Osteoarthritis (OA) is one of the most prevalent chronic musculoskeletal disorders and a leading cause of disability worldwide, especially among the elderly [1]. Globally, the prevalence of knee OA in men is lower compared to women, with 9.6% of men and 18% of women aged over 60 years affected [1, 2]. In China, the prevalence of radiographic OA was 42.8% in women and 21.5% in men; whereas, symptomatic OA occurred in 15% of women and 5.6% of men. The prevalence of radiographic and symptomatic OA in Chinese men was similar to that in white men in the United States (US). However, Chinese women had a higher prevalence of radiographic and symptomatic OA than women in the US [2, 3].
Chronic pain is one of the most common health issues that exerts a significant social and financial burden on the individual and society. Patients with inadequate pain relief are more likely to have worse quality of life (QoL), greater function loss, and greater pain interference with daily activities [4]. OA is a leading cause of deteriorated QoL due to chronic pain [5, 6]. Compared with the radiographic OA without pain, painful OA has been associated with higher cardiovascular risk and mortality [7]. Pain is recognized as one of the hallmark symptoms in OA and is a common reason patients seek medical attention. Mechanisms underlying chronic pain include a complex interaction of physiological, emotional, cognitive, social, and environmental factors [8]. When considering the complex nature of chronic pain, treatment often necessitates the use of a blend of different approaches. In terms of nonsurgical standard interventions for OA, multimodal pain management is a comprehensive treatment of complex chronic pain syndromes that includes 4 core disciplines of multimodal pain management: pain medicine, psychotherapy, exercise therapy (including physiotherapy), and assistant medical professions including nurses. Multimodal pain management protocols aim to address pain control, facilitate functional recovery, and maintain patient satisfaction [9, 10].
Patient-reported outcome is an important consideration in the treatment of patients with OA. All aspects of QoL are compromised when pain is inadequately treated, and effective pain relief has been shown to improve health-related quality of life (HRQoL) [11, 12]. When patients with OA were asked to rank aspects of QoL impacted by their condition, they highlighted enjoyment of life, emotional well-being, fatigue, weakness, and sleep-related problems as the most important areas they would consider when evaluating the success of their pain treatment [13]. The pain caused by OA can have a substantial impact on patients’ QoL [11–13]. In a 2012 online survey of patients with OA in the United Kingdom [14], 52% of the 2001 respondents reported that OA had a large impact on their life, 71% reported having persistent pain even after taking their prescribed pain medication, and 12% said their pain was often unbearable. In a cross-sectional study conducted in 2014 by Kantar Health, only 14% of patients in Japan with diagnosed pain who suffered from joint pain were highly satisfied with their pain medications [4]. Furthermore, a multinational longitudinal survey showed that patients with inadequate pain relief were more likely to have a worse QoL, greater function loss, and greater pain interference [4].
Patient satisfaction is an important indicator of the quality of care provided to patients with OA [15]. Patient-reported outcomes, such as HRQoL and patient satisfaction, were used to capture patients’ experience of chronic disease and can support the physician in clinical practice to facilitate patient-centered care [16]. Thus, QoL and treatment satisfaction assessments are crucial to evaluating the clinical effectiveness of treatment in OA.
Little is known about the impact of chronic knee OA pain on HRQoL and treatment satisfaction in a real-world setting in China. Therefore, the cross-sectional survey presented in this article has been designed to understand the impact of chronic knee OA pain on HRQoL and to evaluate treatment satisfaction of current medications among Chinese patients with knee OA.