Table 1 Baseline characteristics of the matched exposed and unexposed groups
Variables | Unexposed (n = 472,173), n (%) | Exposed (n = 472,173), n (%) |
|---|---|---|
Age (mean (SD)) | 44.14 (16.92) | 44.16 (16.86) |
Sex | ||
 Male | 210,848 (44.7) | 211,683 (44.8) |
 Female | 261,325 (55.3) | 260,490 (55.2) |
Ethnicity | ||
 White | 300,873 (63.7) | 299,609 (63.5) |
 Asian | 59,720 (12.6) | 60,544 (12.8) |
 Black | 18,572 (3.9) | 18,598 (3.9) |
 Mixed | 9,410 (2.0) | 9,448 (2.0) |
 Other | 7,266 (1.5) | 7,208 (1.5) |
 Missing | 76,332 (16.2) | 76,766 (16.3) |
IMD | ||
 1 (Least deprived) | 74,314 (15.7) | 74,123 (15.7) |
 2 | 76,964 (16.3) | 76,637 (16.2) |
 3 | 80,474 (17.0) | 80,293 (17.0) |
 4 | 96,097 (20.4) | 96,506 (20.4) |
 5 (Most deprived) | 102,825 (21.8) | 103,331 (21.9) |
 Missing | 41,499 (8.8) | 41,283 (8.7) |
Smoking Status | ||
 Current smoker | 104,696 (22.2) | 104,986 (22.2) |
 Ex-Smoker | 165,128 (35.0) | 163,759 (34.7) |
 Never smoked | 159,371 (33.8) | 159,655 (33.8) |
 Missing | 42,978 (9.1) | 43,773 (9.3) |
BMI category | ||
 Normal weight | 143,346 (30.4) | 144,426 (30.6) |
 Underweight | 17,363 (3.7) | 17,483 (3.7) |
 Obese | 127,060 (26.9) | 125,086 (26.5) |
 Overweight | 139,589 (29.6) | 138,694 (29.4) |
Missing | 44,815 (9.5) | 46,484 (9.8) |
Number of consultations 3 to 12Â months prior to index date (mean (SD)) | ||
 GP | 2.12 (3.68) | 2.15 (3.44) |
 Nurse | 0.50 (1.59) | 0.50 (1.49) |
 Physiotherapist | 0.01 (0.19) | 0.01 (0.19) |
 Surgery | 1.22 (2.24) | 1.20 (2.03) |
 Home visits | 0.03 (0.45) | 0.07 (0.79) |
 Telephone | 1.37 (2.73) | 1.38 (2.52) |
 Triage | 0.02 (0.30) | 0.02 (0.27) |