Table 3.
Sensitivity analyses of Table 2 results with the use of alternative referent populations and application of bias and age restrictions
| Outcome | Sensitivity analysis∗ mRR (95% CI) No. of studies, I2 (%), Q p-value |
||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Table 2 results | Priority to uniformed service or working comparison | Restricted to general population comparisons | Restricted to uniformed service comparisons | Restricted to mean age ≥55 years at follow-up end or >20 years follow-up | Excludes “major” concern for healthy worker bias | Excludes “major” concern for surveillance bias | |||||||||||||||
| Incidence | |||||||||||||||||||||
| All cancers (C00-C95) | 1.05 (0.99–1.11) | 1.03 (0.98–1.07) | 1.03 (0.98–1.09) | 1.03 (0.99–1.07) | 1.09 (1.01–1.17) | 1.04 (0.97–1.12) | 1.08 (1.02–1.14) | ||||||||||||||
| 14 | 87 | <0.01 | 14 | 79.6 | <0.01 | 13 | 81.3 | <0.01 | 4 | 0.0 | 0.81 | 6 | 83.5 | <0.01 | 11 | 89.2 | <0.01 | 9 | 77.1 | <0.01 | |
| Stomach (C16) | 1.00 (0.87–1.15) | 1.01 (0.86–1.18) | 1.02 (0.88–1.18) | 0.90 (0.29–2.80) | 1.05 (0.84–1.30) | 0.96 (0.79–1.17) | 1.02 (0.81–1.28) | ||||||||||||||
| 12 | 33 | 0.12 | 12 | 39.6 | 0.08 | 11 | 30.2 | 0.16 | 3 | 57.3 | 0.10 | 5 | 23.5 | 0.27 | 9 | 35.0 | 0.14 | 7 | 20.9 | 0.27 | |
| Colon (C18) | 1.19 (1.07–1.32) | 1.13 (1.02–1.26) | 1.16 (1.04–1.29) | — | 1.24 (1.01–1.52) | 1.23 (1.08–1.40) | 1.13 (0.96–1.33) | ||||||||||||||
| 10 | 37 | 0.11 | 10 | 34.4 | 0.13 | 9 | 26.0 | 0.21 | 4 | 51.3 | 0.10 | 7 | 33.3 | 0.17 | 7 | 47.5 | 0.08 | ||||
| Lung (C33-C34) | 0.85 (0.75–0.96) | 0.90 (0.81–1.00) | 0.85 (0.74–0.97) | 1.05 (0.89–1.25) | 0.92 (0.80–1.05) | 0.89 (0.79–1.00) | 0.88 (0.81–0.94) | ||||||||||||||
| 14 | 78 | <0.01 | 14 | 70.0 | <0.01 | 13 | 79.0 | <0.01 | 4 | 0.0 | 0.51 | 6 | 75.1 | <0.01 | 11 | 74.9 | <0.01 | 9 | 0.0 | 0.75 | |
| Melanoma (C43) | 1.36 (1.15–1.62) | 1.19 (1.05–1.35) | 1.27 (1.11–1.46) | 1.05 (0.90–1.21) | 1.32 (0.96–1.80) | 1.33 (1.06–1.69) | 1.45 (1.20–1.75) | ||||||||||||||
| 12 | 83 | <0.01 | 12 | 54.0 | 0.01 | 11 | 61.6 | <0.01 | 4 | 0.0 | 0.97 | 6 | 90.8 | <0.01 | 9 | 86.3 | <0.01 | 9 | 71.7 | <0.01 | |
| Mesothelioma (C45) | 1.58 (1.14–2.20) | 1.64 (1.12–2.42) | 1.54 (0.99–2.38) | — | 1.61 (1.07–2.44) | 1.74 (1.10–2.75) | 1.52 (1.08–2.14) | ||||||||||||||
| 7 | 8 | 0.36 | 7 | 17.9 | 0.29 | 6 | 23.6 | 0.26 | 6 | 19.0 | 0.29 | 5 | 22.2 | 0.27 | 5 | 0.0 | 0.72 | ||||
| Prostate (C61) | 1.21 (1.12–1.32) | 1.12 (1.06–1.18) | 1.19 (1.10–1.29) | 1.08 (0.89–1.32) | 1.16 (1.03–1.30) | 1.19 (1.09–1.30) | 1.22 (1.12–1.33) | ||||||||||||||
| 14 | 81 | <0.01 | 14 | 30.9 | 0.12 | 13 | 75.1 | <0.01 | 4 | 55.0 | 0.08 | 6 | 84.5 | <0.01 | 11 | 73.6 | <0.01 | 9 | 63.0 | <0.01 | |
