13 June 2019 - Indirect comparisons via a common comparator (anchored comparisons) are commonly used in health technology assessment. However, common comparators may not be available, or the comparison may be biased due to differences in effect modifiers between the included studies. 

Recently proposed population adjustment methods aim to adjust for differences between study populations in the situation where individual patient data are available from at least one study, but not all studies. They can also be used when there is no common comparator or for single-arm studies (unanchored comparisons). 

Phillippo et al. have characterised the use of population adjustment methods in technology appraisals submitted to the United Kingdom NICE.

Read International Journal of Technology Assessment in Health Care article