How to use Clinical Evidence to inform
clinical decision making
A case presentation using the CE review on acne
Case study constructed for purpose of Clinical Evidence
demonstration. Not based on any particular individual.
History
• 23-year-old woman, suffering from severe acne
on face and back for past 7 years. GP referral
• Past medical history – acne, low mood for 2
years, links this to acne
• Family history – nil of note
• Drug history – oral contraceptive pill, topical
benozyl peroxide (not using this at present)
• Social history – university student, living with
friends, non-smoker, moderate alcohol. Acne
negatively impacting on social life
Patient’s questions
• Patient reports feeling depressed, which she believes is
linked to the appearance and discomfort of her acne.
Recently the severity of her symptoms have worsened, the
acne is more difficult to cover with make up, and as a result
she is going out less and this is having a negative impact on
her social life, studies, and relationship with boyfriend
• Patient is adamant that she needs a prescription for
Roaccutane, as a friend took this and her acne improved
• Doesn’t want to be ‘palmed off’ with any more ‘creams that
never work’. A previous face cream caused redness and
itching of her skin. The redness was almost as unsightly as
the acne
• Patient wants the acne to reduce as much as possible,
without scarring – plan to look for interventions that will
achieve this
Consultation structure
• You explain that you have understood her concerns and you
will begin by talking about oral isotretinoin (Roaccutane) as
that is what she has requested
• You will look at the benefits and harms associated with this
drug and the evidence behind this information
• You will discuss how this drug compares with other possible
treatments
• You will think about this drug in the context of other options
for acne treatment in order to give her more information with
which to make a decision
• Clinical Evidence can be used to address all these issues…
Oral isotretinoin
• Roaccutane (isotretinoin)
• In our search we found one RCT comparing isotretinoin
versus placebo, and another RCT comparing isotretinoin
versus tetracycline, for our outcome of interest, acne
severity. Both had small numbers of participants and, when
analysed with our GRADE scoring system, provided
moderate-quality evidence
• We have also commented on much larger studies we found,
which looked at issues such as teratogenicity, skin adverse
effects, liver adverse effects, and psychiatric adverse
effects/ suicides. These show that isotretinoin is very
teratogenic, it may affect liver markers, may cause dry skin,
and they have examined the relationship between
isotretinoin and mood disorders and suicide
In our search, we
found one RCT
comparing oral
isotretinoin with
placebo, focusing on
our outcomes of
interest (one of which
is acne severity)
The evidence we
have to support
our conclusion on
oral isotretinoin
compared with
placebo is of
moderate quality
This table line
summarises the
findings from this RCT
The RCT we found did
not provide any
information on these
other outcomes of
interest
The RCT we found
comments on adverse
effects in the 2 treatment
groups but does not
provide statistical
analysis comparing the
groups. Therefore, we
cannot comment on
whether isotretinoin
leads to more adverse
effects than placebo from
this RCT
We found one more RCT
of oral isotretinoin that
looked at our outcomes of
interest. This small RCT
compares oral isotretinoin
with oral tetracycline.
We can refer to the
GRADE table in the
review to see why this
is classed as
‘moderate-quality
evidence’. We will see
this later
From the table, we
can see that oral
isotretinoin is
favoured over oral
tetracycline for
reducing acne cysts,
pustules and
comedones at 24
weeks in this RCT
Here we report absolute
numbers, that is how
many people had adverse
effects in each group
This RCT
compared
adverse effects
in people taking
oral isotretinoin
with people
taking oral
tetracycline.
Although the
numbers of
people
experiencing
adverse effects
were different
in the 2 groups,
the RCT did not
assess statistical
significance, so
we cannot
comment on
which
treatment is
favoured
We also found
some large studies
looking at the
adverse effects
from oral
isotretinoin.
These issues have
been covered in
the media and
attention has
focused on
psychiatric adverse
effects.
Here, we see that
the evidence
strongly suggests
that oral
isotretinoin is
teratogenic.
However,
psychiatric adverse
effects are more
controversial
Following on from the Comments section, we have the Clinical guide, putting the
evidence we found into an overall clinical context.
We have discussed oral isotretinoin, and the patient agrees there are significant risks and limitations to
taking it. She would like to see some other options too. This ‘Key Points’ page summarises the treatments
for acne. It links to the pages containing evidence for each intervention
The categorisation table provides an overview of a range of available treatments and how we have assessed
their effectiveness based on randomised controlled trial evidence. It is easy to navigate to the relevant pages
for each intervention by clicking on the links
These are the clinical
questions this review
answers
Links to
the patient
leaflets are
here
Our patient particularly wanted an oral treatment, and we saw from the interventions table that the
one oral treatment rated as ‘likely to be beneficial’ was erythromycin
After navigating
to
‘erythromycin’
we can see the
systematic
reviews and
RCTs undertaken
on this drug.
Here we see a
comparison with
tetracycline
To find out more about what
this classification means, click
on the icon
Here we see that
tetracycline is
rated as ‘Trade off
between benefits
and harms’. To find
out more about
this particular
case, click on
tetracycline
It would be
interesting to
know how
erythromycin
compared with
placebo. We
found no RCTs on
this
The GRADE table. Here, we can see how the GRADE classifications are decided. For example, oral
erythromycin versus oral tetracycline for acne severity is rated as low-quality evidence
4 points
are given
for RCT
evidence
Here we can see
why points were
deducted
Conclusions
• We have looked at the evidence for the benefits
and harms of a treatment the patient requested
• We have compared this intervention with others
in terms of benefits and harms, and assessed the
quality of evidence behind these
• We have been able to provide the patient with
more knowledge of the range of available
interventions, as well as the pros and cons of
each
• We have been able to see where gaps in the
current evidence base are