Study designs of evaluations included in the review
There were no restrictions on study design.
Specific interventions included in the review
Studies of SPA were included. The cut-off used in the included studies, in terms of the percentage of penetrated ova, ranged from 5 to 20%. SPA without sufficient penetration, i.e. presence of disease, was considered a positive test.
Reference standard test against which the new test was compared
Only studies that used the results of IVF as the reference standard were eligible for inclusion. Failure of IVF, i.e. absence of fertilisation of all oocytes, was considered to represent the presence of disease and a positive reference standard.
Participants included in the review
No inclusion criteria relating to the participant characteristics were specified. Where a study reported the results of more than one SPA per patient, the results of the first SPA were used; studies were excluded if it was unclear which SPA result was used. If multiple studies reported on the same series of patients, the study with the largest number of patients was included.
Outcomes assessed in the review
The included studies were required to report sufficient data to allow the construction of 2x2 contingency tables for SPA versus IVF results. The outcome measures calculated in the review were the sensitivity, specificity, and positive and negative likelihood ratios.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.