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THE PI CO STRATEGY FOR THE RESEARCH QUESTI ON
CONSTRUCTI ON AND EVI DENCE SEARCH
Cr ist ina Mam édio da Cost a Sant os1 Cibele Andr ucioli de Mat t os Pim ent a2 Moacy r Rober t o Cuce Nobr e3
Sant os CMC, Pim ent a CAM, Nobre MRC. The PI CO st rat egy for t he research quest ion const ruct ion and evidence
sear ch. Rev Lat ino- am Enfer m agem 2007 m aio- j unho; 15( 3) : 508- 11.
Evidence based pract ice is t he use of t he best scient ific evidence t o support t he clinical decision m aking. Th e id en t if icat ion of t h e b est ev id en ce r eq u ir es t h e con st r u ct ion of an ap p r op r iat e r esear ch q u est ion an d review of t he lit erat ure. This art icle describes t he use of t he PI CO st rat egy for t he const ruct ion of t he research quest ion and bibliogr aphical sear ch.
DESCRI PTORS: n u r sin g ; ev id en ce- b ased m ed icin e; n u r sin g r esear ch ; d ecision m ak in g ; r ev iew lit er at u r e; bibliogr aph ic dat abases
ESTRATEGI A PI CO PARA LA CONSTRUCCI ÓN DE LA
PREGUNTA DE I NVESTI GACI ÓN Y LA BÚSQUEDA DE EVI DENCI AS
La pr áct ica basada en evidencias per m it e la elección de la m ej or evidencia cient ífica par a subsidiar la t om a de decisión clínica. Para lo cual, se requiere de una adecuada const rucción de la pregunt a de invest igación y de la r evisión de la lit er at ur a. Est e ar t ículo descr ibe el uso de la est r at egia PI CO par a la const r ucción de la pr egunt a de inv est igación y la búsqueda bibliogr áfica.
DESCRI PTORES: enfer m er ía; m edicina basada en ev idencia; inv est igácion en enfer m ar ía; t om a de decisiones; lit er at ur a de r ev isión; bases da dat os bibliogr áficas
A ESTRATÉGI A PI CO PARA A CONSTRUÇÃO DA PERGUNTA
DE PESQUI SA E BUSCA DE EVI DÊNCI AS
Prát ica baseada em evidências é a ut ilização da m elhor evidência cient ífica para subsidiar a t om ada de d ecisão clín ica. I d en t if icar a m elh or ev id ên cia r eq u er ad eq u ad a con st r u ção d a p er g u n t a d e p esq u isa e d e r ev isão d a lit er at u r a e est e ar t ig o d escr ev e o u so d a est r at ég ia PI CO p ar a a con st r u ção d a p er g u n t a d e pesquisa e busca bibliogr áfica.
DESCRI TORES: enferm agem ; m edicina baseada em evidências; pesquisa em enferm agem ; t om ada de decisões; lit er at ur a de r ev isão; bases de dados bibliogr áficas
1
RN Hospit al Alem ão Oswaldo Cruz, Mast er St udent , Graduat e Program in Adult Healt h Nursing, e- m ail: m am edio@usp.br; 2 RN, Full Professor, e- m ail: parpca@usp.br. Universit y of São Paulo, College of Nursing; 3 Reum at ologist ; Physican at t he Heart I nst it ut ion of t he Hospit al das Clínicas Medical School Universit y of São Paulo, e- m ail: m rcnobre@usp.br
Disponible en castellano/ Disponível em língua portuguesa SciELO Brasil w w w .scielo.br/ rlae Rev Lat ino- am Enferm agem 2007 m aio- j unho; 15( 3) : 508- 11
w w w .eer p.usp.br / r lae
509
I NTRODUCTI ON
T
he fir st r andom ized clinical t r ial ( RCT) w as published in t he Brit ish Medical Journal in 1948( 1).I n t he course of t he t went iet h cent ury, healt h
r esear ch t ech n iq u es h av e b een r ef in ed an d clin ical
t rials have im proved. Today, t here are several clinical
t r ials av ailable in t he dat abases.
