Summary of findings for the main comparison. Sedative compared to placebo for children needing dental care.

Sedative compared to placebo for children needing dental care
Patient or population: children needing dental care Setting: hospital Intervention: sedative Comparison: placebo
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	Number of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Risk with placebo	Risk with sedative
Houpt/other behavioural score ‐ Midazolam (oral) SD units: investigators measure behaviour using different scales ‐ Higher values mean better behaviour	The Houpt/other behavioural score in the midazolam (oral) group was on average 1.96 SDs higher (1.59 higher to 2.33 higher) than the placebo group		‐	202 (6 RCTs)	⊕⊕⊕⊝ MODERATE1	As a rule of thumb 0.2 SD represents a small difference, 0.5 a moderate difference, and 0.8 a large difference Adverse events: vomiting/hiccupping reported in 1 study. Amnesia reported in 1 study Oral midazolam probably improves behaviour
Houpt/other behavioural score ‐ Midazolam (intravenous) SD units: investigators measure behaviour using different scales ‐ Higher values mean better behaviour	The Houpt/other behavioural score in the midazolam (intravenous) group was on average 1.21 SDs higher (0.24 higher to 2.18 higher) than the placebo group		‐	20 (1 RCT)	⊕⊝⊝⊝ VERY LOW1, 2	As a rule of thumb 0.2 SD represents a small difference, 0.5 a moderate difference, and 0.8 a large difference No adverse events reported Uncertain whether intravenous midazolam improves behaviour
Houpt/other behavioural score ‐ Nitrous oxide SD units: investigators measure behaviour using different scales ‐ Higher values mean better behaviour	The Houpt/other behavioural score in the nitrous oxide group was on average 0.69 SDs higher (0.13 higher to 1.26 higher) than the placebo group		‐	52 (1 RCT)	⊕⊝⊝⊝ VERY LOW1, 3	As a rule of thumb 0.2 SD represents a small difference, 0.5 a moderate difference, and 0.8 a large difference No adverse events reported Uncertain whether nitrous oxide improves behaviour
Houpt/other behavioural score ‐ Diazepam (oral) SD units: investigators measure behaviour using different scales ‐ Higher values mean better behaviour	The Houpt/other behavioural score in the diazepam (oral) group was on average 0.62 SDs higher (0.28 lower to 1.53 higher) than the placebo group		‐	20 (1 RCT)	⊕⊝⊝⊝ VERY LOW1, 2	As a rule of thumb 0.2 SD represents a small difference, 0.5 a moderate difference, and 0.8 a large difference No adverse events reported Uncertain whether oral diazepam improves behaviour
Good or better behaviour ‐ Chloral hydrate	Study population		RR 1.33 (0.80 to 2.22)	60 (1 RCT)	⊕⊝⊝⊝ VERY LOW3, 4	Adverse events: associated with airway problems Uncertain whether chloral hydrate improves behaviour
	533 per 1000	709 per 1000 (427 to 1000)
Good or better behaviour ‐ Meperidine	Study population		RR 5.33 (1.45 to 19.64)	60 (1 RCT)	⊕⊕⊝⊝ LOW5	Adverse events: nausea, vomiting and unmanageable behaviour were associated with meperidine use Meperidine may improve behaviour
	133 per 1000	711 per 1000 (193 to 1000)
*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; RCT: randomised controlled trial; RR: risk ratio; SD: standard deviation; SMD: standardized mean difference.
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.

¹Downgraded for risk of bias (lack of blinding and randomisation processes unclear).
 ²Downgraded for imprecision (large confidence interval and small numbers).
 ³Downgraded for imprecision (large confidence interval).
 ⁴Downgraded for risk of bias (randomisation unclear and incomplete outcome assessment).
 ⁵Downgraded for risk of bias (randomisation unclear) and imprecision.