Introduction

Knee osteoarthritis (KOA) is a prevalent musculoskeletal disorder that ranks among the primary contributors to disability [,]. Possible long-term ramifications encompass diminished levels of physical activity (PA), the development of body dysmorphic disorder, compromised sleep patterns, depressive symptoms, and the onset of disability [,]. In recent times, there has been a notable shift in the approach to treating KOA, with a greater emphasis on nonpharmacologic interventions. This change is supported by evidence indicating that nonpharmacologic treatments are more effective in delivering sustained symptom alleviation and in delaying or even preventing functional deterioration [,]. The primary nonpharmacological interventions for KOA include educational programs, PA interventions, and weight management strategies []. Patient initiation and adherence to these treatments are essential factors for achieving effective symptom control []. Traditional nonpharmacological interventions, however, require professional guidance to achieve the desired results, which is associated with high costs and unequal health care resources [].

Digital health interventions have the potential to offer widespread, cost-effective, readily available, and easily expandable patient education and self-management interventions for individuals with KOA [-]. Several research investigations have been carried out to substantiate their efficacy in rehabilitating musculoskeletal problems. For instance, digital health interventions have been found to be successful in decreasing pain, improving functionality, and promoting the self-management of musculoskeletal pain syndromes [,]. Significant increases in adherence have also been observed throughout the mid-term follow-up []. These systematic evaluations have focused on summarizing various techniques for digital health or intervention effectiveness in relation to health outcomes [,]. However, digital interventions do not always provide desirable outcomes. Providing guidance on the ideal dosage required to achieve significant benefits or disclosing the elements of effective digital health treatments is challenging owing to the variations in interventions and the insufficient information in interventions []. In recent years, it has been discovered that theory-driven interventions can help organize the content of digital interventions, resulting in improved health outcomes [-].

A growing number of studies have used the behavioral psychology theoretical framework in digital format []. Compared to generic digital interventions, behavioral therapy-based digital interventions are significantly more effective at relieving pain, improving physical dysfunction, and increasing self-efficacy in patients with KOA [,]. Physiotherapists use scalable interventions along with some digital tools to enhance treatment adherence [,]. The concept of behavioral therapy (BT) incorporates various therapeutic approaches, including behavioral change techniques (BCTs), dialectical behavioral therapy (DBT), and cognitive behavioral therapy (CBT). It has been used to aid complex intervention designs that include facilitating the adoption of behavior change, promoting behavioral compliance, sustaining behavioral change, and preventing behavioral relapse []. Previous studies have employed BCTs in combination with digital interventions among individuals with musculoskeletal pain []. These studies have reported the efficacy of such interventions in facilitating the transition of patients from a sedentary lifestyle to an active one [,,]. Multiple studies have demonstrated that the integration of CBT with standard care yielded noteworthy outcomes in the management of KOA. Specifically, the implementation of CBT interventions resulted in a considerable reduction in pain levels and an improvement in insomnia symptoms when compared to the utilization of standard care alone, as indicated by previous investigations [,].

Currently, there are evaluations investigating the rehabilitative impacts of digitalization in KOA and highlighting the significance of behavioral theory in some applications []. Nevertheless, there is a shortage of thorough exposition of the behavioral theory in digital applications, as well as an absence of an assessment of the suitability of these applications from the patient’s point of view. Thus, this review offers a methodical and thorough examination of digital applications rooted in behavioral therapy. It shifts the focus of digital applications from mere practical usability to providing support for behavioral change theories. Additionally, it meticulously analyzes the functional reasoning behind various products, thereby serving as a comprehensive guide for designing future digital interventions. Hence, the objectives of this review are to (1) provide a concise overview of the existing landscape of digital behavioral therapy applications for individuals diagnosed with KOA and examine the potential of digital applications in augmenting the rehabilitation process for KOA patients, and (2) present a comprehensive analysis of the underlying psychological theories, fundamental mechanisms, design methodologies, typical attributes, efficacy of treatment outcomes, and patient preferences pertaining to this particular mode of recovery intervention.

MethodsRegistration

This review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO; registration number: CRD42023430716). Furthermore, the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines have been applied () [].