RCT st udies hav e show ed conflict ing r esult s
i n si t u at i o n s w i t h si m i l ar r esear ch o b j ect i v es an d
obj ect s and gener at e doubt s r egar ding effect iv eness,
f u n d am en t at ion , in d icat ion s an d r esu lt s of sev er al
h e a l t h p r a c t i c e s . Th e s e d o u b t s m o t i v a t e d t h e
co n st r u ct i o n o f a n e w p a r a d i g m , ca l l e d Ev i d e n ce
Based Med icin e ( EBM) . As t h e EBM p r ecep t s w er e
in cor por at ed in t o ot h er disciplin es, it st ar t ed t o be
ca l l e d Ev i d e n ce - Ba se d Pr a ct i ce ( EBP)( 2 ). Th e EBP p r ev iew s m et h od olog ies an d p r ocesses in or d er t o
iden t ify ev iden ce of w h et h er a cer t ain t r eat m en t or
diagnosis is effect ive, st rat egies t o evaluat e t he qualit y
of st udies and m echanism s t o im plem ent it in car e.
Th is ar t icle f ocu ses on t h e in it ial st age of EBP, t h e
ident ificat ion of evidence, which requires t he adequat e
const ruct ion of t he research quest ion and bibliographic
sear ch .
T h e EB P m o v e m e n t s i m u l t a n e o u s l y
occu r r ed at McMast er Un iv er sit y ( On t ar io, Can ad a)
an d at t h e Un iv er sit y of Yor k ( Un it ed Kin g d om )( 3 ). Ev idence is w hat is clear, t he confir m at ion of a t r ut h
t h at elicit s n o dou bt . Scien t if ic ev iden ce r epr esen t s
a p r oof t h at cer t ain k n ow led g e is t r u e or f alse. I n
o r d e r t o h a v e s c i e n t i f i c e v i d e n c e , a p r e v i o u s
r e s e a r c h i s n e c e s s a r y, c o n d u c t e d a c c o r d i n g t o
scien t if ic p r ecep t s( 4 ).
Ar ch ie Coch r an e ( Un it ed Kin g d om ) ex er t ed
a pr of ou n d in f lu en ce on t h e assessm en t of m edical
int er v ent ions, est ablishing t he im por t ance of RCT in
t h e e v a l u a t i o n o f t r e a t m e n t e f f e ct i v e n e ss( 5 ). Th e classical definit ion of EBM is credit ed t o David Sacket t
( Canada) : conscious, ex plicit and sensat e use of t he
b est ev i d en ce av ai l ab l e i n d eci si o n m ak i n g ab o u t
pat ient care, added t o t he physician’s experience and
t he pat ient ’s preferences( 6). EBP aim s t o im prove care t hr ough t he ident ificat ion and pr om ot ion of w or k able
p r a c t i c e s a n d , a t t h e s a m e t i m e , t h r o u g h t h e
e l i m i n a t i o n o f i n e f f i ci e n t a n d p r e j u d i ci a l o n e s( 7 ), m inim izing t he gap bet ween t he generat ion of evidence
and it s applicat ion in pat ient care.
Table 1 present s t he st ages of EBP( 7- 11).
Table1 – St ages of Ev idence Based Pract ice
; m e l b o r p l a c i n il c a f o n o it a c if it n e d I -1
c it a m e t s y S
w e i v e R ; n o it s e u q l a c i n il c c if i c e p s d n a t n a v e l e r a f o n o it a l u m r o F -2
; e c n e d i v e c if it n e i c s f o h c r a e S -3
; e c n e d i v e e l b a li a v a f o n o it a u l a v E -4
; e c n e d i v e f o y t il i b a c il p p a l a c i n il c e h t f o n o it a u l a v E -5
; e r a c t n e it a p e h t n i e c n e d i v e f o n o it a t n e m e l p m I -6
s tl u s e r g n i g n a h c e h t f o n o it a u l a v E -7
S t a g e s 1 , 2 , 3 a n d 4 r e p r e s e n t t h e
dev elopm en t of st u dies called sy st em at ic r ev iew , a f u n dam en t al r esear ch m odel in side EBP. Sy st em at ic r ev iew r epr esent s t he use of a st andar dized m et hod
t o sy nt hesize dat a fr om m ult iple pr im ar y st udies( 8). Tr a d i t i o n a l l i t e r a t u r e r e v i e w s ( n o w a d a y s
called n ar r at iv e r ev iew s) h av e been cr it icized f or a long t im e because t he bibliographic search and st udy se l e ct i o n m e t h o d i s n o t st a n d a r d i ze d a n d m a d e
ex plicit . Th e r esu lt s obt ain ed t h r ou gh su ch r ev iew s are biased, do not exhaust all t he lit erat ure available
about t he t hem e and ar e usually inconclusiv e. The search for evidence requires an adequat e
definit ion of t he r esear ch quest ion and t he cr eat ion of a logical st r uct ur e for t he bibliogr aphic sear ch of evidence in lit erat ure, which facilit at es and m axim izes
t he r esear ch scope( 12- 13).
