Background
Methods
Ethnic groups
Classification of chronic pain
Classification of depression
Potential confounding variables
Ethical approval
Statistical analysis
Results
Ethnic groupa | ||||
---|---|---|---|---|
Overall N = 144,139 | White N = 135,703 | Asian N = 4539 | Black N = 3897 | |
Presence of chronic painb | ||||
Yes N (%) | 58,785 (40.8) | 54,949 (40.5) | 2081 (45.8) | 1755 (45.0) |
Extent of chronic painb | ||||
0 N (%) | 85,354 (59.2) | 80,754 (59.5) | 2458 (54.2) | 2142 (55.0) |
1 | 32,948 (22.9) | 31,040 (22.9) | 1023 (22.5) | 885 (22.7) |
2–3 | 20,975 (14.6) | 19,554 (14.4) | 791 (17.4) | 630 (16.2) |
4–7 | 3371 (2.3) | 3096 (2.3) | 145 (3.2) | 130 (3.3) |
Pain all over the body | 1491 (1.0) | 1259 (0.9) | 122 (2.7) | 110 (2.8) |
Depression (lifetime history)b | ||||
Yes N (%) | 31,080 (21.6) | 29,957 (22.1) | 584 (12.9) | 539 (13.8) |
Depression and chronic pain statusb | ||||
Free of depression and chronic pain N (%) | 69,942 (48.5) | 65,795 (48.5) | 2214 (48.8) | 1933 (49.6) |
Depression only | 15,412 (10.7) | 14,959 (11.0) | 244 (5.4) | 209 (5.4) |
Chronic pain only | 43,117 (29.9) | 39,951 (29.4) | 1741 (38.4) | 1425 (36.6) |
Chronic pain and depression | 15,668 (10.9) | 14,998 (11.1) | 340 (7.5) | 330 (8.5) |
Sexb | ||||
Female N (%) | 79,596 (53.1) | 72,166 (53.2) | 2122 (46.8) | 2308 (59.2) |
Age (years)b | ||||
Mean (SD) | 56.8 (8.1) | 57.1 (8.1) | 53.6 (8.6) | 52.3 (8.0) |
Townsend Index quintiles | ||||
Missing data N | 230 | 210 | 10 | 10 |
1 (least deprived) N (%) | 24,482 (17.0) | 24,091 (17.8) | 304 (6.7) | 87 (2.24) |
2 | 29,077 (20.2) | 28,557 (21.1) | 351 (7.8) | 169 (4.4) |
3 | 29,978 (20.8) | 28,959 (21.4) | 674 (14.9) | 345 (8.9) |
4 | 32,347 (22.5) | 29,760 (22.0) | 1575 (34.8) | 1012 (26.0) |
5 (most deprived) | 28,025 (19.5) | 24,126 (17.8) | 1625 (35.9) | 2274 (58.5) |
Smoking status | ||||
Missing data N | 445 | 389 | 35 | 21 |
Never N (%) | 80,000 (55.7) | 73,679 (54.5) | 3544 (78.7) | 2777 (71.7) |
Former | 53,717 (37.4) | 52,184 (38.6) | 718 (15.9) | 815 (21.0) |
Current | 9977 (6.9) | 9451 (7.0) | 242 (5.4) | 284 (7.3) |
Frequency of alcohol intake | ||||
Missing data N | 66 | 44 | 15 | 7 |
Daily/almost daily N (%) | 30,118 (20.9) | 29,530 (21.8) | 335 (7.4) | 253 (6.5) |
3–4 times/week | 33,362 (23.2) | 32,552 (24.0) | 412 (9.1) | 397 (10.2) |
1–2 times/week | 36,663 (25.5) | 35,204 (30.0) | 664 (14.7) | 795 (20.4) |
1–3 times/month | 16,190 (11.2) | 15,239 (11.2) | 378 (8.4) | 573 (14.7) |
Special occasions only | 16,376 (11.4) | 14,388 (10.6) | 876 (19.4) | 1112 (28.6) |
Never | 11,364 (7.9) | 8745 (6.5) | 1859 (41.1) | 760 (19.5) |
BMI | ||||
Missing data N | 980 | 765 | 126 | 89 |