Search Strategy

Literature searches were conducted in 5 databases: Web of Science, Embase, Science Direct, Ovid, and PubMed. The selection of these databases was based on their provision of comprehensive access to full-text journals and conference proceedings pertaining to prominent conferences and meetings focused on digital technology and medicine.

To locate relevant articles, we conducted a search by filtering papers based on 3 primary categories of MeSH (Medical Subject Headings) terms: “Knee Osteoarthritis,” “Behavioral Therapies,” and “Digitization.” According to MeSH terminology, “Behavioral Therapy” is divided into “Behavioral Therapy,” “Cognitive Behavioral Therapy,” and “Dialectical Behavioral Therapy.” In this review, in order to understand the categorization of all behavioral therapies, we collected information on the subcategories of these 3 categories related to behavior. In relation to the subject of “digital” content, we gathered relevant material from the report by Safari et al [] on digital literature, encompassing topics, such as “Telehealth,” “Email,” “Smartphone,” “Computer Systems,” “Digital Technologies,” and “Mobile Applications,” and other forms of digitization. illustrates sample search strategies used for the PubMed digital library. The article titles, keywords, and abstracts were searched. Similar search strategies were applied to the remaining 3 databases. Relevant articles published between January 2013 and July 2023 were gathered. We included journal papers and peer-reviewed conference proceedings. Only articles written in English were considered.

Table 1. Literature search strategy.MeSHaBoolean logic search stringsKnee Osteoarthritis“Knee Osteoarthritides” OR “Knee Osteoarthritis” OR “Osteoarthritis of Knee” OR “Osteoarthritis of the Knee”Behavior Therapy“Behavior Therapies” OR “Behavior Treatment” OR “Conditioning Therapy” OR “Conditioning Therapies” OR “Behavior Change Techniques” OR “Behavior Change Technique” OR “Behavior Modification” OR “Behavior Modifications” OR “Dialectical Behavior Therapies” OR “Cognitive Behavioral Therapies” OR “Cognitive Therapy” OR “Cognitive Behavior Therapy” OR “Cognitive Psychotherapy” OR “Cognition Therapy” OR “Cognitive Behavior Therapies” OR “Cognitive Behavior Therapy”Digitization“Telemedicine” OR “Mobile Health” OR “Telehealth” OR “ehealth” OR “mhealth” OR “Email” OR “E-mail” OR “Mobile” OR “Smartphone” OR “smart-phone” OR “smart telephone” OR “Tablet” OR “cell” OR “hand-held” OR “Cell Phone” OR “handheld” OR “Remote Consultation” OR “Teleradiology” OR “Telenursing” OR “Computer Systems” OR “Computer-Assisted Instruction” OR “Internet” OR “web” OR “computer” OR “Digital Technologies” OR “APP” OR “Social Media” OR “Internet-Based Intervention” OR “Mobile Application” OR “Mobile App” OR “Smartphone App” OR “Portable Software Application”

aMeSH: Medical Subject Headings.

Eligibility Criteria

The authors DZ and JZ were assisted in the literature search by an experienced librarian well versed in medical database searching. This literature review was guided by the question of how behavioral therapies can be integrated with digital applications in the rehabilitation of patients with KOA. On this basis, we anticipated that this review would (1) generalize and summarize the digital applications used in behavioral therapy, and (2) describe the overall research status and research trends of these digital applications.

Inclusion Criteria

The inclusion criteria were as follows: (1) adult participants (age ≥18 years) with KOA diagnosed by self-reported symptoms or imaging; (2) patients had access to digital applications; (3) any form of intervention or treatment based on the inclusion of at least one behavioral treatment was delivered through any digital application (eg, website or app) within any time frame; and (4) the described interventions were compared to waiting list control (no intervention) or alternative (standard) delivery modalities (eg, face-to-face approaches, classroom-based approaches, and printed materials or handouts), nondigital self-management interventions, and noninteractive digital interventions (eg, web pages with flat copies).

Exclusion Criteria

The exclusion criteria were as follows: (1) patients with KOA were not included; (2) nondigital interventions were assessed; (3) behavioral therapies were not included; (4) research protocols, reviews, conceptual articles, case studies or discussion papers, and conference abstracts; (5) market research; (6) digitization was not designed for the recovery process; (7) text was not written in English; and (8) duplicate reports of the same study from different sources.

