Details of test use for geographically variable tests
| Name of test | Mean age (SD), years | Male, n (%) | Frequent diagnoses/symptoms | Incidence rate ratio (95% CI)a | Tests per patientb (SD) | |||
|---|---|---|---|---|---|---|---|---|
| High use | Low use | High use | Low use | 2005 | 2009 | |||
| Plasma viscosity | 55.31 (18.49) | 53.65 (17.38) | 1018 (36.40) | 103 (40.87) | Number with any diagnosis/symptom recorded in the 2 weeks pre-test = 1323 (43.42) | 1.60 (2.01) | 1.25 (0.83)c | |
| Rheumatoid arthritis, systemic connective tissue disorders (n = 62) | 3.28 (2.46 to 4.37) | |||||||
| Back and neck disorders (n = 60) | 2.16 (1.63 to 2.86) | |||||||
| Joint disorders w/e (n = 72) | 1.91 (1.49 to 2.46) | |||||||
| Neurological/musculoskeletal S&S (n = 177) | 1.80 (1.53 to 2.11) | |||||||
| Cardiac enzymes | 57.35 (19.33) | 54.28 (16.40) | 653 (40.48) | 26 (53.06) | Number with any diagnosis/symptom recorded in the 2 weeks pre-test = 600 (36.12) | 1.48 (1.07) | 1.02 (0.14)d | |
| Blood trace elements/vitamins | 57.03 (20.17) | 52.04 (21.98)c | 506 (34.99) | 112 (35.90) | Number with any diagnosis/symptom recorded in the 2 weeks pre-test = 731 (41.58) | 1.49 (1.03) | 1.15 (0.41)c | |
| Neurological/musculoskeletal S&S (n = 101) | 1.55 (1.25 to 1.91) | |||||||
| Creatine phosphokinase | 59.58 (17.54) | 61.51 (15.44)b | 1298 (45.16) | 491 (51.58)b | Number with any diagnosis/symptom recorded in the 2 weeks pre-test = 1668 (43.60) | 2.52 (2.18 to 2.93) | 1.32 (0.83) | 1.19 (0.51)e |
| Soft tissue disorders (n = 218) | ||||||||
| Blood film report | 51.89 (23.74) | 49.28 (21.48) | 427 (40.02) | 90 (33.46)e | Number with any diagnosis/symptom recorded in the 2 weeks pre-test = 805 (60.25) | 1.83 (1.46 to 2.28) | 1.19 (0.54) | 1.22 (0.58) |
| Fatigue, tiredness, malaise and dizziness (n = 92) | ||||||||
n = number of times the symptoms was recorded in the 2 weeks prior to the test in the patients receiving the test. SD = standard deviation. S&S = signs and symptoms. W/e = with specific exclusions.
↵a Comparing the relative frequency of Read Code Groups recorded in patients who had that test (cases) compared with a cohort of patients matched on sex, age, and geographic region (controls) who underwent a different laboratory test in the same quarter of the year as the case.
↵b The total number of tests they received during the year, given that they had at least one test.
↵c Significant at the 0.1% level when fitting a Poisson model (tests per patient), linear model (age); logistic model (% male) with year as covariate.
↵b Significant at the 1% level.
↵e Significant at the 5% level.