Removing Pathoanatomical Content From Information Pamphlets About Knee Osteoarthritis Did Not Affect Beliefs About Imaging or Surgery, but Led to Lower Perceptions That Exercise Is Damaging and Better Osteoarthritis Knowledge: An Online Randomised Controlled Trial.

Compare the effects of osteoarthritis information, with or without pathoanatomical content, on people's beliefs about managing osteoarthritis. Online randomized controlled trial involving 556 participants. Participants considered a hypothetical scenario where their doctor informed them that they had knee osteoarthritis. Participants were randomized to a control condition, where they received currently available osteoarthritis information with pathoanatomical content or an experimental condition, where they received the same osteoarthritis information but without pathoanatomical content. Primary outcomes were participants' beliefs about the need for x-ray to confirm diagnosis and joint replacement surgery in the future. There were no between-group differences in primary outcomes for x-ray (mean difference [MD], -0.3; 95% confidence interval [CI]: -0.9, 0.4) and surgery (MD, -0.2; 95% CI: -0.7, 0.2), each rated on an 11-point numeric rating scale. Participants in the experimental group had lower perceptions that exercise would damage the knee (MD, -0.4; 95% CI: -0.8, 0.0; rated on an 11-point numeric rating scale) and better osteoarthritis knowledge (MD, 0.9; 95% CI: 0.0, 1.9; rated on a scale ranging from 11 to 55). Among those without tertiary education, participants in the experimental group had lower perceptions that x-ray was necessary than control (MD, -0.8; 95% CI: -1.5, -0.1). Among those who had never sought care for knee pain, participants in the experimental group had lower perceptions about the need for surgery (MD, -0.7; 95% CI: -1.2, -0.2). Removing pathoanatomical content may not change beliefs about imaging and surgery but may lead to lower perceptions that exercise is damaging and may improve osteoarthritis knowledge. However, effects were small and of unclear clinical relevance. Tertiary education or a history of care seeking for knee pain may moderate effects on primary outcomes. .