PDA-OTA

// One-shot Transfer Algorithm

Where Distributed
Studies Get Done.

PDA-OTA is the online workspace that powers PDA collaborations. It helps researchers and data partners coordinate studies, exchange aggregated data securely, monitor project status in real time, and keep multi-site analyses moving efficiently. By centralizing workflow instead of centralizing raw data, PDA-OTA makes collaboration more practical at scale.

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// How It Works

The OTA Workflow

Local Estimation

Each site fits its own local model using patient-level data that never leaves the institution.

Surrogate Transfer

Sites transmit only lightweight summary statistics — gradients and Hessians — to the coordinating center.

One-Shot Aggregation

The coordinating center aggregates summaries using a single Newton-Raphson update step.

Pooled-Equivalent Result

The resulting estimate is asymptotically equivalent to the pooled analysis — in one round.

// PDA-OTA in Action

Real-World Applications

Linear Regression

Federated OLS with exact pooled equivalence. Supports high-dimensional covariates and heterogeneous site populations.

Logistic Regression

Binary outcome models for comparative effectiveness studies. Validated across PCORnet multi-site deployments.

Cox Proportional Hazards

Survival analysis for time-to-event outcomes. Essential for pharmacovigilance and longitudinal EHR studies.

Poisson Regression

Count data and incidence rate modeling for population-level epidemiological analyses.

SCCS Model

Self-controlled case series for vaccine safety surveillance and drug adverse event detection.

Custom Estimators

Extensible API for implementing custom federated estimators. Community contributions welcome on GitHub.