Study designs of evaluations included in the review
Studies were included if they had cross-sectional designs.
Specific interventions included in the review
At least one of the index tests evaluated needed to be the whispered voice test. Six different techniques were used in the studies found.
Reference standard test against which the new test was compared
The reference standard used was hearing impairment by audiometry. It needed to be performed on at least 80% of the participants. In studies of adults, the positivity threshold for hearing impairment by audiometry was 30 dB (3 studies) or 40 dB (1 study); in studies of children, the threshold for hearing impairment ranged from 20 to 35 dB.
Participants included in the review
Both adults (17 years or older) and children (under 17 years) were eligible for inclusion in the review, and were considered separately. Four studies were of children and four were of adults. The participants in the adult studies were generally elderly; only one study included participants younger than 55 years. The prevalence of hearing impairment in these studies ranged from 26 to 61%. The children in the child studies were aged from 3 to 12 years, and the prevalence of hearing impairment ranged from 9 to 31%.
Outcomes assessed in the review
The primary outcome measure was the accuracy of the whispered voice test, as reflected in its sensitivity and specificity. These needed to be reported or calculable from the study data provided. The positive and negative likelihood ratios were also calculated and presented in the review.
How were decisions on the relevance of primary studies made?
Two reviewers independently selected studies for inclusion in the review.