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is likely to be small as <strong>the</strong> outcomes are objectively determined, except in <strong>the</strong> case <strong>of</strong> <strong>the</strong> Hull 42 study,<br />

where <strong>the</strong> outcome adjudicators were not blinded.<br />

All <strong>of</strong> <strong>the</strong> studies except Romera 45 were involved in <strong>the</strong> analyses <strong>of</strong> bleeding rates. Deitcher 2006 41<br />

has similar limitations as <strong>the</strong> study by Hull et al 42 <strong>and</strong> in addition does not provide an ITT analysis.<br />

O<strong>the</strong>rwise, <strong>the</strong> studies generally appear well conducted.<br />

4.4 Critique <strong>of</strong> <strong>the</strong> indirect comparison <strong>and</strong>/or multiple <strong>treatment</strong> comparison<br />

In general, <strong>the</strong> ERG has concerns with <strong>the</strong> way <strong>the</strong> (network) meta-analysis has been implemented<br />

<strong>and</strong> <strong>the</strong> impact that <strong>the</strong> prior in<strong>for</strong>mation has had on <strong>the</strong> results. The ERG has outlined a number <strong>of</strong><br />

problems with <strong>the</strong> conduct <strong>of</strong> <strong>the</strong> MTC above, <strong>and</strong> would like to highlight <strong>the</strong> following points <strong>of</strong><br />

interest:<br />

Overall, <strong>the</strong>re is a lack <strong>of</strong> clarity about where data has come from, <strong>and</strong> a lack <strong>of</strong> depth in <strong>the</strong><br />

analysis <strong>of</strong> study characteristics in relation to one ano<strong>the</strong>r.<br />

Additional searches were not conducted to update <strong>the</strong> Akl et al 31 . The ERG has conducted<br />

update searches following <strong>the</strong> Akl et al. search strategy. The results were sifted, but no fur<strong>the</strong>r<br />

eligible RCT studies were identified.<br />

The MS states <strong>the</strong> study by Romera Villegas et al 45 is an RCT, however it appears from <strong>the</strong><br />

online abstract to be a systematic review. This is also reported as an RCT in <strong>the</strong> citing<br />

Cochrane review, Akl et al. 31<br />

On Pg 71 <strong>of</strong> <strong>the</strong> MS 1 it is stated that<br />

“<strong>the</strong> <strong>treatment</strong> interaction term <strong>for</strong> presence <strong>of</strong> active cancer was xxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxx.<br />

Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxxxxx. Indeed <strong>the</strong> use <strong>of</strong> data that does not come from <strong>the</strong> cancer group in<br />

this MTC seems to negate <strong>the</strong> point <strong>of</strong> <strong>the</strong> comparison, which is to study <strong>the</strong> effects in cancer<br />

patients. There<strong>for</strong>e, <strong>the</strong> ERG feels <strong>the</strong> “secondary analysis 2” presented by <strong>the</strong> MS is more<br />

74<br />

Copyright 2012 Queen's Printer <strong>and</strong> Controller <strong>of</strong> HMSO. All rights reserved.

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