| Testis (C62) | 1.37 (1.03–1.82) | 1.36 (1.09–1.69) | 1.31 (1.04–1.64) | — | 1.19 (0.53–2.63) | 1.49 (1.11–2.02) | 1.54 (0.99–2.39) | ||||||||||||||
| 11 | 56 | 0.01 | 11 | 29.6 | 0.16 | 10 | 25.9 | 0.21 | 5 | 80.3 | <0.01 | 8 | 53.3 | 0.04 | 7 | 55.0 | 0.04 | ||||
| Kidney (C64-C66) | 1.09 (0.92–1.29) | 1.07 (0.91–1.25) | 1.04 (0.89–1.22) | 1.01 (0.60–1.70) | 1.18 (0.89–1.57) | 1.20 (0.90–1.46) | 1.11 (0.84–1.45) | ||||||||||||||
| 12 | 55 | 0.01 | 12 | 37.9 | 0.09 | 11 | 35.0 | 0.12 | 4 | 47.4 | 0.13 | 5 | 62.8 | 0.03 | 9 | 42.5 | 0.08 | 7 | 57.3 | 0.03 | |
| Bladder (C67-C68) | 1.16 (1.08–1.26) | 1.13 (1.01–1.26) | 1.17 (1.07–1.28) | 1.02 (0.74–1.39) | 1.17 (1.06–1.28) | 1.18 (1.09–1.28) | 1.08 (0.92–1.27) | ||||||||||||||
| 10 | 0 | 0.71 | 10 | 8.3 | 0.37 | 9 | 0.0 | 0.62 | 3 | 0.0 | 0.42 | 3 | 0.0 | 0.96 | 8 | 0.0 | 0.79 | 5 | 0.0 | 0.64 | |
| Brain and nervous (C47-C70-C72) | 1.01 (0.86–1.18) | 0.97 (0.84–1.12) | 0.97 (0.82–1.13) | 0.96 (0.73–1.26) | 1.07 (0.87–1.31) | 1.06 (0.88–1.27) | 1.08 (0.89–1.31) | ||||||||||||||
| 11 | 5 | 0.40 | 11 | 0.0 | 0.56 | 10 | 0.0 | 0.50 | 3 | 0.0 | 0.80 | 5 | 0.0 | 0.44 | 9 | 6.6 | 0.38 | 7 | 0.0 | 0.57 | |
| Thyroid (C73) | 1.28 (1.02–1.61) | 1.17 (0.89–1.54) | 1.31 (1.01–1.69) | 1.17 (0.30–4.50) | 1.04 (0.78–1.40) | 1.15 (0.93–1.43) | 1.16 (0.88–1.53) | ||||||||||||||
| 10 | 40 | 0.09 | 9 | 37.2 | 0.12 | 9 | 43.2 | 0.08 | 3 | 70.9 | 0.03 | 4 | 0.0 | 0.68 | 8 | 0.0 | 0.54 | 5 | 0.0 | 0.96 | |
| Non-Hodgkin lymphoma (C82-C85) | 1.12 (1.01–1.25) | 1.07 (0.97–1.18) | 1.07 (0.97–1.18) | 1.13 (0.91–1.40) | 1.11 (0.96–1.28) | 1.13 (0.99–1.29) | 1.12 (0.98–1.29) | ||||||||||||||
| 13 | 0 | 0.51 | 13 | 0.0 | 0.88 | 12 | 0.0 | 0.80 | 4 | 0.0 | 0.69 | 6 | 3.9 | 0.40 | 10 | 3.5 | <0.01 | 8 | 0.0 | 0.63 | |
| Mortality† | |||||||||||||||||||||
| All cancers (C00-C95) | 0.96 (0.88–1.06) | 0.97 (0.88–1.06) | 0.95 (0.86–1.05) | — | 1.04 (0.97–1.12) | 1.01 (0.94–1.07) | 0.96 (0.87–1.05) | ||||||||||||||
| 18 | 87 | <0.01 | 18 | 87.2 | <0.01 | 16 | 88.6 | <0.01 | 7 | 71.7 | <0.01 | 15 | 77.5 | <0.01 | 17 | 87.8 | <0.01 | ||||
| Stomach (C16) | 1.05 (0.87–1.28) | 1.05 (0.87–1.28) | 0.97 (0.82–1.15) | — | 1.14 (0.90–1.43) | 1.12 (0.96–1.30) | 1.00 (0.85–1.18) | ||||||||||||||
| 13 | 41 | 0.06 | 13 | 41.1 | 0.06 | 11 | 14.2 | 0.31 | 7 | 35.4 | 0.16 | 11 | 13.0 | 0.32 | 12 | 18.1 | 0.27 | ||||
| Colon (C18) | 1.03 (0.78–1.37) | 1.03 (0.78–1.37) | 1.05 (0.75–1.48) | — | 0.87 (0.51–1.49) | 0.90 (0.67–1.21) | 0.98 (0.70–1.36) | ||||||||||||||
| 9 | 63 | <0.01 | 9 | 62.6 | <0.01 | 7 | 48.0 | 0.07 | 4 | 49.2 | 0.12 | 7 | 40.5 | 0.12 | 8 | 55.1 | 0.03 | ||||
| Lung (C33-C34) | 0.96 (0.86–1.06) | 0.96 (0.86–1.07) | 0.95 (0.84–1.07) | — | 0.97 (0.87–1.07) | 0.98 (0.90–1.07) | 0.96 (0.86–1.06) | ||||||||||||||
