Summary of findings for the main comparison. Summary of findings TIVA versus inhalational maintenance of anaesthesia.

Intravenous maintenance of anaesthesia compared with inhalational maintenance of anaesthesia in elderly people undergoing non‐cardiac surgery
Participants: elderly people, aged 60 years and above, undergoing non‐cardiac surgery under general anaesthesia Settings: hospitals in: Belgium, Canada, China, Egypt, France, Germany, Greece, Ireland, Japan, Norway, South Korea, Spain, Sweden, Turkey, UK, USA Intervention: intravenous maintenance of anaesthesia with: propofol Comparison: inhalational maintenance of anaesthesia with: sevoflurane, isoflurane, or desflurane
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	Number of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Risk with Inhalational maintenance	Risk with TIVA
Postoperative delirium (One study used DRS, three studies used CAM and in one study diagnostic tool was not reported) Time points were up to 4 days postoperatively	Study population		OR 0.59 (0.15 to 2.26)	321 (5 studies)	very lowa
	61 per 1,000	37 per 1,000 (10 to 129)
Postoperative cognitive dysfunction (9 studies used MMSE, and 2 of these studies used additional diagnostic tools; 1 study used Trail Making Test and additional diagnostic tools; 3 studies did not report diagnostic tools) Time points were up to 30 days postoperatively	Study population		OR 0.52 (0.31 to 0.87)	869 (7 studies)	lowb	Overall, 13 studies (3215 participants) reported data for this outcome. We performed meta‐analysis on 7 studies. We excluded 1 large study from this analysis which used non‐standard anaesthetic management. 5 studies reported data in formats that could not be combined. Of these 5: we noted no apparent differences in mean MMSE scores in 3 studies; 1 study reported similar scores in each group; 1 study included data at 2 years and was not comparable with our other data
	285 per 1,000	172 per 1,000 (110 to 257)
Mortality At 30 days	Study population		OR 1.21, (95% CI 0.33 to 4.45)	271 (3 studies)	very lowc	Overall, 4 studies reported mortality. We did not include 1 study in analysis because number of deaths (3 in total) were not reported by group.
	29 per 1,000	35 per 1,000 (10 to 119)
Intraoperative hypotension (defined by study authors as change in MAP from baseline)	‐	See comment	‐	1145 (12 studies)	lowd	Overall, 12 studies (1145 participants) reported intraoperative hypotension. 1 study reported data in a format that could not be combined with other study data (we noted little or no apparent difference in hypotension in this study). We did not pool data in 11 studies; we noted inconsistencies in visual inspection of the data which could be explained by variation in clinical management and medication used to manage hypotension in each study
Length of stay in PACU (measured in minutes)	‐	see comment	‐	567 (8 studies)	very lowe	We did not pool data in seven studies: we noted inconsistencies in visual inspection of the data and we expected that studies used different definitions of time points to assess length of time in the PACU. Data were unclearly reported in one study
Length of hospital stay (measured in days)	‐	MD 0 days higher (1.32 days lower to 1.32 days higher)	‐	175 (4 studies)	very lowf	Overall, 6 studies (375 participants) reported data for this outcome. Of 4 combined studies, mean scores in the inhalational maintenance group ranged from 1.3 days to 15 days. 2 studies reported data that could not be combined with other studies (we noted little or no difference in median length of stay between groups).
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CAM: Confusion Assessment Method; CI: confidence interval; DRS: Delirium Rating Scale; MAP: mean arterial pressure; MD: mean difference; MMSE: Mini‐Mental State Examination; OR: odds ratio; PACU: postanaesthesia care unit
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect Moderate certainty: 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 certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

^aWe downgraded by one level for study limitations; we noted few included studies for this outcome had sufficiently reported methods of randomization and we were concerned by high risk of attrition bias in two studies and high risk of selective outcome reporting bias in one study. We downgraded by two levels for inconsistency; we could not be certain whether measurements of delirium, and time points of measurement, were equivalent between studies, and we used sensitivity analysis to show that choice of time point in one study may influence direction of this result

^bWe downgraded by one level for study limitations; we noted that some studies had insufficiently reported methods of randomization and we were concerned by high risk of attrition bias in one study. We downgraded by one level for inconsistency; we noted a moderate level of statistical heterogeneity (I² = 41%) which we were unable to explain in subgroup analysis

^cWe downgraded by one level for study limitations; we noted that some studies had insufficiently reported methods of randomization. Analysis included few studies with few participants and, because deaths due to anaesthesia are rare we would require a large sample size to show evidence of a difference; we downgraded by two levels for imprecision.

^dWe downgraded by one level for study limitations; we noted some studies reported insufficient methods of randomization. We downgraded by one level for inconsistency because of statistical heterogeneity (I² = 63%) and noted differences in visual inspection of results; this could be explained by possible variation in clinical management and medication used to manage hypotension in each study

^eWe downgraded by one level for study limitations; we noted some studies reported insufficient methods of randomization. We downgraded by two levels for inconsistency; we noted substantial statistical heterogeneity (I² = 94%) and differences in visual inspection of results which may be explained by likely differences in study designs related to definitions of time points of measurement for this outcome

^fFew studies with few participants; we downgraded by two levels for imprecision. We noted a moderate level of statistical heterogeneity (I² = 41%) and noted differences in visual inspection of results; we downgraded by one level for inconsistency