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How MEDHOST’s cardiac risk prediction successfully leveraged AWS analytic services

MEDHOST has been providing products and services to healthcare facilities of all types and sizes for over 35 years. Today, more than 1,000 healthcare facilities are partnering with MEDHOST and enhancing their patient care and operational excellence with its integrated clinical and financial EHR solutions. MEDHOST also offers a comprehensive Emergency Department Information System with business and reporting tools. Since 2013, MEDHOST’s cloud solutions have been utilizing Amazon Web Services (AWS) infrastructure, data source, and computing power to solve complex healthcare business cases.

MEDHOST can utilize the data available in the cloud to provide value-added solutions for hospitals solving complex problems, like predicting sepsis, cardiac risk, and length of stay (LOS) as well as reducing re-admission rates. This requires a solid foundation of data lake and elastic data pipeline to keep up with multi-terabyte data from thousands of hospitals. MEDHOST has invested a significant amount of time evaluating numerous vendors to determine the best solution for its data needs. Ultimately, MEDHOST designed and implemented machine learning/artificial intelligence capabilities by leveraging AWS Data Lab and an end-to-end data lake platform that enables a variety of use cases such as data warehousing for analytics and reporting.

Getting started

MEDHOST’s initial objectives in evaluating vendors were to:

• Build a low-cost data lake solution to provide cardiac risk prediction for patients based on health records
• Provide an analytical solution for hospital staff to improve operational efficiency
• Implement a proof of concept to extend to other machine learning/artificial intelligence solutions

The AWS team proposed AWS Data Lab to architect, develop, and test a solution to meet these objectives. The collaborative relationship between AWS and MEDHOST, AWS’s continuous innovation, excellent support, and technical solution architects helped MEDHOST select AWS over other vendors and products. AWS Data Lab’s well-structured engagement helped MEDHOST define clear, measurable success criteria that drove the implementation of the cardiac risk prediction and analytical solution platform. The MEDHOST team consisted of architects, builders, and subject matter experts (SMEs). By connecting MEDHOST experts directly to AWS technical experts, the MEDHOST team gained a quick understanding of industry best practices and available services allowing MEDHOST team to achieve most of the success criteria at the end of a four-day design session. MEDHOST is now in the process of moving this work from its lower to upper environment to make the solution available for its customers.

Solution

For this solution, MEDHOST and AWS built a layered pipeline consisting of ingestion, processing, storage, analytics, machine learning, and reinforcement components. The following diagram illustrates the Proof of Concept (POC) that was implemented during the four-day AWS Data Lab engagement.

Ingestion layer

The ingestion layer is responsible for moving data from hospital production databases to the landing zone of the pipeline.

The hospital data was stored in an Amazon RDS for PostgreSQL instance and moved to the landing zone of the data lake using AWS Database Migration Service (DMS). DMS made migrating databases to the cloud simple and secure. Using its ongoing replication feature, MEDHOST and AWS implemented change data capture (CDC) quickly and efficiently so MEDHOST team could spend more time focusing on the most interesting parts of the pipeline.

Processing layer

The processing layer was responsible for performing extract, tranform, load (ETL) on the data to curate them for subsequent uses.

MEDHOST used AWS Glue within its data pipeline for crawling its data layers and performing ETL tasks. The hospital data copied from RDS to Amazon S3 was cleaned, curated, enriched, denormalized, and stored in parquet format to act as the heart of the MEDHOST data lake and a single source of truth to serve any further data needs. During the four-day Data Lab, MEDHOST and AWS targeted two needs: powering MEDHOST’s data warehouse used for analytics and feeding training data to the machine learning prediction model. Even though there were multiple challenges, data curation is a critical task which requires an SME. AWS Glue’s serverless nature, along with the SME’s support during the Data Lab, made developing the required transformations cost efficient and uncomplicated. Scaling and cluster management was addressed by the service, which allowed the developers to focus on cleaning data coming from homogenous hospital sources and translating the business logic to code.

Storage layer

The storage layer provided low-cost, secure, and efficient storage infrastructure.

