Uptake of a New Cervical Cancer Prevention Technology in a

Medicaid Population

Rebecca Anhang PriceAcademyHealth Annual Research

MeetingJune 10, 2008

Funding: Foundation for Informed Medical Decision Making; Novartis Fellowship

Background: Cervical Cancer and Human Papillomavirus (HPV)

• Virtually all cervical cancers are caused by carcinogenic or “high risk” strains of human papillomavirus (HPV).

• In 2000, the FDA approved a DNA test that detects carcinogenic types of HPV. – Two main uses:

• Reflex testing for equivocal Pap results (ASC-US or atypical squamous cells of uncertain significance)

• Primary screening for women age 30+

Background:Timeline of Clinical Guideline Releases

Initial FDA approval of HPV testing for triage of Pap test results deemed ASC-US

Consensus Guidelines by the American Society for Colposcopy and Cervical Pathology (ASCCP) released

American Cancer Society (ACS) guidelines released

U.S. Preventive Services Task Force guidelines released

American College of Obstetricians and Gynecologists guidelines released

Digene’s DTC campaign for HPV DNA testing launched

March

2000

April

2002

November

2002

January

2003

March

2003

August

2003

March2005

FDA approves expanded indication for HPV DNA testing: Primary screening of women over age 30, in conjunction with the Pap test

April2006

June2006

Merck & Co.’s DTC campaign for HPV awareness launched

FDA approves Merck & Co.’s HPV vaccine

Feb2004

Co-sponsored Interim Guidance from National Cancer Institute, ASCCP, ACS published

Research Objectives

• To evaluate the impact of clinical guidelines on the uptake of HPV DNA tests.

• To identify patient and provider characteristics associated with overall and clinically appropriate HPV DNA test use.

Methods: Data

• Florida Medicaid claims database, July 2001 – June 2006.

• Inclusion criteria:– Age 21 to 64– Eligible through TANF/AFDC, family planning or pregnancy – Continuously enrolled for at least 12 months– No hysterectomy during study period

• Resulting dataset included 310,427 cervical screening test claims and 13,550 HPV DNA test claims for 415,239 Medicaid enrollees.

Methods: Analysis

• Dependent Variables: – HPV DNA test (given receipt of cervical cancer screening test)– Appropriate test (given receipt of HPV DNA test)

• Independent Variables of Interest:– Time variables (time trend, dummy dates for clinical guideline releases)– Patient race/ethnicity– Provider specialty

• Other Covariates:– Patient age, ASC-US diagnosis, district of residence, total months

enrolled – Pathology lab volume

• Estimation approach:– Generalized estimating equations with logit link.– Robust standard error estimates to account for patient clustering within

providers.

Results: Sample Characteristics

* Turn 30 at some point during the study period. † ASC-US diagnosis can only be determined among those for whom a cervical screening test claim is filed.

CharacteristicBeneficiaries(n = 415,239)

Age, years (%) 21 – 29 30 – 64*

46.7153.29

Race/ethnicity (%) White Black Hispanic Other

40.3734.1322.90 2.60

Diagnosis (%)† Atypical squamous cells of uncertain significance (ASC-US)

1.15

Screening Behavior (%) Received any cervical screening test Received an HPV DNA test

40.02 2.87

Results: HPV Test Use, July 2001 – June 2006

050

100150

200250300

350400

450500

Jul-

01

No

v-0

1

Ma

r-0

2

Jul-

02

No

v-0

2

Ma

r-0

3

Jul-

03

No

v-0

3

Ma

r-0

4

Jul-

04

No

v-0

4

Ma

r-0

5

Jul-

05

No

v-0

5

Ma

r-0

6

# o

f T

es

ts

Results: Appropriate HPV Test Use, July 2001 – June 2006

0%

20%

40%

60%

80%

100%

Jul-0

1

Nov

-01

Mar

-02

Jul-0

2

Nov

-02

Mar

-03

Jul-0

3

Nov

-03

Mar

-04

Jul-0

4

Nov

-04

Mar

-05

Jul-0

5

Nov

-05

Mar

-06

% o

f H

PV

Tes

ts t

hat

are

Clin

ical

ly A

pp

rop

riat

e

Results: Effects of Guidelines on HPV Test Use

GEE Parameter Estimates(n = 310,427, 13,550 HPV DNA tests)

Time trend (by month) 0.007***

Clinical guidelines

Release of American Society for Colposcopy and Cervical Pathology (ASCCP) guidelines (4/02)

0.882***

Release of American Cancer Society (ACS) guidelines (11/02)

0.160**

FDA approval for 30+ (3/03) 0.193**

Release of American College of Obstetricians and Gynecologists (ACOG) guidelines (8/03)

0.250***

Release of co-sponsored interim guidance (2/04)

-0.038

*p<0.05; **p<0.01; ***p<0.0001Models also control for patient, provider and lab characteristics, as well as the fixed effects of residence in each of 11 Medicaid districts in Florida, and total number of months enrolled in Medicaid.

Results: Differential Diffusion of HPV Test Use by Race/Ethnicity and Provider Specialty

Note: Predicted probabilities from multivariate models including time trend, important dates, patient age, race/ethnicity, and ASC-US diagnosis, provider specialty, pathology lab volume, fixed effects of residence in each of 11 Medicaid districts in Florida, and total number of months enrolled in Medicaid. Models also include interaction effects for monthly time trend * patient race/ethnicity and provider specialty * patient race/ethnicity.

Predicted Probabilities of HPV Test Use, by Provider Specialty and Patient Race/Ethnicity,

July 2001 - June 2006

00.020.040.060.080.1

0.120.140.160.180.2

Jul-0

1

Nov

-01

Mar

-02

Jul-0

2

Nov

-02

Mar

-03

Jul-0

3

Nov

-03

Mar

-04

Jul-0

4

Nov

-04

Mar

-05

Jul-0

5

Nov

-05

Mar

-06

OBGYN Black

OBGYN Hispanic

OBGYN White

PCP Black

PCP Hispanic

PCP White

Results: Predictors of Appropriate HPV Test Use

• Clinical guidelines were not consistently associated with appropriate HPV test use.

• Obstetricians/gynecologists were more likely than primary care providers to administer the test appropriately.

Conclusions

• Uptake of the HPV DNA test was sustained by introduction of multiple sets of clinical guidelines. – Guidelines did not consistently promote appropriate

use.

• Racial/ethnic disparities in HPV DNA test use resolved within three years of the test’s introduction.– Early adoption of testing by

obstetricians/gynecologists helped to close the gap.

Implications

• Release of clinical guidelines is associated with increases in use of a new technology. – However, guidelines may not be associated

with increases in appropriate use.

• Adoption of new technologies may initially occur more slowly in minority groups.– However, these groups can catch up, assisted

by early guideline adherence by specialists.