Table 1.
Characteristics of studies included in the systematic review and meta‐analysis
| Reference | Country | No. of patients |
Age (years)* |
Frail (%) |
Type of operation |
No. of items | Domains† |
Morbidity definiton |
Mortality definition |
|---|---|---|---|---|---|---|---|---|---|
| Amrock et al. 22 (1) | USA | 76 106 | 74·4 | n.r. | Lower GI | 5 | RDA; CO; NS; CF; A | NSQIP | 30 days |
| Amrock et al. 22 (2) | USA | 76 106 | 74·4 | n.r. | Lower GI | 3 | CO; NS; A | NSQIP | 30 days |
| Buettner et al. 23 (1) | USA | 1326 | 65 | n.r. | Mixed GI | 12 | RDA; CO (10); CA | CDC III–IV | 1 year |
| Buettner et al. 23 (2) | USA | 1326 | 65 | 30·0 | Mixed GI | 1 | S | CDC III–IV | 1 year |
| Choi et al. 24 | Korea | 281 | 74·8 | 26·3 | Mixed abdominal | 9 | S; RDA (2); CO; NS (2); CF (2); CA | NSQIP | n.r. |
| Cohan et al. 25 | USA | 2493 | n.r. | 21·3 | Lower GI | 6 | RDA; CO (4); NS | NSQIP | n.r. |
| Courtney‐Brooks et al. 26, ‡ | USA | 37 | 73 | 16 | Gynaecological | 5 | PF; NS; DE; GS; W | NSQIP | n.r. |
| Dale et al. 27, ‡ | USA | 76 | 67·3 | n.r. | Upper GI | 4 | NS; DE; GS; W | CDC III–IV | n.r. |
| Erekson et al. 28 | USA | 22 214 | n.r. | 0·54 | Gynaecological | 1 | NS | Overall | n.r. |
| George et al. 29 | USA | 66 105 | n.r. | 15·5 | Gynaecological | 11 | RDA; CO (9); CF | CDC IV | 30 days |
| Hodari et al. 30 | USA | 2095 | n.r. | n.r. | Upper GI | 11 | RDA; CO (10) | n.r. | 30 days |
| Jones et al. 31 | UK | 100 | 68·6 | 15·0 | Lower GI | 1 | S | n.r. | n.r. |
| Kenig et al. 32, ‡ | Poland | 75 | 75 | 8 | Mixed GI | 8 | RDA (2); M; CO; NS; CF; DE; W | CDC III–IV | n.r. |
| Kim et al. 33, ‡ | Korea | 275 | 75·4 | 35·6 | Mixed abdominal | 9 | S; RDA (2); CO; NS (2); CF (2); CA | NSQIP | 1 year |
| Kristjansson et al. 34, ‡ | Norway | 178 | 76·6 | 42·7 | Lower GI | 7 | RDA (2); M; CO; NS; CF; DE | CDC III–IV | n.r. |
| Kuroki et al. 35 | USA | 122 | 65·9 | 50·0 | Gynaecological | 1 | S | n.r. | n.r. |
| Lascano et al. 36 | USA | 18 384 | 57·7 | n.r. | Urological | 15 | RDA; CO (10); NS; CF (2); CA | CDC IV | 30 days |
| Levy et al. 37 | USA | 23 104 | 61·9 | 54·8 | Urological | 15 | RDA; CO (10); NS; CF (2); CA | CDC IV | 30 days |
| Makary et al. 38, ‡ | USA | 594 | 72·8 | 10·4 | Mixed GI | 5 | RDA; NS; DE; GS; W | NSQIP | n.r. |
| Mogal et al. 39 | USA | 9986 | 64·1 | 6·4 | Upper GI | 11 | RDA; CO (10); | CDC III–IV | 30 days |
| Neuman et al. 40 (1) | USA | 12 979 | 84·4 | 4·3 | Lower GI | 5 | CO; NS; W; F; O | n.r. | 90 days |
| Neuman et al. 40 (2) | USA | 12 979 | 84·4 | 4·3 | Lower GI | 5 | CO; NS; W; F; O | n.r. | 1 year |
| Obeid et al. 41 | USA | 58 448 | n.r. | 12·8 | Lower GI | 11 | RDA; CO (10) | CDC IV | 30 days |
| Ommundsen et al. 42 | Norway | 178 | 80 | 42·7 | Lower GI | 6 | RDA; M; CO; NS; CF; DE | n.r. | 1 year |
