoncommoncoldincidenceintheordinarypopulation,basedon29trialcomparisonsinvolving11,306participants.根据共涉及11306名参与者的29项对照试验,维生素C的有规律摄入对普通人群的普通感冒发病率没有影响。
However,regularsupplementationhadamodestbutconsistenteffectinreducingthedurationofcommoncoldsymptoms,whichisbasedon31studycomparisonswith9745commoncoldepisodes.规则的补充,有一个温和而一致的效果,Infivetrialswith598participantsexposedtoshortperiodsofextremephysicalstress(includingmarathonrunnersandskiers)vitaminChalvedthecommoncoldrisk.在五个试验,598名暴露于极端物理短时间的压力(包括马拉松运动员和滑雪)维生素C的普通感冒的风险减半。
ThepublishedtrialshavenotreportedadverseeffectsofvitaminC.已发表的试验研究没有报告的维生素C的副作用。
TrialsofhighdosesofvitaminCadministeredtherapeutically,startingaftertheonsetofsymptoms,showednoconsistenteffectonthedurationorseverityofcommoncoldsymptoms.However,onlyafewtherapeutictrialshavebeencarriedoutandnonehaveexaminedchildren,althoughtheeffectofprophylacticvitaminChasbeengreaterinchildren.Onelargetrialwithadultsreportedbenefitfroman8gtherapeuticdoseattheonsetofsymptoms,andtwotherapeutictrialsusingfive-daysupplementationreportedbenefit.MoretrialsarenecessarytosettlethepossibleroleoftherapeuticvitaminC,meaningadministrationimmediatelyaftertheonsetofsymptoms.
检索CochraneLibrary:
网址:
以主题浏览(BROWSE BY TOPICS )检索方式(选择“Cochrane Database of Systematic Reviews ”,选择“BROWSE BY TOPICS ”,选择“Ear ,nose ,&throat ”,选择“Nose & sinus ”,选择“Common cold &cough ”)如下图所示:
从而进入到页面:
CochraneReviews:
Commoncold&cough
在CochraneReviews:
Commoncold&cough的Page2发现了与要搜索的问题最相关的一篇,如下图所示:
点击该篇的链接,得到跟前面通过“title,abstract,keywords”检索到的相同的结果
调整检索策略,去除过多的限制词,如prevent等,采用coldANDvitaminc再次通过“title,abstract,keywords”检索:
仍然得到与上述相同的结果。
ClinicalEvidence()
关键词:
检索策略:
搜索结果:
Uptodate数据库(
关键词:
感冒cold,commoncold;维生素Cvitaminc,ascorbicacid,vitaminec,vitc;发病率incidence,incidencerate,morbidity;预防prevention,prevent,preventing,preventive,prophylaxis
检索策略:
SearchResultsfor"vitamincandcommoncold"
(vitamincORascorbicacid)AND(coldORcommoncold)AND(incidenceORmorbidityORprevent*)
vitamincANDcommoncoldAND(incidenceORmorbidityORprevent*)
搜索结果:
Thecommoncoldinadults:
Treatmentandprevention
Vitaminsupplementationindiseaseprevention
Thecommoncoldinchildren:
Treatmentandprevention
What'snewinprimarycareinternalmedicine
Overviewofwater-solublevitamins
What'snewinfamilymedicine
Overviewofdietarytraceminerals
Patientinformation:
Thecommoncoldinadults(BeyondtheBasics)
Patientinformation:
Thecommoncoldinchildren(BeyondtheBasics)
Nutritionalstatus