Abstract / Summary
Osteoporosis knowledge is relevant to bone-health behaviour and fracture prevention in older adults with knee osteoarthritis (KOA). This study examined associations of osteoporosis-related health beliefs, domain-specific self-efficacy and activities of daily living (ADL) with osteoporosis knowledge in patients with KOA. This single-centre cross-sectional questionnaire study included 214 patients with KOA. Measures included the Osteoporosis Knowledge Test (OKT), an administered 31-item Osteoporosis Health Belief Scale (OHBS) form, a 21-item Osteoporosis Self-Efficacy Scale (OSES), and the 10-item Barthel Index. OKT risk-factor scoring treated the menopause and oophorectomy items as structurally not applicable to men. The primary outcome was OKT total percentage. Multivariable linear regression simultaneously adjusted for age, sex, normalized body mass index (BMI), seven OHBS domains, exercise self-efficacy, calcium-intake self-efficacy and Barthel Index. HC3 heteroscedasticity-robust standard errors were used. The sample included 83 men and 131 women, with a mean age of 66.99 years (SD 5.38). OKT total percentage was available for 172 participants and averaged 37.02% (SD 15.34%). In the fully adjusted complete-case model ( n = 153), R2 was 0.174 and adjusted R2 was 0.097. Calcium-intake self-efficacy was positively associated with osteoporosis knowledge (B = 0.243% points per 1-point increase on the 0 to 100 scale, standardized beta = 0.392, 95% CI 0.068 to 0.418, P = 0.0069). No other covariate reached P < 0.05. This association remained positive in anthropometric sensitivity analyses. In this cross-sectional sample of patients with KOA, higher calcium-intake self-efficacy was associated with higher osteoporosis knowledge after simultaneous adjustment for demographic, belief, self-efficacy and functional variables. The findings should be interpreted as associations rather than causal effects. Not applicable. This study was a cross-sectional observational study and did not involve an interventional clinical trial requiring prospective registration.