Background
Materials and methods
Search strategy and selection criteria
Data extraction
Methodological quality assessment
Data synthesis and analysis
Results
Literature search and selection
Description of the studies
NO. | Author(year) | Location/Period | Population | Age (yrs) | Mean EMS response time (minutes) | Outcomes | Adjustment for covariates |
---|---|---|---|---|---|---|---|
1 | Cummins(1985) [28] | Washington, America (1976.04–1983.09) | OHCAs (1297) | Mean 64.7 | N/A | 1.survival to hospital discharge | Witnessed arrest, age, sex, and EMS response time |
2 | Swor(1995) [29] | Oakland, American (1989.06–1993.06) | OHCAs (722) VT/VF (476) | 65.9 | ALS/BLS 6.5/3.6 | 1.VT/VF 2. live discharge 3. ROSC 4. survival to hospital admission 5. survival at 1 year | Age, ALS response interval |
3 | Weston(1997) [17] | Glamorgan, England (1989–1992) | OHCAs (954) | N/A | N/A | 1. admission to hospital 2. discharge from hospital | Age, sex, arrival status, cause of arrest, rhythm of arrest and the delay to ALS |
4 | Stiell(1999) [30] | Ontario (1991.01–1995.01) | OHCAs (5335) | Mean 68 | N/A | 1. survival to discharge | Age, bystanders witnessed arrest, fire CPR, EMS response time |
5 | Holmberg(2000) [18] | Sweden (990.01–1995.05) | OHCAs (9877) | Med 70 | N/A | 1. 30-day survival | Age, location of arrest, witnessed status, time between call to first ECG |
6 | Finn(2001) [32] | Perth,Australia (1996–1999) | OHCAs (1293) VT/VF (286) | Mean65 | N/A | 1. initial cardiac arrest rhythm of VF/VT in bystander-witnessed cardiac arrests of presumed cardiac origin 2. 28-day survival | Age, gender |
7 | Herlitz,(2003) [19] | Goteborg, Sweden (1980.10–2000.10) | OHCAs (5505) | N/A | N/A | 1. survival to hospital discharge | age, previous history, chronic medication before cardiac arrest, events at resuscitation, and status on admission to hospital |
8 | Herlitz(2005) [20] | Sweden (1990–2000) | OHCAs (22024) | Mean71 med 73 | Med 6 | 1. survival to 1 month | age, sex, location of arrest, witnessed status, initial cardiac rhythm, EMS response time |
9 | Iwami(2007) [25] | Osaka, Japan (1998.05–2003.04) | OHCAs (4902) VT/VF (696) | Mean 62 | Mean 9.7 | 1. neurologically favorable 1-year survival 2. return of spontaneous circulation; admission to hospital; and 1-week, 1-month, and 1-year survival 3. VT/VF | Age, witnessed status, place, defibrillation, EMS response time |
10 | Herlitz(2008) [34] | Sweden (1990–2005) | OHCAs (22465) | Mean 67 | N/A | 1. 30-day survival | Age, witnessed status, place, defibrillation, EMS response time |
11 | Nordberg(2009) [21] | Sweden (1992.01–2005.12) | OHCAs (34125) | Mean 63 | Med 7.5 | 1. 30-day survival 2. VT/VF | Age, sex, witnessed status, initial rhythm, EMS response time |
12 | Adielsson(2011) [6] | Sweden (1990.01–2009.12) | OHCAs: VT/VF (7187) | N/A | N/A | 1. 30-day survival 2. patients who survived to hospital admission | Age, sex, the site of cardiac arrest, Increasing delay to defibrillation |
13 | Lindner(2011) [22] | Stavanger, Norway (2001.01–2008.12) | OHCAs (846) | Mean 71 | Med 8.5 | 1. ROSC 2. survival to discharge | age, year, witnessed status, initial cardiac rhythm, EMS response time |
14 | Wissenberg(2013) [23] | Denmark (2001–2010) | OHCAs (19468) | Med 72 | Med 11 | 1. 30-day survival | age, sex |
15 | Nehme(2015) [33] | Victoria, Australian (2002.07–2012.06) | OHCAs VT/VF (5561) | Med 70 | Med 8.0 | 1. survival to hospital discharge 2. survival to hospital discharge (shockable rhythm) | age, sex, year of arrest, witnessed status, initial cardiac rhythm, EMS response time |
16 | Lai (2015) [26] | Singapore (2001–2004,2010–2012) | OHCAs (5453) | Mean 62 | Med 6.2 | 1. survival to discharge | age, year, witnessed status, initial cardiac rhythm, EMS response time, Mechanical CPR by EMS, prehospital advanced airway, medicine |
17 | Hasselqvist-Ax(2015) [24] | Sweden (1990.01–2011.12) | OHCAs (30381) VT/VF (10094) | Med 72 | Med 7 | 1. 30-day survival 2. VT/VF | age, sex, location and cause of cardiac arrest, initial cardiac rhythm, EMS response time, time from collapse to call for EMS, and year of event |
18 | Gaieski(2017) [31] | Philadelphia (2008–2012) | OHCAs (4625) | Med 64 | Med 6.6 | 1. prehospital ROSC 2. 30-day survival | Age, sex, shockable rhythm, time of arrest, witnessed status, location of cardiac arrest, prehospital AED |
19 | Tanaka(2017) [27] | Asia (2009.01–2012.12) | OHCAs (56765) | Mean 72.7 Med 76.0 | N/A | 1. survival to hospital discharge or 30 day hospital survival 2. favorable postarrest cerebral performance | age, bystander-witnessed arrest, shockable rhythm, bystander CPR, out-of-hospital defibrillation, advanced airway and drug administration, and response time |
Quality of the included studies
Study | Selection | Comparability | Outcome | Total |
---|---|---|---|---|
Cummins(1985) | 4 | 2 | 2 | 8 |
Swor(1995) | 4 | 2 | 2 | 8 |
Weston(1997) | 3 | 2 | 2 | 7 |
Stiell(1999) | 3 | 2 | 2 | 7 |
Holmberg(2000) | 3 | 2 | 2 | 7 |
Finn(2001) | 4 | 1 | 2 | 7 |
Herlitz(2003) | 3 | 1 | 2 | 6 |
Herlitz(2005) | 4 | 2 | 2 | 8 |
Iwami(2007) | 4 | 2 | 2 | 8 |
Herlitz(2008) | 3 | 2 | 2 | 7 |
Nordberg(2009) | 3 | 2 | 2 | 7 |
Lindner(2011) | 3 | 2 | 2 | 7 |
Wissenberg(2013) | 4 | 1 | 2 | 7 |
Lai(2015) | 3 | 2 | 2 | 7 |
Nehme(2015) | 3 | 2 | 2 | 7 |
Hasselqvist-Ax(2015) | 4 | 2 | 2 | 8 |
Gaieski(2017) | 4 | 2 | 2 | 8 |
Tanaka(2017) | 4 | 2 | 2 | 8 |
Effects of interventions
Survival of all OHCAs
Survival of OHCAs whose initial rhythm is shockable
Survival of OHCAs whose initial rhythm is non-shockable
Regression and subgroup analyses
VARIABLES | y |
---|---|
Outcome | 0.298 |
−0.19 | |
Year | −0.00502 |
−0.0104 | |
Area | −0.150† |
−0.0636 | |
Constant | 10.5 |
−20.66 | |
Observations | 17 |