Table 2.
Univariate and multivariable Cox regression analysis on the relationship between candidate prognostic factors and Time-to-THR
| Baseline patient characteristic (candidate prognostic factor) | Unadjusted model | Adjusted model | ||
|---|---|---|---|---|
| HR (95% CI) | P value | HR (95% CI) | P value | |
| Male (vs. female) | 1.24 (1.09-1.41) | < 0.01 | 1.43 (1.25–1.64) | < 0.01 |
| BMI, kg/m2 | 1.01 (0.99-1.02) | 0.26 | 0.98 (0.97–1.00) | 0.01 |
| Smoking (vs. no smoking) | 0.83 (0.67-1.03) | 0.09 | 0.70 (0.56–0.87) | < 0.01 |
| Employed (vs. retired) | 1.31 (1.07-1.59) | 0.01 | 1.25 (1.02–1.52) | 0.03 |
| Use of pain medication the last three months (vs. no pain medication) | 1.66 (1.46-1.90) | < 0.01 | 1.42 (1.23–1.63) | < 0.01 |
| Self-reported radiographic OA (vs. no ROA) | 2.81 (2.26-3.48) | < 0.01 | 2.32 (1.87–2.88) | < 0.01 |
|
Comorbidities None One Two Three or more |
Reference category 0.96 (0.84–1.10) 0.92 (0.77–1.09) 0.73 (0.57–0.94) |
0.59 0.34 0.01 |
Ref. category 0.90 (0.79–1.04) 0.85 (0.71–1.02) 0.62 (0.48–0.81) |
0.15 0.08 < 0.01 |
| Wait-listed for THR (vs. not wait-listed) | 2.88 (2.22–3.75) | < 0.01 | 2.17 (1.66–2.83) | < 0.01 |
| Joint replacement in other hip or knees (vs. no previous THR/TKR) | 1.50 (1.26–1.79) | < 0.01 | 1.44 (1.20–1.72) | < 0.01 |
| Bilateral hip symptoms (vs. unilateral symptoms) | 0.73 (0.63–0.84) | < 0.01 | 0.78 (0.67–0.90) | < 0.01 |
| Number of painful areas during the last 24 h (out of 0–56 possible areas) | 0.97 (0.95–0.99) | < 0.01 | 0.94 (0.92–0.96) | < 0.01 |
| Hip pain (VAS 0–100) | 1.01 (1.01–1.2) | < 0.01 | 1.01 (1.00–1.01) | < 0.01 |
| HOOS QoL score (0–100) | 0.97 (0.97–0.98) | < 0.01 | 0.98 (0.97–0.98) | < 0.01 |
| 40 m walk test (m/s) | 0.52 (0.43–0.63) | < 0.01 | 0.64 (0.51–0.80) | < 0.01 |
| 30 s chair stand test (number of rises) | 0.97 (0.95–0.99) | < 0.01 | Excludeda | |
| ASES (10-100) | 0.99 (0.99–0.99) | < 0.01 | Excludeda | |
|
UCLA activity score collapsed to five categories 1–2 3–4 5–6 7–8 9–10 |
Ref. category 1.32 (0.74–2.36) 1.28 (0.72–2.28) 1.35 (0.76–2.40) 1.16 (0.63–2.14) |
0.34 0.41 0.31 0.64 |
Excludeda | |
| Fear of joint damage from activity (vs. no fear) | 1.22 (1.01–1.48) | 0.04 | Excludeda | |
|
Educational level Primary school Secondary school Short-cycle higher Middle-cycle higher Long-cycle higher |
Ref. category 1.04 (0.82–1.31) 1.04 (0.85–1.28) 1.05 (0.89–1.25) 1.12 (0.90–1.40) |
0.76 0.68 0.56 0.31 |
Excludeda | |
| Living alone (vs. living with others) | 0.95 (0.83–1.09) | 0.48 | Excludeda | |
| Sick leave more than 1 month (vs. no sick leave or less than a month) | 1.25 (0.87–1.81) | 0.23 | Excludeda | |
HOOS QoL, Quality of life subscale score from the Hip disability and Osteoarthritis Outcome score (worst to best)
ASES, Arthritis Self-Efficacy Scale (worst to best)
UCLA, University of California, Los Angeles activity score
aExcluded = eliminated in the backward stepwise elimination