Mean (SD)
| 27.5 (1.8) | 27.4 (4.7) | 27.0 (4.4) | 29.6 (5.4) |
Morbidity countb | ||||
Mean (SD)
| 0.9 (1.0) | 0.8 (1.0) | 0.9 (1.1) | 0.9 (1.0) |
Current depressive symptom score | ||||
Missing data N | 11,511 | 10,018 | 833 | 660 |
Mean (SD)
| 1.5 (2.0) | 1.4 (1.9) | 2.5 (2.8) | 2.2 (2.7) |
Description of ethnic groups
Association between depression and the presence of chronic pain
Ethnic group | |||
---|---|---|---|
Level of adjustmenta | White OR (95 % CI)* | Asian OR (95 % CI)* | Black OR (95 % CI)* |
Model 1 - no adjustment | 1.65 (1.61, 1.69) | 1.77 (1.48, 2.11) | 2.14 (1.78, 2.58) |
Model 2 - adjusted for demographic factors | 1.61 (1.57, 1.66) | 1.71 (1.43, 2.05) | 2.12 (1.75, 2.56) |
Model 3 - adjusted for demographic and lifestyle factors | 1.53 (1.45, 1.57) | 1.62 (1.35, 1.95) | 1.99 (1.63, 2.42) |
Model 4 - adjusted for demographic, lifestyle and morbidity count | 1.46 (1.43, 1.51) | 1.53 (1.27, 1.85) | 1.86 (1.52, 2.27) |
Association between depression and the extent of chronic pain
Ethnic group | ||||
---|---|---|---|---|
Level of adjustment^ | Extent of chronic pain | White RRR (95 % CI) | Asian RRR (95 % CI) | Black RRR (95 % CI) |
Model 1 – no adjustment | 1 pain site | 1.36 (1.32, 1.40) | 1.25 (0.99, 1.57)** | 1.58 (1.25, 2.00) |
2–3 pain sites | 1.89 (1.82, 1.95) | 1.97 (1.57, 2.47) | 2.29 (1.80, 2.92) | |
4–7 pain sites | 3.16 (2.94, 3.40) | 3.46 (2.35, 5.09) | 4.26 (2.87, 6.33) | |
Pain all over the body | 2.96 (2.64, 3.31) | 3.65 (2.41, 5.52) | 4.32 (2.82, 6.61) | |
Model 2 - adjusted for demographic factors | 1 pain site | 1.35 (1.31, 1.39) | 1.22 (0.97, 1.54)** | 1.61 (1.27, 2.05) |
2–3 pain sites | 1.82 (1.76, 1.89) | 1.92 (1.53, 2.41) | 2.23 (1.74, 2.86) | |
4–7 pain sites | 2.94 (2.73, 3.17) | 3.30 (2.22, 4.90) | 4.18 (2.78, 6.29) | |
Pain all over the body | 2.80 (2.49, 3.14) | 3.60 (2.37, 5.48) | 4.05 (2.61, 6.29) | |
Model 3 - adjusted for demographic and lifestyle factors | 1 pain site | 1.31 (1.27, 1.36) | 1.16 (0.92, 1.47)** | 1.52 (1.19, 1.95)* |
2–3 pain sites | 1.72 (1.66, 1.78) | 1.82 (1.47, 2.34) | 2.11 (1.64, 2.73) | |
4–7 pain sites | 2.66 (2.47, 2.87) | 3.02 (2.00, 4.58) | 3.63 (2.36, 5.58) | |
Pain all over the body | 2.48 (2.20, 2.79) | 3.23 (2.08, 5.00) | 4.10 (2.59, 6.50) | |
Model 4 – adjusted for demographic, lifestyle and morbidity count | 1 pain site | 1.29 (1.24, 1.33) | 1.14 (0.90, 1.45)** | 1.49 (1.16, 1.91)* |
2–3 pain sites | 1.63 (1.57, 1.69) | 1.77 (1.40, 2.24) | 1.98 (1.53, 2.56) | |
4–7 pain sites | 2.35 (2.17, 2.54) | 2.52 (1.65, 3.87) | 3.23 (2.09, 4.99) | |
Pain all over the body | 2.19 (1.94, 2.47) | 2.63 (1.67, 4.13) | 3.31 (2.05, 5.33) |