developing ct screening guidelines for women >25: the over 20 study & the over 25 evaluation...

Developing CT Screening Guidelines for Women >25:

The Over 20 Study & The Over 25 Evaluation

Region II IPP MeetingNYC, NY

May 17, 2007

“An evaluation of the

performance/appropriateness of national

chlamydia (CT) screening guidelines when

applied to non-pregnant adult women seeking

family planning services in California.”

Background: The Problem

“Excessive” CT screening in populations

with low CT morbidity has implications:

Not an effective use of limited resources

CA uses 3% as cost-effective cut-off

May lead to a higher proportion of false

positive test results

Background: The Problem (CA)

Among adult women, CA FP setting has relatively

low CT rates but high volume of screening:

Significantly less CT in women age >25 than in

younger women, yet screening rates are similar

Almost 50% of all screening occurs in this older age-group

CT prevalence in this population >25 is <3%

CT rates for women age 21-25 <3% in some areas

Background: Why Not Stop Screening

Older Women Altogether? Detecting/treating CT infections has been shown to

reduce such adverse sequelae as PID, infertility

The vast majority of CT infections in all women,

including women >25, are asymptomatic or “silent”:

Over 70% of CT in women >25 do not present with clear

clinical indications for testing

Screening is the only effective mechanism for

detecting “silent infections”

No Screening = Missing >70% of CT in this population

Background: The Solution: Targeted Screening

Evidence-based targeted screening strategies:

Can identify a sub-population with higher CT %

A balance between saving resources and still reducing

the burden of CT in lower-prevalence populations

TS!

Background:Who to Target?

Clear guidelines needed to target CT screening

in adult women:

Though national recommendations support

targeted screening for women >25, they are:

Not well-defined

Inconsistent, and/or

Inefficient

The Over 20 Study

The Over 20 StudyResearch Objectives

Among non-pregnant women age 21-30

seeking family planning services:

Determine predictors of CT infection

Develop efficient targeted screening strategies

for CT infection, specifically in women >25

Determine whether targeted screening is

appropriate for the population of women 21-25

The Over 20 StudyStudy Methods

Patient Eligibility Criteria:

Female clients seeking FP services

Age 21-30

Not pregnant

Sexually Active (self-report of vaginal

sex in past 12 months)

Study Design: Cross-sectional

The Over 20 StudyStudy Methods

Data collected & methods:Self-administered patient questionnaires:

Demographics, relationship status, sexual behavior, STD history

Clinician-completed clinical evaluations: Reason for visit, birth control, STD contact, STD

history, symptoms, clinical signs & diagnoses, presumptive CT/GC Rx

Laboratory databases: CT & GC test results

The Over 20 StudyResults: Participating Agencies &

Project Timeline

Participating Sites:

• 9 clinics (3 CA FP agencies) all

performing universal screening

Timeline: two phases

• May 2003 to May 2004

• August 2004 to November 2005

The Over 20 StudyResults: Final Study Sample

Study Forms Submitted forUnique, Eligible, CT-Tested Clients*

and Successfully Matched with Lab Result Data

Agency Study Forms % CT Positive

Total 4,292 4.2%

Agency A 2,982 4.5%

Agency B 1,042 3.3%

Agency C 268 4.9%

* = Age 21-30 years

The Over 20 Study: Total Sample

Results: DemographicsAge (Years)

22%

78%

CT Positivesn = 180

71%

29%

21 - 25 26 - 30

CT TestedN = 4,292

The Over 20 Study: Total Sample

Results: DemographicsRace/Ethnicity

5%

33%

6%

48%

9%

African American Latina White Asian Mixed/Other

25%

2%7%

48%

17%

CT Positivesn = 180

CT TestedN = 4,292

Report of current contact (exposure) to an STD

CT-indicative clinical syndrome diagnosed on exam:

Cervicitis: endocervical discharge, cervical friability, or

cervical inflammation

Pelvic inflammatory disease (PID): Adnexal/uterine

tenderness or cervical motion tenderness

New STD (confirmed or presumptively treated)

diagnosed in-office on day of visit (trichomoniasis;

presumptive HSV, GC, or genital warts; syphilis, HIV)

Patients with Clinical Indications for CT Testing excluded from screening analysis:

