Bahado‐Singh 2000a.
| Clinical features and settings | High‐risk referral for invasive testing. | |
| Participants | 524 participants. USA ‐ single hospital. August 1995 ‐ April 1999. Singleton pregnancies. Pregnant women. Mean age 36.6 years (SD 5.3 years) in those with Down’s detected and 37.0 years (SD 3.4 years) in those with euploid pregnancies. 14‐22 weeks' gestation. |
|
| Study design | Prospective cohort study. | |
| Target condition and reference standard(s) | Down's syndrome: 24 cases. Reference standard: amniocentesis. |
|
| Index and comparator tests | Maternal age. Second trimester serum hCG (IMX total β‐hCG kit, Abbott Laboratories), uE3 (DSL‐1400 Ultra‐sensitive unconjugated Estriol Radioimmunoassay kit) and AFP (IMX AFP kit, Abbott Laboratories). Second trimester urinary beta core fragment (Spot specimens of urine ‐ 2‐step sandwich assay B120 monoclonal antibody). Frozen samples tested for second trimester urinary hyperglycosylated hCG (Specific monoclonal antibody developed. 2‐step enzyme immunometric assay standardised for creatinine levels). |
|
| Follow‐up | 100% karyotyping. | |
| Aim of study | To compare the concentration of hyperglycosylated human chorionic gonadotropin with serum triple screen for second trimester Down’s syndrome detection. | |
| Notes | ||
| Table of Methodological Quality | ||
| Item | Authors' judgement | Description |
| Representative spectrum? All tests | Yes | Selective testing of high‐risk women as done in practice. |
| Acceptable reference standard? All tests | Yes | Amniocentesis. |
| Partial verification avoided? All tests | Yes | All women had a reference standard. |
| Differential verification avoided? All tests | Yes | All women had the same reference standard. |
| Incorporation avoided? All tests | Yes | Reference standard was independent of the index test. |
| Reference standard results blinded? All tests | Yes | Reference standard interpreted without knowledge of index test results. |
| Index test results blinded? All tests | Unclear | Unclear if index test interpreted with knowledge of reference standard results. |
| Relevant clinical information? All tests | Yes | Information available as would be in standard clinical practice. |
| Uninterpretable results reported? All tests | No | No details given for test failures/uninterpretable measurements. |
| Withdrawals explained? All tests | No | No details of withdrawals given. |