Data Extraction

Data relevant to the purpose of the study were extracted independently by the authors MW, WZ, and BC, and any misunderstandings and disagreements were resolved through negotiation. Extracted data included study context details, study population, and digital application details. In more detail, the template included the following categories: (1) basic information (author, year, origin, study population, sample size, presence of a physiotherapy intervention, and duration of the intervention); (2) digital application details (digitalization of behavioral therapy, interactive device function, study outcomes, and application deficiencies); and (3) type of study (randomized controlled trial, cohort experiment, experimental protocol, and qualitative study).

Quality Assessment

The Mixed Methods Assessment Tool (MMAT) was used to evaluate the methodological quality of the included studies []. This tool was initially created in 2006 through a comprehensive analysis of systematic evaluations that integrated qualitative and quantitative evidence. In 2018, a revised version of the MMAT was developed by assessing its usefulness, reviewing key assessment tools in the literature, and conducting a modified e-Delphi study involving methodology experts to determine the essential criteria (). The MMAT evaluates the caliber of research employing qualitative, quantitative, and mixed approaches. The primary emphasis is on methodological standards, which encompass 5 fundamental quality criteria for 5 distinct study designs: (1) qualitative, (2) randomized controlled, (3) nonrandomized, (4) quantitative descriptive, and (5) mixed methods.

ResultsOverview

provides a summary of the outcomes at various phases of article selection. The search results of the databases are provided in . Based on the search strategy, 2975 articles were found initially, and 2507 articles remained after title and abstract screening and removal of duplicates. Next, full-text articles were chosen based on the inclusion and exclusion criteria. We included a total of 131 articles explicitly related to digital behavioral therapy for KOA. Moreover, 4 articles were identified following a manual search of the references for articles that were cited. Final consideration was given to 36 articles for systematic evaluation ().

‎Figure 1. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flowchart. KOA: knee osteoarthritis. Table 2. Information on the included studies.AuthorYearCountryPopulationSample sizePhysiotherapistDurationDigital formsExperimentQualityBossen et al []2013NetherlandsKOAa/HOAb20Yes6-12 weeksInternet platform + SMS text message/telephoneNonrandomized pilot study4Rini et al []2016United StatesOAc113No9-11 weeksApp + “virtual coaching”Randomized controlled trial5Pearson et al []2016United KingdomKOA/HOA200No—dInternet websiteMixed methods research2Bennell et al []2017AustraliaKOA168Yes24 weeksInternet platform + SMS text message/telephoneRandomized clinical trial5Bennell et al []2017AustraliaKOA148Yes24 weeksInternet platform + SMS text message/telephoneRandomized clinical trial5Li et al []2017CanadaKOA34Yes8 weeks Electronic equipment + telephoneRandomized controlled trial4Lawford et al []2018AustraliaKOA148Yes12-36 weeksPainCOACH software + emailRandomized controlled trial5Button et al []2018United KingdomKOA49Yes12 weeksOnline courseQualitative research4Mecklenburg et al []2018United StatesKOA162Yes12 weeksHinge Health app + wearableRandomized controlled trial5Kline et al []2019United StatesTKRe100Yes—Online course + wearableRandomized controlled trial protocolN/AfNelligan et al []2019AustraliaKOA12No24 weeksSMS text message application + messaging interactionsQualitative research5Pelle et al []2019NetherlandsKOA/HOA427No12-24 weeksBart appRandomized controlled trial5Bailey et al []2020United StatesMDg10,264Yes9 weeksHinge Health app + wearable motion sensorsCohort study4Baker et al []2020United StatesKOA104Yes2 yearsTeleconferencing (remote software)Cohort study4Bennell et al []2020AustraliaKOA/obesity12No24 weeksSMS text message application + messaging interactionsRandomized controlled trial5Fitzgibbon et al []2020United StatesOA203Yes8 weeksF&S! and F&S! Plus + telephoneComparative effectiveness test4Hinman et al []2020AustraliaKOA165Yes24 weeksInternet website + SMS text message/telephoneRandomized controlled trial5Hinman et al []2020AustraliaKOA394Yes12 weeksInternet website + video consultingRandomized controlled trial protocolN/ALi et al []2020CanadaKOA51Yes12 weeksElectronic device + telephone/mailRandomized controlled trial4Nelligan et al []2020AustraliaKOA16Yes—Internet website + SMS text message/telephoneQualitative research2Dunphy et al []2021United KingdomOA59Yes12 weeksInternet websiteTwo-arm parallel randomized controlled trial5Lindberg et al []2021NorwayOA282Yes12 weeksiCBT application + telephoneRandomized controlled trial protocolN/ANelligan et al []2021AustraliaKOA206Yes24 weeksInternet website + SMS text message/telephoneRandomized controlled trial5Pelle et al []2021NetherlandsKOA/HOA214No26 weeksBart appRandomized controlled trial4Rognsvåg et al []2021United KingdomKOA/TKR4Yes—iCBT application + telephoneQualitative research3Bennell et al []2022AustraliaKOA88Yes24 weeksWebsite + remote softwareRandomized controlled trial protocolN/AGroves-Williams et al []2022ScotlandKOA90No12-36 weeksInternet website + SMS text message/telephoneRandomized controlled trial protocolN/AHinman et al []2022AustraliaKOA182Yes14 weeksApp + SMS text messageRandomized controlled trial protocolN/AÖstlind et al []2022SwedenKOA/HOA20Yes12 weeksApp + electronic deviceQualitative research4Östlind et al []2022SwedenKOA/HOA160Yes12 weeksApp+ electronic deviceRandomized controlled trial3Whittaker et al []2022CanadaOA30Yes4 weeksVideo conferencing + wearable + appRandomized trial4Godziuk et al []2023CanadaKOA53Yes12 weeksWebsite + emailCohort study3Lorbeer et al []2023GermanyKOA241Yes1 yearTeleconferencing (remote software)Randomized controlled trial4Scheer et al []2023United StatesMD4051Yes12 weeksApp + electronic deviceCohort study4Truong et al []2023CanadaOA16No—Video conferencing + wearable + appQualitative research5Weber et al []2023GermanyKOA/HOA330Yes3 weekse-Exercise + online physiotherapyRandomized controlled trial protocolN/A