The Over 20 Study Results (Age 21-30): CT Prevalence & Proportion of Cases

by Clinical Presentation ~Exclusion Criteria Applied to Screening Analysis~

27 % of CT Cases 73 % of CT Cases

Total CT-tested Participants

N = 4,292 nCT+ = 180

4.2 % CT+

Patients with clinicalindications for CT

testing:N = 550 nCT+ = 48

STD contactsCervicitis or PIDNew STD dx

8.7 % CT+

Patients screened for CT:

N = 3,742 nCT+ = 132

No STD contact

No cervicitis or PID

No new STD dx

3.5 % CT+

87 % of Pop. Tested13 % of Pop. Tested


N = 3,742 nCT+ = 132

No STD contact


No new STD dx (except GC+)

3.5 % CT+

Patients age 21-25screened for CT:

N = 2655 nCT+ = 100

3.8 % CT+


N = 1,087 nCT+ = 32

2.9 % CT+

CT Prevalence >3% justifies universal screening

Risk factors predictive or protective for CT infection

(statistically significantly):

Partners possible other partners (3 or 12 mos)§

More than 1 or 2 partners (3 or 12 mos)

BV

Married*

Stable relationship (married, engaged or living

with partner)*

New partner in past 3 mos (p-value = 0.06)

The Over 20 StudySummary of Univariate Findings:

Women age 26-30 years

* Protective against CT infection in univariate analysis

§ Independently associated with CT in multivariate analysis (p-value <0.05)

The Over 20 Study

“Partner possible other partners”Actual Question Studied:

Q: At anytime within the past 12 months*, did any of your male partners have sex (of any type) with someone else while they were still in a sexual relationship with you?

A: Yes, definitely Not sure, it is possible

No, it is very unlikely

* Also asked about the past 3 months in a separate question.

Answers

combined

1.14.94679 Ptr possible other ptrs

2.05.41635 BV

02.9100100Universal Screening

2.18.71338 >2 Ptr in 12 mos

2.34.83250 >1 Ptr in 12 mos

2.45.12339 New Partner in 3 mos

The Over 20 Study: Screening AnalysisResults: Performance of

Selective Screening AlgorithmsAge 26-30

1.54.45075 Stable Relationship

% CT+ in pop not

Screened

% CT+ in pop

Screened

% Pop ScreenedN = 1,087

% Cases DetectedN = 32Algorithm of Selected Criteria:

0.03.1198100

Current USPSTF recommendations*: Multiple ptr (>1 in 12 mos) New ptr (3 mos) CT hx (12 mos) Unmarried Inconsistent condom use (3 mos)

0.64.66193

Over 20 Study results: BV Ptr possible other ptrs (12 mos) >2 ptrs (12 mos)

1.55.04976Current CDC recommendations*: Multiple ptr (>1 in 12 mos) New ptr (3 mos) CT hx (12 mos)


The Over 20 Study: Screening AnalysisResults: Performance of

Selective Screening AlgorithmsAge 26-30

% CT+ in pop not

Screened

% CT+ in pop

Screened

% Pop ScreenedN = 1,087

% Cases DetectedN = 32Algorithm of Selected Criteria:

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The Over 20 Study

Key Study Limitations

Convenience sample of clinics mostly located

on California’s central coast and in the

central valley -- may not be representative of

overall CA FP population

Unknown if results applicable to women > 30

The Over 25 Evaluation

IPP Scantron Data

Chart Abstraction

The Over 25 Evaluation: IPP Scantron Data

Benefits & StrengthsCan use existing IPP data collected via Scantron

forms (~3,000) from CA Project Area and Los

Angeles CT prevalence monitoring sites:

Scantron forms newly revised 7/06 with influence

from Over 20 Study result – similar data

CPA and LA Scantron forms now identical

~ 20 geographically diverse clinic sites across CA

Data collected from CT-tested patients of all ages


Challenges & Limitations Needed some supplemental data not available on

forms (e.g., BV status)

Forms had never been validated

Clinic sites already targeting CT screening in

women > age 25 -- data bias

– May give inflated prevalence rates

– May underestimate associations between risk factors and CT

– % of population screened in algorithms may not be accurate

The Over 25 Evaluation: Chart Abstraction

Design/MethodsDesign: Case-Control Chart Abstraction

Use Scantron forms to pull sample of medical

record charts for abstraction:

