Alvaro Nagib Atallah*
Clinical investigation needed
A
s stated in last m o n th 'sin terested in p u b lish in g ,issu e, th is Jo u rn al is k een lyan d th u s reco rd in g , g o o d ev id en ce - b ased m ed icin e fo r th e b en efit o f itsread ers. In th is co u n try , th o u san d s o f p h y sician s are
d ed icatin g im p o rtan t y ears o f th eir Iiv es to m ed ical research
in p o stg rad u ate p ro g ram s. S o m e p o stg rad u ate p ro g ram s
h av e alread y d ecid ed to d em an d , in stead o f th e trad itio n al
th esis, th e p u b licatio n o f th e co rresp o n d en t p ap er in an
in d ex ed , p eer-rev iew jo u rn al. T h is is a farsig h ted m o v e.
H o w ev er, th e n u m b er o f g o o d clin ical in v estig atio n
p ap ers is still lo w co m p ared to th e n u m b er o f p h y sician s
en ro lled in th ese p o stg rad u ate p ro g ram s. C lin ical
in v estig atio n , b ein g v ital fo r th e d ev elo p m en t o f B razil's
m ed ical sy stem , is b ad ly n eed ed . T h ere are m an y d iseases
an d o u tco m es, an d g o o d clin ical research req u ires h u m an
reso u rces m o re th an ad v an ced tech n o lo g y .
T h o se in terested sh o u ld start w ith a g o o d research
q u estio n , th e sim p ler th e b etter, fo r ex am p le: D o es m atern al
ed u catio n d u rin g th e p ren atal p erio d red u ce in fan t
m o rtality ? Is w eek ly m ed icatio n fo r tu b ercu lo sis b etter th an
d aily m ed icatio n ?
A fter d efin in g th e research q u estio n , try to d o a
rev iew o fth e su b ject o n M ed lin e an d E m b ase, as su g g ested
b y M cK ib b o n et al.I T h is w ill h elp to estab lish th e
ap p ro p riate d efin itio n s o f th e p rim ary o u tco m es th e
p h y sician is in terested in . A g ain , th e sim p ler th e to p ic, th e
b etter. F o r ex am p le, "S u rv iv al-p o st m y o card ial in farctio n "
is easier to co n firm an d m o re relev an t th an "C o ro n ary
artery , d iso b stru ctio n ". In ad d itio n , th e rev iew w ill h elp in
co m p ilin g a list o f in clu sio n an d ex clu sio n criteria to b e
u sed in th e stu d y . B e aw are th at y o u r research fin d in g s
* MD, PhD, MSc
Department of Internal Medicine, Escola Paulista de Medicina Chairman, Editor, Sao Paulo Medical Journal.
w ill b e u sefu l o n ly to th e ty p e o f p atien t in clu d ed in th e
stu d y . If th e criteria are v ery restrictiv e, th e ap p licab ility
o f th e resu lts w ill b e, to o .
N ex t, calcu late th e sam p le size n eed ed to an sw er th e
q u estio n . M an y fo rm u las ex ist b ased o n th e co n fid en ce
in terv al calcu latio n ; ch o o se th e o n e m o st ap p ro p riate fo r
y o u r stu d y m o d el.2.3 M ak e su re y o u h av e su fficien t
statistical p o w er to d etect a sig n ifican t clin ical o d d s ratio ,
relativ e risk , o r treatm en t effect. D efin e th e statistical
m eth o d s to b e ap p lied in in terp retin g th e resu lts.
W rite d o w n a co m p reh en siv e p ro to co l, su b m it it to
y o u r ad v iso rs an d ex p erts in th e area, an d p resen t it to
y o u r research d iv isio n . S eek o u t feed b ack , an d in co rp o rate
th e relev an t. P rep are y o u rself fo r an ex h au stin g , b u t u su ally
rew ard in g jo u rn ey .
C o n d u ct th e research carefu lly , as to in crease y o u r
co n fid en ce in th e resu lts o b tain ed . U se y o u r im ag in atio n
to p rev en t d ro p -o u ts at a m ax im u m . W rite a th o ro u g h , w
ell-d o n e p ap er. W h eth er th e resu lts are p o sitiv e o r n eg ativ e,
g o fo r a g o o d jo u rn al.
D o n o t accep t p assiv ely an y rejectio n . A rg u e w ith
th e ed ito rs. U su ally , y o u are b etter in fo rm ed ab o u t th e
su b ject, an d th u s b etter ab le to co n v in ce th em to p u b lish
th an an y o n e else. W elco m e to th e ev id en ce b ased w o rld .
REFERENCES
1. M cK ib b o n K A , W elczy n sk i N L , W alk er-D ilk y C 1 . H o w to
search fo r an d fin d ev id en ce ab o u t th erap y . E v id en ce B ased
M ed 1 9 9 6 ; I (3 ):7 0 -1 .
2 . S ch lesselm an 1 1 . S am p le size req u irem en ts in co h o rts an d
case-co n tro l stu d ies o f d isease. A m 1 E p id 1 9 7 4 ;9 9 :3 8 1 -4 .
3 . P o co ck S 1 . T h e size o f clin ical trial. In : C lin ical T rials. N ew
Y o rk : 1 0 h n W iley & S o n s, 1 9 8 4 : 1 2 3 -3 8 .