aKOA: knee osteoarthritis.

bHOA: hip osteoarthritis.

cOA: osteoarthritis.

dData not available.

eTKR: total knee replacement.

fN/A: not applicable.

gMD: musculoskeletal disorder.

Methodological Quality

Among the included studies, 12 met 100% of the quality assessment criteria, 15 fulfilled 60%-80% of the quality assessment criteria, and 2 met 40% of the quality assessment criteria ( [,,,-]). The remaining 7 studies could not be evaluated for their quality owing to the absence of results. Nevertheless, the application description portion involved in the studies was highly valuable for analysis.

Digitalization of Behavioral TherapyBehavior Change Therapy

The majority of digital applications for KOA rehabilitation are based on BCTs. BCTs (achieving objectives, setting goals, restructuring beliefs, and inducing acceptance) are applicable to addressing the central issues of initiating and maintaining PA []. The primary categories of BCTs used in the reviewed studies were based on the V1 Taxonomy of Behavior Change by Michie et al [], which was devised by behavior change researchers []. The taxonomy comprises 93 distinct BCTs organized into 16 hierarchical structures and has been extensively used in the literature on behavior change (): (1) goals and planning; (2) feedback and monitoring; (3) social support; (4) shaping knowledge; (5) natural consequences; (6) behavioral comparisons; (7) associations; (8) repetition and substitution; (9) outcome comparisons; (10) rewards and threats; (11) regulation; (12) presuppositions; (13) identity; (14) intended consequences; (15) self-confidence; and (16) implicit learning.

Table 3. Behavioral change techniques in digital applications.Cluster label and component behavioral change techniquesReferences1: Goals and planning

1.1: Goal setting (behavior)[,-,-,-,,,,,]
1.2: Problem solving/coping planning[,,,,]
1.4: Action planning[,,-,,,,,,,]
1.5: Review of behavior goal(s)[,,,,,,]
1.7: Review of outcome goal(s)[,,,]2: Feedback and monitoring

2.2: Feedback on behavior[,,,]
2.3: Self-monitoring of behavior[,,,,,,,,-,]
2.4: Self-monitoring of the outcome of behavior[,,,]
2.6: Biofeedback[,-,,,,,-,,]
2.7: Feedback on behavioral outcomes[,]3: Social support

