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Patients who undergo primary Total Knee Replacement surgery (TKR) are often discharged within 1-3 days after surgery. With this relatively short length of hospital stay, a patient’s self-management is a crucial factor in optimizing the outcome of their treatment. In the case of TKR, self-management primarily involves adequate pain management, followed by physiotherapy exercises and daily self-care activities. Patients are educated on all these topics by hospital staff upon discharge from the hospital but often struggle to comprehend this information due to its quantity, complexity, and the passive mode of communication used to convey it.
This study primarily aims to determine whether actively educating TKR patients with timely, day-to-day postoperative care information through an app could lead to a decrease in their level of pain compared to those who only receive standard information about their recovery through the app. In addition, physical functioning, quality of life, ability to perform physiotherapy exercises and daily self-care activities, satisfaction with information, perceived involvement by the hospital, and health care consumption were also assessed.
A multicenter randomized controlled trial was performed in five Dutch hospitals. In total, 213 patients who had undergone elective, primary, unilateral TKR participated. All patients had access to an app for their smartphone and tablet to guide them after discharge. The intervention group could unlock day-to-day information by entering a personal code. The control group only received weekly, basic information. Primary (level of pain) and secondary outcomes (physical functioning, quality of life, ability to perform physiotherapy exercises and activities of daily self-care, satisfaction with information, perceived involvement by the hospital, and health care consumption) were measured using self-reported online questionnaires. All outcomes were measured weekly in the four weeks after discharge, except for physical functioning and quality of life, which were measured at baseline and at four weeks after discharge. Data was analyzed using Student
In total, 114 patients were enrolled in the intervention group (IG) and 99 in the control group (CG). Four weeks after discharge, patients in the IG performed significantly better than patients in the CG on all dimensions of pain: pain at rest (mean 3.45 vs mean 4.59;
In the four weeks following TKR, the active and day-to-day education of patients via the app significantly decreased their level of pain and improved their physical functioning, quality of life, ability to perform physiotherapy exercises and activities of daily self-care, satisfaction with information, perceived involvement by the hospital, and health care consumption compared to standard patient education. Given the rising number of TKR patients and the increased emphasis on self-management, we suggest using an app with timely postoperative care education as a standard part of care.
Netherlands Trial Register NTR7182; https://www.trialregister.nl/trial/6992
Osteoarthritis of the knee is one of the leading causes of disability among adults aged 65 years old and over [
In the last decade, TKR fast-track (or enhanced recovery) pathways have been implemented in many hospitals. These pathways imply a combination of patient education, multimodal analgesia, early mobilization, fluid management and nutrition optimization [
Because of the shortened length of stay, patients’ self-management has become a crucial factor in optimizing their health outcomes. According to the World Health Organization, postoperative self-management is the ability of individuals, families, and communities to cope with illness, with or without the support of a health care provider [
Patients often struggle to comprehend this information due to its quantity, complexity, and the passive mode of communication used to convey it [
Electronic health (eHealth) or mobile health (mHealth) offer a potentially powerful means for active patient education and behavioral change reinforcement [
The aim of this randomized controlled trial was to investigate the effect of an interactive app on patients’ level of pain, physical functioning, quality of life, satisfaction, and health care consumption in the first four weeks of recovery after TKR. We hypothesized that, compared to standard practices of patient education, providing patients with timely, day-to-day information via an app would have a positive effect on all outcomes.
The primary outcome of the study was patients’ level of pain during the first four weeks after discharge. The secondary outcomes of the study were physical functioning, quality of life, patients’ ability to perform physiotherapy exercises and daily self-care activities, satisfaction with the information provided, perceived level of postoperative involvement by the hospital, and health care consumption. All these outcomes were measured by means of self-reported, online questionnaires.
A total of five Dutch hospitals (four nonacademic teaching hospitals and one general hospital) participated in the study. Between May and December 2018, patients scheduled for elective, primary, unilateral TKR were invited to participate in a surgeon-blinded, randomized controlled trial. The study focused on the four-week period following discharge from the hospital and assessed the effectiveness of an interactive app compared to the standard of care in a parallel group design with equal allocation ratio. No changes were made to the design after the study was commenced. We followed the Consolidated Standards of Reporting Trials (CONSORT) guidelines and the CONSORT EHEALTH Checklist [
Consent was gained via hospital staff who contacted patients by phone to ask them to consider participation in the study about two weeks prior to their TKR. Patients willing to participate received an email with all the necessary study information required for informed consent. Patients were offered at least two days to reflect on the information. In case of any questions, patients could contact the local research coordinator by phone or by email. Patients gave consent by signing an online informed consent form. There were no indicators of substantial risk as a function of participating in this study. The study was registered at the Netherlands Trial Registry (NTR), with the reference number 6992. The study was approved by the Institutional Review Board of the Maxima Medical Centre (Eindhoven, The Netherlands) with the reference number N17.158.
