P043 Income-Related Health Inequality and Osteoarthritis Intervention Outcomes: a Cohort Study

• Published in: Rheumatology (Oxford, England) Vol. 62; no. Supplement_2
• Main Authors: Battista, Simone, Kiadaliri, Ali, Englund, Martin, Jönsson, Thérése, Gustafsson, Kristin, Testa, Marco, Dell'Isola, Andrea
• Format: Journal Article
• Language: English
• Published: Oxford University Press 24.04.2023
• ISSN: 1462-0324; 1462-0332
• DOI: 10.1093/rheumatology/kead104.084

Abstract Background/Aims Osteoarthritis (OA) management programmes have been lately developed to tackle the osteoarthritis burden. Though beneficial, OA management programmes can be less effective on people in lower socioeconomic positions and widen the possible pre-existing inequalities gap (‘intervention-generated inequalities’). In Sweden, an OA management programme was implemented in the national healthcare system, including exercise and education. Its results are recorded in the ‘Better Management of People with Osteoarthritis’ (BOA) register, one of the most extensive OA datasets worldwide. Hence, this study investigated the influence of this Swedish osteoarthritis management programme on income-related inequality. Methods A register-based study with data from the BOA register. We calculated Erreygers’ and Wagstaff’s concentration indices and how they changed throughout time. We considered the variables ‘Pain intensity’, ‘Self-efficacy‘, ‘Use of NSAIDs’ and ‘Desire for surgery’ at three-time points (baseline, after three and twelve months from the beginning of the programme). Concentration indices’ values range from -1 to + 1. Zero indicates no income inequality. A positive (or negative) sign indicates an unequal concentration of the variables of interest among those with higher (or lower) income. We used bootstrapping (1000 replications) to compute 95% confidence intervals for changes in the concentration indices from baseline. Results A total of 115,403 people with knee and hip OA were identified. ‘Pain intensity’ and ‘Desire for surgery’ were disproportionately concentrated among those with lower income at the baseline, while the opposite happened for ‘Use of NSAIDs’ and ‘Self-efficacy’ (Table 1). Income inequalities for ‘Pain intensity’, ‘Self-efficacy’ and ‘Desire for surgery’ widened following the programme, though their magnitude was small. Conversely, income-related inequality in the ‘Use of NSAIDs’ narrowed after attending the programme. Conclusion Considering the concentration indices’ values, people with lower income were already experiencing higher levels of pain and desire for surgery and lower levels of self-efficacy than their higher counterparts. This trend got even worse after attending the abovementioned programme. Instead, people with higher income were keener on using NSAIDs but attending this programme narrowed this gap. These results highlighted ‘intervention-generated inequalities’ in the BOA data. OA management programmes should be structured to reduce inequalities among people with different incomes. Disclosure S. Battista: None. A. Kiadaliri: None. M. Englund: None. T. Jönsson: None. K. Gustafsson: None. M. Testa: None. A. Dell'Isola: None. P043 Table 1. Concentration Indices' Values Variables N (T0-T1) Concentration Indices (T0) Concentration Indices (T1) Concentration Indices' Differences (T1-T0) N (T0-T2) Concentration Indices (T0) Concentration Indices (T2) Concentration Indices' Differences (T2-T0) Erreygers’ Concentration Index Erreygers’ Concentration Index Index Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Pain n = 80,304 -0.027 -0.039 -0.011 [-0.015; -0.007] n = 47,487 -0.027 -0.043 -0.016 [-0.021; -0.012] Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Pain n = 80,304 -0.028 -0.039 -0.012 [-0.015; -0.008] -0.027 - 0.044 -0.016 [-0.022; -0.012] Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Self-Efficacy n = 32,598 0.057 0.065 0.008 [0.004; 0.012] n = 25,370 0.058 0.075 0.017 [0.012; 0.021] Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Self-Efficacy n = 32,598 0.063 0.076 0.013 [0.008; 0.017] n = 25,370 0.066 0.082 0.017 [0.012; 0.022] Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index Desire for Surgery n = 78,436 -0.008 -0.020 -0.012 [-0.018; -0.005] n = 46,737 -0.012 -0.024 -0.012 [-0.022; -0.002] Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index Desire for Surgery n = 78,436 -0.012 -0.030 -0.018 [-0.028; -0.009] n = 46,737 -0.019 -0.035 -0.016 [-0.031; -0.001] Erreygers’ Concentration Index Erreygers’ Concentration Index Erreygers’ Concentration Index NSAIDs n = 80,217 0.068 0.038 -0.029 [-0.038; -0.021] Wagstaff’s Concentration Index Wagstaff’s Concentration Index Wagstaff’s Concentration Index NSAIDs n = 80,217 0.069 0.045 -0.025 [-0.034; -0.015] T0, baseline; T1, after three months; T2, after one year; NSAIDs, non-steroidal anti-inflammatory drugs.