3.2: Social support (practical)[,]
3.3: Social support (emotional)[,]4: Shaping knowledge

4.1: Instructions on how to perform a behavior [,,-,-,-,,,]
4.2: Antecedents[,,]5: Natural consequences

5.1: Health consequences[,,,,,,]
5.4: Self-assessment of affective consequences[,]
5.5: Anticipated regret[,,,]6: Comparison of behavior 

6.1: Modeling of behavior[,]
6.2: Social comparison[,,]
6.3: Information about others’ approval[,,-,,,,,-]7: Associations

7.1: Prompts/cues[,,,,,,,,,,,,,,]8: Repetition and substitution

8.1: Behavioral rehearsal/practice[,,,,,-,,,,,,,,-]
8.6: Generalization of a target behavior[,,]
8.7: Graded tasks[,,,,]10: Reward and threat

10.3: Nonspecific reward[,]11: Regulation 

11.2: Regulate negative emotions[,,,,,,]12: Antecedents 

12.4: Distraction[]13: Identity 

13.1: Identification of self as a role model[]15: Self-belief 

15.1: Verbal persuasion to boost self-efficacy[,,]16: Covert learning

16.2: Covert conditioningN/Aa
16.3: Vicarious reinforcement[]

aN/A: not applicable.

In 31 studies, objectives and planning were mentioned, including goal setting (behavior), problem solving or coping planning, and reviewing behavioral or outcome goals. Among these factors, goal setting and action planning were shown to be the most prominent components within the area. A total of 26 applications included goal setting, which has a very broad definition in the taxonomy (setting goals defined according to the behavior or outcome to be accomplished) [,-,-,-,,,,,]. Applications created evidence-based, individualized, progressive home exercise plans; promoted increased general PA; and established short-term objectives. Moreover, 16 applications [,,-,,,,,,,] contained action planning in which patients were asked or chose to perform activities until their pain tolerance was attained, based on which the patients prescribed their own individual therapeutic actions. Additionally, 5 applications [,,,,] addressed problem solving and coping strategies encountered during rehabilitation by other individuals or physiotherapists. Furthermore, 9 applications contained a review of behavioral or outcome objectives [,,,,,,,,], encouraging participants to monitor their progress and assisting them in identifying personal barriers and strategies for overcoming them.

A total of 19 investigations included various forms of feedback and monitoring, such as feedback on behavior, self-monitoring of behavior, biofeedback, self-monitoring of behavioral outcomes, and feedback on behavioral outcomes. Feedback was provided on behavior wherein activities or exercises were recorded on performance metrics through a digital application and discussed by the physiotherapist during follow-up [,,,]. Among the included studies, 12 involved self-monitoring for managing exercise reminders and records, viewing progress charts, and setting or modifying exercise objectives [,,,,,,,,-,]. Moreover, 13 studies offered participants a wearable device with additional features, such as the ability to monitor activity intensity and visualize activity performance over time [,-,,,,,-,,]. These features enabled individuals to monitor progress and receive real-time feedback on objective achievement.

A total of 18 studies applied shaping knowledge. They primarily incorporated videos or lectures on osteoarthritis (OA), the effects of PA, self-management, and coping strategies [,,-,-,-,,,]. Three of these studies presented information about antecedents via multiple online physical therapy consultations using video phone services [,,].

A limited subset of digital applications employed social support. The programs offered online platforms where individuals could engage in discussions pertaining to joint pain. Four studies documented the beneficial effects of engaging with social organizational structures on the rehabilitation of individuals with KOA [,,,].

The concept of natural consequences was addressed in 11 investigations [,,,,,-,,,], and it included information regarding health consequences, monitoring of emotional consequences, and anticipated misgivings. At each online meeting, the interventionist provided the patient with information about the benefits and costs of engaging in or refraining from a particular course of action. In addition, reminders regarding obstacles and facilitators were provided beforehand.

Comparison of behavior was addressed in 16 studies [,,,-,,,,-]. It was primarily implemented with behavior evidence, social comparisons, and information about the approbation of others. Three studies on group therapy prompted patients to establish a “buddy” system to change their behavior [,,]. In some cases, a physiotherapist was included to provide the patient with assistance or instrumental social support. Twelve studies referred to information about other people’s perceptions of a person’s behavior and whether others would approve or disapprove of any proposed behavioral change to encourage people to decide to set overall goals [,,-,,,,,-]. For instance, making behavioral decisions was practiced more the following week, along with identifying obstacles to executing the behavior and devising strategies to overcome them.

