Table 1. Descriptive analysis of patients with knee OA.
| Characteristic n (%)* | HA group (n = 9,476) |
N-HA group (n = 5,306) | All patients (n = 14,782) | P-value** | |
|---|---|---|---|---|---|
| Gender | 0.056 | ||||
| Male | 3,213 (33.91) | 1,717 (32.36) | 4,930 (33.35) | ||
| Female | 6,263 (66.09) | 3,589 (67.64) | 9,852 (66.65) | ||
| Age at diagnosis | <0.0001 | ||||
| Mean (±SD) | 67.90 (±10.15) | 67.26 (±10.85) | 67.67 (±10.41) | ||
| Median [Q1—Q3] | 67 [60–76] | 66 [58–76] | 67 [59–76] | ||
| Presence of long-term disease(s) at diagnosis | 0.702 | ||||
| Yes | 3,228 (34.07) | 1,824 (34.38) | 5,052 (34.18) | ||
| No | 6,248 (65.93) | 3,482 (65.62) | 9,730 (65.82) | ||
| Charlson index | 0.146 | ||||
| 0 | 3,533 (37.28) | 1,901 (35.83) | 5,434 (36.76) | ||
| 1–2 | 4,075 (43.00) | 2,364 (44.55) | 6,439 (43.56) | ||
| ≥ 3 | 1,868 (19.71) | 1,041 (19.62) | 2,909 (19.68) | ||
| Primo-prescriber's specialty | <0.0001 | ||||
| General practice (GP) | 1,540 (16.25) | 2,013 (37.94) | 3,553 (24.04) | ||
| Rheumatology/Physical medicine and rehabilitation | 7,223 (76.22) | 3,003 (56.60) | 10,226 (69.18) | ||
| Orthopedic surgery | 713 (7.52) | 290 (5.47) | 1,003 (6.79) | ||
| Number of annual visits to the GP | <0.0001 | ||||
| Mean (±SD) | 8.32 (±5.70) | 9.05 (±6.76) | 8.58 (±6.11) | ||
| Median [Q1—Q3] | 7.11 [4.68–10.79] | 7.47 [4.90–11.70] | 7.24 [4.74–11.11] | ||
| At least one hospitalization (TKR excluded) | 0.777 | ||||
| Yes | 6,388 (67.41) | 3,589 (67.64) | 9,977 (67.49) | ||
| No | 3,088 (32.59) | 1,717 (32.36) | 4,805 (32.51) | ||
| Number of annual visits to the specialists of joint diseases † | <0.0001 | ||||
| Mean (±SD) | 3.36 (±3.50) | 1.59 (±2.61) | 2.72 (±3.32) | ||
| Median [Q1—Q3] | 2.44 [1.29–4.29] | 0.78 [0.20–1.94] | 1.81 [0.73–3.61] | ||
| Number of annual IA HA injections ‡ | <0.0001 | ||||
| Mean (±SD) | 2.88 (±5.77) | 0 (±0) | 1.84 (±4.82) | ||
| Median [Q1—Q3] | 1.76 [0.93–3.27] | 0 [0–0] | 0.85 [0.00–2.30] | ||
| Number of days between inclusion and first IA HA injection(s) | NA | ||||
| Mean (±SD) | 182 (±330) | - | 182 (±330) | ||
| Median [Q1—Q3] | 70 [23–193] | - | 70 [23–193] | ||
| Number of annual IA CS injections § | <0.0001 | ||||
| Mean (±SD) | 1.57 (±4.63) | 1.64 (±4.52) | 1.60 (±4.58) | ||
| Median [Q1—Q3] | 0.88 [0.45–1.74] | 0.76 [0.37–1.63] | 0.82 [0.41–1.70] | ||
| Number of days between inclusion and first IA CS injection(s) § | <0.0001 | ||||
| Mean (±SD) | 209 (±358) | 98 (±105) | 158 (±278) | ||
| Median [Q1—Q3] | 68 [18–234] | 54 [12–161] | 61 [15–193] | ||
| Number of follow-up days | <0.0001 | ||||
| Mean (±SD) | 1,267 (±791) | 1,329 (±830) | 1,289 (±806) | ||
| Median [Q1—Q3] | 1,131 [585–1,912] | 1,231 [595–2,42] | 1,169 [588–1,957] | ||
| Range | [7–2,916] | [8–2,912] | [7–2,916] | ||
| Type of follow-up end | <0.0001 | ||||
| Total knee replacement (TKR) | 1,296 (13.68) | 366 (6.90) | 1,662 (11.24) | ||
| Death (censor) | 388 (4.09) | 323 (6.09) | 711 (4.81) | ||
| Exit (censor) | 50 (0.53) | 46 (0.87) | 96 (0.65) | ||
| End of study (censor) | 7,742 (81.70) | 4,571 (86.15) | 12,313 (83.30) | ||
No missing data
HA group: patients who received at least one IA HA injection during their follow-up period, N-HA group: patients who received only CS as IA injections, GP: general practionner, TKR: total knee replacement, OA: osteoarthritis, IA: intra-articular, HA: hyaluronic acid, CS: corticosteroids
* n (%) unless stated otherwise
** T-test, Wilcoxon (for mean difference) or Chi-squared tests (for percentage difference) (NA: not applicable)
† Rheumatologist, orthopedic surgeon and physical medicine and rehabilitation practitioner
‡ Calculated by combining mono- and multi-injections treatments
§ Calculated on 11,561 Patients who received at least one IA CS injection during their follow-up period (n = 6,255 for HA group, n = 5,306 for N-HA group)