Table 2 Frequencies of occurrence, characteristics/types, consequences and preventability reported in the included studies on in-hospital AEs

Name of the first author (Publication year), Country/countries

Number of study sites; setting of the study (e.g. medical, surgical, ICU) (number of patients / medical records included in the study)

Frequency of AEs observed in the study

Frequency/Distribution of the characteristics/types of AEs

Consequences of AEs according to classification used in the study (e.g., temporary or permanent harm, death, etc.)

Percentage of AEs judged as preventable

Akbari et al. (2015), Iran, [34]

4 general hospitals; medicine, general surgery, urology, orthopaedics, ICU, CCU, A&E, ENT, ophthalmology, paediatrics and women’s health (n = 1162),

7.3% during stay (3.7% of patients had AEs before admission)

Adverse drug reaction (26.6%); post-op infections (19.5%); pressure ulcers (13.3%); hospital-acquired infections (10.2%); procedural complications (10.2%)

Minimal impairment (< 1 month): 73.4%; moderate impairment (1–12 months): 21.2%; severe impairment: 3.9%; death: 0.8%

34.3%

Aranaz-Andres et al. (2011), Argentina, Colombia, Costa Rica, Mexico, Peru, [51]

58 hospitals; surgery, gynaecology, obstetrics, paediatrics and intensive care (n = 11,379)

10.5% (1191 patients) had at least one AE

Hospital-acquired infections (37.1%); surgical procedures (28.5%); patient management and nursing care (13.4%); medication (8.2%); diagnostics (6.1%). The 5 most frequent AEs (accounting for 36.2% of all AEs): 127 hospital-acquired pneumonia (9.4%); 111 surgical wound infections (8.2%); 97 pressure ulcers (7.2%); 86 other complications related to surgery or procedure (6.4%) and 67 sepsis (5%).

Any kind of disability: (28.8%); death (5.8%)

59%

Aranaz-Andres et al. (2009), Spain, [32]

24 hospitals, all wards (n = 5624)

9.3% (525 patients; 655 AEs) had at least one AE

Medication use (37.4%); nosocomial infections (25.3%); procedure-related (25%); care-related (7.6%); diagnosis-related (2.7%); others (1.8%)

Minor: (45%); moderate: (39%) and severe: (16%resulted in a longer stay: (31.4%); death (4.4%)

42.6% (overall) (84.2% of all diagnostic AEs, 56.6.% of nosocomial infections, 56% care related AEs)

Baker et al. (2004), Canada, [22]

20 hospitals; medical-surgical units (n = 3745)

7.5% (255 patients; 289 AEs) had at least one AE

Surgical procedures (34%), drug-related events (24%), clinical management (12%), diagnostic procedures (11%), medical procedures (7%), others e.g., burns, falls (5%)

Minimal impairment (< 1 month): 64.4%; moderate impairment (1–12 months): 12.5%; permanent impairment: 5.2%; death: 15.9%

36.9%

Brennan et al. (1991), US, [6]

51 hospitals; acute care (n = 30,121)

3.7% (1278 AEs)

Not stated

Minimal impairment (= < 1 month): 56.8%; moderate impairment (> 1 month): 16.5%; permanent disability: 6.5%; death: 13.6%

Preventability not stated;27.6% AE due to negligence

D’Amour et al. (2014), Canada, [52]

11 hospitals; medical units (n = 2699)

15.3% (412 patients; 568 AEs) had at least one AE

Falls (40.5%); administration errors (29.7%); urinary tract infection (12.3%); pressure ulcers (9.1%); inappropriate use of restraints (4.2%); medication pneumonia (4.0%)

167 of AE (29.4%) had consequences

Preventability not stated; 76.8% AEs due to inappropriate nursing care

Davis et al. (2002) & Davis et al. (2003), New Zealand [53, 54]

13 hospitals; acute care (n = 6579)

12.9% (850 AEs)

Operative (24.3%), system: (24%), drug (12.3%), therapy (8.4%), diagnosis (8%), procedure (7.7%), other (e.g., falls) (15.3%)