A total of 16 studies referred to associations, particularly prompts, as reminders for the patient to perform a particular behavior [,,,,,,,,,,,,,,]. The defined frequency, intensity, or duration of the specified behavior, along with a description of at least one context, location, time, and manner, was included. Of those, 12 involved primary distribution by the physiotherapist via short messages or email timed reminders. In addition, 8 studies involved prompts by the application’s included features [,,,,,,,].

Repetition and substitution, which involve behavioral practice or rehearsal, generalization of target behaviors, and grading tasks, were the most common components of the applications. In 27 studies, patients were required to rehearse and repeat KOA exercises [,,,,,-,,,,,,,,-]. Additionally, 1 study described neuromuscular exercises designed to enhance the physical function of the lower extremities, and the targeted behaviors were broken down into daily video bundles sent to patients []. Five studies divided the exercises into varying intensities and progressively increased the difficulty until the desired behaviors were achieved [,,,,]. Individual progress and the patient’s perception of the capacity to exercise without aggravating discomfort were taken into account.

Rewards and threats were mentioned in 2 studies [,]. Mobile health apps were supplemented with motivation-enhancing techniques, such as praise, encouragement, and material rewards, for the achievement of specific goals.

The primary goal of regulation was to reduce negative emotions in patients. Seven studies trained users to recognize negative thoughts and reactions to them by relaxing mood through thoughts, emotions, and behaviors that affect pain [,,,,,,]. One study adhered to the practice by revisiting pleasant imagery and distractions from the previous week []. In addition, 1 study discussed the potential for novel or alternative pain medications in applied implicit learning [].

CBT

Complementary and alternative medicine therapy refers to a deliberate, intentional, and organized form of psychotherapy intervention aimed at improving psychological issues by impacting the beliefs and behaviors of patients [,]. CBT combines techniques to develop more adaptive cognitions and behaviors, such as psychoeducation, cognitive restructuring, relaxation therapy, and guided imagery (eg, to reduce muscle tension and autonomic arousal), as well as positive thinking training, problem-solving, and stress management [,].

Specifically, CBT focuses on reducing pain and distress by altering bodily sensations, catastrophic and contemplative thinking, and maladaptive behaviors, as well as enhancing self-efficacy [,]. Four studies addressed common CBT topics, such as catastrophizing, positive coping methods, and anxiety avoidance, through educational interactive modules and internet courses pertaining to behavior change [,,,]. The remaining 4 studies addressed common barriers to exercise (eg, pain, low confidence, weather, and relapse) and ways to overcome them (eg, increasing confidence through exercise, seeking social support, teaching proper exercise routines and postures, and promoting positive reasoning) in conjunction with programmatic elements of social cognitive theory and goal-setting strategies for exercise behaviors [,,,].

Interactive Device FunctionDigital Presentation Modalities

The emergence of the internet in the health field has drastically altered the medical information available to patients and the manner in which physicians and patients communicate []. A significant number of digital applications involving KOA utilize information and communication technology (ICT) to facilitate behavioral therapy. The included studies covered 5 types of digitization (): (1) app, (2) website, (3) teleconferencing software/remote phone contact, (4) wearable electronic device, and (5) SMS text message/telephone/email.

Table 4. Forms of digital applications.Digital application typeReferencesApp/website + SMS text message/telephone/email[,,,,,,,,-,]App/website[,,,,,,,]Teleconferencing software/remote messaging[,,,,,]Wearable electronic device + SMS text message/telephone/email + app/website[,,,,,,,]Teleconferencing software + wearable electronic device + app/website[,]

Twelve studies adopted the combination of app/website plus SMS text message/telephone/email. Physiotherapists in 2 studies provided verbal and written education or information about OA, benefits of PA or exercise, and strategies to increase adherence [,]. In addition, a progressive individualized home exercise program based on scientific evidence was devised, which included several lower extremity exercises and was accessible through an app or website. In 2 studies, weekly emails containing OA-specific content and resources were sent directly to patients. The emails included (1) nutritional advice; (2) an instructional video on exercise; and (3) a video on positive thinking and advice on self-care, motivation, and stress management [,]. Nine studies supported general health and wellness behavior change through free website support [,,,,,,,,]. To increase patient compliance, physiotherapists conducted regular telephone counseling sessions to determine if the use of optional sessions should be based on participant preference, confidence, and success in achieving the desired behavior change. In 3 other investigations, the aforementioned functions were implemented in their entirety within a single application [,,].

