Table 1.
Description of included studies
| Patient characteristics |
||||||||
|---|---|---|---|---|---|---|---|---|
| Study (Dates) |
Study Type, Data source |
Hospital, n Surgeon, n Patient, n |
Location (Country/ State) |
Age (years)a /M:F |
Stage | Surgery type | Volume definition | Adjusted Results |
| Ptok 2007 39; (2000–2001) |
Prospective cohort, study data (voluntary) |
Patients: 1557 | Germany | Median 66 26–92) / 1.6:1 |
UICC stage I = 16% II= 35% III =48% |
LAR = 39% APR = 61% |
Hospital volume Number of annual surgeries Low <10, Medium 10–19, High ≥20 |
Hospital HR (95%CI) [ref = High] Local recurrence rate: Low 1.01 (0.83–1.52) Medium 1.39 (1.06–1.81)* |
| Yasunaga 2009 33; (2006–2007) |
Retrospective cohort; Web based registration system (voluntary) |
Hospital: 371 Patients: 2285 |
Japan | Mean = 67 (SD=11) / 1.8:1 |
Stage 0 = 2% I = 21% II = 28% III = 37% IV = 12% |
HAR = 20% LAR = 55% APR = 19% Hartman = 6% |
Hospital volume Number of 2005 surgeries Low ≤ 9 High ≥10 Surgeon volume Number of cumulative surgeries Very low ≤49 Low 50–99 High 100–499 Very High ≥500 |
OR (95%CI) [ref =Low] Intraoperative blood loss: Hospital: High 1.09 (0.81–1.48) Surgeon: Low: 1.02 (0.73–1.42) Surgeon: High: 0.93 (0.67–1.28) Surgeon: Very High: 0.67 (0.46–0.99)* RR ratio (95%CI)(ref =Very low) Postoperative complications: Hospital: High: 1.00 (0.75–1.34) Surgeon: Low: 0.92 (0.64–1.33) Surgeon: High: 0.94 (0.69–1.28) Surgeon: Very High: 0.93 (0.65–1.36) Length of stay: Hospital: High 1.41 (1.23–1.62)* Surgeon: Low 0.99 (0.83–1.17) Surgeon: High 0.99 (0.85–1.16) Surgeon: Very High 1.09 (0.87–1.36) |
| Gort 2010 28; (2001–2005) |
Retrospective cohort; North East cancer registry |
Hospital: 16 Patients: 819 |
North East Netherlands | <70 = 58% ≥70 = 42% / 1.6:1 |
TNM Stage I = 32% II = 30% III = 38% |
LAR = 40% APR = 42% Hartmann = 18% |
Hospital volume Mean annual surgeries Low <20, Medium 20–40 High ≥40 Surgeon volume Mean annual surgeries Low <5, Medium 5–10, High ≥10 |
Hospital OR (95%CI) [ref = Low]
Complications: Medium: 0.79 (0.52–1.20); High: 0.65 (0.44–0.96)* Surgeon HR (95%CI) [ref = Low] Overall Survival (3 years): Medium: 1.02 (0.73–1.42); High: 0.70 (0.47–1.03) |
| Elferink 2010 26; (2001–2006) |
Retrospective cohort; Netherlands cancer registry |
Hospital: 97 Patients: 16039 |
Netherlands | <60 = 26% 60–74 = 43% 75+= 30% / 1.4:1 |
Clinical Stage T0/IS-M0 = <1% T1-M0 = 9% T2/T3-M0 = 59% T4-M0 = 10% T/Nany-M1 = 17% Missing = 5% |
LAR = Included APR = Included Other = Included |
Hospital volume Number of annual surgeries Low <25 Medium 25–50 High >50 |
Hospital OR (95%CI) [ref = Low] Postoperative Mortality: Medium: 0.70 (0.44–1.14) High: 0.40 (0.19–0.84)* RER (95%CI) [ref = Low] Overall survival (2 years): Medium: 0.95 (0.88–1.04) High: 1.02 (0.91–1.14) |
| Manchon-Walsh 2011 24; (2005 & 2007) |
Retrospective cohort; Hospital data (Catalonian Hospital Discharge Minimum Basic Data Set) |
Hospital: 51 Patients: 1831 |
Spain/ Catalonia |
Median =70 (29–92) / 1.9:1 |
TNM Stage 0 = <1%; I = 12%; II = 28%; III = 43%; IV = 7%; Missing = 8% |
LAR = 73% APR = 21% Hartmann = 5% Missing = 2% |
Hospital volume Number of annual surgeries Low ≤ 11 Medium 12–30 High ≥30 |
