PainPad – Better quality pain data to optimise care and get patients on the road to recovery

PainPad - Better quality pain data to optimise care and get patients on the road to recovery - Banner


Prof Price and his team of engineers developed the Painpad along with Prof Pearce, consultant orthopaedic surgeon at Milton Keynes University Hospital (MKUH). Clinicians track patient vital signs, including self-reported pain, in order to monitor treatment for many conditions. Keeping pain levels under control can be an important factor in early discharge. Normally pain levels are recorded by nurses every few hours, but the painpad allows more frequent and accurate pain readings while saving nurse time for more important tasks. Painpads have been used across MKUH since 2017 with more hospitals joining in 2021.

Underpinning research

In 2014 Professor Blaine Price from the OU’s Digital Health Lab began collaborating with Professor Oliver Pearce, a consultant orthopaedic surgeon at Milton Keynes University Hospital. Prof Pearce is the UK lead for the Zimmer Biomet rapid recovery programme aimed at helping people recover faster from joint replacement surgery. He had found that many practices surrounding the recovery process were based on custom rather than evidence and he wanted to better understand what factors influenced the speed of patient recovery. He was particularly interested in recovery from total knee replacement surgery, where nearly 20% of patients report no improvement up to 1 year after surgery.

Together, Profs Price and Pearce began looking at tangible and wearable technology to better understand the recovery process. Together with Research Engineers in the OU School of Computing and Communications they adapted an early Fitbit with a 3-month battery to measure patient activity in the 6 weeks following surgery [O1]. In parallel, they began developing a handheld device for patients to self-log pain levels, as accurate management of pain is a key aspect of recovery and understanding pain levels over time can provide insights into the success of the surgery.

Designing a device for use by in-patients has technical design challenges, but patients having joint replacement surgery tend to be older, often do not own a smart phone, and may have lower dexterity than younger adults which present another level of challenge. The team designed a handheld tangible device with a one button operation for simplicity along with an audio and visual prompt to encourage regularly logging. The design was also kept deliberately simple in order to avoid it looking valuable enough to steal. The result of the co-design process with clinicians and patients was the painpad which was found to perform better, especially with older adults, than virtual interfaces on a tablet and patients also seemed to report more frequently and more accurately than with traditional charting queries by nurses [O2].

Since starting the work on painpad, Prof Price and the Digital Health Lab have been awarded over £2.2M in funding from the EPSRC on projects related to self-logging and health for older adults.


Patient Reported Outcome Measures (PROMs) are the data about patients which only the patient can supply, such as where they have been, what they eat, their mental state or the amount of pain they are in. Clinicians get contemporaneous PROMs simply by asking the patient. For data over a longer period this is not practical so patients are often asked to keep diaries – however these are often incomplete because patients forget to fill them in, or they are back-filled from an incomplete memory, resulting in inaccurate data. Experience sampling, sometimes called ecological momentary assessment, involves prompting the user to record data in the moment in order to maximize the volume and accuracy of data. The Painpad makes use of this by reminding the patient at the programmed interval (usually every 1-2 hours between 08:00 and 22:00) to enter their current pain score by playing a tune and flashing its LED lights. The pain score is entered by pressing one of the 11 buttons numbered from 0 (no pain) to 10 (worst pain imaginable) which uses the well validated Numerical Rating Scale [O3]. The timestamped data is immediately transmitted via the hospital wifi network to a server along with the patient’s hospital record number. This data can then be presented to clinicians on a dashboard or longer term data over multiple patients can be extracted for research purposes. There is a current project to send the data directly into the observations on the patient’s electronic patient record.

Time Saving, Accuracy, Frequency
For in-patients on a hospital ward, nursing staff will regularly take observations from patients, including their pain level. Due to reduced staffing levels, emergencies or other operational priorities, some of these observations may often be missed. Nurses may also arrive for observations when the patient is asleep and either record nothing, or in some cases to record zero pain. When we compared pain levels which patients reported to nurses with pain levels they self-logged either just before or just after being asked, we found that patients recorded on average one point lower when self-logging when compared to answering the nurse [O2]. This suggests that patients could be giving more accurate (lower) answers when they have time to reflect or that they wish to appear more brave when answering a nurse. We also found that patients who self-logged provided more frequent data than those who only reported orally to a nurse. An additional benefit of painpad is the nurse time savings: with a target of asking every patient on the ward every 2 hours, this amounts to over an hour of nursing time saved per day per ward.

Deployments in Multiple Locations
Painpad has been used by hundreds of patients in the Orthopaedic surgery recovery wards in Milton Keynes University Hospital (MKUH) since 2016. In 2021 it was added to the maternity wards to monitor women who have had a caesarean section. Before the Covid-19 pandemic it was used in the surgical recovery ward in MKUH as well as the orthopaedic ward of the Circle Hospital in Reading. With the 2021 easing of restrictions trials will be beginning in other hospitals.

Future Work and Other PROMs
The EPSRC-funded projects resulting from the Painpad work have begun using tangible devices and apps to help older adults log and manage mood, including the use of a mantlepiece-sized wooden clock [O4]. Other versions of the painpad are also being developed with a display screen and alternative user interfaces, such as a slider or rotary dial, are being developed to allow patient logging of arbitrary data in other categories.


O1. Kelly, R., Jones, S., Price, B., Katz, D., McCormick, C. and Pearce, O. (2021) ‘Measuring Daily Compliance With Physical Activity Tracking in Ambulatory Surgery Patients: Comparative Analysis of Five Compliance Criteria’, JMIR mHealth and uHealth, vol. 9, no. 1, p. e22846 [Online]. DOI: 10.2196/22846.

O2. Price, B. A., Kelly, R., Mehta, V., McCormick, C., Ahmed, H. and Pearce, O. (2018) ‘Feel My Pain: Design and Evaluation of Painpad, a Tangible Device for Supporting Inpatient Self-Logging of Pain’, Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems – CHI ’18, Montreal QC, Canada, ACM Press, pp. 1–13 [Online]. DOI: 10.1145/3173574.3173743

O3. Farrar, J. T., Young, J. P., LaMoreaux, L., Werth, J. L. and Poole, R. M. (2001) ‘Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale’, Pain, vol. 94, no. 2, pp. 149–158.

O4. Gooch, D., Mehta, V., Price, B., McCormick, C., Bandara, A., Bennaceur, A., Bennasar, M., Stuart, A., Clare, L., Levine, M., Cohen, J. and Nuseibeh, B. (2020) ‘How are you feeling?: Using Tangibles to Log the Emotions of Older Adults’, Proceedings of the Fourteenth International Conference on Tangible, Embedded, and Embodied Interaction, Sydney NSW Australia, ACM, pp. 31–43 [Online]. DOI: 10.1145/3374920.3374922


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