Patients scheduled for elective, primary, unilateral TKR and aged 40 years and above were eligible for inclusion. Additionally, participants were required to be fluent in Dutch and in the possession of an email address and smartphone or tablet.
The Patient Journey App (Interactive Studios, Rosmalen, The Netherlands) was used as the intervention to provide information to both patient groups. All patients had access to the app to guide them after discharge. The control group only received basic information about the recovery process about two times per week. The intervention group could unlock day-to-day information by entering a personal code. Participants in the intervention group received this personal code by email after completing the baseline questionnaire.
All patients in the intervention group received the same information via the app. However, aligning the timing of the information to the individual patient’s phase of recovery gave it a personalized character. Patient’s date of discharge was used to assure the timing of the information was correct. Push notifications were used to actively alert patients about information being available. The timing of the push notifications was configured per information item (eg, information about pain medication was available 1 day after discharge at 11 am and information about physiotherapy exercises was available 2 days after discharge at 2 pm).
The text, photos, and videos that patients in the intervention group received were developed specifically for this trial and composed and based upon interviews with orthopedic surgeons, physician assistants, nurses, and physiotherapists from participating hospitals. Furthermore, electronic health records of 50 patients who had previously undergone TKR were checked to determine for what reasons they had contacted the hospital. Based on this information, an interactive timeline was developed (
Examples of the interactive app used as an intervention, translated from Dutch (language used in the study) to English. From left to right: the welcoming of patients to the app, video and text information about medication usage, an invitation to send a photo of the wound (in case of fever, increased levels of pain or wound leakage) and a patient-reported pain score progress tracker.
Information in the app was tailored for each hospital and based on existing protocols. During the 28-day period after discharge, every patient in the intervention group received over 30 notifications with supporting information, related to topics such as pain, physiotherapy exercises, wound care, and daily self-care activities (see
As the primary outcome, the patients’ ability to manage their pain was assessed in the four weeks following discharge from the hospital. As secondary outcomes, we assessed patients’ physical functioning and quality of life at baseline and four weeks after discharge. Additionally, patients’ ability to perform physiotherapy exercises and daily self-care activities, satisfaction with the information provided, perceived level of postoperative involvement by the hospital, and health care consumption were assessed weekly during the four weeks following discharge (
Overview of used questionnaires per outcome.
Outcome | Questionnaire |
Level of paina | Three questions concerning pain while at rest, during activity and during the night. NRSb scores were used to measure the outcome, ranging from 0 (no pain at all) to 10 (worst pain imaginable). |
Physical functioninga | The Knee injury and Osteoarthritis Outcome Score short form [ |
Quality of lifea | EuroQol 3-level questionnaire, EQ-5D-3. Measuring 5 dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety depression) on a 3-level scale (no problems, some problems, extreme problems). Additionally, a VASc was used to assess patients self-rated health. VAS endpoints range from 0 (Worst imaginable state) to 100 (Best imaginable state) [ |
Physiotherapy exercises |
One question concerning patients’ ability to perform their physiotherapy exercises. NRS score was used to measure the outcome, ranging from 0 (not capable at all) to 10 (perfectly capable). |
Daily self-care activities |
One question concerning patients’ ability to perform their daily self-care activities. NRS score was used to measure the outcome, ranging from 0 (not capable at all) to 10 (perfectly capable). |
Satisfaction with information |
One question concerning patients’ satisfaction about the information they received from the hospital after discharge. NRS score was used to measure the outcome, ranging from 0 (not satisfied at all) to 10 (very much satisfied). |
Perceived involvement |
One question concerning the patient-perceived level of involvement by the hospital postoperatively. NRS score was used to measure the outcome, ranging from 0 (not satisfied at all) to 10 (very much satisfied). |
Health care consumption |
Three dichotomized questions concerning health care consumption at the hospital, the general practitioner and home-care organization. When a patient indicated they had contacted one of these organizations, the outcome was assessed (ie, no action required or follow-up action required). If follow-up was required, that could entail things like a consultation or referral to another organization. |
aThese questionnaires are part of the Patient Reported Outcome Measures guidelines of the Dutch Orthopedic Association (Nederlandse Orthopaedische Vereniging, NOV) for TKR.
bNRS: numeric rating scale.
cVAS: visual analogue scale.
