Baseline and cross-harvest eGFR and IKI by risk factor category
| Harvest finishers only | Including also dropouts | ||||||||
| Total (n) | Continuous eGFR (mL/min/1.73 m2) | IKI | |||||||
| Mean difference at baseline§ (95% CI) | Mean cross-harvest eGFR slope (ΔeGFR) difference§ (95% CI) | IKI-Measured* event | Total (n) | IKI-All† event | |||||
| n (%) | Univariate IR (95% CI) | n (%) | Univariate IR (95% CI) | Adjusted‡ IR (95% CI) | |||||
| All | 427 | Not applicable | Not applicable | 32 (7) | Not applicable | 525 | 63 (12) | Not applicable | Not applicable |
| Sex | |||||||||
| Female | 111 | Ref | Ref | 0 (0) | Not applicable | 131 | 5 (4) | 1 (–) | 1 (–) |
| Male | 316 | −6.1 (−11 to 1.5) | −0.4 (−3.8 to 3.0) | 32 (10) | 394 | 58 (15) | 3.89 (1.55 to 9.62) | 1.24 (0.44 to 3.50) | |
| Age | |||||||||
| 18–29 | 233 | Ref | Ref | 19 (8) | 1 (–) | 292 | 36 (12) | 1 (–) | 0.98 (0.94 to 1.01) |
| 30–39 | 153 | −13 (−17 to 8.6) | 1.5 (−1.4 to 4.5) | 11 (7) | 0.88 (0.42 to 1.85) | 178 | 21 (12) | 0.96 (0.56 to 1.64) | |
| 40–49 | 32 | −20 (−26 to 13) | 3.4 (−1.8 to 8.6) | 2 (6) | 0.77 (0.18 to 3.29) | 43 | 5 (12) | 0.94 (0.37 to 2.40) | |
| 50–60 | 9 | −26 (−38 to 13) | 7.0 (−2.4 to 16) | 0 (0) | Not applicable | 12 | 1 (8) | 0.68 (0.09 to 5.00) | |
| Job category | |||||||||
| Cane cutters | 128 | −6.1 (−11 to 1.2) | −9.2 (−13 to 5.6) | 27 (21) | 6.24 (2.40 to 16.2) | 157 | 43 (27) | 14.2 (1.96 to 103) | 11.8 (3.93 to 35.4) |
| Seed cutters | 148 | −5.8 (−10 to 1.5) | −4.3 (−7.5 to 1.0) | 5 (3) | 1 (–) | 188 | 16 (9) | 4.55 (0.59 to 33.4) | 3.54 (1.17 to 10.7) |
| Irrigation repair | 109 | Ref | Ref | 0 (0) | Not applicable | 128 | 3 (2) | 1.22 (0.13 to 11.7) | 1 (–) |
| Field support | 42 | 0 (0) | Not applicable | 52 | 1 (2) | 1 (–) | |||
| Pesticide use | |||||||||
| No | 415 | Ref | Ref | 29 (7) | 1 (–) | Pesticide use data were not collected among dropouts. | |||
| Yes | 13 | −3.4 (−14 to 7) | −7 (−15 to 0.8) | 3 (23) | 3.29 (1.00 to 10.8) | ||||
| Incident fever | |||||||||
| No | 383 | Ref | Ref | 23 (6) | 1 (–) | Symptoms data were not collected among dropouts. | |||
| Yes | 43 | −0.9 (−6.8 to 5.1) | −4.7 (−9.1 to 0.3) | 9 (21) | 3.49 (1.77 to 9.22) | ||||
| Chikungunya during harvest | |||||||||
| No | 425 | Ref | Ref | 31 (7) | 1 (–) | 516 | 59 (11) | 1 (–) | 1 (–) |
| Yes | 2 | −9.0 (−35 to 17) | −13 (−32 to 6.8) | 1 (50) | 6.85 (0.94 to 50.2) | 9 | 4 (44) | 3.89 (1.41 to 10.7) | 2.58 (0.93 to 7.14) |
| NSAID use | |||||||||
| No | 330 | Ref | Ref | 21 (6) | 1 (–) | 409 | 47 (11) | 1 (–) | 1 (–) |
| Yes | 97 | −1 (−5.3 to 3.3) | −2.9 (−6.1 to 0.3) | 11 (11) | 1.78 (0.86 to 3.70) | 116 | 16 (14) | 1.2 (0.68 to 2.12) | 1.14 (0.64 to 2.02) |
| Current smoking¶ | |||||||||
| No | 303 | Ref | Ref | 19 (6) | 1 (–) | 373 | 39 (10) | 1 (–) | 1 (–) |
| Yes | 124 | 3.9 (−0.3 to 8) | −1.3 (−4.4 to 1.9) | 13 (11) | 1.67 (0.83 to 3.39) | 147 | 24 (16) | 1.56 (0.94 to 2.60) | 1.25 (0.74 to 2.11) |
