Table 1.
Studies examining the association between hospital volume and patient outcome after radical prostatectomy*
| Study | Design | Data source | Risk adjustment | Hospital volume | End points |
|---|---|---|---|---|---|
| Yao and Lu-Yao [5] | Retrospective | SEER Medicare claims (n = 101 604), 1991–1994 | Age, race, CCI, surgeon specialty, teaching status | RP volume Categorized in 4 groups: ≤38 (low), 39–74 (medium-low), 75–140 (medium-high), ≥141 (high) | 30 d Mortality (RR; 95% CI): low vs high (1.51; 1.25–1.77), medium-low vs high (1.43; 1.17–1.69), medium-high vs high (1.42; 1.16–1.68) Major complications (RR; 95% CI): low vs high (1.43; 1.37–1.48), medium-low vs high (1.25; 1.19–1.31), medium-high vs high (1.09; 1.03–1.15) Prolonged length of stay (mean; 95% CI): low (8.5 d; 8.47–8.56), medium-low (8.2 d; 8.1–8.2), medium-high (7.7 d; 7.7–7.7), high (7.8 d; 7.8–7.9), p < 0.001 |
| Ellison et al [4] | Retrospective | NIS (n = 66 693), 1989–1995 | Age, CCI | RP volume Categorized in 3 groups: <25/yr (low), 25–54/yr (medium), >54/yr (high) | In-hospital Mortality (OR; 95% CI): low vs high (1.8; 1.2–2.6), medium vs high (1.7; 1.1–2.5) Prolonged length of stay (median): low (5 d), medium (4 d), high (4 d); p < 0.001 Total hospital charges (median): low ($15 560), medium ($15 100), high ($13 500); p < 0.001 |
| Imperato et al [36] | Cross sectional | SEER Medicare beneficiaries in New York State (n = 583), 1996 only | – | RP volume categorized in 3 groups: [1] 1–4, [2] 5–9, [3] ≥10 | RP specimen on operative quality indicators: perineural involvement, vascular involvement, perioprostatic fat status, number of nodes submitted, prostate intraepithelial neoplasia (all p < 0.05) |
| Ellison et al [7] | Retrospective | SEER Medicare claims (n = 12 635), 1990–1999 | Age, CCI, tumor grade, clinical stage | RP volume categorized in 4 groups: low (1–33), medium (34–61), high (62–108), very high (≥108) | Risk of adjuvant therapy (HR; 95% CI): high vs very high (1.0; 0.9–1.1; p = 0.6), medium vs very high (1.1; 1.0–1.2; p = 0.02), low vs very high (1.3; 1.1–1.4; p < 0.001) |
| Hollenbeck et al [29] | Retrospective | NIS (n = 141 052), 1993–2003 | Age, CCI, race, admission acuity, insurance status | RP volume categorized in 2 groups: low (bottom decile), high (top decile) | In-hospital mortality (OR; 95% CI): low vs high (3.9; 1.8–7.9) Prolonged length of stay (OR; 95% CI): low vs high (4.8; 3.5–6.7) |
| Judge et al [23] | Retrospective | Hospital Episode Statistics, Department of Health in England (n = 18 027), 1997–2004 | Age, CCI, Socioeconomic status, year of surgery | RP volume categorized in 5 groups: low (1–13), 2nd (14–20), 3rd (21–28), 4th (29–41), high (42–93) | Perioperative complications (OR; 95% CI): 2nd vs low (0.9; 0.8–1.1), 3rd vs low (0.9; 0.8–1.0), 4th vs low (1.0; 0.9–1.1), high vs low (0.9; 0.8–1.1) Late urinary complications (OR; 95% CI): 2nd vs low (1.0; 0.9–1.2), 3rd vs low (1.0; 0.9–1.2), 4th vs low (0.8; 0.7–1.0), high vs low (0.8; 0.7–0.9) |
| Siu et al [33] | Retrospective | NIS (n = 9266), 2003 only | Age, CCI, race, socioeconomic status, admission acuity, hospital structure characteristics | RP volume Categorized in 3 groups: low (≤32), medium (33–82), high (83–383/yr) | Prolonged length of stay (OR; 95% CI): low vs high (3.7; 2.0–6.8; p < 0.001) |
| Mitchell et al [31] | Retrospective | University HealthSystem Consortium Clinical Data Base (n = 48 086), 2003–2007 | Hospital size, hospital region, total hospital discharges | RP volume was categorized in 3 groups: low (1–99), medium (100–499), | Prolonged length of stay (mean; p value): low 3.8 d), medium (2.7 d), high (2.1 d); p < 0.001 Intensive care unit (%, p value): low (19%), medium (4%), high (1.3%); p < 0.001 Postoperative complications (%, p value): low (16%), medium (8.8%), low (5.7%); p < 0.001 In-hospital mortality: p > 0.05 |
| Hanchanale et al [22] | Retrospective | Hospital Episode Statistics, Department of Health in England (n = 14 300), 1998–2005 | Age, waiting time | RP volume categorized in 4 groups: very low (≤16), low (16–25), medium (25–37), high (≥38/yr) | Perioperative mortality (%): very low (0.4%), low (0.3%), medium (0.1%), high (0.2%); p = 0.08 Prolonged length of stay (% above 75th percentile): very low (36%), low (25%), medium (16%), high (23%); p < 0.001 |
| Trinh et al [30] | Retrospective | NIS (n = 89 965), 2001–2007 | Age, CCI, race, surgical approach, hospital region, teaching status, insurance status, year of surgery | RP volume categorized in 3 groups: low (≤34), intermediate (35–90), high (≥91/yr) | Homologous blood transfusion (OR; p value): high vs low (0.35, p < 0.001) Prolonged length of stay (OR; p value): high vs low (0.19; p < 0.001) Intraoperative complications (OR; p value): high vs low (0.80; p = 0.01) Postoperative complications (OR; p value): high vs low: 0.63; p < 0.001 |
| Trinh et al [32] | Retrospective | NIS (n = 89 965), 2001–2007 | Age, CCI, race, surgical approach, hospital region, hospital location, teaching status, insurance status, morbidity status, year of surgery | RP volume categorized in 3 groups: low (≤34), intermediate (35–90), high (≥91/yr) | Prolonged length of stay (OR; p value): high vs low (0.2; p < 0.001), intermediate vs low (0.5; p < 0.001) Adverse discharge disposition (OR; p value): high vs low (0.6; p < 0.001), intermediate vs low (0.5; p < 0.001) |
| Sammon et al [34] | Retrospective | NIS (n = 77 616), 2009 only | Age, CCI, race, insurance status, teaching status, hospital location, hospital region, surgical approach, year of surgery | RP volume categorized in 4 groups: low (≤14), intermediate (15–32), high (33–78), very high (≥79/yr) | Available in original publication |
CCI = Charlson Comorbidity Index; CI = confidence interval; NIS = Nationwide Inpatient Sample; OR = odds ratio; RP = radical prostatectomy; RR = relative risk; SEER = Surveillance Epidemiology and End Results.
*
Displayed in chronological order.