Some questions were developed especially for this study. These questionnaires were checked by surgeons and researchers from participating hospitals (see
Study outcomes were measured five times in total: at baseline and on a weekly basis in the four weeks after discharge (
Overview of outcomes per time point measurement.
Baseline | Follow-up week 1, 2 and 3 | Follow-up week 4 |
Patient characteristics | –a | – |
Physical functioning | – | Physical functioning |
Quality of life | – | Quality of life |
– | Level of pain | Level of pain |
– | Physiotherapy exercises | Physiotherapy exercises |
– | Daily self-care activities | Daily self-care activities |
– | Satisfaction with information | Satisfaction with information |
– | Perceived involvement | Perceived involvement |
– | Health care consumption | Health care consumption |
aNot applicable.
The sample size calculation was based on the 2018 Hardt et al study [
We performed an
Patients were randomized by a computer to either a control or intervention group. Randomization was performed without block or stratification restrictions. After being allocated to one of the groups, patients received an email that included the link to the online informed consent form and the baseline questionnaire.
For our primary analysis we used an intention-to-treat approach including all randomized patients. Normally distributed continuous variables (eg, physical functioning and quality of life) were presented as a mean value with an SD and were statistically compared between the groups using independent Student two-tailed
Patients’ level of education was split into two groups for the purpose of analysis: group 1 (none, elementary school, and secondary [vocational] education) and group 2 (higher secondary education, preuniversity education, and university [of applied science]).
Between May and December 2018, a total of 262 eligible patients were willing to participate in the study. A total of 41 patients (15.6%) withdrew from the study without completing the baseline questionnaire (for reasons unknown). One patient (0.4%) only completed the baseline questionnaire, and an additional two patients (0.8%) did not complete more than two follow-up questionnaires. In total, 114 patients were actively enrolled in the intervention group and 99 patients in the control group. In the intervention group, 93 patients downloaded and used the app (
Baseline characteristics of the study population were largely similar between groups (
Patient flow diagram.
Patient characteristics.
Characteristics | Intervention group (n=114) | Control group (n=99) | |
|
|||
|
Male | 40 (35.1) | 39 (39.4) |
|
Female | 74 (64.9) | 60 (60.6) |
Age (years), mean (SD) | 64.74 (7.57) | 65.63 (7.90) | |
|
|||
|
Group 1 | 52 (46.0) | 47 (47.5) |
|
Group 2 | 61 (54.0) | 52 (52.5) |
|
|||
|
Living alone | 27 (23.7) | 21 (21.2) |
|
Living together | 87 (76.3) | 78 (78.8) |
KOOS PSa, mean (SD) | 45.27 (12.71) | 44.05 (11.10) | |
|
|||
|
EQ-5D-3, mean (SD) | 0.67 (0.21) | 0.65 (0.24) |
|
EQ-5D-3 VASb, mean (SD) | 69.59 (16.38) | 67.42 (19.56) |
aKOOS PS: Knee injury and Osteoarthritis Outcome Score short form.
bVAS: visual analogue scale.
In both the intervention and control group, patients’ levels of pain decreased on all three dimensions of pain during the first four weeks after discharge (
Pain at rest (measured weekly in the first four weeks after discharge, 95% CI).
Pain during activity (measured weekly in the first four weeks after discharge, 95% CI).
Pain at night (measured weekly in the first four weeks after discharge, 95% CI).
Level of pain.
Wk | Pain at rest | Pain during activity | Pain during the night | |||||||||
|
Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | |||
1 | 5.20 | 5.54 | 0.25 |
.46 | 5.86 | 5.65 | –0.20 |
.52 | 5.94 | 6.11 | 0.08 |
.81 |
2 | 4.40 | 5.38 | 0.96 |
.004 | 5.01 | 5.84 | 0.81 |
.01 | 5.23 | 6.01 | 0.80 |
.02 |
3 | 4.11 | 5.05 | 0.88 |
.001 | 4.56 | 5.16 | 0.60 |
.06 | 4.89 | 5.98 | 1.05 |
.002 |
4 | 3.45 | 4.59 | 1.07 |
.001 | 3.99 | 5.08 | 1.11 |
<.001 | 4.18 | 5.21 | 1.02 |
.003 |
Four weeks after discharge, patients in the intervention group reported a significant, 14% decrease in functional limitations (Knee injury and Osteoarthritis Outcome Score short form [KOOS PS]) compared to the control group (
Physical functioning and quality of life.
