Table 4.
Summary of findings: is shift work associated with an increased risk of cardiovascular events?*
| Outcomes | Risk of bias | Inconsistency | Indirectness | Imprecision | Publication bias | No of participants (studies) | Relative effect (95% CI) | Quality of evidence (GRADE) |
|---|---|---|---|---|---|---|---|---|
| Myocardial infarction | Not likely† | No serious inconsistency‡ | No serious indirectness§ | No serious imprecision¶ | Not likely** | 1 082 977 (10) | 1.23 (1.15 to 1.31) | Moderate††⊕⊕⊕О |
| Coronary events | Not likely† | Inconsistency‡‡ | No serious indirectness§ | No serious imprecision¶ | Not likely** | 1 530 070 (28) | 1.24 (1.10 to 1.39) | Low††⊕⊕ ОО |
| Ischaemic stroke | Not likely† | No serious inconsistency‡ | No serious indirectness§ | No serious imprecision¶ | Undetected§§ | 80 787 (2) | 1.05 (1.01 to 1.09) | Moderate†† ⊕⊕⊕О |
†Median Downs and Black score for included studies was 60% (interquartile range 34-86%).
‡I2=0%.
§Population, outcome, and intervention were consistent with question of interest, although individual studies varied.
¶No of events and participants studied in review is large, and confidence interval does not include null value.
**Estimates adjusted for publication bias did not differ from observed estimates.
††Dilution effect of single time point exposure ascertainment allows upgrading of evidence.
‡‡I2=85%.
§§Publication bias could not be tested for two studies.