This Mapping Pathways poster was presented at the AIDS 2012 conference on Monday July 23, 2012.

1. Synthesising the empirical
evidence to map pathways
for HIV prevention planning
BACKGROUND METHODS
New trial data has begun to provide empirical The Mapping Pathways study has developed and synthesised the evidence base for ARV-
support for innovation in the use of antiretroviral based prevention, and the implications for India, South Africa, and the United States.
(ARV) drugs for HIV prevention. However, there has A structured literature review mapped and analysed published empirical data on ExpertLens methodology
been little synthesis of the full breadth of individual, four ARV-based prevention strategies: testing, linkage to care plus (TLC+), pre-
clinical, social, political, and economic impacts of exposure prophylaxis (PrEP), microbicides, and post-exposure prophylaxis (PEP).
ARV-based prevention strategies, and the evidence ROUND 1 ROUND 2 ROUND 3
for them. Share views and Online, interactive Incorporate new
A Delphi-based 'ExpertLens' identified fault-lines in the evidence for existing knowledge discussions generate knowledge into your
new knowledge reflections
implementation of the strategies as perceived by HIV/AIDS experts. Respond to questions
ExpertLens harnesses the about the patient- Engage with other Revisit the first set of
centred, economic, experts from South questions. Apply new
wisdom of groups and can bring PrEP Microbicides TLC+, Test PEP social, and clinical Africa, India, and the insights gained in the
geographically dispersed and Treat
implications and United States. Experts discussions to the
What is the efficacy? How robust is it? impacts of HIV/AIDS compare answers with answers
participants together. treatment as prevention others’ and share
What are the effectiveness measures? What is missing? strategies perspectives
What is the data for comparative cost-effectiveness?
1.
Empirical What do we know about indirect outcomes? What more can we know? Reflect, compare, engage, deliberate. Repeat
evidence base What information can inform epidemiological, or other modelling?
What are the framework conditions needed for drug development?
map by relevance
to key research
200
Number of articles
questions
RESULTS
150
100
50
The literature review retrieved 5,811 articles from a keyword search and
0
302 abstracts were mapped for their methodology and relevance to
efficacy, cost-effectiveness, indirect outcomes, and epidemiological
?
?
s?
ra s
gy
?
?
en s
ra ct
s?
gy
te l
iti rk
st es
ra a
iv e
Empirical evidence
gy
es
gy
ra y
st ire
co ew s
of ffic es
of io es
ct uss
st ic
on
te
nd o
te
st ac
am se
of en
impacts (Figures 1 and 2). One-hundred articles were fully
2.
te
a log
e s
g em ss
nd
fr cus
s
s iv
ffe sc
cu
lin d cu
es i
re ect
-e i
st D
is
es
is
el epi Dis
analysed. There is a relatively sparse evidence base for the efficacy
of
D
base for ARV-based
su eff
D
om ss
tc cu
ea s
m sse
of ARV-based prevention. Modelling and cost-effectiveness studies
ou Dis
co
cu
prevention strategies
is
revealed optimism for effectiveness of TLC+ and PrEP strategies,
od
D
m
TLC+, Test & Treat, etc. although caveats about adherence, risk compensation, and drug
Microbicides resistance exist. Overall we observe gaps in the evidence base in 30
Number of studies
PrEP the following areas: examination of indirect outcomes of ARV- 25
PEP
based prevention strategies; clinical trial data for microbicides 20
and ‘treatment as prevention’ strategies; and divergent, context- 15
dependent evidence about the epidemiological implications of 10
different strategies. 5
0
g
dy
dy
y
od dy
at ase dy
ca udy
y
y
rt
al
ud
nt tud
ud
Pa ent ellin
po
tri
tu
tu
tu
u
st
st
st
st
re
ts
ls
ls
s
al
e
tie ion
Sc se
c
na
na
os
ic
e
ifi
tiv
M
nc
lin
“Let us not pitch one prevention option against another - people have unique situations
C
tio
di
c
ip Type of study
re
ie
C
itu
nt
e
cr
ec
iv
rv
fe
es
ng
-s
te
at different points of their lives and are likely to make different choices. Some
on
D
ss
lit
in
Lo
C
ro
ua
er
migration might happen but overall most people will have more options to choose from.”
C
Q
th
O
(ExpertLens participant) TLC+, Test & Treat, etc.
