Globally, approximately 55 million people are living with dementia [1]. Osteoarthritis is experienced by approximately 528 million people worldwide [2] and is associated with a 20% to 25% increase in dementia risk [3,4]. The prevalence of osteoarthritis has been reported in almost half of people living with dementia [5,6]. Both dementia and osteoarthritis are associated with increased pain and depression [7-9] and reduced quality of life (QoL) [8,10]. Comorbid conditions, such as osteoarthritis, depression, and dementia, exacerbate symptoms of a disease; for example, a higher number of comorbidities (ie, multimorbidity) correlates with more severe pain and depression [1].

Depression, anxiety, and reduced QoL are common in dementia [9,11] and osteoarthritis [12], in addition to pain [7]. Furthermore, osteoarthritis has been associated with a 1.2- to 1.5-fold increase in dementia risk [13] and rises to 5.7-fold when experienced with an additional chronic condition [14]. However, most older adults, including people experiencing cognitive decline, are living with comorbid conditions such as osteoarthritis [15,16]. Depression and anxiety are also commonly found as comorbid conditions along with cognitive decline [17] and osteoarthritis, and depression has also been linked with increased dementia risk [18].

Nonpharmacological lifestyle approaches involving physical activity (PA) have been shown to improve health outcomes for 26 different chronic conditions [19], including dementia [20] and osteoarthritis [7]. Osteoarthritis and other chronic conditions are associated with increased dementia risk [20,21], and PA and other nonpharmacological approaches improve health outcomes in older adults while reducing dementia risk [20]. PA interventions improve cognition in people living with dementia [22] as well as reduce dementia risk in older adults [20]. Studies have shown that PA and lifestyle approaches reduce dementia risk [14,20,23] and improve cognition and QoL for people already experiencing cognitive decline [24-26]. Furthermore, nonpharmacological approaches have been shown to be cost-effective [27] and preferable to pharmacological approaches for people living with dementia and their families and care partners [28].

Systematic reviews have shown that PA has a positive effect on cognition [29], depression, and QoL [30]. However, findings are inconsistent regarding the most effective type of PA. Multimodal and mind- and body-focused approaches tend to outperform singular or unimodal approaches [30]. Interventions shown to be effective in reducing pain in osteoarthritis include aerobic and strengthening exercises and multimodal approaches that incorporate lifestyle education specific to osteoarthritis, such as pain coping skills training [31]. Multimodal approaches have been shown to be more effective than unimodal approaches in reducing pain [7] and improving depressive symptoms. PA has positive effects on mental health [32] and improves outcomes for older adults living with anxiety and depression. Meta-analyses have shown that nonpharmacological approaches reduce symptoms of depression in people with cognitive decline [9] and osteoarthritis [7]. Nonpharmacological approaches include care staff education and reminiscence therapy for people living with dementia and multimodal exercise approaches (eg, combined strength, balance, aerobic, and mind-focused approaches such as tai chi and yoga) for people with osteoarthritis.

Despite this evidence, there is a lack of accessible, implementable, and scalable lifestyle programs for people living with comorbid conditions, such as cognitive decline and osteoarthritis. This gap reflects a major opportunity for improving health outcomes and reducing dementia risk. Guidelines for multidisciplinary approaches that include PA have been developed for people living with cognitive decline [33,34], but effective interventions are specifically needed to target people living with comorbidity [15,35] and reduce dementia risk. It is vital to consider associations between conditions and how symptoms may be exacerbated (eg, symptoms of depression resulting from limitations in completing usual daily activities due to osteoarthritis-related pain and cognitive difficulties).

We will pilot the evidence-based Healthy Body and Mind Program (HBMP), which includes PA, nutrition, lifestyle, and behavior change education on health outcomes in people living with cognitive decline and osteoarthritis. The evidence base for development of the program is outlined in Figure 1. The primary aims of this pilot randomized controlled trial (RCT) are to determine (1) the feasibility (ie, recruitment, retention, and adherence) of the HBMP for people living with osteoarthritis and cognitive decline in a community clinic and the University of New South Wales (UNSW) Medicine and Health Lifestyle Clinic, Sydney, Australia, and (2) the acceptability of the program to people living with osteoarthritis and experiencing cognitive decline. The secondary aim is to obtain pilot data on health outcomes in people with osteoarthritis and cognitive decline, following the program when compared to usual care. Health outcomes are QoL, cognition, pain, psychological health (depression, anxiety, and stress), and physical health (weight, waist circumference, blood pressure, cardiorespiratory fitness, strength, mobility, and balance). We hypothesize that individuals who complete the program will have better health outcomes when compared to the baseline and the control groups.