Minimal impairment (< 1 month): 61.6%; moderate impairment (1-12 months): 19.0%, permanent disability: 10.2%; death: 4.5%; unclear (4.7%)

37.1%

Forster et al. (2004), Canada, [35]

1 hospital (multi-campus); (n = 502)

12.7% (64 patients)

Adverse drug events (50%), surgical complications (31%), nosocomial infections (19%), diagnostic errors (9%), system problems (8%), procedure injuries (8%), anaesthetic injuries (2%), obstetric injuries (2%)

Temporary disability: 10.4%; permanent disability: 1.8%; death (not preventable): 0.6%

37.5%

Grira et al. (2015), Tunisia, [25]

1 hospital; internal medicine (n = 500)

5.2% (26 patients)

Adverse drug events (73%), healthcare associated infections (19%), non-surgical procedures (4%), pressure ulcers (4%)

Prolongation of hospitalization: (27%); disability: (15.4%); readmission: (42.9% of hospitalizations due to AE)

57.7%

Halfon et al. (2017), Switzerland, [55]

1 medium size community hospital; medical and surgical setting (n = 1007)

12.3% AEs (64 AEs in 55 medical patients, 82 AEs in 72 surgical patients)

Surgical patients: operative procedures (74%), medications (15%), non-surgical procedures (7%), diagnostic procedures (4%), medical patients: medication (52%), non-surgical procedures (27%), operative procedures (11%), therapeutic decisions (6%), diagnostic procedures (5%)

No or minimal impairment: 60%, Severe impairment: 23%

42%

Kable et al. (2002), Australia, [28]

28 hospitals; surgery (n = 5432)

21.9% (1190 AEs)

Operation-related (74.9%): wound infections (2.1%); bleeding (1.4%), wound problems (1.2%), deep vein thrombosis/pulmonary embolisms (0.3%), and pneumonia (0.2%)

Minimal disability (< 1 month): 46.9%, moderate impairment (1-12 months): 36.1%,permanent disability: 17%; death: 4.0%

Letaief et al. (2010), Tunisia, [33]

1 hospital; 18 units (n = 620)

10% (62 AEs)

Surgical/invasive related (54.8%), therapeutic errors (20.9%), diagnostic errors (12.9%), drug-related (6.5%); others (4.9%)

Minimal impairment (< 1 month): 16.1%moderate impairment (1–12 months):56.5%permanent disability: 6.4%; death: 21%

60%

Mendes et al. (2009), Brazil, [56]

3 hospitals; acute care (n = 1103)

7.6% had at lease one AE (84 patients; 103 AEs)

Surgical procedures (35.2%), medical procedures(30.6%), diagnoses (10.2%), obstetric (8.3%), medication (5.6%,), fractures (1.9%), anaesthetic (0.9%), system events (6.5%), others (0.9%)

Not stated

66.7%

Rafter et al. (2017), Ireland, [57]

8 hospitals; acute care (n = 1574)

12.2% (247 AEs)

Operation related (25.48%), therapeutic events (24.55%), medication related (14.1%), diagnostic events (11.55%), other events, not covered elsewhere (9.25%), non surgical procedure related (7.9%), fracture related (3.92), pregnancy related (1.17%), anaesthetic related (1.14%), fluid related (0.94%)

Minimal impairment (< 1 month): 33.6%moderate impairment (1–12 months): 25.8% permanent disability: 9.9%; death: 6.7%

72.7%

Sari et al. (2007), England, [29]

1 hospital (n = 1006)

13.5% (136 AEs)

Not stated

Not stated

Not stated

Sommella et al. (2014), Italy, [26]

1 hospital (n = 1501)

3.3% (46 AEs)

Not stated

Not stated

Not stated

Soop et al. (2009), Sweden, [58]

28 hospitals; acute care units (n = 1967)

12.3% (241 AEs)

Invasive procedures including surgical operations (49.4%), drug treatment (30.1%), diagnostic procedure (11.3%), other procedures (14.2%)

