Supplemental Table 2. Design and findings of eligible studies
Study (design)
Lee 2014 (22)
United States
(retrospective)
Abraham 2013 (23)
United States
(retrospective)
Objective/Methods (data source)
Review of 4,577 patients to assess
impact of age on surgical outcomes
(registry)
Review of 20,312 patients from
1994-2008 to assess determinants of
receipt of surgery, chemotherapy
(registry)
Amin 2013 (24)
United States
(retrospective)
Cheung 2013 (25)
United States
(retrospective)
Faraj 2013 (26)
United States
(retrospective)
Fitzgerald 2013 (27)
United States
(retrospective)
Hyder 2013 (28)
United States
(retrospective)
Review of 45,509 patients from
1983-2007 to assess impact of age
on treatment and survival (registry)
Review of 58,747 patients from
2004-2007 to asses determinants of
treatment outcomes (registry)
Review of 2,045patients from 20082009 to assess impact of age on
surgical outcomes (registry)
Review of 239 patients from 19962012 to assess impact of increasing
volume over time (single site)
Review of 1,488 patients from
1998-2007 to assess determinants of
readmission following surgery
(registry)
Lee 2013 (29)
United States
(retrospective)
Review of 1,008 patients from
1993-2007 to assess impact of race
on treatment and survival (registry)
Shah 2013 (30)
United States
(retrospective)
Review of 31,495 patients from
1988-2007 to assess impact of race
on receipt of surgery (registry)
Findings
Patients ≥80 years in age had higher 30-day mortality (p=0.003)
and major complications (p=0.048) compared with younger patients
Determinants
Patient (age)
Risk of Bias
Moderate
African-American patients less likely than Caucasians to receive
surgery (OR 0.66, 95 % CI 0.54–0.80) and chemotherapy (OR 0.75,
95 % CI 0.58 to 0.98). Non-insured patients more likely than
insured patients to receive surgery (OR 1.7, 95 % CI 1.4– 2.2),
uninsured less likely to receive adjuvant therapy (OR 0.54, 95 % CI
0.30 to 0.98)
Younger patients (<50 years) had higher surgery (p<0.001) and
radiation rates (p<0.001) and higher survival rates (p<0.0001)
compared with older patients
Race, socio-economic factors (low county family income, ruralurban residence, lower county education attainment) and female sex
associated with lower absolute cause specific survival (p=0.0001)
Older patients (>65 years) had higher thirty-day mortality
compared with younger patients (OR 1.94, p=0.017)
Patient (sex, race,
insurance status)
Low
Patient (age)
Moderate
Patient (age, sex,
SES)
Moderate
Patient (age)
Low
Appropriate use of surgical resection (p=0.0125), and palliative and
adjuvant therapy (p=0.0144, p<0.0001) increased
Institutional
(volume)
Moderate
Lowest volume hospitals and surgeons had longest length of stay
(p<0.001) and highest 90-day mortality (p<0.05). Factors
associated with variation in patient readmission: 95.4% patient,
4.3% hospital, and 0.3% for physician factors. Elizhauser
comorbidity >13 associated with readmission (OR 2.06, 95% CI
1.56 to 2.71 p<0.001)
Surgical resection (OR 1.06, 95 % CI 0.60 to 1.89), chemotherapy
(OR 0.92, 95 % CI 0.49 to 1.73) or radiotherapy (OR 1.14, 95 % CI
0.61 to 2.10) were similar between African-American and
Caucasian patients, as was median overall survival (p=0.17)
Pancreatic resection was less often recommended to (p=0.001) and
performed (p<0.001) on African-American patients compared with
Caucasians. African-American patients refused surgery more often
when recommended (p<0.001) but this disparity decreased over
time (p=0.001)
Institutional
(volume)
Low
Patient (race not
significant)
Low
Patient (race)
Low
Supplemental Table 2 continued. Design and findings of eligible studies
Study (design)
Tamagno (31)
2013
United Kingdom
(before-after)
Al-Refaie 2012 (32)
United States
(retrospective)
Singal 2012 (33)
United States
(retrospective)
Visser 2012 (11)
United States
(retrospective)
Objective/Methods (data source)
Review of 91 patients before, and
42 patients after introducing a
multidisciplinary management
approach (single center)
Review of 9,611 patients from
2003-2008 to assess determinants
of complex surgery at low-volume
hospitals (registry)
Review of 16,282 patients from
from 1988-2007 to assess impact
of race on treatment and outcomes
(registry)
Review of 3,706 patients from
2001-2006 to assess factors
influencing receipt of guidelinerecommended care (registry)
Wray 2012 (34)
United States
(retrospective)
Review of 1,039 patients from
1998-2010 to assess the impact of
race on treatment and survival (two
centers)
Lemmens 2011 (35)
The Netherlands
(retrospective)
Review of 1,139 patients before
(1995-2000), and 990 patients after
(2005-2008) centralizing care to
higher volume centers (registry)
Review of 351 patients from 20032006 to assess determinants of
treatment received (registry)
Review of 249 patients from 19962008 to assess impact of
centralizing care to high volume
centers (registry)
Borgida 2011 (37)
Canada
(retrospective)
Gooiker (36)
2011 Netherlands
(retrospective)
Findings
The multidisciplinary approach improved consistency in
biochemical, imaging, and pathological findings before treatment
initiation and during follow-up, and in receipt of guidelinerecommended management
Non-Caucasian patients (p<0.0001) and patients with lower income
(p<0.0001) were more likely to undergo surgery at low-volume
sites. Low-volume sites had higher inpatient mortality compared
with higher volume sites (OR 2.53, 95% CI, 2.03 to 3.04)
African-Americans had lowest survival compared with nonAfrican-Americans (HR 1.19, 95% CI 1.12 to 1.26). AfricanAmericans, Hispanics less likely to receive any treatment compared
with Caucasians and Asians (p<0.0001)
Older patients (>65 years) less likely to receive guidelinerecommended care (OR 0.68, 95% CI 0.46 to 0.99, p<0.045) and
had higher mortality (OR 2.2, 95% CI 1.42 to 3.49, p<0.0001).
