| Outcome | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No. of participants(studies) | GRADE quality of evidence | |
|---|---|---|---|---|---|
| Assumed risk in control group, no. per million | Corresponding risk with treatment, no. per million | ||||
| Referral rates to intervention (ASQ-II screening tool), 18-mo follow-up | |||||
| Screening with office support | 102 158 | 198 861 (152 471-259 370) | RR 1.95 (1.49-2.54) | 1399 (1 study18) | Moderatea,b,c,d,e |
| Screening without office support | 102 158 | 174 599 (132 826-229 519) | RR 1.71 (1.30-2.25) | 1388 (1 study18) | Moderatea,b,c,e,f |
| Time to intervention referral (ASQ-II screening tool), 18-mo follow-up | |||||
| Screening with office support | 0 | 0 (0 to 0) | RR 0.30 (0.19-0.48) | 1399 (1 study18) | Moderatea,b,c,e,g |
| Screening without office support | 0 | 0 (0 to 0) | RR 0.36 (0.23-0.59) | 1388 (1 study18) | Moderatea,b,c,e,h |
| Academic performance, by outcome measures (VTO screening tool), 81-mo follow-up | |||||
| Attendance of special school | 37 150 | 26 388 (18 007-38 674) | RR 0.71 (0.48-1.04) | 5406 (1 study19) | Lowb,e,i,j,k |
| Repeating a grade | 141 333 | 139 920 (114 579-170 886) | RR 0.99 (0.81-1.21) | 5334 (1 study19) | Lowb,e,i,j,l |
| Repeating a grade (language problems) | 48 809 | 61 616 (43 298-87 680) | RR 1.26 (0.89-1.80) | 4122 (1 study19) | Lowb,e,i,j,m |
| < 10th percentile of oral test | 97 297 | 85 612 (61 229-119 695) | RR 0.88 (0.63-1.23) | 2195 (1 study19) | Lowb,e,i,j,n |
| < 10th percentile of reading test | 46 687 | 46 687 (33 456-65 147) | RR 1.00 (0.72-1.40) | 3172 (1 study19) | Lowb,e,i,j,o |
| < 10th percentile of spelling test | 42 449 | 28 857 (17 370-47 938) | RR 0.68 (0.41-1.13) | 2953(1 study19) | Lowb,e,i,j,p |
Note: ASQ-II = Ages and Stages Questionnaire II, CI = confidence interval, GRADE = Grading of Recommendations Assessment, Development and Evaluation, RR = relative risk, VTO = VroegTijdige Onderkenning Ontwikkelingsstoornissen Language Screening instrument.
*The assumed risk in the control group is based on event rates in control groups across studies. The corresponding risk (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).
aUsing Cochrane's risk-of-bias tool, for this outcome the study was rated as having a low risk of bias. There was low risk of bias for all domains except blinding, which was assessed as being high risk because parents and clinicians were aware of their screening status. Because the control participants received usual care (developmental milestone screening) in this study, lack of blinding was not considered as having a large impact on outcomes of interest. Given that all of the information for this outcome is from a study with low risk of bias, the evidence was not downgraded for serious study limitations.
bBecause this was a single study, inconsistency could not be assessed.
cThis study included boys and girls < 12 months of age with an average risk of developmental delay (mean ages: intervention group A, 10.5 ± standard deviation 8.2 months; intervention group B, 10.5 ± 8.1 months; control group, 10.4 ± 8.6 months). The intervention groups were screened using ASQ-II (one group with office support [group A], one group without [group B]); the control group received usual care. The study took place in a primary care setting in the United States, and the report was published 2013. The evidence was downgraded because the population was not restricted to children aged 1-4 years.
dAdequate sample size (704 in intervention group A, 695 in control group) and sufficient number of events (140 in intervention group A, 71 in control group). The pooled effect estimate is precise, with a narrow 95% CI (RR 1.95, 95% CI 1.49-2.54). The evidence was not downgraded for imprecision.
eThere were too few studies (< 10) to assess publication bias.
fAdequate sample size (693 in intervention group B, 695 in control group) and sufficient number of events (121 in intervention group B, 71 in control group). The pooled effect estimate is precise, with a narrow 95% CI (RR 1.71, 95% CI 1.30-2.25). The evidence was not downgraded for imprecision.
gAdequate sample size (704 in intervention group A, 695 in control group). The pooled effect estimate is precise, with a narrow 95% CI (RR 0.30, 95% CI 0.19-0.48). The evidence was not downgraded for imprecision.
hAdequate sample size (693 in intervention group B, 695 in control group). The pooled effect estimate is precise, with a narrow 95% CI (RR 0.36, 95% CI 0.23-0.59). The evidence was not downgraded for imprecision.
iUsing Cochrane's risk-of-bias tool, for this outcome the study was rated as having unclear risk of bias. There was low risk of bias for all domains except allocation concealment and blinding of participants/personnel, which were assessed as having unclear risk of bias because there was insufficient information to evaluate these domains. Given that all of the information for this outcome is from a study with unclear risk of bias, the evidence was downgraded for serious study limitations.
jThis study included boys and girls aged 15 months at study entry with an average risk of developmental delay (mean ages not reported). The intervention group was screened using the VTO instrument; the control group received usual care. The study took place in a primary care setting in the Netherlands, and the report was published in 2007. There were no serious concerns regarding directness of this evidence.
kAdequate sample size (3118 in intervention group, 2288 in control group), but fairly low number of events (83 in intervention group, 85 in control group). The pooled effect estimate is not precise, with a 95% CI that includes the no-effect value (RR 0.71, 95% CI 0.48-1.04). The evidence was downgraded for imprecision.
lAdequate sample size (3084 in intervention group, 2250 in control group) and sufficient number of events (443 in intervention group, 318 in control group). The pooled effect estimate is not precise, however, with a 95% CI that includes the no-effect value (RR 0.99, 95% CI 0.81-1.21). The evidence was downgraded for imprecision.
mAdequate sample size (2401 in intervention group, 1721 in control group) and sufficient number of events (146 in intervention group, 84 in control group). The pooled effect estimate is not precise, however, with a 95% CI that includes the no-effect value (RR 1.26, 95% CI 0.89-1.80). The evidence was downgraded for imprecision.
nAdequate sample size (1270 in intervention group, 925 in control group) and sufficient number of events (112 in intervention group, 90 in control group). The pooled effect estimate is not precise, however, with a 95% CI that includes the no-effect value (RR 0.88, 95% CI 0.63-1.23). The evidence was downgraded for imprecision.
oAdequate sample size (1844 in intervention group, 1328 in control group), but fairly low number of events (86 in intervention group, 62 in control group). The pooled effect estimate is not precise, with a 95% CI that includes the no-effect value (RR 1.00, 95% CI 0.72-1.40). The evidence was downgraded for imprecision.
pAdequate sample size (1728 in intervention group, 1225 in control group), but low number of events (48 in intervention group, 52 in control group). The pooled effect estimate is not precise, with a 95% CI that includes the no-effect value (RR 0.68, 95% CI 0.41-1.13). The evidence was downgraded for imprecision.