|
Baseline | Week 4 | |
|
|||
Intervention group, mean (SD) | 45.91 (12.77) | 37.61 (10.17)a | |
Control group, mean (SD) | 43.83 (10.87) | 43.08 (12.96)a | |
|
|||
Intervention group, mean (SD) | 0.66 (0.16) | 0.76 (0.16)a | |
Control group, mean (SD) | 0.65 (0.24) | 0.67 (0.25)a |
a
In both the intervention and control group, the patients’ ability to perform their physiotherapy exercises and daily self-care activities during the first four weeks after discharge increased. Patients in the intervention group performed better on each of the dimensions from the second week onwards (
Ability to perform physiotherapy exercises and activities of daily self-care.
|
Performing physiotherapy exercises | Performing daily self-care activities | ||||||
|
Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | ||
Week 1 | 6.54 | 6.52 | 0.01 |
.98 | 6.73 | 6.30 | –0.45 |
.05 |
Week 2 | 7.28 | 6.53 | –0.72 |
.001 | 7.84 | 6.98 | –0.83 |
<.001 |
Week 3 | 7.35 | 6.93 | –0.41 |
.13 | 8.19 | 7.36 | –0.79 |
.001 |
Week 4 | 7.50 | 6.88 | –0.60 |
.03 | 8.32 | 7.64 | –0.67 |
.004 |
In both the intervention and control group, patients’ satisfaction with the provided information and patients’ perceptions on how the hospital was involved in their recovery process decreased during the first four weeks after discharge. However, patients in the intervention group demonstrated a much smaller decrease over time (
Satisfaction with information and patient-perceived involvement by the hospital.
Week | Satisfaction with the Information | Patient-perceived involvement | ||||||
|
Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | ||
1 | 7.90 | 7.40 | –0.51 |
.07 | 7.52 | 6.87 | –0.74 |
.002 |
2 | 7.96 | 6.61 | –1.38 |
<.001 | 7.75 | 6.14 | –1.64 |
<.001 |
3 | 7.45 | 6.16 | –1.29 |
<.001 | 7.23 | 6.13 | –1.13 |
<.001 |
4 | 7.61 | 5.32 | –2.28 |
<.001 | 7.24 | 4.90 | –2.35 |
<.001 |
Patients in the intervention group had, on average, 1.22 points of contact with the hospital, their general practitioner (GP), or home-care organization compared to 1.62 points of contact in the control group, which is a 33% difference (
Health care consumption.
Hospital | GPa | Home care | Total | Average points of contactb | ||
|
69 | 34 | 25 | 128 | 1.22 | |
|
No action required | 26 | 14 | 6 | 46 | –c |
|
59 | 58 | 28 | 145 | 1.62 | |
|
No action required | 23 | 30 | 12 | 65 | – |
aGP: general practitioner.
bThe average number of contacts with the hospital, GP, or home-care organization (corrected for the time points patients participated in the measurement).
cNot applicable.
In total, patients in the intervention group used the app 2418 times, which was an average of 26 times per patient. Most patients used a smartphone to access the information (75% vs 25% tablet use). The app was primarily used in the first 2 weeks, in which most of the information was offered (26/32 unique information items). Text-only information items related to pain, wound care, and self-care activities were consulted most frequently. Information about the start of the third and fourth week and reminders for anticoagulant usage and participation in study questionnaires were the least consulted information items.
Over the course of the four-week intervention, an average of 25 videos were offered to each patient. In total, these videos were viewed 2950 times, which was an average of 36 views per patient. Video-enriched information items related to physiotherapy exercises, pain, and wound care were viewed most frequently. Videos related to wearing a Thrombo-Embolic Deterrent (TED) hose, reminders for usage of anticoagulation medication, and information on what to expect in the fourth week were the least frequently viewed videos.
All results presented so far were analyzed using the intention-to-treat method. Analysis based on the per protocol method also resulted in the primary outcome (level of pain) being in favor of the intervention group, albeit somewhat more pronounced (
Per protocol analysis for level of pain.
