Table 1 Market conditions fostering FFS Medicare utilization of endoscopy services, and variables used in modeling

Dependent Variable: Avg. Annual % Endoscopy Utilization

7.4

1.2

7.9

1.3

100% of traditional FFS Medicare endoscopy claims

 Age < 65

16.9

6.1

18.4

6.1

100% Medicare denominator files, averages 2001-2005; 2006-2010

 Age 65-74

44.5

3.7

43.5

3.9

 Age 75-84

28.6

3.6

27.2

3.5

 Age 85+

9.9

2.4

10.9

2.8

 Female

55.0

2.8

54.2

2.5

 Caucasian

90.6

13.2

90.2

13.5

 African American

7.3

12.7

7.5

12.9

 Hispanic

1.0

3.2

1.0

2.9

 Asian

0.3

0.8

0.3

1.0

 American Indian and other races/ethnicities

0.8

4.3

1.0

4.9

 Dual/ESRD/disabled benefits

20.9

10.7

27.9

10.6

 Persons Aged 65+ with little or no English language ability (2000)

14.3

14.7

14.3

14.7

US Census 2000; American Community Survey, 2006-2010;

Census SAIPE

 Persons aged 65+ with graduate or professional degrees (2000; 2006-2010)

4.4

2.8

5.7

4.0

 Average poverty in the area over the past 20 years (1990-2000; 1995-2005)

14.8

6.7

14.1

5.7

 Population density (2000, 2005) per sq. mile

235.1

1661.8

242.8

1713.4

Area Health Resource Files

 Percent of the population with Medicare Part A benefits (2001, 2006)

14.1

2.0

14.8

2.0

 Prevalence of managed care plans: Medicare managed care penetration, lagged 1 year (2000, 2005)

4.9

9.7

4.6

8.4

RTI Spatial Impact Factor Database

 Prevalence of endoscopy providers: average distance from FFS claimants to closest provider (2001, 2006)

10.4

8.8

11.7

9.2

 Competition among endoscopy providers (2001, 2006) index, where 1 = perfect and 0 = no competition

0.020

0.046

0.021

0.052