Treatment Satisfaction after Switching to Another Therapy in Spanish Orthopaedic Clinic Outpatients with Knee or Hip Osteoarthritis Previously Refractory to Paracetamol

Background and Objective: Hip and knee osteoarthritis is highly prevalent in the elderly, and the incidence is estimated to increase in the coming decades. Prior to surgery, symptomatic treatment, starting with non-pharmacological therapies, should be prescribed. Paracetamol (acetaminophen) is the recommended first pharmacological treatment for osteoarthritis. If paracetamol is ineffective, non-steroidal anti-inflammatory drug (NSAID) treatment is indicated. The superiority of NSAIDs over paracetamol has been demonstrated in several studies. Furthermore, the assessment of patient satisfaction could be an adequate indicator of the quality of care given and is likely related to the evolution of the condition and the therapeutic regimen. The objective of this study was to assess the satisfaction of patients diagnosed with hip and/or knee osteoarthritis who had been previously treated with paracetamol and switched to NSAID treatment due to a lack of effectiveness by paracetamol.

Methods: An observational, prospective, multicentre and comparative study was conducted in 2009 among patients diagnosed with hip and knee OA who visited outpatient orthopaedic clinics. The evaluation of treatment effectiveness was carried out using a patient-based visual analogue scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The satisfaction regarding change of treatment due to a lack of effectiveness and/or the presence of adverse effects was evaluated using the osteoARthritis Treatment Satisfaction (ARTS) questionnaire.

Results: A total of 2437 patients were evaluated (knee OA: 1438 [59%]; hip OA: 621 [25.5%]; knee and hip OA: 124 [5.1%]; and without OA location registered: 254 [10.4%]). The study findings showed an increase in patient satisfaction after abandoning the use of paracetamol to treat OA. Statistically significant increases in both overall satisfaction mean (from 57.7 [SD 13.5] to 71.3 [SD 12.0]) and in each of the four domains of the ARTS questionnaire were observed (p < 0.0001 in all cases). According to the WOMAC and a VAS, treatment effectiveness increased significantly after 3 months (p < 0.0001) and significant correlations with satisfaction were observed (r = −0.32 and r = −0.29, respectively; p < 0.0001). The mean (SD) change in global satisfaction in patients treated with NSAIDs was 14.9 (15.5) versus 7.2 (14.4) for patients treated with non-NSAIDs (p < 0.0001). Patients taking NSAID treatment showed substantially more improvement over those taking non-NSAID treatment.

Conclusion: NSAIDs relieve pain due to O A in paracetamol-resistant patients and improve treatment effectiveness and patient satisfaction with treatment. Furthermore, paracetamol-refractory subjects under conventional medical treatment with NSAIDs experienced the drug as more effective and also tended to be more satisfied with treatment than those treated with non-NSAIDs.