Background/Purpose: Exercise, weight loss, simple analgesic medications and joint injections are effective non-surgical treatments for knee osteoarthritis (OA) to reduce pain and improve function. While these treatments are recommended in international guidelines and appropriate for virtually all patients, they are substantially under used. Furthermore, many patients receive opioid analgesia in place of recommended therapies. Reduced mobility due to knee OA increases risk for CV events, diabetes, and all-cause mortality; while opioid use for chronic non-cancer pain is associated with increased mortality without added therapeutic benefit. Currently, little is known about patient factors that influence use of recommended non-surgical OA care, as well as non-recommended care such as opioids, and thus which patients to target in implementation strategies.

Methods: Knee OA patients were assessed prior to orthopaedic surgical consultation using a standardized online questionnaire that assessed: sociodemographic factors (age, sex, education, income, employment, and Lubben social network score), medical comorbidities, OA disease severity (pain numeric rating scale, WOMAC pain scale, KOOS-physical function score, Gignac coping efficacy scale, and pain catastrophizing scale), and non-surgical therapies used (both ever tried and currently using). Comprehensive non-surgical treatment was defined as use of analgesia (acetaminophen, NSAIDs or injection) plus exercise or physical therapy plus weight loss if BMI ≥25 kg/m². Multivariate logistic regression was used to assess the relationship between patient factors (sociodemographics, comorbidities, and OA severity) with lack of current use of comprehensive treatment, as well as with current use of opioid analgesia for knee OA.

Results: 2,220 patients were included: mean age 65.6 ± 9.1 years, 58.8% female, mean BMI 32.7 ± 6.6 kg/m², mean WOMAC pain 11.6/20 ± 3.6 and mean KOOS-PS 56.5/100 ± 17.7. 654 (29.5%) patients were currently using comprehensive treatment; 609 (27.4%) tried and stopped and 957 (43.1%) never used. 635 (28.6%) patients were currently using opioid analgesia for knee OA. In multivariate analysis, lack of use of comprehensive care was significantly associated with older age (OR 1.02, 95% CI 1.01-1.04), male sex (1.67, 1.34-2.08), high school education or less (1.25, 1.01 – 1.56; 1.82, 1.30-2.55), lower social support (0.97, 0.95-0.99), and higher BMI (1.03, 1.01-1.04). Use of opioids was significantly associated with comorbid hypertension (1.26, 1.01-1.59), depression (1.69, 1.30-2.20), other painful joints (1.27, 1.01-1.59), and worse physical function on the KOOS-PS (1.02, 1.01-1.03).

Conclusion: In a cohort with moderate-to-severe knee OA, less than one third were using comprehensive non-surgical OA treatment and over one quarter were using opioid analgesia. Sociodemographic factors including lower level of education and social support were associated with less uptake of comprehensive treatment, suggesting that clinicians should be aware of these barriers to care. Medical comorbidity and lower function, but not pain severity, were associated with opioid use, meriting further research to better understand opioid prescribing in OA.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/patient-factors-associated-with-gaps-in-osteoarthritis-care/