evidence for quality of surgical care in rural america samuel r. g. finlayson, md, mph

Evidence for Quality of Surgical Care in Rural America

Samuel R. G. Finlayson, MD, MPH

Overview

1. General Issues Related to Quality of Surgical Care in Rural Areas

2. Evidence for Quality of Rural Surgical Care– review of scant literature

3. Preview of new data from Mithoefer/Dartmouth collaboration

Quality in Rural Surgical Practice

• Providing high quality surgical care may not be enough to satisfy all stakeholders– Payers want evidence of high quality– Patients do, too

• Challenge is in providing evidence of high quality surgical care

Quality in Rural Surgical Practice: Challenges

• Can I just keep track of my outcomes?– Problem of Small Numbers– Practical Realities

• payer interests

• Potential Solutions– Participation in quality initiatives

• NSQIP, Michigan BC/BS, SCOAP

– Aggregate measure

Low-Volume Providers are Stuck Nearly Impossible to Demonstrate High Quality Results

When rates of adverse outcomes are low, or few procedures are performed …

… statistical power is often insufficient to show any difference between your own outcome rate and the “benchmark” rate.

The Problem of Power

Survived Died

The Nation(benchmark)

You

48,500

46 4

1500 3%

8%

difference in mortality is NOT statistically significant!


Survived Died


You

48,500

46 0

1500 3%

0%



Survived Died


You

48,500

100 0

1500 3%

0%




• payer interests


• NSQIP, Michigan BC/BS, SCOAP

– Aggregate measure

Practical Realities

• Payers may not care about individual results– Bariatric Surgery in Durant, OK.

• Proxies for quality are easier for insurers, align with their interests (easy approximations)– Procedure volume– Crude mortality rates– Special certifications



• payer interests


• NSQIP, Michigan BC/BS, SCOAP• Documents attention to quality

– Aggregate outcome measures

Aggregation to Achieve Sample Size

• Individual case volumes may be too small to demonstrate one’s results are in line with quality benchmarks

• Evaluation of surgical results in the aggregate may help – Irate letter from Iowa

Aggregating Data Tells a Story

Survived Died

Highest volume surgeon

Rest of Iowa 1331

233

4

7 3%

0.3%

HV surgeon’s mortality is higher (p<0.001)

“Are you just pissing and moaning, or can you verify what you’re saying with data?”

Evidence for Quality in Rural Surgical Practice

(adj. OR 1.1)

Mithoefer/Dartmouth

• Recall prior study of surgeon workforce based on Hospital Service Area (showed results at last symposium)– HSAs categorized along the urban-rural spectrum

using RUCA designations– Calculated surgeons per capita (age/sex-adjusted)

in each HSA– Compared surgeon workforce levels

• across specialties• across the urban-rural spectrum

6.946.54 6.30

5.52

0

2

4

6

8

10

12

Urban Large Rural Small Rural Isolated

Ge

ner

al S

urg

eon

s p

er

100

,00

0

pop

ula

tion

# of HSAs Low supply HSAs

Urban 1273

Large Rural 689

Small Rural 660

Isolated 445

Proportion of HSAs with Low Surgeon Supply (< ½ nat’l ave.)

# of HSAs Low supply HSAs

Urban 1273 254 (20%)

Large Rural 689 147 (21%)

Small Rural 660

255 (39%)

Isolated 445 295 (66%)

Proportion of HSAs with Low Surgeon Supply (< ½ nat’l ave.)

Brief Review of Methods

• Rural definitions • Hospital Service Areas

Defining Rural

• Rural-Urban Commuting Areas (RUCA)– Developed by US Dept of Agriculture, the Health

Resources and Service Administration (HRSA), and the Univ. of Washington

– Classify U.S. census tracts using measures of• population density and urbanization• size and direction of daily commuting flow

– UW developed ZIP code approximation of the RUCA codes based on an overlay of ZIP code areas on census tracts

http://www.ers.usda.gov/briefing/Rurality/RuralUrbanCommutingAreas

Hospital Service Areas (HSA)

• Developed using national Medicare inpatient claims • Defined as geographic area that includes one or

more hospitals to which local residents generally have the plurality of their inpatient admissions

• Based on zip code tabulation areas (ZCTA)– ZCTA is an approximate area representation of the US

Postal Service's ZIP code service areas created by the US Census Bureau

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A 6 A’s8 B’s2 C’s

8 A’s6 B’s0 C’s

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Hospital Service Areas (HSA)

• US parsed into 3067 HSAs• Reflect “health care markets”• Where people actually go for care (not

necessarily closest hospital)

Defining Rural vs. Urban HSAs

• Categorized hospital service areas into one of 4 RUCA categories– Urban– Large rural– Small rural– Isolated rural

• RUCA categorization of a given HSA determined by the plurality of that HSA’s population

C

A

B

Small Rural Small Rural

Large Rural LargeRural

LargeRural

LargeRural

LargeRural

Preview of New Data from Mithoefer/Dartmouth

• Effort to study outcomes– By rurality of the HSA (patient origin) – By level of surgeon supply (surg-per-capita)

• Appendectomy• A good model for studying access to surgical care

– timeline, clinical decision making– proposed as potential quality indicator

• rural patients have slightly higher rates of perforated appendectomy (adj. OR 1.11, 95%CI 1.02-1.22)*

*NIS study, to be presented at ACS Surgical Forum 2009

Mithoefer/Dartmouth

• Appendicitis Outcomes Study– National 100% sample of Medicare discharges

(age over 65, 3 years of data, >92,000 cases)– Stratified outcomes by urban-rural designation

– Specific Outcomes Studied• perforation rates• abdominal abscess rates• negative appendectomy rates

32.833.631.633.5

0

20

40

60

80

100

Pro

po

rtio

n o

f C

as

es

wit

h P

erf

ora

tio

n (

%)*

Urban/Suburban Large Town Small Town Isolated Rural

Diagnosis of Perforation with Appendectomy

*Adjusted for age, sex, race

14.4 14.7 13.112.7#

0

20

40

60

80

100

Pro

po

rtio

n o

f C

ases

wit

h A

bsc

ess

(%)*


Diagnosis of Abscess with Appendectomy

*Adjusted for age, sex, race

39.8 42.4 45.2#44.5#

0

20

40

60

80

100

Ap

pen

dec

tom

y w

ith

No

Dia

gn

osi

s o

f A

pp

end

icit

is (

%)


Negative Appendectomy Rate

Surgeon Supply and Appendicitis Outcomes

• From prior work, we know surgeons per capita for each HSA (population age sex adjusted)

• Outcomes stratified by RUCA and surgeon supply– No surgeons– ½ the national average surg-to-pop ratio– ½ to 2x national average surg-to-pop ratio– >2x national average surg-to-pop ratio

Perforation Rates and Surgeon Supply

29

30

31

32

33

34

35

36

37

none <1/2 nationalaverage

1/2 to 2xnational ave

>2x nationalaverage

overall urban/suburban small rural