Courtesy of our partners, The University of Exeter- UK
A recent study from Activity Informatics – the partnership centre from University of Exeter and Activinsights – has shown the potential for improving patient outcomes with digital wearables called accelerometers.
The project took advantage of Activinsights’ technology to use accelerometers – wrist-worn digital devices that monitor a range of biometric functions – to gather a comprehensive range of data on patients recovering from knee replacement surgery for osteoarthritis. After new algorithms were developed to monitor the recovery process, Professor Melvyn Hillsdon analysed this data to discover how certain forms of physical activity impacted upon patient recovery, both before and after surgery.
Accelerometers are instruments which measure changes in velocity over time. In a medical context, accelerometers can track different changes in movement to give a more detailed picture of patient recovery, which can be crucial to making rehabilitation programmes as efficient and effective as possible.
The Challenge
The challenge facing Professor Hillsdon and the Activity Informatics team was not only to establish how feasible it is for accelerometers to track and improve patient outcomes in practice, but more specifically, how they might improve outcomes for osteoarthritis patients undergoing total knee replacements.
Total knee replacement (TKR) is a common surgical procedure for people suffering from severe osteoarthritis, which often – but not in all cases – leads to improved physical function, and reduced pain and disability.
While TKRs are largely successful, a significant number of patients suffer from prolonged recovery and continued pain. Given that 100,000 operations are performed in the UK each year and the additional costs of treatment for patients who face a prolonged recovery is £5136 on average, there’s not only a health motive for improving recovery, but an economic one.
From either perspective, interventions that can improve the physical activity and recovery outcomes of osteoarthritis patients are highly desirable.
Despite this, the evidence needed to find effective interventions is often unreliable. Recovery is typically measured by patients reporting on their own experience, a process which is subject to naturally-occurring gaps in memory (otherwise known as recall bias) and a tendency to overly report more socially acceptable outcomes (social desirability bias).
For this reason, bringing accelerometers into the treatment and recovery cycle can give a detailed and unbiased picture of patient outcomes, and help identify the most effective treatments.
The Project
Driven by this motive and with funding from the Medical Research Council, Professor Melvyn Hillsdon and the Activity Informatics team trialled the use of accelerometers for osteoarthritis patients as they underwent Alternative Knee Alignment surgery.
“New algorithms were developed to discover how certain forms of physical activity impact on patient recovery, both before and after surgery.”
After creating new algorithms to ensure the accelerometers generated the right metrics for knee replacement research and patient care, patients were monitored before and immediately after surgery, then for a further period at 12-weeks.
By developing a strong data set to analyse, Professor Hillsdon and the team were able discover exactly how certain forms of physical activity and behaviour impact on patient recovery, in a more detailed and comprehensive way than previously possible.
Activinsights’ digital accelerometers can monitor a range of biometric functions.
The Results
The study provided several new insights into the early recovery of people undergoing total knee replacement.
In particular, measuring day-to-day changes in behaviour for the first 21-days after discharge from hospital highlighted why simple self-report measures of physical activity – or average day/week metrics – hide important patterns of behaviour. These could have significant benefits for clinicians and patients alike, both in managing expectations and creating personalised care plans.
The project also generated several digital biomarkers of recovery from total knee replacement, based on wrist worn accelerometery. It showed that the remote, continuous monitoring of behaviour is feasible, compliant with digital monitoring regulations, and a low burden for both clinicians and patients.
The results – finding that this intervention is not only feasible and compliant, but beneficial to both patients and clinicians – make a strong case for using accelerometers after surgery, to improve the experience and treatment of recovering patients in future.
Who are Activity Informatics?
Building on ten years of partnership, The University of Exeter and Activinsights have built a specialist research capability in human physical activity and behaviour measurement. Their collaborative centre of excellence, Activity Informatics, is a complete service for public-funded research and clinical trials that want to use wearable sensors to understand participant activity.
The service is designed for health and population surveillance researchers and service providers, who currently use or would like to use wearable devices for the measurement of lifestyle, activity and sleep.
The professional wearables record data about the participant’s movement and environment. Algorithms are then used to infer information about the type, duration, and characteristics of physical behaviours that make up daily living. Together, these tools provide a wide range of digital health measures that, to date, have supported trials in heart failure rehabilitation, bone health, inflammatory bowel disease, and behavioural interventions.
The Activity Insights offering includes all aspects of trial management: deploying/retrieving devices, managing data, and processing digital health biomarkers. Combining Activinsights’ infrastructure, devices and development resources with the University’s contracts and health expertise, the partnership offers a unique, adaptable, and capability-led service.