All data will be deidentified and participants will be allocated a unique identification number. Personal identifying information will be stored separately from research data in a password-protected file accessible only to the research team. Deidentified research data will be stored securely for a minimum of 7 years as per institutional requirements, after which it will be destroyed. Only deidentified data will be used in publications and presentations. All participants will provide written informed consent before participation, after reading the participant information sheet and having the opportunity to ask a researcher any questions. Participation is entirely voluntary and participants may withdraw at any time without penalty or impact on their access to services. Participants who withdraw can request that their data be destroyed, provided the data has not yet been deidentified and aggregated. All participants will receive a lifestyle program provided by accredited exercise professionals and psychologists free of charge (valued at approximately US $2000). Participants who additionally take part in the focus group will receive a voucher worth US $50 to compensate for the extra time commitment involved in this component of the study. All electronic data will be stored on password-protected, encrypted devices and secure university servers. Hard copy materials will be stored in locked cabinets in a secure research office. Only named members of the research team will have access to identifiable data. Ethics approval for this study has been obtained from the UNSW Human Research Ethics Committee (HC230506). This is the third version of the protocol and aligns with approved ethics amendments (most recently approved on June 14, 2024; first approval on September 18, 2023). Changes from the first version pertained to the inclusion criteria, where “Montreal Cognitive Assessment (MoCA) [36] score 18-25 indicating mild cognitive impairment or mild dementia” was removed, and the age requirement was reduced to people aged 45 years or older. These changes were made due to recruitment challenges, although they do not change the overall aims of the study. Other amendments included changes to the terminology used in study materials (“dementia,” “cognitive decline,” and “thinking difficulties” to improve recruitment) and updates to the list of staff members. All team members received email correspondence regarding submitted changes and were requested to review amended documentation where appropriate. The clinical trial has been prospectively registered on ClinicalTrials.gov (NCT06070818). This protocol has been prepared in accordance with the SPIRIT (Standard Protocol Items: Recommendations for Intervention Trials) guidelines (Multimedia Appendix 1) [37].

This 12-week pilot RCT of the HBMP with a waitlist control group will use quantitative and qualitative research methodologies. Data collection will comprise the following: (1) clinical observations routinely completed as part of standard care (eg, clinical interviewing, physical assessment, and exercise monitoring), (2) validated patient-reported outcome measures (including QoL, cognition, pain, and psychological health), and (3) focus group or interviews (Table 1). Clinical observations and questionnaires will be completed at baseline (0 wk) and after intervention (12 wk). Initial community and stakeholder engagement has assisted in developing the group program and ensuring it is feasible and acceptable to participants. The study team includes accredited exercise physiologists (AEPs), accredited practicing dietitians, a health psychologist, and research assistants (RAs). All study activities will take place within the UNSW Medicine and Health Lifestyle Community Clinic facilities.

For pilot trials, using a 90% 1-sided CI, it is estimated that a sample size should be at least 9% of that calculated for a fully powered RCT [49]. Given a minimal clinically important difference of 0.5 SD (medium effect size), QoL measured using the Short Form Health Survey-36 [50], α of .05 (with Holm-Šídák correction), and power of 90% (β=.20) for a 2-group comparison, the required sample size would be approximately 85 participants per group (170 total). Accounting for potential dropout or attrition (15%-20%), 102 participants per group (N=204 total) would need to be recruited for a fully powered trial, and 16 participants would be required for a pilot trial. This study aims to recruit 20 participants.