Eight studies used apps or websites for self-management and coping with arthritis pain through exercise [,,,,,,,]. The websites included information on PA or exercise, goal setting, action plans, pacing, medication management, diet, home exercise, understanding pain, pain management, and relaxation modules. One study explained how individuals can input data and view graphical feedback regarding the amount of exercise they have performed, their activity levels, and their mood [].

Five investigations [,,,,] applied teleconferencing software or telemessaging, and 3 programs provided patients with complimentary access to online webinars featuring “expert advice” [,,]. Participants could ask the facilitator queries about nutrition, exercise, or positive thinking. Registered dietitians, registered psychologists, and kinesiologists led the sessions in pairs according to a rotating schedule. Two other studies addressed recommendations for the development of health behavior interventions utilizing only SMS text messaging on mobile phones [,].

Eight studies used the combination of wearable electronic devices plus SMS text message/telephone/email plus app/website to guide participants in setting specific, measurable, achievable, pertinent, and time-bound PA goals [,,,,,,,]. Self-monitoring is typically assessed using commercially available wrist-worn wearable activity trackers (such as Fitbit) or other similar devices. These devices collect measures and communicate them through Bluetooth to a smartphone, tablet, or computer application. Subsequently, the application transmits the data to the Fitbit server. Individuals who possess apprehensions over engaging in PA have the option to communicate their concerns via electronic mail to their physiotherapists.

Two studies [,] employed teleconferencing plus electronic devices plus apps. The program comprised 3 elements: (1) a 1-time knee boot camp where participants worked at home on their exercise therapy and PA goals; (2) weekly personalized in-home exercise therapy, PA, and tracking where participants received a Fitbit Inspire activity tracker; and (3) weekly physiotherapist-guided exercise therapy and activity action plans via videoconference on Zoom, optional group exercise classes, and exercise therapy and PA goal setting. In the TeleHab app, exercise therapy objective completion levels, target rating of perceived effort, and any associated pain were recorded, and Fitbit data were synchronized with the Fitbit online dashboard.

Design Methodology

Although researchers and developers typically validate their digital applications with end users, it is uncommon for relevant studies to include end-user participation in the design phase. Of the 36 studies in our review, 8 (22%) reported end-user participation in the design phase [,,,,,,,], and 6 (75%) of these 8 studies also reported the participation of stakeholders other than end users [,,,,,]. These stakeholders also included caregivers, coaches, physiotherapists, and other individuals who provide care or services to the target population.

Heuristic assessments were used in a study to explore usability of the intervention for patients with KOA. Based on the outcomes of the interviews and heuristic evaluations, the program’s time structure was modified to be more flexible. In the most recent iteration, users had the option of repeating modules and adjusting module difficulty. The strategy also addressed improper website design and placement of multiple icons []. In addition, a study involved 3 patients with KOA who provided feedback on the prototype to inform the final design. Regarding how participants perceived interventions used outside the study setting, the majority suggested that health professionals, particularly general practitioners or physiotherapists, could deliver interventions to enhance or improve care [].

Additional stakeholders were included in the qualitative study analysis. One study referred to experimental websites where patients with KOA and physiotherapists provided feedback on prototypes to inform the final design [,,]. In a separate study, the app was also developed in collaboration with physiotherapists, physicians, and patient representatives. Named members of the project team submitted a list of 30 SMART (Specific, Measurable, Achievable, Relevant, and Time-bound) objectives related to OA treatment [].

Study Outcomes

A total of 23 experimental studies, 7 experimental protocols, and 6 qualitative studies were included in this literature review. The primary outcomes of using digital behavioral therapy for rehabilitation of patients with KOA were (1) pain, (2) symptoms, (3) physical functioning, and (4) PA. Moreover, the secondary outcomes included (1) self-efficacy, (2) usability and user needs, (3) health-related quality of life, (4) satisfaction, (5) negative emotions, (6) quality of sleep, (7) adherence, (8) surgical intent, and (9) understanding of the condition ().

