Table 2.
Primary outcomes.
| Routine Care (Total n = 81) | Decision Aid (Total n = 79) | Adjusted Odds Ratioa (95% CI) | |
|---|---|---|---|
| Knowledge Questionnaire (5-item), n correct/N (%) | |||
| Over time, without surgery, what usually happens to the pain from hip (knee) osteoarthritis? | 75/81 (92.6) | 74/79 (93.7) | 1.18 (0.33–4.33) |
| After knee replacement surgery, about how many months does it take most people to get back to doing their usual activities? | 49/81 (60.5) | 69/79 (87.3) | 4.45 (2.04–10.43)∗ |
| About how many people who have hip (knee) replacement surgery will need to have the same hip (knee) replaced again in less than 15 years? | 28/81 (34.6) | 48/79 (60.8) | 3.00 (1.57–5.85)∗ |
| If 100 people like you have knee replacement surgery, how many people improve and have NO or SLIGHT pain or discomfort after surgery? | 22/81 (27.2) | 24/79 (30.4) | 1.11 (0.55–2.24) |
| Out of 100 people who have hip (knee) replacement surgery, about how many will have a serious complication (e.g., death, life-threatening blood clots, infection, heart attack) within the 3 months after surgery? | 33/81 (40.7) | 60/79 (75.9) | 5.35 (2.66–11.25)∗ |
| Knowledgeable (3 of 5 knowledge questions correct), n/N (%) | 43/80 (53.1) | 65/79 (82.3) | 4.01 (1.97–8.60)∗ |
| Treatment Preference, n/N (%) | |||
| Surgery | 59/81 (72.8) | 65/79 (82.3) | 0.59 (0.03–6.48) |
| Non-surgical | 1/81 (1.2) | 2/79 (2.5) | Reference |
| Unsure | 21 /81 (25.9) | 12/79 (15.2) | – |
| Decided (vs unsure) | 1.98 (0.90–4.52) | ||
| Treatment Decision, n/N (%) | |||
| Surgery | 69/80 (86.3) | 54/74 (73.0) | 0.41 (0.17–0.93) |
| Non-surgical | 11/80 (13.8) | 20/74 (27.0) | Reference |
| Concordant (treatment Preference equals Decision), n/N (%) | 53/80 (66.2) | 52/75 (69.3) | 1.15 (0.58–2.29) |
| Quality Decision (knowledgeable and concordant), n/N (%) | 33/80 (41.3) | 45/75 (60.0) | 2.08 (1.08–4.02)∗ |
a
Models do not account for clustering by surgeon given findings on ICC, but do adjust for sex; ∗p < 0.05.