Analysis of Chlamydia Re-testing Rates

Massachusetts

2008-2009

Family Planning Update

Background

“Repeat infections confer an elevated risk for PID and other complications when compared with the initial infection. Therefore, recently infected women are a major priority for repeat testing for C. trachomatis. Clinicians and health-care agencies should consider advising all women with chlamydial infection to be retested approximately 3 months after treatment. Providers also are strongly encouraged to retest all women treated for chlamydial infection whenever they next seek medical care within the following 3–12 months, regardless of whether the patient believes that her sex partners were treated.”

(From CDC’s 2006 STD Treatment Guidelines )

Background

• Purpose of this analysis: – Assess usefulness of interventions to

increase retesting rates– Feedback to clinics– Compare to other regions in the United States

Conclusions from MA Baseline Analysis (2005-2006 data)

• Among women tested for Chlamydia at Massachusetts family planning clinics, approximately 29% were re-tested within 3-12 months of initial diagnosis

– 25% of women re-tested for chlamydia had recurrent infection

• Age < 18 years was associated with greater rates of re-testing

Intervention

• In 2006, MDPH began a monthly “report-back” system to notify clinics of positives and facilitate call backs for re-testing.

Bill Dumas faxed lists once a month to the family planning clinics. The lists had names of patients who tested positive for Chlamydia 3 months ago and were due for a rescreen.

• Was this intervention effective at increasing Chlamydia re-testing rates at the family planning clinics?

Methods for the 2008-2009 Update

• Records reviewed in 3 lab databases at MA State Lab for females with positive Chlamydia tests at IPP clinics between 1/1/2008 and 12/31/2008. I looked for follow-up tests through 12/31/2009.

• Variables used: Name and DOB (for match), specimen #, facility name and type, race/ethnicity, date of original specimen collection, date and result of follow-up test.

• SAS 9.1 used for analysis• Fisher’s exact test to compare proportions

Proportion of Women at Family Planning Clinics Re-tested for Chlamydia 3-12 Months (90-365 Days) after Initial Positive Diagnosis

28.9%

71.1%

Women Re-tested Women Not Re-tested

N=402

36%

64%

retested not retested

2008-2009

N=300

2005-2006

Results in Family Planning Clinics

P=0.0495

Proportion of Positives in Women in FP Clinics Re-tested for Chlamydia 3-12 Months (90-365 Days) after Initial Positive Diagnosis

2005-2006

N=116

25.4%

74.6%

Positive Negative

15%

85%

positive negative

2008-2009

N=107

P=0.0483

Within each age group, what percent of women in FP clinics got re-tested?

41

25

0

5

10

15

20

25

30

35

40

45

Women < 18 years Women > 18 years

46.7%

32.0%

0.0%

6.0%

12.0%

18.0%

24.0%

30.0%

36.0%

42.0%

48.0%

54.0%

<=18 yrs >18 yrs

2005-2006 2008-2009

N=75 N=225N=104 N=297

P=0.0025 P=0.0260

Percent of Women in FP Clinics Re-tested for Chlamydia by Race/Ethnicity

0%

10%

20%

30%

40%

50%

60%

White, Non-Hispanic

Black Non-Hispanic

Hispanic Other, Non-Hispanic

Unknown

2005-2006 2008-2009

Conclusions

• Rescreening rates significantly increased from 29% (2005-2006) to 36% (2008-2009).

• Of the women who re-tested in 2008-2009: – 15% of women re-tested for chlamydia had recurrent

infection– Age < 18 years still associated with greater rates of

re-testing.

Strengths of this analysis

• Easily available electronic data

• I’ll be able to break down results by individual clinic and share results with them.

• SAS code can be modified for alternate re-testing timeframes, to compare with analyses in other regions of the U.S.

Limitations

• Re-testing rates may be higher than this data shows, if clinics sent 2nd test to different lab. No chart review was done at clinics for this analysis. Only State Lab databases were used.

• Findings based on retrospective record review with only a limited number of factors available for analysis.

• Re-testing analysis cannot currently be done at the regional level using IPP database, because we don’t use client IDs. This analysis used names and dates of birth to identify patients.

Next Steps

• What do you think is the next intervention we should use to increase re-testing rates?

• It will be interesting to combine these results of this analysis with results from other New England states, and compare Region I to other regions.

• Contact me if you want more info on methods, so you can conduct an analysis in your state: Laura Smock, Data Manager for the Massachusetts IPP, MA Dept of Public Health, (617) 983-6961,Laura.Smock@state.ma.us