Eligibility criteria will be as follows: (1) aged 45 years or older, (2) living with osteoarthritis diagnosed by a health care professional, (3) living with cognitive concerns or dementia, (4) able to safely undertake study assessments and complete exercise without assistance, and (5) have appropriate medical clearance to take part. Exclusion criteria will be as follows: (1) MoCA score of less than 18; (2) unwilling or unable to provide written informed consent and comply with study requirements; (3) inability to speak and understand English unless a translator is available; and (4) contraindications to exercise in accordance with American College of Sports Medicine (ACSM) guidelines (Multimedia Appendix 2) [51], such as symptomatic hernias, proliferative retinopathy, uncontrolled arrhythmias, or rapidly progressing or terminal illness. Consent will be obtained by the lead researcher (CVB).

A total of 20 participants with osteoarthritis and cognitive decline will be recruited through the UNSW Medicine and Health Lifestyle Clinic, StepUp for Dementia Research, and general practitioner and health district referrals. Study advertisements will also be displayed electronically via online social media platforms (eg, X, formerly known as Twitter [X Corp]; Facebook [Meta Platforms, Inc]; and LinkedIn [LinkedIn Corporation]). Initial contact will be made by potential participants emailing the study investigators through the study email or the StepUp team or by referral from a health professional. A member of the research team will then contact potential participants. Participants will be screened in person, online, or over the telephone to confirm their eligibility. The lead investigator will review participant screening data and confirm participant eligibility before providing the participant information sheet and consent form (Multimedia Appendix 3). If eligible and after written consent has been obtained, potential participants will be invited to an in-person screening visit. Demographic information, chronic disease history, lifestyle behaviors, and medication use will be documented. Potential participants will complete the Adult Pre-Exercise Screening System and Exercise and Sports Science Australia [42] screening questionnaires for exercise-induced symptoms (eg, chest pain and musculoskeletal pain; Multimedia Appendix 4). To ensure safety, only people cleared through the screening will be enrolled and randomized. Once deemed eligible, participants will complete written informed consent, and baseline testing will commence. Participants will be assigned a unique ID number to ensure personal details are not linked to collected data.

Due to ethical considerations where many potential participants may not be aware of cognitive decline, the term “thinking difficulties” will be used throughout study advertisements and participant information sheets. An ethically approved protocol is in place for advising people of their health assessment results (eg, cognition and depression) and referring them to their general practitioner where appropriate. Eligible participants will have mild cognitive impairment; therefore, they will have the capacity to provide informed consent.

Following successful screening, the participant will be allocated a unique ID number using the generated list. The RA who performs the randomization will advise the data collectors of the participants’ IDs by referring to the password-protected spreadsheet of participant names and allocated ID numbers. After completion of baseline testing, participants will be randomly assigned to the intervention (n=10) or waitlist control groups (n=10) using a computer-generated randomization list produced by a researcher external to the study group. In total, 20 participants will complete the program. After completing a 12-week period of usual care, those in the waitlist control group will then complete the 12-week HBMP. A 12-week follow-up will be performed to examine sustainability. Participants are allowed to withdraw from the trial at any time they wish and are assured that doing so would not alter their care or relationship with the university or the community clinic.

The questionnaires will be completed within the UNSW Medicine and Health Lifestyle Clinic facilities. The data captured on Qualtrics and the Cambridge Neuropsychological Test Automated Battery software using a computer or tablet will be exported to Microsoft Excel and SPSS Statistics (IBM Corp) for data analysis and stored on a secure OneDrive (Microsoft Corporation) database hosted by UNSW, Sydney. The data will be entered, checked, and cleaned by 2 members of the research team. Only members of the research team will have access to the data. All recruited participants will be assigned a unique study ID number, ensuring no personal details, such as their names, are stored alongside data.

PA may cause concern in older adults and people living with chronic conditions. Adverse events may occur (eg, a fall), despite the safety protocols we have put in place (eg, AEP or RA closely monitoring participants during exercise in a purposefully designed clinic or laboratory setting with handrails). Throughout the trial and follow-up, adverse events will be documented, and risk will be continually assessed by appropriately trained professionals (ie, AEP). Reported adverse events will include details about the type of event, date, time, and duration; severity (mild to severe); whether it could have been avoided; outcome (solved to fatal); and whether it was related to the study (certainly, probably, possibly, unlikely, or cannot say). The relevant ethics committee and participant’s general practitioner will be informed about any serious event (eg, requiring hospitalization) that takes place during the study. Adverse events will be reported transparently alongside study outcomes. In accordance with the CONSORT (Consolidated Standards of Reporting Trials) statement [48] and similar to other studies [53], data from participants who are suspended from the trial due to an adverse event will be entered into the analysis by their allocated treatment group. The lead researcher will continue to communicate and support the participant and signpost them to relevant support services where appropriate. An independent safety monitoring process has been established (the data safety monitoring board) to oversee participant safety and review this trial. These arrangements have been documented in a safety monitoring plan, reviewed and approved by the human research ethics committee. All research staff involved in this trial have completed training and certification in Good Clinical Practice guidelines.