| 12 | 55 | 0.01 | 12 | 54.3 | 0.01 | 10 | 59.0 | 0.01 | 6 | 51.1 | 0.07 | 11 | 39.5 | 0.09 | 12 | 54.6 | 0.01 | ||||
| Melanoma (C43) | 1.05 (0.48–2.30) | 1.05 (0.48–2.30) | 1.28 (0.45–3.66) | — | — | 1.05 (0.48–2.30) | 1.05 (0.48–2.30) | ||||||||||||||
| 4 | 0 | 0.43 | 4 | 0.0 | 0.43 | 3 | 0.0 | 0.47 | 4 | 0.0 | 0.43 | 4 | 0.0 | 0.43 | |||||||
| Mesothelioma (C45) | 1.75 (0.83–3.69) | 1.75 (0.83–3.69) | — | — | — | 1.75 (0.83–3.69) | 1.75 (0.83–3.69) | ||||||||||||||
| 3 | 0 | 0.56 | 3 | 0.0 | 0.56 | 3 | 0.0 | 0.56 | 3 | 0.0 | 0.56 | ||||||||||
| Prostate (C61) | 1.07 (0.95–1.20) | 1.06 (0.94–1.19) | 1.08 (0.96–1.22) | — | 1.01 (0.76–1.35) | 1.07 (0.95–1.21) | 1.08 (0.97–1.21) | ||||||||||||||
| 11 | 30 | 0.16 | 11 | 26.6 | 0.19 | 9 | 23.0 | 0.24 | 7 | 53.1 | 0.05 | 10 | 34.4 | 0.13 | 10 | 15.2 | 0.30 | ||||
| Kidney (C64-C66) | 1.10 (0.66–1.83) | 1.10 (0.66–1.83) | 1.07 (0.58–1.99) | — | 0.92 (0.59–1.44) | 1.08 (0.60–1.94) | 1.10 (0.66–1.83) | ||||||||||||||
| 9 | 53 | 0.03 | 9 | 52.7 | 0.03 | 8 | 58.6 | 0.02 | 6 | 33.1 | 0.19 | 8 | 58.5 | 0.02 | 9 | 52.7 | 0.03 | ||||
| Bladder (C67-C68) | 1.22 (0.70–2.11) | 1.23 (0.70–2.15) | 1.34 (0.74–2.43) | — | 0.95 (0.67–1.34) | 1.07 (0.63–1.81) | 1.22 (0.70–2.11) | ||||||||||||||
| 9 | 67 | <0.01 | 9 | 66.8 | <0.01 | 8 | 67.3 | <0.01 | 4 | 30.5 | 0.23 | 8 | 57.0 | 0.02 | 9 | 66.9 | <0.01 | ||||
| Brain and nervous (C47-C70-C72) | 1.33 (0.98–1.79) | 1.26 (0.94–1.67) | 1.37 (0.98–1.93) | — | 1.58 (0.96–2.60) | 1.27 (0.93–1.74) | 1.33 (0.98–1.79) | ||||||||||||||
| 11 | 53 | 0.02 | 11 | 39.4 | 0.09 | 10 | 57.2 | 0.01 | 5 | 71.1 | 0.01 | 10 | 52.3 | 0.03 | 11 | 52.8 | 0.02 | ||||
| Thyroid (C73) | 1.90 (0.36–10.0) | 1.90 (0.36–10.0) | 1.76 (0.08–39.1) | — | — | 1.90 (0.36–10.0) | 1.90 (0.36–10.0) | ||||||||||||||
| 4 | 58 | 0.07 | 4 | 58.4 | 0.07 | 3 | 72.1 | 0.03 | 4 | 58.4 | 0.07 | 4 | 58.4 | 0.07 | |||||||
| Non-Hodgkin lymphoma (C82-C85) | 1.20 (1.03–1.40) | 1.18 (1.00–1.40) | 1.20 (1.03–1.40) | — | 1.21 (1.04–1.41) | 1.20 (1.03–1.40) | 1.20 (1.03–1.40) | ||||||||||||||
| 5 | 0 | 0.74 | 5 | 0.0 | 0.67 | 5 | 0.0 | 0.74 | 4 | 0.0 | 0.77 | 5 | 0.0 | 0.74 | 5 | 0.0 | 0.74 | ||||
Abbreviations: mRR, meta-rate ratio; CI, confidence interval.
∗
Random-effects models were used with between-study variance estimated using the restricted maximum-likelihood estimator. Hartung-Knapp-Sidik-Jonkman (HKSJ) adjustments and an ad hoc variance correction (using wider confidence intervals) were used to calculate confidence intervals. The variance of individual study estimates is based on the reported confidence interval bounds and may differ from estimates obtained using exact methods when there are few cases.
†
Outcomes with fewer than three available studies were not meta-analyzed.