Table 4.
Sensitive Analysis (OA Status Updated before Mediators)
| Neither Radiographic Knee OA nor Knee Pain (n=1,302) | Radiographic Knee OA Only (n=1,462) | Knee Pain Only (n=525) | Symptomatic Knee OA (n=1,209) | |
|---|---|---|---|---|
| Number of Death | 81 | 88 | 28 | 86 |
| Deaths per 1000 Person-years (95% CI) | 9.3 (7.4 to 11.5) | 12.8 (10.3 to 15.7) | 8.7 (5.8 to 12.5) | 15.8 (12.6 to 19.5) |
| Total Effect, HR (95% CI) | 1.0 (reference) | 2.0 (1.5 to 2.7) | 1.0 (0.6 to 1.5) | 2.4 (1.8 to 3.3) |
| Total Effect, HR (95% CI) * | 1.0 (reference) | 1.7 (1.2 to 2.4) | 0.9 (0.6 to 1.3) | 2.0 (1.4 to 2.9) |
| Disability Score | ||||
| Direct, HR (95% CI) * | 1.0 (reference) | 1.7 (1.4 to 2.0) | 0.6 (0.5 to 0.8) | 1.1 (0.9 to 1.4) |
| Indirect, HR (95% CI) * | 1.0 (reference) | 1.0 (0.9 to 1.2) | 1.4 (1.2 to 1.6) | 1.7 (1.5 to 2.0) |
| Mediation effect (%) | - | 2.4 | Not same direction | 85.5 |
| PCS of QoL | ||||
| Direct, HR (95% CI) * | 1.0 (reference) | 1.7 (1.5 to 2.0) | 0.7 (0.6 to 0.9) | 1.6 (1.4 to 1.9) |
| Indirect, HR (95% CI) * | 1.0 (reference) | 1.0 (0.8 to 1.2) | 1.2 (1.0 to 1.4) | 1.2 (1.0 to 1.5) |
| Mediation effect (%) | - | 0.0 | Not same direction | 38.9 |
| MCS of QoL | ||||
| Direct, HR (95% CI) * | 1.0 (reference) | 1.7 (1.5 to 2.0) | 0.8 (0.7 to 1.1) | 2.0 (1.7 to 2.4) |
| Indirect, HR (95% CI) * | 1.0 (reference) | 1.0 (0.8 to 1.2) | 1.0 (0.8 to 1.2) | 1.0 (0.8 to 1.2) |
| Mediation effect (%) | - | 2.4 | Not same direction | 0.0 |
| Oral Pain Medications Use | ||||
| Direct, HR (95% CI) * | 1.0 (reference) | 1.7 (1.5 to 2.0) | 0.8 (0.6 to 1.1) | 1.9 (1.6 to 2.3) |
| Indirect, HR (95% CI) * | 1.0 (reference) | 1.0 (0.8 to 1.2) | 1.1 (0.9 to 1.3) | 1.1 (0.9 to 1.3) |
| Mediation effect (%) | - | 2.4 | Not same direction | 11.4 |
n, number; OA, osteoarthritis; CI, confidence interval; HR, hazard ratio; PCS, physical component summary score; MCS, mental component summary score; QoL, quality of life.
*
Adjusted for age, race, sex, body mass index, education level, weekly alcohol consumption, smoking habits, history of knee injury, comorbidities, depressive symptoms and widespread pain.