Week | Pain at rest | Pain during activity | Pain during the night | |||||||||
|
Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | Intervention group, mean | Control group, mean | Model estimated difference (95% CI) | |||
1 | 4.98 | 5.54 | 0.54 |
.13 | 5.71 | 5.65 | –0.20 |
.95 | 5.95 | 6.11 | 0.16 |
.65 |
2 | 4.37 | 5.38 | 1.08 |
.002 | 4.94 | 5.84 | 0.99 |
.003 | 5.20 | 6.01 | 0.90 |
.01 |
3 | 4.05 | 5.05 | 1.01 |
.001 | 4.65 | 5.16 | 0.63 |
.06 | 4.91 | 5.98 | 1.09 |
.002 |
4 | 3.31 | 4.59 | 1.26 |
<.001 | 3.83 | 5.08 | 1.34 |
<.001 | 4.04 | 5.21 | 1.18 |
.001 |
The results of our study demonstrate the effectiveness of using an app to actively educate patients on a day-to-day basis in the first four weeks of their recovery after TKR. Regarding the primary outcome, patients in the intervention group experienced a lower level of pain while at rest, during activity and at night. Furthermore, the app had a positive effect on physical functioning, quality of life, performing physiotherapy exercises and activities of daily self-care, satisfaction with the information, how the hospital was involved in the recovery process, and health care consumption. Finally, the intervention resulted in a trend towards less health care consumption.
To our knowledge, our study is the first to assess the effectiveness of an app to improve TKR patients’ self-management during the first four weeks of their recovery. In 2014, a Cochrane review on self-management programs for osteoarthritis showed that these programs (mainly including face-to-face and by-phone educational interventions) did not substantially improve self-management skills, pain, symptoms, physical functioning, or quality of life [
With regards to economic benefits, using the app resulted in a decrease in health care consumption within the intervention group. This is in line with a 2017 review on the economic evidence for mobile health interventions, in which apps are reported to be an ideal platform for behavioral change in patients because of their popularity, connectivity, and increased sophistication when compared to text message or telephone follow-up [
A major strength of our study was the holistic approach to the early-phase recovery of TKR patients, combining insights from orthopedic surgeons, physiotherapists, and (specialized) nurses. In addition, historical data on TKR health care consumption was used to form an interactive timeline to guide patients during their recovery. Using push notifications to actively alert patients about newly available information resulted in an average use of the app of 26 times per patient. Additionally, the usage of short, one subject only videos has proven to be of added value, as patients watched many of the 25 available videos multiple times. This was especially the case with videos related to pain, wound care, and physiotherapy exercises, demonstrating patients’ needs for this type of information.
A limitation of our study is the number of patients in the intervention group that did download and use the app. Out of the 114 possible app users, 93 patients downloaded the app (82%). This demonstrates the necessity of assessing a patient’s digital health literacy and supporting them during the initial usage of interventions like these. Nevertheless, a per protocol analysis showed similar results. Another limitation could be the usage of self-developed questions which might introduce a risk of bias. To minimize this, questions were developed together with health care providers, were screened for readability by a specialized organization and were evaluated by several patients. Finally, we did not consider direct patient feedback when developing the content for the app but instead based it solely on the knowledge and experience of hospital staffs. In future research, patients should have a more prominent role to play in the development and evaluation of the app’s (patient-specific) content, the desired timing of notifications, and the preferred mode of information to further optimize outcomes. In addition, future research could focus on the generalizability of interventions like these in other treatments, as well as their cost-effectiveness.
In conclusion, we found that, in comparison with standard patient education, the active education and coaching of patients on a day-to-day basis via the app in the four weeks after TKR resulted in a significant decrease in patients’ levels of pain. Additionally, there was a significant improvement in patients’ physical functioning, quality of life, their ability to perform physiotherapy exercises and activities of daily self-care, their satisfaction with the information, their perceived involvement by the hospital, and their health care consumption. Given the rising number of TKR patients and the increased emphasis on self-management, we suggest using an app with timely postoperative care education as a standard part of care.
Overview of information offered to patients in the intervention group.
Self-developed questions for the study.
Consort eHealth checklist.
analysis of variance
Consolidated Standards of Reporting Trials
electronic health
general practitioner
mobile health
Numeric Rating Scale
Thrombo-Embolic Deterrent
total knee replacement
The authors would like to thank all the participating hospitals, their medical professionals, research coordinators, and research assistants for their contribution to the success of this study. Furthermore, they would like to thank the team of Interactive Studios for creating the app and Sam Credgington for language editing. Finally, they would like to thank all patients who were willing to participate in the study.
TT conceived the study and designed the trial, with the help of LJ, WW, RK and OLH. TT, WW, BZ, and BT supervised the data collection. TT managed the data. TT, LJ, WW and GH provided statistical analysis. OLH, WJM, DD, AP, and JWS provided the content used on the patients’ timeline. TT drafted the manuscript. All authors contributed to its revision.
The principal investigator, Thomas Timmers, is one of the cofounders of Interactive Studios. Interactive Studios is the company that developed the app used in this study. Interactive Studios offered the app used in this study free of charge.