All CT-positive patients (~100)

A random-sample of CT-negative patients, chosen by

clinic site, using a 4 negatives:1 positive ratio (~400)

Collect supplemental data for research purposes

Collect identical data, as possible, for validation

purposes

Successfully abstracted 82% of sample goal (446/544 charts in total; 83/100 CT+ charts):• ~ 8% pregnant• ~ 1.5% males• Other issues: wrong DOBs – out of eligible age range;

clients not tested for CT; missing charts Data concordance:

• Demographics/other core variables: > 90%• Lab data: > 95%• CT symptoms: 96% of No’s / 33% of

Yes’s• Clinical data: 96% of No’s / 38% of Yes’s• Behavioral data: 60-97% of No’s / 38-60% of Yes’s


Validation Results

Summary of Study DifferencesOver 20 Study Over 25 Evaluation

Study designCross-sectional:

self report, clinician report and lab results

Case-Control: chart review

Sample population Non-pregnant female patients

Non-pregnant female patients

Age range 26-30 26-44

# Clinics participating 9 17

Clinic types8 FP-only and

1 community clinic

3 FP-only, 3 FP/STD integrated, 9

community, 2 free clinics

Clinic locations

8 CPA sites (3 central coast, 4 central valley, 2 Sacramento);1 LA site (Santa Monica)

8 CPA sites (3 San Bern Co., 1 north, 2 southern border, 2 central valley);9 LA sites (diverse)

Clinic CT screening protocol Universal – all ages Targeted in ages > 25

CT prevalence Low to moderate Moderate to high

CA Chlamydia Rates by County, 2005

7/2006 Provisional Data - CA DHS STD Control Branch

Rate per 100,000

< 100100 to 199200 to 299300 +

Over 20 & Over 25Site Distributions

Over 20 Study: Age 26-30

Over 25 Evaluation: Age 26-44

The Over 25 Evaluation: Total *Weighted Chart Abstraction Sample

Results Total Sample: Age (Years)

18%

12%

70%

CT Positivesn = 83

51%

27%

22%

26 - 30 31 - 35 36 - 44

CT TestedN = 2,634*

5%

33%

6%

48%

9%

25%

2%7%

48%

17%

4% 14%

60%

3%

20%

African American Latina White Asian Mixed/Other

20%

4%8%

58%

10%

n = 83N = 2,616*

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Results Total Samples: Race/EthnicityCT PositivesCT Tested

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N = 4,292 n = 180

The Over 25 Evaluation Results (Age 26-44): CT Prevalence & Proportion of Cases

by Clinical Presentation ~Exclusion Criteria Applied to Screening Analysis~

29 % of CT Cases 71 % of CT Cases

Total CT-tested Participants

N = 2,634 nCT+ = 83

3.2 % CT+

Patients with clinicalindications for CT

testing:N = 346 nCT+ = 24

STD contactsCervicitis or PIDNew STD dx

6.9 % CT+


N = 2,287 nCT+ = 59

No STD contact


No new STD dx

2.6 % CT+

87 % of Pop. Tested13 % of Pop. Tested

Patients screened for CT:Age 26-44

N = 2,287 nCT+ = 59

No STD contact


No new STD dx (except GC+)

2.6 % CT+


N = 1,162 nCT+ = 41

3.5 % CT+


N = 1,126 nCT+ = 18

1.6 % CT+

Risk factors predictive for CT infection (statistically significantly):

Age < 30 (26-30)§

Partners possible other partners (no time frame)§

New partner (2 mos)

Vaginal DC on exam – unknown etiology (not cervicitis, trich, BV, or yeast)

More than 1 partner (12m) (p-value = 0.13)

Complaints of pain or bleeding with sex, pelvic pain, or spotting (p-value = 0.18)

Asian race (p-value = 0.18)

The Over 25 EvaluationSummary of Univariate/Multivariate Findings:

Women age Over 25 (26-44)

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Risk factors predictive for CT infection:

Age < 35 (31-35)

(p-value = 0.12)

Partners possible other partners (no timeframe)

(p-value = 0.26)