CO N S T R U CT I O N O F T H E R ES EA R CH
QUESTI ON
EBP p r o p o se s t h a t cl i n i ca l p r o b l e m s t h a t em er ge fr om car e pr act ice, t eaching or r esear ch be
d e c o m p o s e d a n d o r g a n i z e d u s i n g t h e PI CO st r a t e g y( 7 , 1 1 - 1 2 ). PI CO r e p r e se n t s a n a cr o n y m f o r Pa t i e n t , I n t e r v e n t i o n , Co m p a r i so n a n d Ou t co m e . These four com ponent s are t he essent ial elem ent s of t he r esear ch quest ion in EBP and of t he const r uct ion
o f t h e q u e s t i o n f o r t h e b i b l i o g r a p h i c s e a r c h o f evidence( 7,9- 10,13- 15). The PI CO st rat egy can be used t o c o n s t r u c t s e v e r a l k i n d s o f r e s e a r c h q u e s t i o n s , or iginat ed fr om clinical pr act ice, hum an and m at er ial r e s o u r c e m a n a g e m e n t , t h e s e a r c h o f s y m p t o m
assessm ent inst rum ent s, am ong ot hers. The adequat e ( w ell con st r u ct ed) r esear ch qu est ion allow s f or t h e
cor r ect definit ion of w hich infor m at ion ( ev idence) is needed t o solv e t he clinical r esear ch quest ion( 7,11- 12), m axim izes t he r ecover y of evidence in t he dat abase,
focuses on t he research scope and avoids unnecessary sear ch in g .
Table 2 present s t he four com ponent s of t he PI CO st rat egy and Table 3 present s an exam ple of it s use t o const r uct a r esear ch quest ion( 13,15).
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Table 2 – Descr ipt ion of t he PI CO st rat egy Select ion of t he sear ch t er m s: ident ificat ion
of t er m s ( descr ipt or s) r elat ed t o each com ponent of
t he PI CO st rat egy. The descr ipt or s ar e classified as:
Co n t r o l l e d : k n o w n a s “ m e d i c a l s u b j e c t
h ead in g s” or “ su b j ect d escr ip t or s”, w h ich ar e u sed
f or t h e in dex at ion of ar t icles in t h e dat abases. Th e
m ost known vocabularies of cont rolled descript ors are:
Me S H ( MED LI N E/ Pu b Me d ) , D e CS ( B I REME) a n d
EM TREE ( EM B A S E) . A n e x a m p l e o f c o n t r o l l e d
descript ors for t he P com ponent of t he PI CO st rat egy:
( foot ulcer ) , ( diabet ic foot ) .
Not con t r olled: r epr esen t t h e t ex t u al w or ds
a n d t h e i r s y n o n y m s , o r t h o g r a p h i c v a r i a t i o n s ,
acronym s and correlat es. An exam ple of not cont rolled
descript ors for t he P com ponent of t he PI CO st rat egy:
(diabet ic ulcer) , (diabet ic w ound) .
