Study Characteristic | Reference Number |
---|---|
Number and data source of included studies | |
USa data (n = 50) | |
National Inpatient Sample | 17,18,26,39,45,48,58,72 |
National Readmission Database: 21 states | 32 |
CMSb Medicaid (MAX) data | 22 |
US claims data | 27,70 |
US perinatal data networks | 28,43 |
Hospital discharge data: 7 states | 33 |
Hospital discharge data: Illinois | 84 |
Hospital discharge data: Maryland | 81 |
Hospital discharge ± birth certificate data: New York State | 19,44,53 |
Hospital discharge + birth certificate data: 3 states | 29 |
Hospital discharge + birth certificate data: Iowa | 38 |
Hospital discharge + birth certificate data: New York City | 46,47,49,50,78 |
Hospital discharge, birth, ± death certificate data: California | 36,40,52,55-57,68,69,76 |
Hospital discharge, birth, + death certificate data: Georgia | 91 |
Hospital discharge, birth, ± death certificate data: Washington | 42,62–64 |
Hospital discharge + medical record data: 16 California hospitals | 51 |
Hospital discharge + medical record data: Massachusetts | 21 |
Hospital discharge + SARTc + vital statistics data: Massachusetts | 23 |
Birth certificate data: Ohio | 71 |
Birth certificate and SART data: 8 states | 67 |
Medical record data single hospital: California | 93 |
Medical record data single hospital: New York | 73 |
Medical record data single hospital: Missouri | 83 |
Medical record data single hospital: Tennessee | 41 |
Non-US data (n = 31) | |
Multiple countries including US | 60 |
Multiple countries not including US | 90 |
Japan | 16 |
Korea | 75 |
Sweden | 92 |
Finland | 77 |
France | 25,54,88 |
Canada: Ontario | 34,35,80,89 |
Canada: British Columbia | 61,85,86 |
Canada: multiple provinces | 3,8,65,66,74,79,94 |
Australia: New South Wales | 20,24,30,31,37,82,87 |
Australia: Victoria | 59 |
Study design and population | |
Study design nested case-control (n = 6) | |
Yes | 16,21,34,42,54,88 |
Hospital-level risk factors with specific hypotheses (n = 8) | |
Patient-level data adjusted for clustering among hospitals | 19,27,29,32,39 |
Hierarchical models | 36,91 |
Hospital-level data | 49 |
Delivery discharges limited by: (n = 22) | |
Community hospitals | 36 |
Annual delivery volume less than 1000 | 45 |
Low risk | 19,40,65,66 |
Low risk breech presentation | 24 |
Medicaid eligibility | 22 |
Nulliparous | 85 |
Prior cesarean delivery with parity = 1 | 94 |
Prior cesarean delivery ≥3 | 73 |
No prior cesarean delivery | 66 |
Cesarean delivery 22–34 gestational weeks | 25 |
Elective cesarean delivery | 16 |
Preterm gestation | 20,68 |
Term laboring patients with prolonged second stage | 74 |
Preeclampsia | 27 |
Hemorrhage | 80 |
Race/ethnicity Hispanic or White | 46 |
Race Black or White | 47,48 |
SMMddefinition CDCe basis [7] (n = 37) | |
25 indicators | 17,18,23,29,33,36,38,42,46-53,58,60,68,69,71,72,75,76,91,93 |
18 indicators | 19,26,27,41,44,55-57,78,83,84 |
SMM definition not using CDC basis (n = 44) | |
Adapted from other US work (Bateman et al. [22]) | 32,39,45,61–63 |
Adapted from Canadian work (Wen et al. [3]/Joseph et al. [8]) | 3,8,22,34,35,66,74,89,94 |
Adapted from Australian work (Roberts et al. [8]) | 20,24,30,31,37,59,79,82,87 |
Adapted from Swedish work (Wahlberg et al. [92]) | 90,92 |
Adapted from Geller et al. (5 factor) [95] | 43,85 |
Death | 80 |
Intensive care unit admission | 21,25,28,40,53,65,67,71,73 |
Other | 16,54,64,77,86,88 |
Sensitivity analysis for use of transfusion in SMM definition (n = 15) | |
Yes | 26,33,38,44,46,47,49,50,55-57,60,78,91,94 |
Blood transfusion threshold was 4 units of packed red blood cells (n = 6) | |
Yes | 43,51,54,85,88,93 |
Blood transfusion not included in definition (n = 10) | |
Yes | 22,32,37,39,45,77,80,86,90,92 |
Key risk factors studied | |
General risk factors (no hypotheses) (n = 16) | |
Yes | 3,8,22,38,42-45,52,53,59,60,80,81,83,90 |
Patient-level risk factors with specific hypotheses (n = 57) | |
Race/ethnicity | 18,26,33,46-48,50,57,58,72 |
BMIf or gestational weight gain | 35,55,62,71,73,78,86,88 |
Maternal age | 63,76,85 |
Preterm birth | 25,51,68 |
Infertility/IVFg/ARTh | 23,34,54,67,70,93 |
Preeclampsia | 64 |
Hemorrhage | 37 |
Obstructive sleep apnea | 28 |
Congenital heart disease | 79 |
Inflammatory bowel disease | 87 |
Autoimmunity | 30 |
Idiopathic arthritis | 31 |
Rural vs. urban | 61 |
Maternal birthplace or immigration country | 89,92 |
Amphetamine/opioid use | 17 |
Route of delivery | 20,21,24,41,56,66,74,77,84,94 |
Induction of labor | 40,65,82 |
Anesthesia for cesarean delivery | 16 |
Off-hours delivery | 69,75 |
Hospital-level risk factors with specific hypotheses (n = 8) | |
Delivery volume | 27,29,39 |
Level of care | 32,91 |
Percent midwives delivering | 19 |
Presence of laborist | 36 |
Hospital quality indicators | 49 |