The Over 25 EvaluationSummary of Univariate/Multivariate Findings:

Women age Over 30 (31-44)

Summary of Cross-Study Statistical Findings: Risk factors predictive of CT infection

Younger age n/a √: Age 26-30

Partner possible other partners (12m) √ √

>1 ptr (12m) √ Borderline

New ptr (2-3m) Borderline √

CT+ (12m)

Vaginal DC on exam – unknown etiology √

BV √

Complaints of pain or bldg w/sex, pelvic pain, or spotting Borderline

Over 25 EvalAge 26-44

Over 20 Study

Age 26-30Predictive Risk Factor

1.55.04976Current CDC recommendations±: Multiple ptr (>1 in 12 mos) New ptr (2 mos) CT hx (12 mos)

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0.84.57093Current CDC recommendations± plus: Ptr possible other ptrs


% CT+ in pop not

Screened

% CT+ in pop

Screened

% Pop Screened£ N = 1,087

% Cases Detected£

N = 32Algorithm of Selected Criteria:

The Over 20 Study: Screening Analysis

Results: Performance of Selective Screening AlgorithmsAge > 25 (26-30)

0.54.47596Current CDC recommendations± plus: Ptr possible other ptrs Vaginal DC-no known etiology

0.64.27896Current CDC recommendations± plus: Ptr possible other ptrs BV

0.64.27996Current CDC recommendations± plus: Ptr possible other ptrs Vaginal DC-no known etiology BV

1.17.45288Current CDC recommendations± plus: Ptr possible other ptrs Vaginal DC-no known etiology

1.47.54481Current CDC recommendations± plus: Ptr possible other ptrs

2.36.03558Current CDC recommendations±: Multiple ptr (>1 in 12 mos) New ptr (2 mos) CT hx (12 mos)

1.63.55169 Age 26-30


% CT+ in pop not

Screened

% CT+ in pop

Screened

% Pop Screened*N = 2,228

% Cases Detected£

N = 59Algorithm of Selected Criteria:

The Over 25 Evaluation: Weighted Screening Analysis

Results: Performance of Selective Screening AlgorithmsAge > 25 (26-44)

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1.74.77087Current CDC recommendations± plus: Ptr possible other ptrs BV

1.44.97390Current CDC recommendations± plus: Ptr possible other ptrs Vaginal DC-no known etiology BV

1. Partner(s) possibly having had other concurrent partners (during past 12 mos) was the strongest

predictor of CT in these research projects; 2. Other fairly consistent behavioral predictors of CT

included: > 1 partners in past 12 mos New partner in past 2-3 mos

3. Younger age, specifically age 26-30, was a strong demographic predictor of CT

4. Possible clinical predictors include: BV and Vaginal DC on exam with no known etiology

Implications for Screening Recommendations for Non-Pregnant

Women > Age 25

Testing based on clear clinical indications:• Current contact (exposure) to any STD• Clinical signs of cervicitis or PID• Newly confirmed or presumptively treated other STD dx? Additional discussion about other clinical considerations for

clinician discretion:• Vaginal DC on exam with unknown etiology (cervicitis?)• BV dx in some populations

Retesting: Encourage CT+ clients RTC in 3 mos Targeted Screening based on risk factors:

• Partner possible other partners during past 12 mos!!!• More than 1 partner during past 12 mos (more than 2 partners)• New partner during past 2-3 mos

Additional discussion: higher CT risk often associated with younger age – emphasis on prioritizing age 26-30

Proposed CT Testing & Screening Recommendations for Non-Pregnant Women > Age 25

CADHS-STDJoan Chow, Heidi Bauer, Erika Samoff, Gail Bolan

CFHCMelanie Deal, Christy Ngo, Jackie Provost, Rebecca Braun, Lani Pasion

Lab PartnersQuest Diagnostics, Medical Group Pathology Laboratory,

UCSF Chlamydia Research Laboratory (Julius Schachter), Planned Parenthood Mar Monte Laboratory (Jill A. MacAfee)

And all The Over 20 & Over 25 Participating Clinic Sites

For further information, please contact: Holly Howard at [email protected]

AcknowledgementsThank you!

developing ct screening guidelines for women >25: the over 20 study & the over 25 evaluation...

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