Use of Boolean operat ors: represent ed by t he
connect or t erm s AND, OR and NOT. These t erm s allow
for com bin at ion s of descr ipt or s t h at w ill be u sed in
t h e sear ch , w it h AND f or a r est r ict iv e com bin at ion ,
OR f o r a n a d d i t i v e co m b i n a t i o n a n d NOT f o r a n
ex clu d in g com b in at ion . On e ex am p le of t h e u se of
Boolean oper at or s f or a com bin at ion of descr ipt or s
of t he P com ponent of t he PI CO st r at egy :
P = (foot ulcer) OR (diabet ic foot) OR (diabet ic ulcer) OR (diabet ic w ound) NOT (v enous w ound) .
Co m b i n a t i o n o f co m p o n e n t s o f t h e PI CO
st r at egy f or t h e f in alizat ion of t h e sear ch st r at egy :
af t er t h e select ion of t h e sear ch t er m s an d u se of
Booleans oper at or s for each of t he four com ponent s
of t he PI CO st r at egy, t hese m ust be int er - r elat ed in
t he follow ing final st r at egy :
( P) AND ( I ) AND ( C) AND ( O) . Su ch f in al
st r at egy m ust be inser t ed in t he sear ch box exist ent
in t he dat abases, so t hat evidence is locat ed by m eans
of a bibliogr aphic sear ch.
The use of t he PI CO st r at egy r ev eals t o be
t h at ef f icien t in t h e ef f ect iv e r ecov er y of ev id en ce
t hat t he m ain elect r onic dat abase, MEDLI NE/ PubMed,
alr eady offer s an int er face, in a bet a ( t est ) v er sion,
for t he direct insert ion of t he four com ponent s of t he
PI CO st rat egy. This int erface can be accessed on ht t p: /
/ ask m ed lin e. n lm . n ih . g ov / ask / p ico. p h p .
CONCLUSI ON
Now aday s, t h er e ex ist s a lar ge qu an t it y of
m an y t im es con t r ad ict or y scien t if ic in f or m at ion . I t
i s al so v er y easy t o access st u d i es d ev el o p ed al l
m y n o r c
A Definition Description
P Paitentor problem
f o p u o r g a ,t n e it a p e n o y l n o e b n a C a r o n o it i d n o c r a l u c it r a p a h ti w s t n e it a p m e l b o r p h tl a e h
I Interveniton
,t s e r e t n i f o n o it n e v r e t n i e h t s t n e s e r p e R l a r e v e s . g . e ( c it u e p a r e h t e b n a c h c i h w . g . e ( e v it n e v e r p , ) s g n i s s e r d f o s d n i k d o o l b . g . e ( c it s o n g a i d , ) n o it a n i c c a v , c it s o n g o r p , ) e r u s a e m e r u s s e r p c i m o n o c e o t d e t a l e r r o e v it a r t s i n i m d a s e u s s i
C Controlorcomparison
, n o it n e v r e t n i d r a d n a t s a s a d e n if e D o n r o n o it n e v r e t n i d e s u t s o m e h t n o it n e v r e t n i
O Outcome Expectedresutl
Dat a f r om t h e sy st em at ic r ev iew by Ber gin
and Wraight( 16) are used t o exem plify t he const ruct ion of t he research quest ion using t he PI CO st rat egy. The
aut hor s of t his sy st em at ic r ev iew dem onst r at ed t hat
t he incidence of foot ulcer s in diabet ics is high and
t hat t his is a predict or of am put at ion in t hese pat ient s.
When analyzing t he dressings available, t hey det ect ed
t h a t m o d e r n d r e s s i n g s p o s s e s s s i l v e r i n t h e i r
com posit ion ( ant i- m icr obial) but ar e not w idely used.
Th e r e s e a r c h i d e a e m e r g e d i n t h i s s c e n a r i o ,
quest ioning why dressing/ t opical agent s wit h silver in
t he t reat m ent of foot ulcers in diabet ic pat ient s were
n ot bein g u sed. Th e au t h or s u sed PI CO t o descr ibe
all t he com ponent s r elat ed t o t he ident ified pr oblem
an d t o st r u ct u r e t h e r esear ch qu est ion , w h ich w as:
What is t he effect of dressing/ t opical agent s wit h silver
in t heir com posit ion on t he t reat m ent of diabet ic foot
u lcer s?