Table 5. Rehabilitation outcomes for patients with knee osteoarthritis.Outcome of the interventionReferencesPain[,,,,,,,,,,,,-,-,]Symptoms[,,,,,,-,]Physical function[,,,,,,,,,,-,,,-,,]Physical activity[,,,,,,,,,,-,-,,,]Self-efficacy[,,,,,,,,-]Usability and user requirements[,,,,,,,,,]Satisfaction[,,,,,,,]Health-related quality of life[,,,,,,-,-,,]Negative emotions[,,,,,,]Quality of sleep[,]Adherence[,,,,,,]Surgical intention[,,]Understanding of the condition[,]

A total of 24 studies that aimed to reduce pain in patients with KOA were ultimately identified in this review [,,,,,,,,,,,,-,-,]. Moreover, 12 studies reported statistically significant decreases in pain [,,,,,,,,,-]. Of the 12 studies that did not demonstrate improvement, 6 involved randomized controlled trial protocols and 2 involved qualitative studies. In the studies that showed improvement, intervention durations ranged from 9 weeks to 9 months, and in those that did not show positive results, intervention durations ranged from 8 weeks to 6 months.

Overall, 21 studies assessed physical dysfunction [,,,,,,,,,,-,,,-,,], and of these, 6 reported statistically significant improvements [,,,,,]. Among the 15 studies that did not demonstrate improvement, 7 were randomized controlled trial protocols and 2 involved qualitative research. In studies that demonstrated improvement, intervention durations ranged from 3 weeks to 9 months, while in studies that demonstrated no improvement, intervention durations ranged from 4 weeks to 4 months.

A total of 12 studies measured PA outcomes [,,,,,,,,,,-,-,], and 5 of them reported statistically significant improvements [,,,,]. Among the 15 studies that did not demonstrate improvement, 6 were randomized controlled trial protocols and 2 involved qualitative research. In studies that demonstrated improvement, intervention durations ranged from 3 weeks to 9 months, while in studies that demonstrated no improvement, intervention durations ranged from 4 weeks to 12 months.

Physical symptoms were assessed in 11 studies [,,,,,,-,], and of these, 4 studies reported statistically significant improvements [,,,]. In studies that demonstrated improvement, the intervention duration was 2 months, while in studies that demonstrated no improvement, intervention durations ranged from 2 to 9 months.

Self-efficacy was examined in 11 studies [,,,,,,,,-], and of these, 3 studies reported statistically significant improvements [,,]. A total of 15 studies reported health-related quality of life [,,,,,,-,-,,], and of these, 3 studies reported statistically significant improvements [,,]. Satisfaction was assessed in 8 studies [,,,,,,,], and of these, 1 study reported significant improvements []. Seven studies reported improvements in self-reported negative affect after the intervention [,,,,,,]. Adherence was evaluated in 7 studies [,,,,,,], and of these, 2 studies reported statistically significant improvements [,]. Sleep quality was assessed in 2 studies [,], and of these, 1 study [] reported significant improvements. Three studies examined surgical intent [,,]; however, none of the studies reported significant changes in patients’ surgical intent. Patients’ understanding of their condition was examined in 2 studies [,]; however, no improvement was identified.

Application Deficiencies

The design recommendations of users and stakeholders for the app were reported at different stages of the final app study design. Two studies identified the negative emotions associated with the app [,]. For instance, Östlind et al [] found that a wearable activity tracker facilitated PA in various ways and increased the awareness of the optimal number of steps to treat OA symptoms. However, not all participants found the wearable activity tracker to be motivating, and in some cases, if they missed a weekly PA, the app’s prompts about PA caused them to feel anxious and frustrated [].

Two studies examined the efficacy of applying various characteristics. For instance, the study by Lindberg et al [] demonstrated the combined efficacy of education, exercise therapy, and internet-based CBT, but was unable to distinguish between these interventions individually. Moreover, Dunphy et al [] suggested that some participants viewed the physiotherapist’s participation as positive, customizing the digital program and monitoring their progre