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xamining the confdence intervals is the easiest
ay to assess whether the study sample was too
mall and there ore did not have the statistical
wer to detect a clinically important di erence (as
ected by wide confdence intervals). Even when
study is positive or shows statistically sig-
fcant results it is important to consider whether
e fndings are clinically signifcant and applicableyour practice.
!or example i a study showed a
ug reduces the ris" o heart attac" by one in a
illion patients we would probably be s"eptical
out its utility. #i"ewise the fndings show ing
at daily borscht reduces ractures its a study
one in $ussian doc"wor"ers may or may not be
plicable in the %nited &tates. 'he acceptability o
intervention (e.g. electroconvulsive therapy orpression) may
vary. oreover the ability to
plicate the fndings o a study done in a typical
search setting is o ten reduced in real-world
actice. n intervention or osteoporosis
*uiring daily in+ections may be demonstrated to
e,cacious but in the average practice setting
e ectiveness may be much more limited.
inicians re*uently rely on the synthesis o manyudies rather than
a single study to change our
actices. &uch reviews can be systematic, in which
gorous attempts are made to uncover all studies
ublished and unpublished in English and in other
levant languages or they may be more limited
views that consider only a portion o the
ublished literature. &ome use ormal mathematical
ethods to combine the results o studies (i.e. meta-alysis) and
others are qualitative and synthesi e data
cording to an author/s overall +udgment. ommon
ases to consider related to published reviews
clude whether all sources o evidence were
nsidered0 how disparate results were combined1
hether relevant patient- oriented outcomes were
sessed1 i there was ade*uate attention to the
*uality o the studies and their generali ability1 and
whether the authors analy ed why di erences in
outcomes may have occurred based on such
actors as study design population and
intovention. 2ublished reviews including
systematic reviews and clinical guidelines have
become increasingly important tools or the
busy clinician.linicians may hone critical appraisal s"ills
through involvement with local +ournal clubs
soothing with the !amily 2hysicians/ 3n*uiries
4etwor" (wwwipin.org ). lthough it is important to
understand basic concepts or interpreting medical
literature si ting through original research studies
can be a tedious impractical process or busy
clinicians. any practical E5 tools have emerged in
recent years to help physicians *uic"ly access
comprehensive expert reviews o published studies
in the middle o a busy practice ('able 6-7). 'he
ability to criti*ue articles using a structured
approach is acilitated by using widely available
wor"sheets and tools (see 8eb $esources). lthough
many taxonomies exist or level o evidence two o
the most widely available are the entre or
Evidence-5ased edicine ( E 5 ) and the
taxonomy used in this boo" 'he &trength o
$ecommendation 'axonomy is specifcally tailored
to amily medicine (Ebel/ et al.. 9::;).
Using Evidence at the 2oint o are
2hysicians have many sources o clinical
in ormation rom throwaway or non-peer-
reviewed +ournals to evidence- based searchable
databases. Each o these has advantages
disadvantages and di erent methods o access
('able 6-;).
http://wwwipin.org/http://wwwipin.org/http://wwwipin.org/http://wwwipin.org/