Hispanic patients were less likely to receive guidelinerecommended care (p<0.0001). Survival was higher at academic
(OR 0.66, 95% CI 0.51 to 0.84, p<0.0001) and higher-volume
centers (OR 3.2, 95% CI 2.4 to 4.3, p < 0.0001)
Older patients (OR 0.97, 95% CI 0.96 to 0.98, p<0.001), African
Americans (OR 0.62, 95% CI 0.44 to 0.87, p=0.01) and Asians (OR
0.44, 95% CI 0.22 to 0.96, p=0.04) were less likely to receive
chemotherapy. Mortality was higher among males (OR 0.84, 95%
CI 0.73 to 0.97, p=0.02), African Americans (OR 1.2, 95% CI 1.0
to 1.4, p=0.05) and older patients (OR 1.02, 95% CI 1.0 to 1.3,
p<0.001)
Centralization increased resection rates (p<0.001), decreased inhospital mortality (p<0.001) and increased two-year survival
(p=0.001)
Determinants
Intervention
(multidisciplinary
approach)
Risk of Bias
Low
Institutional
(volume); Patient
(race, SES)
Low
Patient (race)
Low
Patient (age,
race); Institution
(academic,
volume)
Low
Patient (race, sex,
age)
Moderate
Intervention
(centralization)
Low
Younger patients (≤70 years) were more likely to undergo curative
resection (p=0.03). Resections were less frequently aborted in
academic compared with non-academic centers (p<0.001)
Centralization increased surgical treatment (from 14.3% to 18.4%,
p=0.08), decreased risk of death (HR 0.50, 95% CI 0.34 to 0.73),
and increased two-year survival from adenocarcinoma (from 28%
to 49%, p=0.04).
Patient (age);
Institution
(academic)
Institutional
(volume)
Moderate
Moderate
Supplemental Table 2 continued. Design and findings of eligible studies
Study (design)
Woodmass 2011 (37)
Canada
(retrospective)
Objective/Methods (data source)
Review of 124 patients from 20042006 to asses determinants of
surgical referral and receipt of
surgery (registry)
Cheung 2010 (38)
United States
(retrospective)
Review of 16,104 patients from
1998-2002 to assess impact of SES
on treatment and outcomes
(registry)
Review of 3,777 patients from
1992-2002 to assess impact of race
on receipt of surgical care
(registry)
Review of 375 patients from 20002004 to assess determinants of
receipt of surgery (single center)
Riall 2010 (39)
United States
(retrospective)
Sandroussi 2010 (40)
Canada
(retrospective)
Simunovic 2010 (41)
Canada
(retrospective)
Chang 2009 (42)
United States
(retrospective)
Eppsteiner 2009 (43)
United States
(retrospective)
Sharp 2009 (15)
United Kingdom
(retrospective)
Stitzenberg (44)
2009
United States
(retrospective)
Review of 1,859 patients before,
and 1,396 patients to assess
surgical mortality after
centralization of surgery in high
volume centers (registry)
Review of 8,370 patients from
2000-2005 to assess patient factors
associated with referral to high
volume centers (registry)
Review of 3,581 patients from
1998-2005 to assess determinants
of surgical mortality (registry)
Review of 3,173 patients from
1994-2003 to assess determinants
of receiving surgery, chemotherapy
(registry)
Review of 13,472 patients from
1996 to 2006 to assess surgical
mortality after centralization
(registry)
Findings
Among eligible patients, 39% were not referred to a surgeon, 11%
underwent surgery, and 70% received no treatment. Patients
younger than 65years were more likely to be referred for surgical
consultation (OR 5.57, 95% CI 1.5 to 21) or undergo surgery (OR
4.6, 95% CI 1.2 to 17)
Low SES patients were less likely to receive surgery (p<0.001),
chemotherapy (p<0.001) or radiotherapy (14.3% vs. 16.9%
p=0.003); had higher 30-day mortality (p<0.001) and lower median
survival (p<0.001)
African-Americans were less likely to receive surgical consultation
compared with Caucasians (OR 0.57, 95% CI 0.42 to 0.77) and
resection (OR 0.64, 95% CI 0.49 to 0.84)
Determinants
Patient (age)
Risk of Bias
Moderate
Patient (SES)
Low
Patient (race)
Low