| Change in 24-hour liquid intake over harvest (L) | |||||||||
| <0 | 74 | 1.6 (−5.0 to 2.6) | −1.2 (−5.0 to 2.6) | 6 (8) | 1.28 (0.48 to 3.40) | Liquid intake data were not collected among dropouts. | |||
| +0–5 | 189 | Ref | Ref | 12 (7) | 1 (–) | ||||
| +5–10 | 140 | 3.1 (−1.0 to 7.3) | 1.6 (−1.5 to 4.6) | 10 (7) | 1.13 (0.49 to 2.60) | ||||
| +>10 | 23 | 3.2 (−5.1 to 12) | 4.8 (−1.4 to 11) | 4 (18) | 2.74 (0.88 to 8.49) | ||||
| Electrolyte solution intake per 24 hours at end of harvest (number of 300 mL bags) | |||||||||
| 0 | 126 | Ref | Ref | 8 (6) | 1 (–) | Liquid intake data were not collected among dropouts. | |||
| 1-3 | 188 | 1.4 (−2.8 to 5.7) | 1.9 (−1.3 to 5.0) | 18 (10) | 1.51 (0.66 to 3.47) | ||||
| ≥4 | 112 | −1.3 (−6.0 to 3.5) | 4.8 (1.3 to 8.4) | 6 (5) | 0.84 (0.29 to 2.43) | ||||
| Sugary beverage intake per 24 hours at end of harvest (L) | |||||||||
| <0.5 | 184 | Ref | Ref | 8 (4) | 1 (–) | Liquid intake data were not collected among dropouts. | |||
| 0.5–1.5 | 188 | 0.8 (−3 to 4.6) | −3.9 (−6.7 to 1) | 18 (10) | 2.2 (0.96 to 5.06) | ||||
| >1.5 | 54 | −2.2 (−7.9 to 3.6) | −2.9 (−7.2 to 1.3) | 6 (11) | 2.56 (0.89 to 7.37) | ||||
| Baseline eGFR (mL/min/1.73 m2) | |||||||||
| >90 | 305 | Ref | Ref | 16 (5) | 1 (–) | 373 | 31 (8) | 1 (–) | 1 (–) |
| 75–90 | 67 | −28 (−30 to 25) | 3.3 (−0.6 to 7.1) | 7 (10) | 1.99 (0.82 to 4.84) | 83 | 13 (16) | 1.88 (0.99 to 3.60) | 1.52 (0.77 to 2.97) |
| 60–74 | 43 | −43 (−46 to 40) | 3.3 (−1.4 to 7.9) | 8 (19) | 3.55 (1.52 to 8.29) | 52 | 13 (25) | 3.01 (1.57 to 5.75) | 2.76 (1.38 to 5.49) |
| <60 | 12 | −59 (−64 to 53) | 7.9 (−0.2 to 16) | 1 (8) | 1.59 (0.21 to 12.0) | 17 | 6 (35) | 4.25 (1.77 to 10.2) | 3.48 (1.42 to 8.50) |
| Diabetes (self-reported) | |||||||||
| No | 425 | Ref | Ref | 32 (8) | Not applicable | 522 | 63 (12) | Not applicable | |
| Yes | 2 | 4.3 (−22 to 31) | −4.8 (−24 to 15) | 0 (0) | 3 | 0 (0) | |||
| Hypertension (self-reported and/or measured (>140/90 mm Hg))** | |||||||||
| No | 412 | Ref | Ref | 31 (8) | 1 (–) | 508 | 60 (12) | 1 (–) | 1 (–) |
| Yes | 12 | −8.1 (−19 to 3) | 3.5 (−4.8 to 12) | 1 (8) | 1.11 (0.15 to 8.11) | 14 | 3 (21) | 1.81 (0.57 to 5.78) | 1.95 (0.59 to 6.42) |
*SCr at the end of harvest ≥0.30 mg/dL higher than or ≥1.5 times the baseline value.
†SCr at the end of harvest ≥0.30 mg/dL higher than or ≥1.5 times the baseline value or self-reported elevated SCr during harvest leading to sick leave or dismissal from job.
‡Model: job category (combining irrigation repair workers and field support staff), age (continuous), sex and risk factor.
§Adjusted for job, sex and age category and their interaction with test occasion.
¶5 with missing data on smoking.
**3 with missing data on hypertension.
eGFR, estimated glomerular filtration rate; IKI, incident kidney injury; IR, incidence ratio; NSAID, non-steroidal anti-inflammatory drug; SCr, serum creatinine.