Table 3.
Short-term and longer-term prediction of response to IASI: patient and treatment factors.
| Predictor Variable in Regression | Short-term Responder (Yes/No) | Longer-term Responder (Yes/No) | ||
|---|---|---|---|---|
| N | Relative Risk (95% CI) | N | Relative Risk (95% CI) | |
| Demographic/prior knee injury | ||||
| Age (per yr) | 199 | 1.00 (0.99–1.01) | 199 | 0.98 (0.95–1.01) |
| Sex, female vs male (ref.)* | 199 | 1.18 (0.99–1.40) | 199 | 1.09 (0.63–1.91) |
| Symptoms | ||||
| Pain on nominated activity VAS (0–10 cm) | 190 | 1.01 (0.96–1.06) | 190 | 1.08 (0.91–1.27) |
| Pain in the last week VAS (0–10 cm) | 194 | 1.01 (0.97–1.05) | 194 | 1.05 (0.92–1.21) |
| No. pain sites (range 0–10) | 177 | 0.98 (0.94–1.02) | 177 | 0.83 (0.72–0.97) |
| Chronic widespread pain (ACR) | 150 | 0.95 (0.76–1.19) | 150 | 0.32 (0.10–0.98) |
| Psychological factors | ||||
| HADS anxiety (0–21) | 170 | 0.99 (0.97–1.01) | 170 | 0.93 (0.86–1.01) |
| HADS depression (0–21) | 170 | 0.98 (0.95–1.01) | 170 | 0.89 (0.81–0.99) |
| IPQ-B consequences score (0–10) | 175 | 1.00 (0.97–1.04) | 175 | 0.93 (0.83–1.05) |
| IPQ-B timeline score (0–10) | 172 | 0.98 (0.95–1.02) | 172 | 0.86 (0.78–0.94) |
| IPQ-B personal control score (0–10) | 173 | 1.00 (0.97–1.04) | 173 | 0.99 (0.89–1.10) |
| IPQ-B treatment score (0–10) | 174 | 1.05 (1.01–1.09) | 174 | 1.08 (0.94–1.24) |
| IPQ-B identity score (0–10) | 175 | 1.01 (0.97–1.06) | 175 | 0.98 (0.85–1.13) |
| IPQ-B illness concern score (0–10) | 174 | 1.00 (0.97–1.04) | 174 | 0.95 (0.85–1.07) |
| IPQ-B coherence score (0–10) | 172 | 1.03 (0.98–1.08) | 172 | 1.12 (0.95–1.32) |
| IPQ-B emotional representation score (0–10) | 172 | 0.99 (0.96–1.02) | 172 | 0.97 (0.88–1.07) |
| Quality of life | ||||
| SF-12 physical component summary (0–100) | 184 | 1.00 (0.99–1.01) | 184 | 1.00 (0.97–1.04) |
| SF-12 mental component summary (0–100) | 184 | 1.00 (1.00–1.01) | 184 | 1.01 (0.99–1.04) |
| Treatment-related factors | ||||
| Synovial fluid aspiration, yes vs no (ref.)* | 199 | 0.79 (0.66–0.95) | 199 | 0.82 (0.47–1.45) |
| Ultrasound-guided knee injection vs unguided (ref.)* | 199 | 1.09 (0.92–1.29) | 199 | 1.16 (0.57–2.34) |
*
Ref. indicates the reference category in the log-binomial regression [e.g., yes vs no (ref.) indicates that “no” was the reference category]. IASI: intraarticular steroid injection; VAS: visual analog scale; HADS: Hospital Anxiety and Depression Scale; IPQ-B: Illness Perception Questionnaire-Brief; SF-12: Medical Outcomes Study Short Form-12; ACR: American College of Rheumatology.