An i2b2-based, generalizable, open source, self-scaling chronic disease registry

Abstract

Objective: Registries are a well-established mechanism for obtaining high quality, disease-specific data, but are often highly project-specific in their design, implementation, and policies for data use. In contrast to the conventional model of centralized data contribution, warehousing, and control, we design a self-scaling registry technology for collaborative data sharing, based upon the widely adopted Integrating Biology & the Bedside (i2b2) data warehousing framework and the Shared Health Research Information Network (SHRINE) peer-to-peer networking software.

Materials and methods: Focusing our design around creation of a scalable solution for collaboration within multi-site disease registries, we leverage the i2b2 and SHRINE open source software to create a modular, ontology-based, federated infrastructure that provides research investigators full ownership and access to their contributed data while supporting permissioned yet robust data sharing. We accomplish these objectives via web services supporting peer-group overlays, group-aware data aggregation, and administrative functions.

Results: The 56-site Childhood Arthritis & Rheumatology Research Alliance (CARRA) Registry and 3-site Harvard Inflammatory Bowel Diseases Longitudinal Data Repository now utilize i2b2 self-scaling registry technology (i2b2-SSR). This platform, extensible to federation of multiple projects within and between research networks, encompasses >6000 subjects at sites throughout the USA.

Discussion: We utilize the i2b2-SSR platform to minimize technical barriers to collaboration while enabling fine-grained control over data sharing.

Conclusions: The implementation of i2b2-SSR for the multi-site, multi-stakeholder CARRA Registry has established a digital infrastructure for community-driven research data sharing in pediatric rheumatology in the USA. We envision i2b2-SSR as a scalable, reusable solution facilitating interdisciplinary research across diseases.

Figure 1

The i2b2-SSR architecture. The diagram illustrates the interaction of i2b2-SSR core web services C and D, which are customized, i2b2-SSR ‘drop-in’ replacements for the standard SHRINE Broadcaster/Aggregator and i2b2 Project Manager Cell, respectively. In coordination with the i2b2-SSR Overlay Service (E), these modules support introduction of peer-group overlays for sharing of multiple datasets (I) using standard i2b2 nodes and SHRINE adapters (detail H). The authorized end-user (A) constructs a query based on shared ontologies that are pre-defined for the shared datasets. The Shared Ontology Service (F) may employ a standard i2b2 Ontology cell; alternatively, we provide an i2b2 Ontology module with the i2b2-SSR distribution that implements memory-based caching with ontology term search and autocomplete capabilities.

Figure 2

End user query interface. The Site Investigator dashboard view is shown, illustrating a sample visualization of summary statistics for site ‘ABC’ versus the entire CARRAnet registry.

Figure 3

Self-scaling architecture—adding new sites (network nodes) and/or studies to an i2b2-SSR network. With appropriate approvals, a Site Administrator (K) configures the local SHRINE adapter to communicate with a particular registry Broadcaster/Aggregator endpoint (C) and installs a digital certificate distributed by a certificate authority (L) that is mutually trusted by the site and the i2b2-SSR Network Administrator (J).

Figure 4

CARRA Registry, selected demographics (as of February 2012, data from 53 sites), see also table 1. (A) Distribution of subject enrollment by site. The majority of registry subjects (3647 out of 6175 total subjects enrolled, or ∼60%) are found at sites enrolling <200 subjects (N=44 sites), reflecting the broad collaboration needed within this research community to achieve sufficient populations to conduct significant research investigations; (B) age at onset of disease symptoms by disease diagnosis. Upper age distribution is right-censored due to pediatric-onset inclusion criteria.