Sociodemographic and clinical characteristics among participants with radiographically confirmed knee OA by use of injections. Values are % or mean ± SD unless otherwise specified.
| Characteristics | Baselinea | Index Year | One Year after Injection Initiation | ||||||
|---|---|---|---|---|---|---|---|---|---|
| CO | HA | Nonuser | CO | HA | Nonuser | CO | HA | Nonuser | |
| Total, n* | 318 | 94 | 576 | 318 | 94 | 576 | 257 | 66 | 559 |
| Proportions relative to baseline | 100 | 100 | 100 | 100 | 100 | 100 | 80.1 | 70.2 | 97.0 |
| Injection use, n | 0 | 0 | 0 | 318 | 94 | 0 | 63 | 15 | 0 |
| Age, yrs | 66.9 ± 9.2 | 65.0 ± 8.6 | 64.0 ± 9.3 | 67.9 ± 9.2 | 66.0 ± 8.6 | 65.0 ± 9.3 | 68.5 ± 9.1 | 66.0 ± 8.8 | 65.8 ± 9.4 |
| Women | 64.2 | 44.7 | 55.6 | 64.2 | 44.7 | 55.6 | 65.4 | 43.9 | 55.5 |
| Ethnicity/race | |||||||||
| Non-Hispanic white | 77.4 | 88.3 | 67.9 | 77.4 | 88.3 | 67.9 | 75.5 | 87.9 | 67.4 |
| Non-Hispanic black | 17.9 | 6.4 | 30.0 | 17.9 | 6.4 | 30.0 | 21.0 | 7.6 | 30.4 |
| Other | 4.7 | 5.3 | 2.1 | 4.7 | 5.3 | 2.1 | 3.5 | 4.6 | 2.2 |
| Education | |||||||||
| High school or less | 18.6 | 12.9 | 20.9 | 18.6 | 12.9 | 20.9 | 20.2 | 10.8 | 20.2 |
| Some college | 27.1 | 23.7 | 26.7 | 27.1 | 23.7 | 26.7 | 28.8 | 24.6 | 27.1 |
| College graduate | 22.1 | 20.4 | 19.2 | 22.1 | 20.4 | 19.2 | 19.5 | 18.5 | 19.8 |
| Graduate school | 32.2 | 43.0 | 33.3 | 32.2 | 43.0 | 33.3 | 31.5 | 46.2 | 32.9 |
| Income (US$) | |||||||||
| < 25,000 | 15.5 | 4.3 | 17.9 | 15.5 | 4.3 | 17.9 | 17.1 | 4.6 | 18.1 |
| 25,000–50,000 | 30.9 | 22.6 | 27.8 | 30.9 | 22.6 | 27.8 | 32.7 | 16.9 | 27.6 |
| > 50,000 | 53.6 | 73.1 | 54.3 | 53.6 | 73.1 | 54.3 | 50.2 | 78.5 | 54.3 |
| KL grade | |||||||||
| 2 | 40.1 | 22.1 | 52.3 | 35.7 | 16.3 | 50.0 | 38.9 | 22.2 | 50.7 |
| 3 | 39.1 | 44.2 | 30.3 | 37.9 | 45.0 | 30.8 | 41.2 | 46.3 | 31.2 |
| 4 | 20.8 | 33.7 | 17.4 | 26.4 | 38.8 | 19.3 | 19.9 | 31.5 | 18.2 |
| Symptom-related multijoint OA | 55.4 | 57.5 | 55.2 | 55.7 | 60.6 | 50.4 | 56.0 | 62.1 | 49.0 |
| History of knee injury | 40.6 | 57.5 | 49.3 | 47.2 | 58.5 | 50.2 | 49.4 | 57.6 | 51.2 |
| History of knee surgery | 28.6 | 48.9 | 34.6 | 32.1 | 54.3 | 35.8 | 35.8 | 50.0 | 35.2 |
| BMI, kg/m2 | |||||||||
| < 25 | 12.9 | 14.9 | 13.2 | 12.9 | 16.0 | 13.0 | 12.1 | 15.2 | 14.5 |
| 25 to < 30 | 40.6 | 31.9 | 39.7 | 40.6 | 30.9 | 37.7 | 40.5 | 31.8 | 36.3 |
| ≥ 30 | 46.5 | 53.2 | 47.1 | 46.5 | 53.2 | 49.3 | 47.5 | 53.0 | 49.2 |
| Knee alignment | |||||||||
| Normal | 20.5 | 18.9 | 18.4 | 17.4 | 15.9 | 15.9 | 18.4 | 11.9 | 16.0 |
| Varus | 39.3 | 40.0 | 41.9 | 42.9 | 44.3 | 45.9 | 38.2 | 44.1 | 46.5 |
| Valgus | 40.3 | 41.1 | 39.7 | 39.7 | 39.8 | 38.2 | 43.4 | 44.1 | 37.5 |
