Table 2. Hip OA crude and stepwise ANCOVA adjusted WOMAC and RAND-36 scores§.
| Hip OA patients | Crude and Model 3 (Fully adjusted model) | Model 1 | Model 2 | |||
|---|---|---|---|---|---|---|
| Unlikely NP (n = 74) | Possible NP (n = 43) | Unlikely NP | Possible NP | Unlikely NP | Possible NP | |
| WOMAC score | ||||||
| Total | Crude: 59.5 (55.3–63.7) | 49.0 (42.1–55.9)* | 58.7 (54.0–63.4)a | 50.6 (43.9–57.2)b* | 49.9 (40.8–59.0)b | 41.7 (31.3–52.1)c |
| Model 3: 50.3 (42.3–58.2)b | 51.1 (41.6–60.7)c | |||||
| Pain | Crude: 63.5 (59.2–67.8) | 52.8 (45.9–59.7)* | 62.6 (57.8–67.4)a | 53.5 (46.7–60.2)b* | 53.8 (44.6–62.9)b | 44.9 (34.4–55.4)c |
| Model 3: 54.2 (46.1–62.4)b | 53.8 (44.0–63.7)c | |||||
| Stiffness | Crude: 51.9 (46.7–57.1) | 43.9 (38.4–49.4) | 51.5 (46.4–56.5)a | 43.8 (36.7–51.0)b | 40.4 (30.8–49.9)b | 35.0 (24.1–45.9)c |
| Model 3: 40.7 (32.0–49.3)b | 43.8 (33.4–54.2)c | |||||
| Function | Crude: 59.2 (54.8–63.6) | 48.53 (41.1–55.9)* | 58.4 (53.4–63.4)a | 50.5 (43.5–57.5)b | 49.8 (40.2–59.5)b | 41.6 (30.6–52.5)c |
| Model 3: 50.2 (42.7–58.7)b | 51.2 (41.0–61.5)c | |||||
| RAND-36 score | ||||||
| Physical Functioning | Crude: 56.9 (51.6–62.2) | 42.4 (35.1–49.7)a* | 56.0 (50.8–61.2)a | 45.9 (38.5–53.4)c* | 54.4 (35.6–55.2)b | 37.1 (25.9–48.2)c |
| Model 3: 45.8 (36.4–55.1)b | 43.9 (32.6–55.1)c | |||||
| Role-Physical | Crude: 56.1 (46.5–65.7) | 25.0 (15–35)* | 56.0 (46.7–65.3)a | 31.2 (18.1–44.2)b* | 38.2 (20.4–55.9)b | 16.6 (-3.6–36.8)c* |
| Model 3: 39.1 (22.1–56.2)b | 27.7 (7.2–48.3)c | |||||
| Bodily Pain | Crude: 60.7 (57–64.4) | 43.3 (37.5–49.1)* | 60.2 (56.1–64.4)a | 44.2 (38.4–50.0)b* | 48.7 (41.3–56.2)b | 34.5 (26.1–43.0)c* |
| Model 3: 49.2 (42.8–55.6)b | 42.4 (34.7–50.1)c* | |||||
| General Health | Crude: 64.4 (60.5–68.3) | 61.4 (56.6–66.2) | 64.0 (60.2–67.9)a | 63.0 (57.6–68.5)b | 65.1 (57.8–72.3)b | 67.1 (58.8–75.3)c |
| Model 3: 65.7 (58.5–72.8)b | 60.2 (60.5–77.8)c | |||||
| Vitality | Crude: 65.0 (61.1–68.9) | 56.6 (51.1–62.1)* | 64.5 (60.4–68.6)a | 58.40 (52.6–64.2)b | 61.3 (53.5–69.2)b | 57.0 (48.1–66.0)c |
| Model 3: 62.1 (54.4–69.8)b | 59.4 (50.1–68.7)c | |||||
| Social Functioning | Crude: 85.0 (80.9–89.1) | 70.9 (62.5–79.3)* | 84.5 (79.4–89.7)a | 74.0 (66.7–81.3)b* | 76.9 (66.9–86.9)b | 68.1 (56.7–79.5)c |
| Model 3: 77.1 (67.4–86.8)b | 74.2 (62.6–85.9)c | |||||
| Role-Emotional | Crude: 91.0 (85.2–96.8) | 72.1 (60.1–84.1)* | 90.4 (83.1–97.7)a | 75.8 (65.5–86.1)b* | 86.8 (72.4–101.1)b | 74.5 (58.2–90.8)c |
| Model 3: 88.0 (73.8–102.2)b | 76.6 (59.5–93.7)c | |||||
| Mental Health | Crude: 80.4 (76.9–83.9) | 78.1 (73.9–82.3) | 80.7 (77.2–84.2)a | 79.6 (74.7–84.5)b | 82.8 (76.0–89.6)b | 83.3 (75.6–91.1)c |
| Model 3: 83.4 (76.8–90.0)b | 86.3 (78.3–94.3)c | |||||
§ All values are presented as mean (95% CI)
Crude: Unadjusted values
Model 1: adjusted for age, sex, BMI
Model 2: Additionally adjusted for back disorders, painful body regions, comorbidities and previous surgery (includes model 1)
Model 3: Fully adjusted model, additionally adjusted for pain intensity and analgesic usage (includes model 2)
Unlikely NP = unlikely neuropathic pain phenotype (mPDQ≤12); Possible NP = possible neuropathic pain phenotype (mPDQ>12); WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index; RAND-36 = RAND 36-item Health Survey; WOMAC/RAND-36 score = 100 indicates no symptoms/problems and 0 indicates extreme symptoms/problems
a There was 1 individual with missing data on this variable
b There were 2 individuals with missing data on this variable
c There were 3 individuals with missing data on this variable
* A P-value <0.05 was considered to be statistically significant