Feasibility, acceptability, and preliminary efficacy of the program will be analyzed. Feasibility will be examined by assessing group session attendance, quantified as total sessions attended out of a maximum possible and reported as a percentage. Feasibility will be quantified as session compliance with criteria for success, requiring performance of at least 10 minutes of aerobic training and 5 progressive resistance training exercises per session. Participant attendance, exercise programming, and adverse events will be recorded. Reasons for nonattendance will be collected and reported. Adverse events will be recorded, and ongoing monitoring and reporting will be completed in accordance with CONSORT guidelines [48]. Acceptability will be determined by participants’ perspectives and experiences of the program based on final participant feedback (focus groups or interviews). Acceptability will encompass what participants liked most and least about the program and their suggestions for the content and format of the sessions. Preliminary efficacy of the program will involve analysis of health outcomes (QoL, cognition, and psychological health). Quantitative data will be analyzed using SPSS Statistics (version 30.0.0.0, 172), with normality checks and descriptive statistics for frequencies and distributions. Baseline data will be compared between control and intervention groups to ensure there are no significant differences between groups at baseline. Health outcomes will be compared pre- and postprogram completion and between the intervention and control groups using 1-tailed t tests and repeated measures ANOVAs. Statistical significance will be set to P<.05. Effect sizes will be calculated using Cohen d for t tests and ηp² for ANOVAs. Results will be reported comparing the intervention versus the waitlist control group and before versus after the 12-week program. Qualitative data will be analyzed using thematic content analysis [47].

The project findings will be submitted to national and international conference presentations and scientific journal publications. Findings will also be prepared appropriately for other stakeholder groups (eg, lay summaries for people with lived experience of chronic conditions, families, and the public and reports for health care, government, and industry partners). When participants provide consent, they will be invited to indicate whether they would be interested in receiving study findings. Preliminary findings from this project have been presented at national and international conferences (eg, the Australian Dementia Research Forum and the Alzheimer’s Association International Conference). The outcomes will be published in high-quality peer-reviewed scientific journals.

The design of the program was informed by meetings with people living with osteoarthritis and dementia. WY is a study investigator and is a dedicated professional in the dementia and health care community. They currently serve as a living experience associate consultant at HammondCare, are a member of the Alzheimer’s Disease International (ADI) Global Review Panel for Accreditation, the Public Involvement Panel for StepUp for Dementia Research, and the Sleep, Lifestyle, Engagement, and Activity Program (SLEAP). They have been a member of the Dementia Australia Advocacy Program since 2020. In addition, they hold the role of vice chair at Dementia Alliance International and are part of the Forward with Dementia co-design group. Their professional engagement includes participation in numerous international and national conferences, such as the ADI Global Conferences in Krakow and London; the ADI Asia-Pacific Conference in Taiwan; and various Australian conferences, including the International Dementia Conference and Australian Dementia Research Forum. They have also established their own website, awakeningyourpositivity.com, to further share their insights and expertise.

WY is a lead investigator on this project and has been involved in all stages of developing this research. Prestudy consultation identified specific considerations for people living with osteoarthritis and experiencing cognitive decline and highlighted different experiences and expectations of a program such as the HBMP. In summary, feedback included practical considerations, such as transport and accessibility to take part in the program (eg, building and environmental considerations, ease of access, and lighting), the option of having a support person while participating in the program, ensuring the program included multiple components though considering that individuals may differ in how much support they would like to receive from each component (eg, nutritional advice sought by some and considered less important by others), including a social component to the program or considering social factors, and ensuring a tailored approach is adopted to suit participants’ unique needs. We have set up a community lived experience group of 30 people within our clinic who were invited to provide feedback on this study at the beginning of the project development. Participants and support persons will be invited to take part in a focus group or interview at the end of the pilot RCT to provide their feedback and share their experiences. These meetings and focus groups will inform the interpretation and dissemination of findings and guide future large-scale implementation.

