ObjectiveThere is a lack of knowledge about health-related quality of life (HRQoL) in Saudi patients with musculoskeletal impairment, particularly among older adult populations. Thus, the current research aimed to determine the association of knee osteoarthritis (OA) severity with knee pain (KP) and HRQoL among older patients in Riyadh, Saudi Arabia.MethodsIn a multicenter cross-sectional study, we recruited 209 consecutive males and females aged ≥55 years with radiographically diagnosed knee OA from five hospitals across Riyadh, Saudi Arabia. According to the Kellgren & Lawrence classification, patients were classified into two groups: mild/moderate knee OA (n = 126) and severe knee OA (n = 83). KP and HRQoL were assessed using the pain visual analogue scale (VAS) and the 36-Item Short Form Health Survey (SF-36), respectively. A higher score on the pain VAS and the SF-36 represented worse KP and better HRQoL, respectively.ResultsSevere knee OA was significantly associated with an increased score of 3.47 (p <.0001) points on the pain VAS compared with the score reported by patients with mild/moderate knee OA. Additionally, it was significantly associated with reduced scores of 6.83 and 5.82 (both: p <.0001) points on the physical and mental composite summary subscales of the SF-36, respectively, compared with the scores of patients with mild/moderate knee OA, even after adjusting for all covariates.ConclusionOlder patients with severe knee OA had significantly worse KP and reduced HRQoL compared to patients with mild/moderate knee conditions, even after controlling for confounders.