Table 3.
Quality of evidence
| Quality assessment | No. of patients | Effect | Quality | Importance | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of studies | Study design | Risk of bias | Inconsistency | Indirectness | Imprecision | Other considerations | Prophylactic endotracheal intubation | No intubation | Relative (95% CI) | Absolute (95% CI) | ||
| Mortality | ||||||||||||
| 8 | Observational studies | Seriousa | Very seriousb | Not serious | Not seriousc | None | 407/2768 (14.7%) | 304/3050 (10.0%) | OR 1.92 (0.71-5.23) | 76 more per 1000 (from 27 fewer to 267 more) | ⨁◯◯◯ Very Low | Critical |
| Pneumonia | ||||||||||||
| 5 | Observational studies | Seriousa | Seriousd | Not serious | Not seriouse | Very strong association | 127/484 (26.2%) | 107/1428 (7.5%) | OR 4.17 (1.82-9.57) | 178 more per 1000 (from 54 more to 362 more) | ⨁⨁◯◯ Low | Critical |
| Aspiration | ||||||||||||
| 6 | Observational studies | Seriousa | Seriousf | Not serious | Not seriousg | Very strong association | 54/252 (21.4%) | 38/368 (10.3%) | OR 3.58 (1.46-10.25) | 189 more per 1000 (from 41 more to 438 more) | ⨁⨁◯◯ Low | Critical |
| Hospital length of stay (days) | ||||||||||||
| 6 | Observational studies | Seriousa | Not serious | Not serious | Not serioush | None | 2426 | 1762 | - | MD 0.86 days more (0.13 more to 1.59 more) | ⨁◯◯◯ Very Low | Important |
CI – Confidence interval; OR – Odds ratio; MD – Mean difference; a – We rated down the quality of evidence by one level for risk of bias as non-adjusted estimates were used; therefore, we are uncertain if the observed treatment effect is a result of a confounder or a true effect; b – We rated down the quality of evidence by two levels for inconsistency, the I2=95%; c – Although the confidence interval included significant benefit and harm, we did not rate down the quality of evidence for imprecision; d – We rated down the quality of evidence by one level for inconsistency, the I2=57%; e – Although the CI was wide including small and large harm, we did not rate down the quality of evidence for imprecision; f – We rated down the quality of evidence for inconsistency, I2=64%; g – Although the confidence interval included both small and substantial harm, we did not rate down the quality of evidence for imprecision; h – Although the confidence interval included small and moderate harm, we did not rate down the quality of evidence for imprecision