MEDHOST used Amazon S3 as a core component of its data lake. AWS DMS migration tasks saved data to S3 in .CSV format. Crawling data with AWS Glue made this landing zone data queryable and available for further processing. The initial AWS Glue ETL job stored the parquet formatted data to the data lake and its curated zone bucket. MEDHOST also used S3 to store the .CSV formatted data set that will be used to train, test, and validate its machine learning prediction model.

Analytics layer

The analytics layer gave MEDHOST pipeline reporting and dashboarding capabilities.

The data was in parquet format and partitioned in the curation zone bucket populated by the processing layer. This made querying with Amazon Athena or Amazon Redshift Spectrum fast and cost efficient.

From the Amazon Redshift cluster, MEDHOST created external tables that were used as staging tables for MEDHOST data warehouse and implemented an UPSERT logic to merge new data in its production tables. To showcase the reporting potential that was unlocked by the MEDHOST analytics layer, a connection was made to the Redshift cluster to Amazon QuickSight. Within minutes MEDHOST was able to create interactive analytics dashboards with filtering and drill-down capabilities such as a chart that showed the number of confirmed disease cases per US state.

Machine learning layer

The machine learning layer used MEDHOST’s existing data sets to train its cardiac risk prediction model and make it accessible via an endpoint.

Before getting into Data Lab, the MEDHOST team was not intimately familiar with machine learning. AWS Data Lab architects helped MEDHOST quickly understand concepts of machine learning and select a model appropriate for its use case. MEDHOST selected XGBoost as its model since cardiac prediction falls within regression technique. MEDHOST’s well architected data lake enabled it to quickly generate training, testing, and validation data sets using AWS Glue.

Amazon SageMaker abstracted underlying complexity of setting infrastructure for machine learning. With few clicks, MEDHOST started Jupyter notebook and coded the components leading to fitting and deploying its machine learning prediction model. Finally, MEDHOST created the endpoint for the model and ran REST calls to validate the endpoint and trained model. As a result, MEDHOST achieved the goal of predicting cardiac risk. Additionally, with Amazon QuickSight’s SageMaker integration, AWS made it easy to use SageMaker models directly in visualizations. QuickSight can call the model’s endpoint, send the input data to it, and put the inference results into the existing QuickSight data sets. This capability made it easy to display the results of the models directly in the dashboards. Read more about QuickSight’s SageMaker integration here.

Reinforcement layer

Finally, the reinforcement layer guaranteed that the results of the MEDHOST model were captured and processed to improve performance of the model.

The MEDHOST team went beyond the original goal and created an inference microservice to interact with the endpoint for prediction, enabled abstracting of the machine learning endpoint with the well-defined domain REST endpoint, and added a standard security layer to the MEDHOST application.

When there is a real-time call from the facility, the inference microservice gets inference from the SageMaker endpoint. Records containing input and inference data are fed to the data pipeline again. MEDHOST used Amazon Kinesis Data Streams to push records in real time. However, since retraining the machine learning model does not need to happen in real time, the Amazon Kinesis Data Firehose enabled MEDHOST to micro-batch records and efficiently save them to the landing zone bucket so that the data could be reprocessed.

Conclusion

Collaborating with AWS Data Lab enabled MEDHOST to:

• Store single source of truth with low-cost storage solution (data lake)
• Complete data pipeline for a low-cost data analytics solution
• Create an almost production-ready code for cardiac risk prediction

The MEDHOST team learned many concepts related to data analytics and machine learning within four days. AWS Data Lab truly helped MEDHOST deliver results in an accelerated manner.

About the Authors

Pandian Velayutham is the Director of Engineering at MEDHOST. His team is responsible for delivering cloud solutions, integration and interoperability, and business analytics solutions. MEDHOST utilizes modern technology stack to provide innovative solutions to our customers. Pandian Velayutham is a technology evangelist and public cloud technology speaker.

George Komninos is a Data Lab Solutions Architect at AWS. He helps customers convert their ideas to a production-ready data product. Before AWS, he spent 3 years at Alexa Information domain as a data engineer. Outside of work, George is a football fan and supports the greatest team in the world, Olympiacos Piraeus.