OR (95%CI) [ref=Low] Postoperative complications: Medium: 0.65 (0.49–0.88)* High: 0.74 (0.56–0.99)* Postoperative Mortality: Medium: 0.93 (0.38–2.31) High: 1.02 (0.42–2.46) |
| Kolfschoten 2011 25; (2010) |
Retrospective cohort; Dutch Surgical Colorectal Audit |
Hospital: 90 Patients: 2419 |
Netherlands | <70 = 59% 70–80 = 30% 80+ = 11% / 1.6:1 |
TNM Stage I = 30%; II = 27%; III = 32%; IV = 10%; X = 1% |
LAR = 67% APR = 30% Other = 3% |
Hospital volume Number of annual surgeries Low <50, High 50–100 |
Hospital SMR (95%CI)
Postoperative Mortality: Low: 1.00 (0.72–1.38) High: 1.0 (0.63–1.59) |
| Yun 201235; (2001–2005) |
Retrospective cohort; Korean cancer registry |
Hospital:>180 Patients: 19028 |
South Korea | Compositeⱡⱡ | Compositeⱡⱡ | Compositeⱡⱡ |
Hospital volume Mean 5 year surgeries Low <23, High ≥23 |
Hospital HR (95%CI) [ref = High] Overall survival (5 years): Low: 1.39 (1.27–1.52)* |
| Comber 2012 40; (2007) | Retrospective cohort; National cancer registry | Hospital: 49 Surgeon: 86 Patients: 457 |
UK/ Ireland | 30–49 = 11% 50–69 = 51% 70+ = 34% Missing=4%/NRⱡ |
NRⱡ | NRⱡ |
Hospital volume Number of annual surgeries Low <10, Medium 10–19, High ≥20 Surgeon volume Continuous |
Hospital OR (95%CI) [ref = High] Overall survival (1 year): Hospital: 1.03 (1.00–1.06)* Surgeon: 0.97 (0.93–1.01) |
| Richardson 2013 36; (2002–2006) |
Retrospective cohort; Nova Scotia Cancer Registry | Hospital: 10 Surgeon: 51 Patients: 466 |
Canada/ Nova Scotia | Mean=66 (27–94) / 1.9:1 |
AJCC stage I = 31% II= 27% III =35% IV = 7% |
LAR = Included APR = Included Hartman= Included Other= Included |
Hospital and surgeon volume Mean annual surgeries Hospital and surgeon volume: based on volume distribution (actual definitions not reported) |
OR (95%CI)(ref = High) Permanent colostomy: Hospital: Medium: 2.02 (0.90–4.57) Hospital: Low: 2.10 (0.85–5.20) Surgeon: Low: 1.23 (0.58–2.62) RR ratio (95%CI)(ref = High) Inappropriate colostomy: Medium: 3.32 (1.08–10.27)*; Hospital: Low: 5.03 (1.44–17.54)* Surgeon: Low: 1.50 (0.54–4.16) |
| Richardson 2013 37; (2002–2006) |
Retrospective cohort; Nova Scotia Cancer Registry and surgeon survey (voluntary) | Surgeon: 25 Patients: 377 |
Canada/ Nova Scotia | Mean=67 (27–96) / 1.8:1 |
AJCC stage
I = 31% II = 28% III =35% IV = 7% |
NRⱡ |
Surgeon volume 2002–2006 mean surgeries based on volume distribution (actual definitions not reported) |
Surgeon OR (95%CI) [ref = Low] Permanent colostomy: High: 0.49 (0.25–0.97)* TME: High: 3.59 (2.21–5.83)*1 12 nodes examined: High: 0.95 (0.55–1.64)* HR (95%CI) [ref = Low] Local recurrence: High: 0.54 (0.29–0.99)* 1 Disease specific survival: High: 0.71 (0.42–1.02) Overall survival: High: 0.67 (0.43–1.02) |
| van Erning 2013 27; (2008–2011) |
Retrospective cohort; Eindhoven cancer registry | Hospital: 10 Patients: 1721 |
Southern Netherlands | <60 = 26% 60–69 = 31% 70–79 = 32% ≥80 = 8% / 1.7:1 |
AJCC T stage (%) T1 = 9%; T2 = 32%; T3 = 52% T4 = 7% AJCC N stage (%) N0= 65%; N1= 23%; N2= 12% AJCC M stage (%) M0 = 92%; M1 = 8% |
LAR = Included APR = Included |
Hospital volume Number of annual surgeries Low <130 High ≥130 |
Hospital OR (95%CI)[ref = <130] Overall survival (3 years): High: 1.0 (0.7–1.4) |
