Studies included in a review of impact of three national confidential enquiries (Confidential Enquiry into Maternal Deaths (CEMD), Confidential Enquiry into Stillbirths and Deaths in Infancy (CESDI), National Confidential Enquiry into Patient Outcome & Death (NCEPOD))
| Study | National confidential enquiry | Period | Design | Participants | Sampling method | Participation rate (%) | Data collection | Impact on structure, process or outcome (examples) | Impact-assessment method |
| Derrington et al 199729 | NCEPOD | 1995 | Cross-sectional | Anaesthetists (n=72) | Random sample; one per hospital | 72 | Questionnaire (mailed) | Structure (local guidelines; staffing; equipment) | Clinicians' opinion |
| Pryce et al 199836 | NCEPOD | 1997 | Cross-sectional | Surgeons and anaesthetists (n=2195) | Stratified sample | 70 | Questionnaire (mailed) | Structure (staffing; facilities); process (timing of surgery; operative surgeon) | Clinicians' opinion |
| Guryel et al 200437 | NCEPOD | 2001 and 2002 | Before-and-after | Surgical patients (n=38 and 22) | Consecutive cases; one hospital | 100 | Case-note review | Process (operative delay) | Quantitative measurement |
| Foy et al 200030 | CEMD | 1998 | Cross-sectional | Obstetricians and midwives | Sample in each unit in Scotland | 97 | Questionnaire (telephone) | (Clinicians' awareness only) | Clinicians' opinion |
| Henderson 200135 | CESDI | 1999 | Cross-sectional | Maternity units (n=12) | All in one region | 63 | Questionnaire (mailed) | Process (CTG interpretation) | Clinical managers' opinion |
| Benbow et al 199834 | CEMD | 1996–1997 | Cross-sectional | Maternity units (n=259) | All in UK | 100 | Questionnaire (mailed) | Structure (unit site; transfusion facilities) | Organisational reports |
| Hibbard 199433 | CEMD | 1993 | Cross-sectional | Maternity units (n=248) | All in UK | 95 | Questionnaire (mailed) | Structure (unit site; transfusion facilities) | Organisational reports |
| Bolton et al 200339 | CEMD | 2001–2002 | Before-and-after | Obstetric anaesthetists (n=179 and 198) | All in UK | 75 and 77 | Questionnaire | Process (drug utilisation) | Organisational reports |
| Cook et al 199431 | CEMD | 1993 | Cross-sectional | Maternity units (n=44) | Random sample | 100 | Questionnaire | Structure (staffing); process (intubation method) | Organisational reports |
| Cordingley et al 199732 | CEMD | 1994 | Cross-sectional | Maternity units (n=232) | All in UK | 89 | Questionnaire (mailed) | Structure (staffing; equipment) | Organisational reports |
| Rankin et al 200640 | CESDI | 2002 | Qualitative | NCE reviewers (n=22) | Purposive sample | 100 | Semistructured interview | (Clinicians awareness and attitude only) | Clinicians' opinion |
| Barthelmes et al 200438 | NCEPOD | 2001 and 2002 | Before-and-after | Not specified (n=17 and 17) | All hospitals in Wales | 100 | Questionnaire | Structure (staffing; facilities) | Organisational reports |