Table S1.
Methodological quality checklist
| 1. Design |
|---|
| a. Cohort (4) |
| b. Case-control (3) |
| c. Cross-sectional (2) |
| d. Using aggregated data (1) |
| 2. Timeframe |
| a. Reported (0.5) |
| b. Unknown (0) |
| 3. Country where the study was carried out |
| a. With good working and living conditions AND/OR high socio-economic standard (2) |
| b. Difficult conditions AND/OR lower socio-economic standard (1.5) |
| c. Very difficult conditions AND/OR very low socioeconomic standard (1) |
| d. Unknown (0) |
| 4. Mode of selection |
| a. Random AND/OR considerable part OR the whole target population (3) |
| b. Non-random OR unknown (0) |
| 5. Response rate |
| a. ≥80% OR, if not reported, considerable part of the target population (3) |
| b. 60–80% (1) |
| c. <60% OR unknown (0) |
| 6. Final sample size |
| a. Completely satisfactory AND/OR justified by power analysis OR total population (3) |
| b. Somewhat satisfactory AND no statistical justification (1) |
| c. Not satisfactory AND no statistical justification (0) |
| 7. Participants |
| a. Clearly described (1) |
| b. Ambiguous description OR unknown (0) |
| 8. Representativeness of the sample |
| a. Representative of the population/whole population (3) |
| b. Somewhat representative (1) |
| c. Not representative/unknown (0) |
| 9. Definition and assessment of ischemic heart disease/myocardial infarction |
| a. Official WHO diagnostic criteria/official registry/database/records/physician-diagnosed (3) |
| b. Self-reported (1) |
| 10. Assessment of noise exposure |
| a. Long term personal dosimetry/at-site measurement (3) |
| b. Job-exposure matrix/hygienists assessment (2) |
| c. Self-report noisiness/vocal effort (1) |
| d. Unknown method (0) |
| 11. Biological plausibility for ischemic heart disease/myocardial infarction given the overall noise exposure and the compared noise exposure categories |
| a. Plausible (1.5) |
| b. Speculative (0.5) |
| c. Unplausible/unknown (0) |
| 12. Adjustments for personal covariates |
| a. All/almost all of the relevant covariates (age, smoking, dyslipidemia, abdominal obesity, diabetes, history of hypertension, psychosocial factors, unhealthy diet, regular |
| alcohol consumption, irregular physical activity) (5) |
| b. Some of the covariates (2) |
| c. No adjustments OR none of the above included (0) |
| 13. Adjustments for environmental covariates |
| a. Other occupational AND residential risks (eg, air pollution, chemicals, noise, shift work, etc) (4) |
| b. Other occupation OR residential risks (2) |
| c. No adjustments (0) |
| 14. Effect size calculation for meta-analysis |
| a. No transformations AND no data imputation OR transformations not creating bias (3) |
| b. Transformations creating bias OR data imputation (1) |
| c. Transformations creating bias AND data imputation (0) |
| 15. Additional transformations/imputation to the data AND/OR other source of bias associated with data extraction/interpretation |
| a. None (3) |
| b. Creating minor bias (1) |
| c. Major source of bias (0) |