This is a pilot RCT with complementary quantitative and qualitative components that aims to determine the feasibility and acceptability of a 12-week HBMP. Furthermore, we will examine whether the program improves QoL, cognition, and other health outcomes (pain, depression, and physical health) in people with osteoarthritis and cognitive decline. Currently, there is no program available to meet the specific needs of this population, despite the prevalence of dementia rapidly increasing and the fact that half of older adults globally are living with chronic pain, often attributable to osteoarthritis. The program has been developed in partnership with people with lived experience of dementia and osteoarthritis, AEPs, clinical researchers, chronic disease specialists, and accredited practicing dietitians. The program will continue to be codeveloped, ensuring it is feasible in a real-world setting and easily scalable.

The anticipated findings of this study are that the 12-week program will be feasible and acceptable for people living with osteoarthritis and thinking concerns. Participant feedback will be valuable in informing a larger clinical trial. Regarding secondary outcome measures, we hypothesize that improvements will be observed for pain, QoL, physical function, and cognition in those who complete the program, though these may not be significant given the small sample size.

This is the first program that has been developed to target osteoarthritis and thinking concerns, both of which are specific risk factors associated with dementia. Currently, people are not aware that they can reduce their dementia risk [60], and societal awareness of dementia is lacking [61] even among health care professionals. The World Alzheimer Report [60] found that 62% of the health care professionals and 70% of the general population surveyed (across 155 countries) think dementia is a part of normal aging. Alarmingly, 25% believe that nothing can be done to prevent dementia [60]. This is particularly concerning given the overwhelming evidence demonstrating that approximately 45% of dementia cases could be prevented or delayed if modifiable risk factors, such as those that form the focus of this program (ie, physical inactivity and obesity), were eliminated [20], highlighting an opportunity for universal dementia prevention. With regard to interventions for osteoarthritis, medicines can have serious adverse side effects and have been associated with increases in addiction, morbidity, and mortality [62]. Many studies have demonstrated positive effects on pain, QoL, and depression following PA [7,63], dietary interventions [64], pain education [65], and other lifestyle behaviors. However, none have combined effective PA and lifestyle education into a single program as we have done here, nor have the effects on outcomes associated with dementia, such as cognition, been investigated in this higher-risk group.

The first stage of the study involved conducting interviews with people with lived experience of osteoarthritis and dementia to inform the design of the HBMP. Their recommendations were incorporated into the final design of the program. In the second stage, participants have been recruited to complete a pilot RCT. Feasibility and acceptability will be examined. Health outcomes, including QoL, pain, cognition, psychological and physical health, will be compared before and after intervention and between program and control groups. Following the program, participants will take part in interviews or focus groups to determine the acceptability of the program and investigate the views of participants, including their recommendations for future programs. In the third stage, stakeholder workshops with individuals, health care providers, and policymakers will take place to discuss future implementation of similar programs at a larger scale with broader outreach. Recruitment and feasibility challenges may impact the success of the trial. Mitigation strategies include considering the language used in recruitment materials, advertising the trial widely using multiple recruitment platforms and health care contacts, and ensuring smooth communication processes between researchers and participants.

Strengths of this study are the range of health outcomes being investigated (eg, QoL, pain, cognition, and psychological measures), allowing for in-depth inquiry into multiple factors associated with comorbidity and dementia risk. The qualitative component will provide feedback from experts living with osteoarthritis and cognitive decline regarding whether the program was enjoyable and feasible and met their needs as well as providing an opportunity to gather recommendations to improve the program and deliver it on a larger scale to benefit more people.

A multicomponent, evidence-based program that has been informed by diverse experts, including those with lived experience, may improve health outcomes for older adults with osteoarthritis and cognitive decline and reduce dementia risk. This is timely, given the substantial increases in dementia cases predicted globally.