Older patients (OR 1.1, p<0.001), non-English speaking (OR 4.3,
p=0.001), tumor type (p=0.001), and Charlson combined
comorbidity index (OR 1.239, p=0.001) were associated with an
increased risk of not undergoing resection
Operative mortality decreased (OR 0.46, 95% CI 0.29 to 0.72,
p<0.001)
Patient (age, race)
Low
Institutional
(volume)
Low
Patients referred were more likely to be younger than 85 years (OR
0.33, 95% CI 0.18 to 0.61, p<0.001) or non-Caucasian (OR 0.59,
Patient (age, race)
Low
Institutional
(volume); Patient
(age)
Patient (age,
marital status)
Low
Institutional
(volume)
Low
95% CI 0.48 to 0.72 African American; OR 0.57, 95% CI 0.45
to 0.72 Hispanic; OR 0.61, 95% CI 0.43 to 0.86 Asian)
Surgical mortality lower in high-volume centers (p<0.0001). Patient
age associated with surgical mortality (HR 1.04, CI 1.01 to 1.07,
p=0.002)
Patients aged 65 to 74 (OR 0.5, 95% CI 0.37 to 0.69, p<0.001) or
75 to 84 (OR 0.18, 95% CI 0.11 to 0.28, p<0.001) and unmarried
(OR 0.68, 95% CI 0.5 to 0.92, p=0.013) were less likely to receive
surgery or chemotherapy
After centralization surgery at low-volume centers declined (OR
0.85, 95% CI 0.84 to 0.87)
Low
Supplemental Table 2 continued. Design and findings of eligible studies
Study (design)
Yermilov 2009 (45)
United States
(retrospective)
Bilimoria 2007 (46)
United States
(retrospective)
Birkmeyer 2007 (47)
United States
(retrospective)
Riall 2007 (48)
United States
(retrospective)
Birkmeyer 2006 (49)
United States
(retrospective)
Liu 2006 (50)
United States
(retrospective)
Objective/Methods (data source)
Review of 2,023 patients from
1994-2003 to assess determinants
of readmission following surgery
(registry)
Review of 700 patients at Veterans
Administration hospital and 28,009
patients at other hospitals from
1985-2004 to assess receipt of
treatment, surgical mortality and
survival (registry)
Review of 855 patients from 19922002 to assess impact of hospital
volume on treatment and mortality
(registry)
Review of 3,189 patients from
1999-2004 to assess determinants
and outcomes of surgery at a highvolume center (registry)
Review of 5,607 patients from
2000-2002 to assess impact of
hospital volume on surgical
mortality (registry)
Review of 2,216 patients from
2000-2004 to assess determinants
of treatment at high-volume
centers (registry)
Findings
59% were readmitted within one year, and readmission was
associated with lower median overall survival (p<0.0001). Patients
older than 73 years were more likely to be readmitted (OR 1.37,
95%, p<0.02)
VA hospitals were more likely to use surgery (OR 2.20, 95% CI
1.73 to 2.79) and adjuvant chemotherapy (OR 1.77, 95% CI 1.28 to
2.46). Adjusted perioperative mortality and 3-year survival rates
after surgery were similar at VA and academic hospitals.
Determinants
Patient (age)
Risk of Bias
Low
Institutional
(hospital type)
Low
Patients at low volume hospitals were substantially less likely to
receive either adjuvant radiation therapy or chemotherapy
(p<0.001). Mortality was lower at high-volume hospitals (OR 0.74,
95% CI 0.60–0.92)
High-volume centers had lower surgical mortality compared with
low-volume centers (p<0.0001). Patients who were >75 years (OR
0.51), female (OR 0.86), Hispanic (OR 0.58), and living >75 miles
from a high-volume center (OR 0.93) were less likely to be resected
at high-volume centers (all p<0.05)
High-volume centers has lower surgical mortality (OR 4.28, 95%
CI 2.93 to 6.27)
Institutional
(volume)
Low
Institutional
(volume)
Low
Institutional
(volume)
Low
African-Americans (OR 0.40, 95% CI 0.21 to 0.67, p<0.05) and
Hispanics (OR 0.46, 95% CI 0.32 to 0.68, p<0.05, and uninsured
patients (OR 0.29, 95% CI 0.07 to 0.73, p<0.05) were less likely to
receive care at a high-volume
Patient (race,
insurance)
Low