Supplementary Table 2.
Modified Newcastle - Ottawa Quality Assessment Scale
| Case Control Studies |
| 1. Selection of controls |
| a. From study base (2) |
| b. Not from study base (1) |
| c. Other, incl. ecological, no description (0) |
| 2. Adjustment of confounders |
| a. Adjustment for most important potential confounders (2) |
| b. Adjustment for some potential confounders (1) |
| c. Adjustment for no confounders except age, gender, race/ethnicity, calendar period (0) |
| 3. Ascertainment of exposure |
| a. Objective record (eg employment records, biomarkers) (2) |
| b. Structured interview blind to case/control status, GIS (1) |
| c. Interview not blinded to case/control status, self-report, proxy (e.g., residence) (0.5) |
| d. No description (0) |
| 4. Response rate |
| a. Both groups over 90% (2) |
| b. One or both groups between 60- 90% (1) |
| c. One group under 60%, no description (0) |
| 5. Latency |
| a. Adequate latency between exposure and outcome (>15 yrs) (2) |
| b. Limited latency between exposure and outcome (5-15 yrs) (1) |
| c. Inadequate latency between exposure and outcome (<5 yrs), no description (0) |
| 6. Outcome |
| a. Cancer registration (2) |
| b. Death certificates, hospital records (1) |
| c. Self report (0.5) |
| d. No description (0) |
| Cohort Studies |
| 1. Selection of unexposed cohort |
| a. Derived from the same population as the exposed (2) |
| b. Derived from a different source (1) |
| c. Other, no description (0) |
| 2. Adjustment of confounders |
| a. Adjustment for most important potential confounders (2) |
| b. Adjustment for some potential confounders (1) |
| c. Adjustment for no confounders except age, gender, race/ethnicity, calendar period (0) |
| 3. Ascertainment of exposure |
| a. Objective record (e.g., employment records, biomarkers) (2) |
| b. Structured interview blind to outcome status, GIS (1) |
| c. Interview not blinded outcome status, self-report, proxy (e.g., residence) (0.5) |
| d. No description (0) |
| 4. Follow-up rate |
| a. Follow-up of both groups over 90% (2) |
| b. Follow-up of one or both groups between 60- 90% (1) |
| c. Follow-up of one group under 60%, no description (0) |
| 5. Latency |
| a. Adequate latency between exposure and outcome (>15 yrs) (2) |
| b. Limited latency between exposure and outcome (5-15 yrs) (1) |
| c. Inadequate latency between exposure and outcome (<5 yrs), no description (0) |
| 6. Outcome |
| a. Cancer registration (2) |
| b. Death certificates, hospital records (1) |
| c. Self report (0.5) |
| d. No description (0) |