Minimal impairment (< 1 months): 53.5% moderate impairment (1–12 months): 29.8% permanent disability: 10.8%; death: 4.1%

70.1%

Sousa et al. (2014), Portugual, [30]

3 hospitals; acute care (n = 1669)

11.1% (186 AEs)

Surgical related (27%), drug errors (18.3%), hospital acquired infections (12.2%)

Minimal impairment (< 1 months): 61% moderate impairment (1–12 months): 4.1% permanent disability: 5.7%; death: 10.8%

53.2%

Tartaglia (2012), Italy, [59]

5 hospitals (n = 7573)

5.2% (n = 470 Aes in 386 patients)

Medical patients (37.5%), surgical patients (30.1%), emergency department (6.2%), obstetric patients (4.4%),

Prolongation of hospitalization (66.7%); disability (18.0%); death (10.6%)

56.7%

Thomas et al. (2000), US, [27]

28 hospitals; all acute care units (n = 14,700)

2.9% (587 AEs)

Surgery (44.9%), drugs (19.3%), medical procedures (13.5%), diagnoses (6.9%), therapy (4. 3%), obstetric (3.6%), falls (1.3%), fractures (0.4%), others (1.5%

Temporary impairment: 73.8%,permanent impairment: 7.5%; death: 6.6%

Preventability not stated;29.2% negligent AEs

Vincent et al. (2001), Great Britain, [23]

2 hospitals; general medicine, general surgery, orthopaedics, obstetrics (n = 1014)

10.8% (110 patients, 119 AEs) with at least one AEs

General medicine (9.2%), general surgery (16.2%), obstetrics (4%), orthopaedics (14.4%)

Minimal impairment: 66% moderate impairment: 19%permanent disability: 6%; death: 8%

48%

Williams et al. (2008), Scottland, [24]

2 hospitals, acute medical, surgical and obstetric admissions (n = 354)

7.9% (Range: 0% obstetrics, 7.2% medicine, 13% surgery)

Nature of problem: medical and nursing management and monitoring (32.1%), infection related (35.7%), technical procedure related (21.4%), drug/i.v. fluid problem (7.1%), fall (3.6%)

No physical impairment (17.9%), minimal physical impairment (35.7%), moderate impairment (28.6%), permanent impairment (7.1%), contributed to patient death (10.7%)

43%

Wilson et al. (2012), Egypt, Jordan; Kenya; Morocco; Tunisia; Sudan; South Africa; Yemen; [31]

26 hospitals; paediatric hospital; obstetric hospital; general public hospital; teaching hospital (n = 15,548)

8.2% (between country-variability ranging from 2.5 to 18.4%)

Therapeutic errors (34%), diagnostic (18%), operative (17%); obstetrics (8%), neonatal (7%), non-surgical procedures (5%),drug related (4%), fractures (3%), falls (2%), anaesthesia (2%)

Minimal impairment (< 1 months): 32% moderate impairment (1–12 months): 16% permanent disability: 12%; death: 30%

83%

Wilson et al. (1995), Australia, [60]

28 hospitals (n = 14,179)

16.6%

Operative (50.3%), diagnoses (13.6%), therapy (12%), drug (10.8%), medical procedures (8.6%), fractures (5.5%), obstetrics (5.5%), falls (2.9%), others (19.1%)

Minimal disability: 46.6% permanent disability: 13.7%; death: 4.9%

51.2%

Zegers et al. (2009), Netherland, [61]

21 (university, teaching and general) hospital (n = 7926),

5.7% (6.8% surgical; 4.8% non-surgical)

Surgery (54.2%), medical procedures (17%), drug/fluid (15.3%), diagnostic (6.3%), other clinical management (3.7%), other (e.g. falls) (2.1%), discharge (1.4%)

No or minimal physical impairment: 56.8%permanent disability: 5.0%; death: 7.8%

39.6% (surgical: 39.5%, non-surgical 40.3%)