Sovereign
Core Functionality
The Sovereign Weave represents the secure, remote execution of GA4GH TES analyses within Trusted Research Environments (TREs).
The functionality represented in the Weave is the closest to current day activity of TREs and offers the maximum control and isolation, requiring no TRE-TRE connectivity.
Built on international open standards from GA4GH, it uses an enhanced GA4GH Task Execution Service to receive federated analysis requests. This approach supports the essential disclosure control processes within TREs, ensuring outputs are reviewed to prevent disclosive data from leaving secure environments.
Weave details
Patterns
| Component | Used in this Weave |
|---|---|
| Interface | Five Safes TES, via the Five Safes TES open source software stack |
| Computational Pattern | Traditional Pattern |
| Egress Inspection Pattern | Full local control: all results are checked and authorised at each TRE before being released |
What a researcher can do
The researcher submits their own analysis code as a TES task, which is run at each TRE. This supports any analysis in the Traditional Pattern, where each TRE’s results are:
- compared: any analysis that can run within a TRE gives a separate result for each location, and these can be compared centrally
- combined exactly: results such as counts, means, contingency tables and linear regression combine to give the same result as the pooled data
- combined as an estimate: results such as quantiles, distinct counts and Cox regression give a close estimate of the pooled result, or each TRE’s results are combined statistically, as in a meta-analysis
Effect on results
Exact analyses stay exact, provided the egress check releases each TRE’s results unchanged. If the check rounds or suppresses results, for example small cells in a table, the totals no longer combine exactly, and a TRE whose results are withheld drops out of the analysis.
What it can’t do
- Shared Pattern analyses. Each round of an iterative analysis would need a manual check at every TRE, so iterative model fitting is not practical. Analyses that need a single pass, such as piecewise-exponential models in place of Cox regression, or combining each TRE’s results as in a meta-analysis, can often be used instead (see When an analysis becomes Shared).
- Pooled Pattern analyses. Row-level data does not leave the TRE, so records cannot be linked across TREs, and individuals present in more than one TRE may be counted more than once.
Practical constraints
- Each result waits for a person to check it at every TRE, so turnaround is set by the slowest review.
- Settings such as time grids, histogram bins and output formats need to be agreed in advance, so that each TRE produces results that can be combined and checked.
- The same analysis code runs at every TRE, so variables need to be defined in the same way at each one.