| Leonard 2014 38; (2006–2010) |
Retrospective cohort; Belgian cancer registry (BCR); (exclude PROCARE results) | Hospital: 108 Patient: 5869 |
Belgium | NRⱡ | NRⱡ | NRⱡ |
Hospital volume Continuous |
Hospital HR (95%CI) Postoperative mortality: 0.99 (0.98–1.00)*2 Overall survival (5-years): 0.99 (0.99–1.00)* |
| Ortiz 2015 22; (2006–2013) |
Prospective cohort; Rectal Cancer Project of the Spanish Society of Surgeons (voluntary) | Hospital: 84 Patients: 9809 |
Spain | <65 =39%, 65–80=48% >80=13% / 1.5:1 |
AJCC T stage (%) T0 = 11%; T1 = 7%; T2 = 26%; T3 = 49%; pT4 = 6% AJCC N stage (%) Nx-0= 67%; N1–2= 33% AJCC M stage (%) pM0 = 90%; pM02 = 10% |
LAR = 74% APR = 26% |
Hospital volume Median annual surgeries Very low 11 Low 12–23 Medium 24–35 Very high ≥36 |
Hospital OR (95%CI) [ref=Low] Postoperative mortality: Low 1.852 (0.710, 5.881) High 1.700 (0.649, 5.248) Very high 1.309 (0.483, 4.238) |
| Aquina 2016 31; (2000–2011) | Retrospective cohort; New York Statewide Planning and Research Cooperative System | Hospitals: 206 Surgeons: 849 Patients: 7798 |
US/ New York | 18–65 = 50% 65–79 = 38% ≥80= 12% / 1.4:1 |
NRⱡ | LAR = 64% APR = 35% |
Hospital and Surgeon volume Mean surgeries/period Hospital: Low <25, High ≥25 Surgeon: Low <10, High ≥10 Categories1 LVS/LVH, HVH only, HVS only, HVS/HVH |
OR (95%CI) [ref = LVS/LVH] Non-restorative protectomy: HVH only: 0.86 (0.70–1.05); HVS only: 0.84 (0.60–1.17); HVS/HVH: 0.65 (0.48–0.89)* Postoperative mortality: HVH only: 1.06 (0.52–2.15); HVS only: 0.72 (0.32–1.62); HVS/HVH: 0.43 (0.21–0.87)* |
| Baek 2016 32; (2000–2011) | Retrospective cohort; California Office of Statewide Health Planning and Development | Hospital: 321 Patients: 7187 |
US/ California | <65 = 38% ≥65 = 49% Missing= 13% / 1.7:1 |
NRⱡ | LAR = Included APR = Included |
Hospital volume Number of 20006–2007 surgeries Low 1–5, Medium 6–10, High 11–24 |
Hospital OR (95%CI) [Low] Sphincter preserving surgery: Medium: 1.14 (0.99–1.29) High: 1.63 (1.40–1.89)* Postoperative mortality: Medium: 0.46 (0.27–0.78)* High: 0.45 (0.24–0.84)* |
| Yeo 2016 20; (2000–2013) | Retrospective cohort; New York Statewide Planning and Research Cooperative System | Surgeons: 1860 Patients: 14833 |
US/New York | <65 = 48% 65–75 = 26% ≥75= 26% / 1.2:1 |
NRⱡ | LAR = 74% APR = 26% |
Surgeon volume
Low cumulative; 0–23 High cumulative; ≥24 Low annual; 0–4 High annual; ≥5 Categories2 LC/LA, LC/HA, HC/LA and HC/HA |
Surgeon HC/HA OR (95%CI) [ref=LC/LA] Major events: 0.82 (0.67–0.99)* Prolonged LOS: 0.74 (0.65–0.85)* Surgical complications: 0.71 (0.60–0.83)* Anastomic leak: 1.04 (0.88–1.24) Nonroutine discharges: 0.89 (0.79–1.00) High charges: 0.73 (0.63–0.86)* 30-day readmission: 0.92 (0.80–1.05) Reoperation: 0.98 (0.82–1.17) |
| Bos 2016 29; (2005–2012) | Retrospective cohort; Netherlands cancer registry | Hospital: 95 Patients: 20481 |
Netherlands | <60 = 24% 60–69 = 32% 70–79= 31% ≥80 = 13% / 1.5:1 |
AJCC T stage (%) T1 = 11%; T2 = 33%; T3 = 25%; T4 = 28% AJCC N stage (%) N0= 67%; N1= 22%; N2= 11% |
NRⱡ |
Hospital volume Number of annual surgeries Low <20 Medium 20–39 High ≥40 |
