Knee osteoarthritis is a common condition that can cause pain, stiffness, and difficulty with daily activities. Many patients interpret these symptoms as signs of ongoing joint damage, which can influence their expectations and decisions about treatment.

This randomized controlled trial compares three approaches used during a routine orthopedic visit: a health aid, a decision aid, and usual care. The health aid is designed to improve patients' understanding of knee osteoarthritis by addressing common misconceptions and helping patients develop a more accurate and less distressing understanding of their condition. The decision aid provides structured information about treatment options. In the usual care group, patients receive standard clinical consultation without additional educational materials.

The main goal of the study is to evaluate differences in patients' understanding of knee osteoarthritis immediately after the clinic visit. Secondary outcomes include patients' interest in additional care options such as imaging, physical therapy, injections, and surgery, as well as measures of trust in the clinician and care experience.

The results of this study may help improve how information is communicated to patients with knee osteoarthritis and guide future approaches to patient education and shared decision-making.

Knee osteoarthritis is a highly prevalent musculoskeletal condition and a leading cause of pain and disability in adults. Patients often interpret symptoms such as pain, stiffness, and functional limitation as evidence of progressive structural damage or "wear and tear." These interpretations may contribute to distress, increased demand for imaging or invasive treatments, and misalignment between patient expectations and evidence-based care.

Traditional decision aids are designed to support shared decision-making by presenting information about treatment options and potential outcomes. However, these tools primarily assume that patients make rational decisions based on accurate information. Emerging evidence from cognitive psychology suggests that decision-making is also influenced by automatic, intuitive processes, prior beliefs, emotional responses, and cognitive biases. As a result, providing information alone may not be sufficient to meaningfully shift misconceptions or improve alignment between patient values and treatment choices.

This randomized controlled trial evaluates the impact of a novel "health aid" compared with a standard decision aid and usual care in patients presenting for an initial consultation for knee osteoarthritis. The health aid is designed not only to provide information but also to address common misconceptions about knee osteoarthritis, reduce unnecessary fear related to symptoms, and support a more adaptive understanding of aging-related joint changes. In contrast, the decision aid focuses on presenting structured information about available treatment options.

Participants will be randomized in a 1:1:1 ratio to receive either the health aid, the decision aid, or usual care during their clinic visit. The intervention is delivered immediately after diagnosis is established, and patients complete outcome assessments immediately following the visit.

The primary outcome is post-visit understanding of knee osteoarthritis, measured using a misconception questionnaire. Secondary outcomes include patient-reported interest in subsequent healthcare utilization (including imaging, physical therapy, injections, and surgery), as well as measures of trust and care experience (TRECS).

The study aims to determine whether addressing cognitive and perceptual aspects of illness understanding through a health aid leads to improved patient understanding and potentially influences downstream healthcare preferences compared with traditional decision support tools and usual care.

Inclusion Criteria:

• New patient seeking musculoskeletal specialty care
• English literacy
• Aged 18-89 years
• Diagnosed with knee osteoarthritis

Exclusion Criteria:

• Cognitive or physical impairment precluding tablet use

Individual participant data will not be shared with other researchers. The study involves patient-reported outcomes collected during clinical encounters, including measures of health perceptions, treatment preferences, and trust. Due to the sensitive nature of these data and the absence of a predefined data-sharing infrastructure or funding mandate for data deposition, individual participant data will not be made publicly available. Aggregate study findings will be reported in peer-reviewed publications.