Although individual patient data meta-analysis (IPD MA) is considered the gold standard of systematic reviews (SRs), a recent International Network of Agencies for Health Technology Assessment survey indicates that IPD MA is not frequently included in a health technology assessment (HTA), or conducted by HTA researchers. The objective of this presentation is to describe our first experience with including an IPD MA in a HTA report, discuss the added value for an evidence-based decision-making process, and advocate for expanding work in this field.

An overview of SRs on endovascular therapy for acute ischemic stroke included one IPD MA and six study-level SRs/MAs. Methodological quality was appraised by two reviewers independently using the tool recommended by the Cochrane IPD MA working group for the IPD MA, and the AMSTAR (A MeaSurement Tool to Assess systematic Reviews) for the study-level reviews. Pooled results from subgroup analyses based on access to primary patient data were compared to those reported in SRs that conducted subgroup analyses based on the published data to identify patients or clinical factors that would impact clinical outcomes.

The overall findings were similar between the IPD MA and other SRs/MAs. However, when compared to aggregated data used in study-level SRs/MAs, subgroup analyses based on patient data allowed for adjustment of confounders, multiple categories within a subgroup, standardization of outcomes across trials, and detailed data checking. Larger sample sizes of each pre-defined subgroup permitted for more precise estimates of treatment effects. A number of methodological issues in the IPD MA were identified; particularly, no assessment of risk of bias of included trials was conducted.

Access to original patient data is demanding and conducting IPD MA requires extensive resources. The advantages of having an improved quality analysis, an appropriate quantification of the effects in the analyzed subgroups, and precision of results may justify additional efforts, and may increase confidence in the decision-making process.