Study designs of evaluations included in the review
Diagnostic accuracy studies or studies comparing ultrasonography with other screening methods were eligible for inclusion. The included studies comprised randomised controlled trials (RCTs), non-randomised studies and studies with historical controls.
Specific interventions included in the review
Studies assessing ultrasonography were eligible for inclusion.
Reference standard test against which the new test was compared
The reference standard was any alternative screening method for DDH.
Participants included in the review
Studies in an unselected population of newborns were eligible for inclusion. Studies of infants with suspected or apparent DDH, or notable risk factors for DDH, were excluded.
Outcomes assessed in the review
The outcomes for diagnostic accuracy studies were not specified as part of the eligibility criteria. The outcomes used were sensitivity, specificity, positive and negative likelihood ratios, and positive and negative predictive values. The eligibility criteria specified that other study designs should report on the following outcomes: any long-term functional outcomes (such as osteoarthritis); false diagnostic labelling; adverse events; time to, and duration of, treatment; and the rates of treatments, operative intervention, abduction splinting and delayed diagnosis.
How were decisions on the relevance of primary studies made?
Two reviewers independently assessed studies for inclusion, with any disagreements resolved by consensus.