| CES-D (> 16) | 11.0 | 8.9 | 11.0 | 14.3 | 12.2 | 13.3 | 13.2 | 12.9 | 12.1 |
| Charlson CI | |||||||||
| 0 | 65.4 | 70.2 | 65.7 | 62.0 | 71.0 | 63.4 | 56.7 | 78.5 | 63.0 |
| 1 | 18.2 | 22.3 | 19.3 | 19.9 | 20.4 | 19.9 | 21.7 | 15.4 | 19.9 |
| ≥ 2 | 16.4 | 7.5 | 15.1 | 18.0 | 8.6 | 16.7 | 21.7 | 6.2 | 17.1 |
| WOMAC pain | 5.0 ± 3.9 | 5.1 ± 3.9 | 4.9 ± 4.1 | 6.2 ± 4.2 | 5.7 ± 3.6 | 4.4 ± 3.9 | 5.6 ± 4.0 | 5.2 ± 3.7 | 4.2 ± 3.8 |
| WOMAC stiffness | 2.7 ± 1.7 | 2.5 ± 1.7 | 2.5 ± 1.8 | 2.8 ± 1.7 | 2.8 ± 1.6 | 2.4 ± 1.8 | 2.7 ± 1.7 | 2.5 ± 1.6 | 2.2 ± 1.8 |
| WOMAC physical function | 16.8 ± 13.0 | 16.7 ± 11.8 | 15.3 ± 13.0 | 19.2 ± 13.2 | 17.1 ± 11.3 | 14.4 ± 12.8 | 17.9 ± 13.2 | 16.9 ± 11.1 | 14.1 ± 12.8 |
| KOOS-QoL | 54.6 ± 19.9 | 52.2 ± 18.8 | 56.0 ± 21.7 | 48.3 ± 20.2 | 49.0 ± 20.1 | 57.4 ± 22.4 | 50.6 ± 20.3 | 50.5 ± 19.5 | 58.4 ± 22.0 |
| SF-12 physical component score | 42.8 ± 9.6 | 42.7 ± 9.2 | 44.8 ± 9.7 | 40.8 ± 9.4 | 40.8 ± 9.9 | 44.4 ± 10.1 | 41.1 ± 9.5 | 40.6 ± 9.3 | 44.4 ± 10.0 |
| SF-12 mental component score | 54.1 ± 8.4 | 55.4 ± 7.1 | 53.8 ± 8.3 | 54.1 ± 9.5 | 55.4 ± 8.2 | 53.4 ± 9.3 | 53.6 ± 9.1 | 55.1 ± 8.5 | 53.2 ± 9.2 |
| Joint space width, mm | 4.6 ± 1.9 | 4.2 ± 2.2 | 5.1 ± 1.6 | 4.4 ± 1.9 | 4.0 ± 2.1 | 4.9 ± 1.7 | 4.4 ± 1.9 | 4.3 ± 2.1 | 4.9 ± 1.6 |
↵a One year before the index year.
↵* No. participants with missing information: At baseline — education (4), income (3), KL grade (114), body mass index (1), knee alignment (99), CES-D (63), Charlson Comorbidity Index (5), WOMAC pain (29), WOMAC stiffness (27), WOMAC physical function (3), KOOS-QoL (27), SF-12 physical component score (70), SF-12 mental component score (70), joint space width (234). At index year — education (4), income (3), KL grade (153), knee alignment (123), CES-D (72), Charlson Comorbidity Index (5), WOMAC pain (25), WOMAC stiffness (27), WOMAC physical function (41), KOOS-QoL (27), SF-12 physical component score (93), SF-12 mental component score (93), joint space width (300). One year after injection initiation — education (3), income (2), KL grade (145), knee alignment (120), CES-D (80), Charlson Comorbidity Index (6), WOMAC Pain (56), WOMAC Stiffness (56), WOMAC Physical function (71), KOOS-QoL (56), SF-12 Physical Component Score (93), SF-12 Mental Component Score (93), joint space width (292). OA: osteoarthritis; CO: corticosteroid; HA: hyaluronic acid; KL grade: the Kellgren-Lawrence grade; CES-D: Center for Epidemiologic Studies Depression Scale; WOMAC: The Western Ontario and McMaster Universities Osteoarthritis Index; KOOS-QoL: Knee Injury and Osteoarthritis Outcome Score quality of life subscale; SF-12: 12-item Medical Outcomes Study Short Form; CI: Comorbidity Index; BMI: body mass index.