Table V.
Race-specific IRs per 1000 person-years and their 95% CIs for hip symptoms and OA outcomes by sociodemographic characteristics and hip OA risk factors
| Hip symptoms | OA outcomes
|
||||||||
|---|---|---|---|---|---|---|---|---|---|
|
|
Radiographic
|
Symptomatic
|
|||||||
| African American |
White
|
P value† (PTrend‡)
|
African American |
White
|
P value† (PTrend‡)
|
African American |
White
|
P value† (PTrend‡)
|
|
| IR (95% CI) | IR (95% CI) | IR (95% CI) | IR (95% CI) | IR (95% CI) | IR (95% CI) | ||||
| Overall | |||||||||
| Crude | 28 (20, 39) | 39 (34, 44) | 7 (5, 10) | 24 (21, 27) | 7 (5, 11) | 15 (13, 18) | |||
| Age-standardized* | 30 (22, 42) | 41 (36, 47) | 9 (7, 13) | 28 (23, 34) | 9 (6, 14) | 19 (16, 22) | |||
| Age- and sex-standardized* | 30 (22, 41) | 41 (36, 47) | 9 (7, 13) | 29 (24, 36) | 9 (6, 14) | 19 (16, 22) | |||
| Sociodemographic characteristics | |||||||||
| Age (years) | 0.32 | <0.001§ | <0.001§ | ||||||
| 45–54/50–54║ | 27 (18, 38) | 36 (30, 43) | (0.025) | 5 (3, 7) | 15 (11, 19) | (<0.001§) | 5 (3, 8) | 10 (7, 14) | (<0.001§) |
| 55–64 | 29 (20, 41) | 39 (33, 46) | 10 (7, 14) | 32 (26, 39) | 9 (6, 13) | 18 (14, 23) | |||
| 65–74 | 34 (24, 47) | 46 (38, 55) | 10 (7, 15) | 32 (25, 42) | 10 (6, 15) | 20 (15, 27) | |||
| ≥75 | 35 (21, 60) | 48 (30, 76) | 10 (5, 20) | 32 (17, 59) | 12 (7, 21) | 25 (18, 37) | |||
| Sex | 0.008§ | 0.22 | 0.014§ | ||||||
| Men | 23 (16, 34) | 32 (26, 39) | 7 (5, 10) | 22 (18, 27) | 6 (4, 9) | 12 (9, 16) | |||
| Women | 32 (23, 45) | 44 (38, 51) | 8 (6, 11) | 26 (22, 31) | 9 (6, 13) | 19 (16, 22) | |||
| Highest education | 0.36 | 0.12 | 0.72 | ||||||
| <High school (HS) | 31 (22, 45) | 44 (34, 57) | (0.022) | 8 (5, 13) | 28 (20, 38) | (0.003§) | 8 (5, 12) | 17 (12, 25) | (0.81) |
| Some/completed HS | 29 (20, 42) | 41 (34, 49) | 8 (6, 11) | 26 (22, 31) | 6 (4, 10) | 14 (12, 18) | |||
| >HS | 25 (16, 37) | 35 (28, 43) | 6 (4, 8) | 19 (14, 25) | 7 (4, 11) | 16 (12, 22) | |||
| Annual household income | 0.005§ | 0.39 | 0.44 | ||||||
| $0–<$15,000 | 32 (23, 46) | 50 (42, 60) | 8 (6, 10) | 25 (21, 31) | 7 (5, 11) | 17 (14, 21) | |||
| $15,000–<$35,000 | 23 (16, 34) | 36 (28, 45) | 8 (5, 11) | 25 (20, 32) | 6 (4, 11) | 15 (11, 20) | |||
| ≥$35,000 | 19 (12, 29) | 29 (22, 39) | 6 (4, 9) | 20 (14, 27) | 6 (3, 10) | 13 (8, 20) | |||
| Hip OA risk factors | |||||||||
| Self-reported BMI at age 18 (kg/m2) | 0.37 | 0.84 | 0.008§ | ||||||
| Under/healthy (<25) | 25 (18, 34) | 38 (33, 43) | (0.11) | 8 (6, 11) | 24 (21, 28) | (0.45) | 8 (5, 12) | 16 (13, 19) | (0.19) |
| Overweight/obese (≥25) | 30 (16, 59) | 47 (30, 72) | 8 (5, 13) | 23 (16, 33) | 3 (1, 6) | 6 (3, 12) | |||
| Clinically measured BMI at baseline (kg/m2) | <0.001§ | <0.001§ | 0.94 | ||||||
| Under/healthy weight (<25) | 16 (11, 23) | 25 (20, 31) | (<0.004§) | 11 (7, 16) | 32 (25, 39) | (0.50) | 7 (4, 12) | 15 (12, 19) | (0.71) |
| Overweight (25–<30) | 29 (20, 41) | 44 (37, 53) | 6 (4, 9) | 19 (15, 23) | 7 (4, 11) | 15 (12, 20) | |||
| Obese (≥30) | 34 (23, 51) | 53 (41, 68) | 8 (6, 11) | 24 (19, 32) | 7 (4, 10) | 14 (11, 19) | |||
| Obese Class I (30–<35) | 35 (24, 51) | 54 (40, 71) | 7 (5, 10) | 21 (15, 30) | 7 (4, 11) | 15 (11, 21) | |||
| Obese Class II–IV (≥35) | 33 (16, 67) | 51 (29, 90) | 11 (7, 17) | 34 (23, 50) | 6 (3, 11) | 12 (7, 21) | |||
| History of hip injury | 0.28 | 0.14 | 0.011§ | ||||||
| No | 24 (18, 34) | 38 (34, 43) | 7 (5, 10) | 24 (21, 27) | 7 (4, 10) | 15 (13, 18) | |||
| Yes | 38 (17, 86) | 60 (27, 134) | 12 (6, 21) | 36 (20, 65) | 15 (7, 29) | 33 (19, 59) | |||
*
Standardized to the 2000 projected US population.
†
P-value for differences in IRs.
‡
P-value for trend in IRs; performed through assessment of the slope for continuous variables for age, highest education, self-reported BMI at age 18, and clinically measured BMI at baseline.
§
Statistically significant at Bonferroni-corrected α = 0.0166.
║
Hip symptoms: 45–54 years; radiographic and symptomatic OA: 50–54 years.