Treatment satisfaction with pharmaceutical interventions in Japanese adults with osteoarthritis and chronic knee pain: an analysis of a web-based survey

PURPOSE: Patient satisfaction is an important outcome in successful osteoarthritis (OA) treatment. The aim of this study was to evaluate treatment satisfaction for medication (TSM) in people with knee OA (KOA), identify the factors predictive of treatment satisfaction, and describe the burden of illness. PATIENTS AND METHODS: This cross-sectional, patient-reported study used an Internet-based survey and analyzed responses of respondents with KOA (N=400) on characteristics including pain sites and levels (including pain ratings using the Numerical Rating Scale and Short-Form McGill Pain Questionnaire), treatment satisfaction (Global, Effectiveness, and Convenience scores) based on the Treatment Satisfaction Questionnaire for Medication (TSQM-9), and quality of life (QoL; based on the Arthritis Impact Measurement Scale 2-Short Form). Respondents with only KOA (n=237) were compared with those having KOA and additional painful sites (KOA+; n=163). Factors predicting TSM were identified using multivariable linear regression analyses. RESULTS: Respondents with KOA were more likely to report intermittent pain for 3 months or more compared with those with KOA+ (58.6% vs 48.5%, respectively; P=0.044), while those with KOA+ were more likely to report consistent pain for 3 months or more (P=0.022). Respondents with KOA+ also had more difficulty due to their knee pain while sleeping (P=0.022) and resting (P=0.015). Reported TSM did not differ significantly across KOA vs KOA+ groups, with both groups reporting low satisfaction; all domains of QoL were worse for those with KOA+. Knee pain reduction by medication predicted higher satisfaction across domains, while lower pre-medication pain and post-medication pain matching expectations predicted higher TSQM-9 Global and Effectiveness scores. CONCLUSION: Medication treatment satisfaction rates were low among Japanese respondents with KOA. Given that lower pain, greater pain reduction post-medication, and meeting pain management expectations were predictive of higher satisfaction, treatment strategies that can better address pain may prove beneficial for overall patient satisfaction.