Hospital OR (95%CI) [ref = High] Anastomic leakage: Low: 1.03 (0.79–1.34) Medium: 0.97 (0.83–1.15) Postoperative Mortality: Low: 1.42 (1.09–1.84)* Medium: 1.12 (0.92–1.36) Hospital HR (95%CI)(ref = High) Overall survival (5 years): Low: 0.98 (0.91–1.07) Medium: 1.00 (0.95–1.06) |
| Ortiz 2016 23; (2006–2010) |
Prospective cohort; Rectal Cancer Project of the Spanish Society of Surgeons (voluntary) | Hospital: 36 Patients: 2910 |
Spain | <65 =37%, 65–80=49% >80=14% / 1.4:1 |
AJCC T stage (%) T0 = 8%; T1 = 10%; T2 = 28%; T3 = 49%; T4 = 5% AJCC N stage (%) pN0-ypN0= 68%; pN1-pN2= 32% |
LAR = 69% APR = 23% Hartmann = 8% |
Hospital volume Number of annual surgeries Low 12–23 Medium 24–35 High ≥36 |
Hospital OR (95%CI) [ref=Low] Overall survival (5 years): Medium: 0.858 (0.653, 1.126) High: 0.727 (0.556, 0.951)* Local recurrence: Medium: 1.098 (0.630, 1.916) High:0.835 (0.480, 1.452) Metastasis: Medium: 0.951 (0.683, 1.324) High: 0.727 (0.636, 1.217) |
| Ortiz 2016 21; (2006–2013) |
Prospective cohort; Rectal Cancer Project of the Spanish Society of Surgeons (voluntary) | Hospital: 84 Patients: 7231 |
Spain | <65 =41%, 65–80=47% >80=12% / 1.9:1 |
AJCC T stage (%) T0 = 11%; T1 = 8%; T2 = 26%; T3 = 50%; T4 = 6% AJCC N stage (%) Nx-0= 67%; N1–2= 33% AJCC M stage (%) M0= 90%;M1= 10% |
LAR = 100% |
Hospital volume Median number of annual surgeries Very low 11 Low 12–23 High 24–35 Very high ≥36 |
Hospital OR (95%CI) [ref=Very low] Anastomic leakage: Low: 0.836 (0.492, 1.449); High: 0.833 (0.485, 1.455); Very high: 0.852 (0.487, 1.518) |
| Gietelink 2016 30; (2011–2012) | Retrospective cohort; Dutch Surgical Colorectal Audit | Hospital: 91 Patients: 5161 |
Netherlands | <75= 72–74% >75= 26–28% / 1.7:1 |
AJCC T stage (%) T1-T2 = 32%; T3 = 54%; T4 = 9% |
LAR = 67% APR = 30% Other = 12% |
Hospital volume Mean annual surgeries Low <20 High ≥20 |
Hospital OR (95%CI) [ref = High] CRM involvement: Low: 1.54 (1.12–2.11)* |
| Lorimer 2017 34; (2004–2014) |
Retrospective cohort; National Cancer Database | Hospital: 1179 Patients: 27532 |
US | Mean = 59 (18–90) / 1.7:1 |
Stage II/III only AJCC T stage (%) T1 = <1%; T2 = 5%; T3 = 87%; T4 = 8% AJCC N stage (%) N0= 46%; N1= 46%; N2= 8% |
NRⱡ |
Hospital volume Mean annual surgeries Low <2.2 Very low 2.2–4.37 High 4.37–7.82 Very high >7.82 |
Hospital OR (95%CI) [ref =Very high] Pathological complete response: Low: 0.66 (0.58–0.74)*; Very low: 0.96 (0.86–1.08); High: 0.93 (0.83–1.04) Positive surgical margins: Low: 1.45 (1.25–1.70)*; Very low: 1.32 (1.13–1.54); High: 0.96 (0.82–1.13) |
*
Key: = Significant p-value<0.0005
ⱡ
NR =Not reported in the article
ⱡⱡ
Composite = Cannot delineate between rectal and other cancer with regard to information for this variable
1
High volume hospital (HVH), Low volume hospital (LVH), High volume surgeon (HVS), Low volume surgeon (HVS)
2
High cumulative volume surgeon (HC), Low cumulative volume surgeon (LC), Low annual volume surgeon (HA), Low annual volume surgeon (LA); Odds ratio (OR); Hazard ratio (HR); Relative risk ratio (RR); Relative excess risks (RER); Standard mortality ratio (SMR); High anterior resection (HAR; Low anterior resection (LAR); Abdominoperineal resection (LAR); American Joint Committee on Cancer (AJCC); Union for International Cancer Control’s (UICC), Complete resection margin (CRM)