Table 3 – Descr ipt ion of t he com ponent s of PI CO in
t he sy st em at ic r ev iew by Ber gin e Wr aight( 16)
P r o c i m e h c s i , d n i k c i h t a p o r u e n h t i w , s e t e b a i d II r o I e p y t h t i w e l p o e P f o e c n e s e r p e h t g n i d r a g e r n o it c i r t s e r o N . s r e c l u t o o f c i m e h c s i o r u e n s e t e b a i d t u o h t i w e l p o e p d e d u l c n i t a h t s e i d u t S . e n il e s a b t a n o it c e f n i f o s d n i k r e h t o d e s u t a h t s e i d u t s d n a d e d u l c n i e r e w e n il e s a b t a y e h t t a h t d e d i v o r p , d e s u e r e w ) s it il u c s a v r o s u o n e v . g . e ( s r e c l u , s e t e b a i d o n x s e t e b a i d ( s e s y l a n a tl u s e r e h t n i d e if i c e p s e r e w ) r e c l u c it e b a i d o n x r e c l u c it e b a i d I s t i n i r e v li s d e n i a t n o c t a h t g n i s s e r d r o t n e g a l a c i p o t f o d n i k y n A t o o f f o t n e m t a e r t e h t r o f n o it a n i b m o c n i r o e n o l a d e s u , n o it i s o p m o c t a h t s e i d u t s g n i d r a g e r n o it c i r t s e r o n s a w e r e h T . s c it e b a i d n i s r e c l u e t a i v e ll a o t t n e m p i u q e , s c it o i b it n a h t i w s t n e m t a e r t d e s u y l s u o e n a tl u m i s . s g n i s s e r d y r a d n o c e s r o e r u s s e r p e h t C g n i s s e r d o b e c a l p , g n i s s e r d o n h t i w e b d l u o c n o s i r a p m o c e h T t u o h t i w s t n e g a l a c i p o t / s g n i s s e r d d n a ) r e v li s o n h t i w t u b ,l a c it n e d i ( . n o it i s o p m o c r i e h t n i r e v li s
O Prercoopvoerryitoonrocfhcaonmgipnlgetienlythheeatoletadlaulrceearsa,nditmseigsnpse/snytmunpttolimcosmopflectilenical . n o it c e f n i
Once t he research quest ion is form ulat ed, t he
follow ing st age is t he beginning of t he bibliogr aphic
search for evidence, w hich allow s for t he recovery of
ev idence in t he dat abases, and can be schem at ized
in t he following st ages( 7- 8,12- 15). The PI CO st rat egy for t he research...
Sant os CMC, Pim ent a CAM, Nobre MRC.
511
o v e r t h e w o r l d . Ha v i n g a cce ss t o t h e k n o w l e d g e
pr oduced about a cer t ain subj ect is essent ial for t he
dev elopm ent of good r esear ch and adequat e clinical
act ion . Th e in t er n et an d t h e por t als of open - access
j our nals allow for accessibilit y t o k now ledge, but t his
is not enough, because it is necessar y t o k now w hat
t o select f r om t h is im m en se sou r ce of in f or m at ion
and how t o do it . The PI CO st r at egy helps in t hese
definit ions, because it or ient s t he const r uct ion of t he
r esear ch q u est ion an d of t h e b ib liog r ap h ic sear ch ,
an d p er m i t s cl i n i cal an d r esear ch p r o f essi o n al , i n
c a s e o f d o u b t o r q u e s t i o n i n g , t o r a p i d l y a n d
a ccu r a t e l y l o ca t e t h e b e st sci e n t i f i c i n f o r m a t i o n
av ai l ab l e.
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16. Bergin SM, Wraight P. Silver based w ound dressings and t op ical ag en t s f or t r eat in g d iab et ic f oot u lcer s. Coch r an e D at ab ase Sy st Rev 2 0 0 6 ( 1 ) : CD 0 0 5 0 8 2 .
Recebido em : 5.7.2006 Aprovado em : 1.3.2007
The PI CO st rat egy for t he research...
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