| Pearl et al. 43 | USA | 4329 | n.r. | 67·2 | Urological | 11 | RDA; CO (10) | n.r. | n.r. |
| Reisinger et al. 44, ‡ | The Netherlands | 159 | n.r. | 25·8 | Lower GI | 7 | RDA; PF; M; NS; CF; VH; DE | Sepsis | 30 days |
| Revenig et al. 45, ‡ | USA | 214 | 62 | 16 | Mixed abdominal | 5 | PF; NS; DE; GS; W | Overall | n.r. |
| Revenig et al. 46, ‡ | USA | 80 | 60·0 | 23·4 | Mixed abdominal | 5 | PF; NS; DE; GS; W | CDC II–III–IV | n.r. |
| Revenig et al. 1, ‡ | USA | 351 | 63 | 27·3 | Mixed abdominal | 5 | RDA; NS; DE; GS; W | n.r. | 30 days |
| Robinson et al. 12, ‡ | USA | 72 | 74 | 33 | Lower GI | 8 | RDA; CO; NS; CF; W; A; F; O | VASQIP | n.r. |
| Saxton and Velanovich47 (1) | USA | 226 | 61 | n.r. | Mixed GI | 70 | CSHA | Overall | 30 days |
| Saxton and Velanovich47 (2) | USA | 226 | 61 | n.r. | Mixed GI | 70 | CSHA | CDC II–III–IV | n.r. |
| Sur et al. 48 | USA | 100 | 65·6 | 31·0 | Upper GI | 1 | DE | NSQIP | n.r. |
| Suskind et al. 49 | USA | 95 108 | n.r. | 21·5 | Urological | 11 | RDA; CO (10) | NSQIP | n.r. |
| Tan et al. 50, ‡ | Japan | 83 | 81·2 | 28 | Lower GI | 5 | RDA; NS; DE; GS; W | CDC II–III–IV | n.r. |
| Tegels et al. 51 (1) | The Netherlands | 127 | 69·8 | 23·6 | Upper GI | 7 | RDA; PF; M; NS; CF; VH; DE | CDC III–IV | In hospital |
| Tegels et al. 51 (2) | The Netherlands | 127 | 69·8 | n.r. | Upper GI | 7 | RDA; PF; M; NS; CF; VH; DE | CDC III–IV | 6 months |
| Uppal et al. 52 (1) and (2)§ | USA | 6551 | n.r. | n.r. | Gynaecological | 11 | RDA; CO (10) | CDC III–IV | n.r. |
| Velanovich et al. 53 (1) | USA | 727 041 | n.r. | n.r. | Mixed abdominal | 11 | RDA; CO (10) | Overall | 30 days |
| Velanovich et al. 53 (2) | USA | 23 569 | n.r. | n.r. | Gynaecological | 11 | RDA; CO (10) | Overall | 30 days |
| Wagner et al. 54 | USA | 518 | 72 | 25·1 | Upper GI | 1 | S | n.r. | 1 year |
Values are mean or median.
Values in parentheses are number of items used to create the domain.
Prospective studies; the others were retrospective.
Uppal and colleagues52 considered two different scores for the same metric system, on the same population; morbidity outcomes are reported separately for the two scores. n.r., Not reported; GI, gastrointestinal; RDA, reduced daily activities; CO, co‐morbidity; NS, nutritional status; CF, cognitive function; A, anaemia; NSQIP, National Surgical Quality Improvement Program; CA, cancer; CDC, Clavien–Dindo classification; S, sarcopenia; PF, physical fitness; DE, depression/exhaustion; GS, grip strength; W, walking test; M, medication; F, falls; O, others; VH, visual and hearing deficit; VASQIP, Veterans Affairs Surgical Quality Improvement Program; CSHA, Canadian Study of Health and Aging 70 Item Frailty Score.