4. Assay characteristics.
| Study | Type of Assay | Manufacturer | Stimulation? | Reported basal cut‐off | Assay switching | Included in cut‐off covariate analysis (10 pg/mL) |
| Rieu 1995 | RIA (1989) IRMA (1990‐1993) |
Mallinckrodt Medical SA, France CIS‐Oris International, France |
Yes | 35 pg/mL 10 pg/mL |
Yes | No |
| Ozgen 1999 | RIA | Diagnostic System Laboratories Inc., US | No | 30 pg/mL | No | No |
| Hahm 2001 | IRMA | BioSource Europe S.A., Belgium | Yes | 10 pg/mL | No | Yes |
| Hatzl‐Griesenhofer 2002 | ICMA | Nichols Institute diagnostics, US | Yes | Females: 4.6 pg/mL Males: 11.5 pg/mL |
No | No |
| Elisei 2004 | IRMA | CIS, France | Yes | 20 pg/mL | No | No |
| Karanikas 2004 | ICMA | Nichols Institute Diagnostics, US | Yes | 10 pg/mL | No | Yes |
| Vierhapper 2005 | IRMA (1994‐1999) ICMA (1999‐2004) |
CIS‐biointernational, France Nichols Institute Diagnostics, US |
Yes | 10 pg/mL | Yes | Yes |
| Papi 2006 | ICMA | Nichols Institute diagnostics, US | Yes | 5 pg/mL | No | Yes |
| Schuetz 2006 | ICMA | Nichols Institute diagnostics, US | Yes | 10 pg/mL | No | No |
| Costante 2007 | ICMA | Nichols Institute diagnostics, US | Yes | 10 pg/mL | No | Yes |
| Rink 2009 | IRMA | IBL GmbH, Germany and Medipan GmbH, Germany |
Yes | 10 pg/mL | No | Yes |
| Hasselgren 2010 | IRMA ICMA |
MediLab A/S, Denmark Siemens Medical Solutions Diagnostics, Germany |
No | 100 pg/mL | Yes | No |
| Herrmann 2010 | ICMA | Siemens Healthcare Diagnostics, Germany | Yes | 10 pg/mL | No | Yes |
| Schneider 2012 | ICMA | Siemens Healthcare Diagnostics, Germany | Yes | 13 pg/mL | No | No |
| Giovanella 2012 | ICMA | Siemens Healthcare Diagnostics, Germany | Yes | 10 pg/mL | No | Yes |
| Grani 2012 | ICMA | Not reported | No | 10 pg/mL | No | Yes |
ICMA: immunochemiluminometric ASSAY; IRMA: immunoradiometric assay; pg/mL: picograms per millilitre; RIA: radioimmuno assay.