. 2018 Jun;15(6):735–744. doi: 10.1513/AnnalsATS.201712-961OC

Table 1.

GRADE summary of findings for the impact of inspiratory muscle training in critically ill patients

Outcome	Impact Effect (95% CI)	No. of Participants (RCTs)	Quality of the Evidence (GRADE)
Change in maximal inspiratory pressure from baseline after IMT	Mean difference in change 6 (5 to 8) cm H₂O higher in IMT group than in control group	647 (15 RCTs)	⊕◯◯◯ Very low^*^,^†^,^‡
	Pooled ratio of means for change in MIP relative to baseline MIP, 1.21 (1.16 to 1.26)	647 (15 RCTs)	⊕◯◯◯ Very low^*^,^†^,^‡
Change in maximal inspiratory pressure from baseline after IMT (sensitivity analysis excluding studies at high risk of bias)	Mean difference 9 (7 to 12) cm H₂O higher in IMT group than in control group	175 (3 RCTs)	⊕⊕⊕⊕ High
Maximal inspiratory pressure after IMT	Mean difference 7 (6 to 8) cm H₂O higher in IMT group than in control group	575 (15 RCTs)	⊕⊕◯◯ Low^*^,^‡
Change in maximal expiratory pressure from baseline after IMT	Mean difference in change 9 (5 to 14) cm H₂O higher in IMT group than in control group	153 (4 RCTs)	⊕⊕⊕◯ Moderate^*
	Pooled ratio of means for change in MEP relative to baseline MEP, 1.39 (1.27 to 1.54)	153 (4 RCTs)	⊕⊕⊕◯ Moderate^*
Change in maximal expiratory pressure from baseline after IMT (sensitivity analysis excluding studies at high risk of bias)	Mean difference in change 9 (5 to 14) cm H₂O higher in IMT group than in control group	106 (2 RCTs)	⊕⊕⊕⊕ High
Duration of ventilation	Pooled duration of ventilation was 4.1 (0.8 to 7.4) d shorter in IMT group than in control group	325 (9 RCTs)	⊕◯◯◯ Very low^*^,^†^,^‡^,^§
Duration of ventilation (sensitivity analysis excluding studies at high risk of bias)	Pooled duration of ventilation was 4.6 (−1.0 to 10.1) d shorter in IMT group than in control group	220 (4 RCTs)	⊕⊕◯◯ Low^†^,^§
Duration of weaning from mechanical ventilation	Pooled duration of weaning from mechanical ventilation was 2.3 (0.7 to 3.9) d shorter in IMT group than in control group	257 (8 RCTs)	⊕◯◯◯ Very low^*^,^†^,^§
Duration of weaning (sensitivity analysis excluding studies at high risk of bias)	Pooled duration of weaning from mechanical ventilation was 3.2 (0.6 to 5.8) d shorter in IMT group than in control group	209 (5 RCTs)	⊕⊕◯◯ Low^†^,^§
ICU length of stay	Length of stay in ICU was 3.1 (−1.0 to 7.1) d shorter in IMT group than in control group	28 (2 RCTs)	⊕◯◯◯ Very low^*^,^‡^,^§
Mortality in ICU	Pooled relative risk of death in ICU was 0.67 (0.20 to 2.20) in IMT group compared with control group	197 (3 RCTs)	⊕⊕◯◯ Low^‡^,^§
GRADE Working Group grades of evidence
High quality: We are very confident that the true effect lies close to that of the estimate of the effect.
Moderate quality: We are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low quality: Our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect.
Very low quality: We have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

Definition of abbreviations: CI = confidence interval; GRADE = Grading of Recommendations, Assessment, Development, and Evaluation; ICU = intensive care unit; IMT = inspiratory muscle training; MEP = maximal expiratory pressure; MIP = maximal inspiratory pressure; RCT = randomized controlled trial.

^{^*}

Multiple studies were at high risk of bias.

^{^†}

Inconsistency: statistical heterogeneity was substantial (I² > 75% and P < 0.05), and confidence intervals show no or minimal overlap.

^{^‡}

Studies employed cointerventions.

^{^§}

Imprecision: confidence intervals did not exclude statistically significant benefit or harm.