Microbicides
PrEP
PEP
The views of thirty-two experts, including clinicians, health providers, policy-makers,
advocates, and researchers were solicited on factors which would influence the
ExpertLens effectiveness of different strategies, such as socio-economic or clinical delivery
contexts. Levels of agreement were highly varied and distributed amongst the
comparative assessment
3. of biomedical prevention
strategies
strategies and the different conditions for implementation (Figure 3).
When asked about the comparative strengths of the strategies, experts generally
thought TLC+ had the strongest scientific evidence, was ready for
ExpertLens
1 implementation, and most deserving of funds. While agreement between
4.
experts varied on these comparative strengths, consensus only emerged for comparative assessment
Relative assessment
0.8
the TLC+ strategy in three areas: strength of the science, readiness for
0.6
implementation, and allocation of funds. There was disagreement on the
of factors affecting
0.4 cost feasibility issue, with no consensus emerging for any strategy. implementation
Relative ranking/rating
1
between strategies
0.2
0
Qualitative analysis of the ExpertLens discussions revealed
e
s
of tion
n
sc of
ty
nc
nd
tio
en ss
as t
ili
gy h
fe os
ie
fu
ca
ta
em ne
ib
te gt
faultlines on the viability of 'treatment as prevention' strategies
C
lo
ra n
pl di
st Stre
Al
m ea
0
and risk disinhibition in relation to TLC+ (Figure 4). The chart
R
ro Oc wh ave ua ha nce
lin dic lin te ow e
ic a ica stin -up
te rug l H are
ef e
m exu or en
ail y & ult ted nt m
il c al ina ion
ro or at av us div urs
rd , h l h x w u ls
t, ero lth h m rs
ex l c ers
ng of Sex oup s
u o s
C -im car ssa s
e c ide s
s
In in mu co ditio s
st ua ity dit s
pu tur & ct s
s
s
ble rap o f pta g
sid ista k
M In ros isk dhe ility
nin D ve lthc y
le s lt
H & con ed nd taff
l c ple
se w le
a r
it
Fa ial nt- live linic line
lth m mic on ion
fra eq n n n
Po c ty ru n
la e & dis ure
ct
c id ll c
e nc
le a it
t e in
ed es ris
co nt na se ug ua
om p e u
an et ea it se
C alth al rke
Av bilit C mit me yste
o n
Pa l & and gu g k
ru li st io
n- he par
fe
k
Se disc cup o h no l in vio
ab a ur f at
Sk Su ity ces acc nc
ri
en t e b re
e R a b
ua ou
shows the relative distribution of the mean rating of each
dis da io e dr id
ea co o c it
t co s
nd r IV
& elia
m & rela ry al
w
fo
e
ce l r
os a
an ica
l
he x
implementation issue as they varied between strategies. Where
of s
TLC+, Test & Treat, etc.
pli g
ho s
r x
m lo
tio
o
co bio
So tie d
ro s
a l
St tim
ily e
nt &
Microbicides the markers overlap, this indicates similar mean rankings between
et
ille ita
Vic
U
C me
tie al
H
pa nic
c
d
a
h Cli
PrEP
ail
strategies, and where they are spread apart, the mean ranking was
Av
ig
PEP
Se
H
different. The analysis reveals that questions were raised about
implementation issues, such as who would monitor patient
compliance and drug resistance, while consensus emerged around the
TLC+, Test & Treat, etc.
importance of socioeconomic conditions being favourable to
Microbicides
implementation of the strategies; the importance of community and PrEP
political buy-in; expanded testing alongside treatment; and the need for the PEP
strategies to be implemented alongside other prevention strategies.
“It is important to keep attention on treatment which requires
political and financial resources.” (ExpertLens participant)
CONCLUSIONS
There is little published, systematic analysis of the full evidence base
for ARV-based prevention to utilize for policy development. Existing
data is inconsistent with regard to efficacy and effectiveness, varies
by country, and expert perspectives are divergent and dynamic.
Critical gaps exist in the evidence base and the need for policy-
relevant and robust evidence remains.
Mapping Pathways has six partner organisations: AIDS Foundation of Chicago, AIDS United, Baird's CMC, Desmond Tutu HIV Foundation, Naz India and RAND. Mapping Pathways is funded by an initial grant from
Merck & Co., as well as an additional NIH ‘Be the Generation Bridge’ grant for dissemination and community engagement activities.
Blog: www.mappingpathways.blogspot.com
Facebook: www.facebook.com/MappingPathways
Twitter: @MappingPathways
DESMOND TUTU
HIV FOUNDATION
BAIRD’S CMC