Associations between symptoms and positive urine dipstick results and kidney function and kidney injury
| Symptoms and Results | Number of Events (N) | Mean Difference (95% CI) | Relative Means (95% CI) | ||||||||
| eGFR | NGALb | NAGb | IL-18b | ACR | |||||||
| Crude | Adjusteda | Crude | Adjusteda | Crude | Adjusteda | Crude | Adjusteda | Crude | Adjusteda | ||
| Symptoms, prior 3 moc,d | |||||||||||
| Abdominal, back, flank pain | 63 | −3.1 (−8.3 to 2.1) | −2.3 (−6.5 to 1.9) | 1.2 (0.9 to 1.7) | 1.2 (0.8 to 1.6) | 1.3 (0.9 to 1.7) | 1.2 (0.9 to 1.6) | 1.0 (0.7 to 1.3) | 0.9 (0.7 to 1.2) | 1.3 (0.9 to 1.8) | 1.3 (0.9 to 1.8) |
| Burning or pain during urination | 28 | 3.0 (−1.6 to 7.6) | 3.7 (−2.1 to 9.4) | 1.5 (1 to 2.3) | 1.4 (0.9,2.1) | 1.1 (0.7 to 1.7) | 1.0 (0.7 to 1.6) | 1.3 (0.9 to 1.9) | 1.2 (0.8 to 1.8) | 1.0 (0.6 to 1.7) | 1.1 (0.7 to 1.8) |
| Periods of frequent urination | 21 | −1.4 (−8.5 to 5.7) | 0.2 (−6.3 to 6.7) | 1.3 (0.8 to 2.1) | 1.1 (0.7 to 1.8) | 0.8 (0.5 to 1.3) | 0.7 (0.5 to 1.2) | 1.4 (0.9 to 2.2) | 1.3 (0.8 to 2) | 1.3 (0.7 to 2.3) | 1.3 (0.8 to 2.3) |
| Any fever or chills | 28 | −2.1 (−8.3 to 4.1) | 1.2 (−4.8 to 7.1) | 1.5 (1 to 2.4) | 1.2 (0.8 to 1.9) | 1.8 (1.2 to 2.8)e | 1.5 (1 to 2.2) | 1.2 (0.8 to 1.8) | 1.0 (0.7 to 1.5) | 1.0 (0.6 to 1.6) | 1.0 (0.6 to 1.7) |
| Chistataf | 81 | 1.7 (−2.6 to 5.9) | 1.4 (−2.5 to 5.4) | 1.4 (1 to 1.8)e | 1.3 (1 to 1.7) | 1.2 (0.9 to 1.6) | 1.1 (0.9 to 1.5) | 1.2 (0.9 to 1.5) | 1.1 (0.9 to 1.5) | 0.8 (0.6 to 1.2) | 0.9 (0.6 to 1.2) |
| Health-related behaviors and diagnoses, prior 3 moc,d | |||||||||||
| Taken antibiotics | 31 | −0.4 (−6.4 to 5.6) | −1.3 (−6.8 to 4.1) | 1.1 (0.7 to 1.7) | 1.2 (0.8 to 1.9) | 1.3 (0.9 to 2) | 1.5 (1 to 2.2)e | 1.1 (0.8 to 1.6) | 1.2 (0.8 to 1.7) | 1.1 (0.7 to 1.8) | 1.2 (0.7 to 1.8) |
| Taken pain medications >3 d | 34 | −5.3 (−12.4 to 1.8) | −2.8 (−8.2 to 2.5) | 1.4 (0.9 to 2) | 1.3 (0.9 to 1.9) | 1.5 (1 to 2.3)e | 1.4 (1 to 2.1) | 1.5 (1.1 to 2.2)e | 1.4 (1 to 2) | 0.7 (0.5 to 1.2) | 0.7 (0.5 to 1.1) |
| Dipstick parameters, preharvestg | |||||||||||
| Leukocyte esterase | 11 | −2.7 (−12.2 to 6.9) | −1.8 (−10.6 to 7.0) | 1.6 (0.8 to 3.3) | 1.5 (0.8 to 2.9) | 1.5 (0.8 to 2.9) | 1.3 (0.7 to 2.5) | 1.3 (0.7 to 2.5) | 1.3 (0.7 to 2.3) | 1.0 (0.5 to 2.2) | 1.1 (0.5 to 2.3) |
| Proteinuria | 6 | −0.9 (−13.7 to 11.9) | 2.8 (−8.9 to 14.5) | 6.7 (2.7 to 16.2)e | 4.9 (2.1 to 11.6)e | 3.8 (1.6 to 9.1)e | 3.0 (1.3 to 6.7)e | 3.0 (1.3 to 6.6)e | 3.1 (1.4 to 6.9)e | 5.7 (2.1 to 15.7)e | 5.5 (2.1 to 14.4)e |
| Dipstick parameters, late harvestg,h | |||||||||||
| Leukocyte esterase | 29 | −13.3 (−25.0 to −1.6)e | −12.9 (−18.7 to −7.0)e | 3.4 (2.2 to 5.1)e | 2.8 (1.8 to 4.3)e | 1.5 (1 to 2.2) | 1.0 (0.7 to 1.6) | 0.6 (0.4 to 0.9)e | 0.5 (0.3 to 0.7)e | 1.0 (0.6 to 1.6) | 0.9 (0.6 to 1.5) |
| Proteinuria | 8 | −14.1 (−37.5 to 9.3) | −10.9 (−21.1 to −0.7)e | 3.7 (1.7 to 8.1)e | 3.0 (1.4 to 6.6)e | 2.5 (1.2 to 5.5)e | 2.1 (1 to 4.3) | 2.5 (1.3 to 5.1)e | 3.1 (1.5 to 6.3)e | 12.4 (5.3 to 28.9)e | 9.4 (4.2 to 21.4)e |
| Blood | 21 | −10.6 (−23.0 to 1.9) | −8.5 (−15.0 to −2.0)e | 0.9 (0.5 to 1.4) | 0.8 (0.5 to 1.3) | 1.6 (1 to 2.7)e | 1.5 (0.9 to 2.3) | 1.0 (0.6 to 1.5) | 1.0 (0.7 to 1.6) | 1.7 (1 to 3) | 1.6 (0.9 to 2.7) |
NGAL, neutrophil gelatinase-associated lipocalin; NAG, N-acetyl-β-d-glucosaminidase; ACR, albumin-creatinine ratio.
↵a Adjusted for age, employment duration, and job category.
↵b All crude and adjusted models predicting NGAL, NAG, and IL-18 were additionally adjusted for urinary creatinine.
↵c Reference was workers not reporting symptoms or health-related behaviors.
↵d Workers reported symptoms and health-related behaviors during late-harvest data collection.
↵e P<0.05.
↵f Chistata is a colloquial term that describes a set of symptoms including painful urination, burning during urination, and back pain.
↵g Reference was workers with negative dipstick results.
↵h Cross-sectional analyses.