Evaluation and discussion: the PamBayesian project
LHS in the context of generating the Realistic Synthetic Electronic Health Record
Accessing EHR for secondary use purposes such as data research, modelling and artificial intelligence training presents with challenges, notably:
Attaining ethics approval for access to collections of EHR.
Difficulty when consent is required from each individual patient.
Over-reliance on anonymisation that can reduce or remove important contextual detail.
The CoMSER Realistic Synthetic Electronic Health Record (RS-EHR) and ATEN Realism in Synthetic Data projects operate following the approach described in figure 5 and focus on satisfying the need for access to EHR for secondary uses relying on a privacy-preserving knowledge-intensive method to generate locally realistic, but not real, synthetic EHR without needing access to the real EHR.
Figure 5The ATEN approach to RS-EHR generation. CPG, clinical practice guideline; RS-EHR, Realistic Synthetic Electronic Health Record.
The relationship between LHS and RS-EHR can be two-way. LHS can help provide the aggregated statistical data and knowledge described as rules and relationships that exist in EHR data sets. In this way, RS-EHR generation need never be exposed to real EHR during the definition or generation of synthetic EHR. Conversely, LHS can be built, trained and validated by projects like PamBayesian using collections of RS-EHR, prior to being productionised to work for real patients and clinicians.
The LHS paradigm allowed us to fully exploit the routinely collected data from the healthcare system. This made development of knowledge-intensive methods for generating synthetic EHR successful, making it easy to create collections of realistic synthetic EHR for use in secondary uses where privacy concerns prevent release of real data. Further, development of knowledge-intensive models enables prediction of patient risk for particular negative outcomes and recommending appropriate and more effective treatments based on patient characteristics, history and current symptomatology possible.
To fulfil RS-EHR’s aims the following LHS types from the LHS pathway, which apply to the levels of medical practice from the application pathway (in brackets), are needed:
Cohort identification—learning evidence (EBM) and operating within the context of the learning healthcare organisation level of the system pathway to identify a prescribed cohort of patients with similar health conditions or characteristics such as demographics and symptomatology consistent with the disease to be modelled and generated.
Positive deviance and negative deviance—learning evidence (EBM) and operating within the context of the learning healthcare organisation level of the system pathway; of commonly used treatments, both effective and ineffective to ensure synthetic patients receive realistic treatments and outcomes.
Predictive patient risk modelling—specific to patient (precision medicine) and operating within the LHS level of the system pathway to identify patterns and model risk factors consistent with adverse events.
Clinical decision support system—specific to patient (precision medicine) and operating within the LHS level of the system pathway to identify characteristics of synthetic patients that make them compatible for generation of specific disease or treatment outcomes.
LHS in the context of patient risk and decision modelling
There are numerous approaches for developing intelligent systems supporting clinical decision-making for diagnosis, prognosis or treatment selection. Bayesian networks (BNs) are one such approach. BNs model uncertainty and allow the user to update prior belief, such as when assessing the probability for presence of a medical condition in light of new evidence (additional symptoms, risk factors and test results). However, the process of building these intelligent systems for chronic conditions is not yet fully explored and understood. Chronic conditions are particularly challenging in this context as the patient’s condition must be monitored for extended periods during which many decisions may be undertaken. Ideally, doctors and nurses should be able to monitor patients without the resource-intensive, expense and inconvenience of clinic visits, except when such visits are necessary. Current clinical records and care processes do not easily receive, integrate or enable patients in the home to collect and transmit self-monitoring data from inexpensive sensor-based devices like the Apple Watch and continuous glucose monitors.
PamBayesian is developing a new framework for distributed probabilistic decision-support systems. As shown in figure 6, PamBayesian combines patient data with clinical expertise and patient input, for use in developing intelligent systems. The novelty of this framework is the use of ‘conventional’ EHR (eg, blood tests, imaging results) combined with near real-time continuous data from local sensors for learning and providing new knowledge. This allows for autonomy in a collaborative decision-making environment that includes clinicians and patients, to avoid unnecessary visits to a clinic or hospital. Once the patient’s condition crosses the diagnostic threshold (in green), the clinician prescribes the treatment (in yellow) and treatment review (in red) thresholds. The patient self-monitors the parameters of their condition and enters these into the LHS application. If assessment and prediction of their condition rises above the treatment threshold, the patient receives treatment, be it medication or otherwise. If it rises above the treatment review threshold, the clinician is alerted that the patient requires review so that an appointment can be offered.
Figure 6The PamBayesian project as a learning health system (LHS). BN, Bayesian network; EHR, electronic health record.
To fulfil PamBayesian’s aims the following LHS types from the LHS pathway, which apply to the levels of medical practice from the application pathway (in brackets), are needed:
Cohort identification—learning evidence (EBM) and operating within the context of the learning healthcare organisation of the system pathway to identify patients with similar demographic and clinical characteristics.
Clinical decision support system—specific to patient (precision medicine) to collect and analyse daily data and operating within the LHS level of the system pathway to provide relevant patient feedback.
Predictive patient risk modelling—specific to patient (precision medicine) and operating within the LHS level of the system pathway to predict and identify potential future adverse events.
LHS in the context of empowering patient participation in healthcare
Despite advances in modern medicine, many chronic conditions such as diabetes and rheumatoid arthritis have generally proven incurable. The daily life of patients with chronic conditions is highly affected by disease progression; over time disease symptoms exacerbate until they overwhelm the patient. Patients must constantly evaluate their condition, making day-to-day decisions regarding care and relying on advice from their treating clinicians to guide those decisions. Again, despite medical advances, access to healthcare remains a significant issue for all patients. Regular appointments with doctors or nurses are time consuming, expensive, inconvenient and, in many cases, cannot be scheduled to coincide with times when the worst symptomatology may present.
PamBayesian aims to empower patients to undertake day-to-day self-care within boundaries; diagnostic, treatment and treatment review thresholds that are defined by the patient’s clinician. As shown on the right side of figure 7, home health monitoring devices and applications will be used to gather patient symptoms, measurements and reports about their condition, and with BN intelligence will tailor clinical knowledge and generate patient advices. In this way, PamBayesian promotes continuous monitoring of the patient’s condition while supporting patient self-management and engagement of timely interventions. PamBayesian also promotes a more effective and efficient interaction model between patients and clinicians whereby expensive and time-consuming clinic visits need only occur when a patient’s monitoring shows that their symptomatology has escalated and surpassed the treatment review threshold as discussed in the previous section.
Figure 7Using PamBayesian to promote patient empowerment.
To fulfil PamBayesian’s aims the following LHS types from the LHS pathway, which apply to the levels of medical practice from the application pathway (in brackets), are needed:
Cohort identification—learning evidence (EBM) and operating within the context of the learning healthcare organisation of the system pathway to identify patients with similar demographic and clinical characteristics.
Clinical decision support system—specific to patient (precision medicine) to collect and analyse daily data and operating within the LHS level of the system pathway to provide relevant patient feedback.
Predictive patient risk modelling—specific to patient (precision medicine) and operating within the LHS level of the system pathway to predict and identify potential future adverse events.