Identifying Physician-Hospital
Networks to Profile Variation in
Surgical Practice
Julie Bynum, MD MPH
Assistant Professor
Dartmouth Medical School
Goals
• Review limitations of current quality
measurement in surgical care
• Describe how we can measure hospitalspecific population surgical rates
• Discuss how these measures might be
used to improve surgical care
Currently
• Measurement of what occurs as direct
result of surgery – peri & post op
◦ Process measures
◦ Complication rates
◦ Mortality rates
• These quality domain of misuse
• How do we get at underuse & overuse?
Variations in quality and spending
The Dartmouth Atlas
Ratio of rates of PCI to the U.S.
average, by hospital referral region (2005)
But who do we talk to if we want to take action?
1.30 to 3.40
1.10 to < 1.30
0.90 to < 1.10
0.75 to < 0.90
0.33 to < 0.75
Not Populated
Accountable Care Organizations
“experimental model”
Physician-Hospital Networks
Physicians and beneficiaries make
naturally occurring groups centered
around hospitals.
Virtual Physician-Hospital Network
Cohort of Linked Medicare Beneficiaries
Medical
sub-specialists
PCP
PCP
Surgeons
Other
specialties
Hospital
Physician-Hospital Network
PCP
PCP
Percent Physicians able to link
Surgeons
Primary care
specialists
96% linked
93% linked
Hospital
Other
specialties
88% linked
Medical
sub-specialists
97% linked
Physicians bill at hospital
Surgeons
Primary care
specialists
87% have hosp billing
76% have hosp billing
Other
specialties
77% have hosp billing
Hospital
Medical
sub-specialists
88% have hosp billing
Physicians concentrate billing at
only 1 hospital
Surgeons
Primary care
specialists
87% have hosp billing
51% at only one hosp
76% have hosp billing
56% at only one hosp
Other
specialties
77% have hosp billing
55% at only one hosp
Hospital
Medical
sub-specialists
88% have hosp
35% at only one hosp
Physicians concentrate billing at
only 1 hospital
Surgeons
Primary care
specialists
87% have hosp billing
51% at only one hosp
81% of work at PHN
76% have hosp billing
56% at only one hosp
85% of work at PHN
Other
specialties
77% have hosp billing
55% at only one hosp
81% of work at PHN
Hospital
Medical
sub-specialists
88% have hosp
35% at only one hosp
80% of work at PHN
Linking Beneficiaries and Primary Care MD
PCP
PCP
Hospital
PCP
PCP
Virtual Physician-Hospital Network
PCP
Medical
sub-specialists
PCP
Surgeons
Other
specialties
PCP
Hospital
PCP
Virtual Physician-Hospital Network
Cohort of Linked Medicare Beneficiaries
Medical
sub-specialists
PCP
PCP
Surgeons
Other
specialties
Hospital
Physician-Hospital Network
PCP
PCP
Concentration of Care: Physician Visits
Reliance on PHN for Physician Visits
Number of
Medicare
Beneficiaries
in Network
Percent of
Total
Beneficiaries
Number of
Local
Networks
Percent of
E&M Visits
Within PHN
Under 5,000
21.9%
2616
61.6
5,000 -10,000
26.4%
941
70.4
10,000 –15,000
21.1%
422
72.6
15,000 +
31.6%
376
73.8
Concentration of Care: Hospital Stays
Percentage of Hospitalizations occur at PHN hospital
Number of Medicare
Beneficiaries in
Network
Percent of Medical
Hospitalizations in
PHN
Percent of Surgical
Hospitalizations in
PHN
Under 5,000
61.5
18.9
5,000 -10,000
65.7
46.2
10,000 –15,000
66.1
54.4
15,000 +
65.3
59.8
Concentration of Work: Hospital
Percentage Hospital admits and costs
accounted for by linked cohort
Number of Medicare
Beneficiaries in
Network
Percent of all Medical
Hospitalizations at
hospital by linked
cohort
Percent of all
Surgical
Hospitalizations at
hospital by linked
cohort
Under 5,000
71.1
64.0
5,000 -10,000
67.5
59.2
10,000 –15,000
66.5
57.6
15,000 +
65.9
55.9
Regional Variation in Surgical Rates
Columbia, MO
Back Surgery per 1000
14
HRR National Rank
(out of 306)
12
10
8
6
4
2
0
269th: Back Surgery
164th: Total Hip Replacement
50th Percutaneous Cardiac
Interventions
Hospital Variation in Surgical Rates
Back Surgery Rates:
Columbia, MO
14
12
10
8
6
4
2
0
Surgery Rates: Columbia, MO
Hospital Surgical Signature
HRR
Back
surgery
CEA
THR
CABG
PCI
CA-Los
Angeles
MABoston
GAAtlanta
FLOrlando
NYE Long Is
lowest quintile



 highest quintile
Hospital Surgical Signature
HRR
PHN
Back
surgery
Hip Fx
THR
CABG
PCI
CA-Los Angeles
Cedars Sinai
Huntington Memorial
St. John’s Health Ctr
MA-Boston
Cape Cod Hosp
Massachusetts Gen
North Shore Med Ctr
lowest quintile



 highest quintile
Advantages of PHN method for
health services research
• Base population allows study of:
◦
◦
◦
◦
Access
Racial disparities
Diffusion of technology
Efficiency of surgical-disease treatment
Implications for health policy
and surgical disease
Performance Measurement and Accountability:
• Efficiency of not only the surgery that occurred but
the decisions of when to use surgery
• Possible broader definition of surgical episode
• Assessment of access & disparities
Summary
• Surgical care for Medicare populations is
concentrated within large physician-hospital
networks
• Enough variation exist to allow studies of
hospital-specific practice patterns.
• In the future, these population based measures
could be used in performance reporting
Acknowledgments
NIA PO1 Coinvestigators
Jon Skinner
Elliott Fisher
Team
Dan Gottlieb
Don Carmichael
Kathy Stroffolino
Stephanie Tomlin
Dartmouth Atlas team
Jack Wennberg
David Goodman
Collaborators
John Birkmeyer