The value of Chlamydia trachomatis-specific IgG antibody testing and hysterosalpingography for predicting tubal pathology and occurrence of pregnancy

Fertility and sterility volume 88 no. 1 July 2007

INTRODUCTION

Tubal pathology accounts for approximately 14% causes of subfertility

Gold standard : laparoscopy and dye test Several diagnosis test assess tubal

statusCAT (chlamydial antibody testing)HSG

INTRODUCTION

The aim : Assessed diagnostic accuracy of CAT and

HSG compared with laparoscopy + dye Prognostic value of both tests to assess

occurrence of pregnancy

MULTICENTER, RCT PERFORMANCE OF HSG AS ROUTINE

INVESTIGATION IN FERTILITY

Division of Reproductive MedicineLeiden University

178 subjects

Recruitment strategyDescription of subjects Published elsewhere

STAGE 1

65 HSG +

laparoscopy

88 Laparoscopy

only

25 HSG only

STAGE 2

CTSIgG +/- CTSIgG +/-

153

DIAGNOSTIC TEST

CTSIgG VS LAPAROSCOPY AND DYE

HSG VS LAPAROSCOPY AND DYE

PROGNOSTIC TEST CTSIgG

HSGPREGNANCY

18 MONTHS

HSG Abnormal (A) : occlusion on one or both tubes Normal (B) : no occlusion

LAPAROSCOPY AND DYE Abnormal (A) : one / both tube occlusion

or peritubal adhesion Normal (B) : no occlusion

CHLAMYDIA TRACHOMATIS SPECIFIC IgG (CTIgG) Positive (A) Negative (B)

DIAGNOSTIC TESTS 2 x 2 tables

DIAGNOSTIC TESTS

Laparoscopy

CTSIgG

A B

A 14 21 35

B 17 101 118

31 121 153

SENSITIVITY : 14 / 31 = 45 %

SPECIFICITY : 101 / 121 = 83 %

Positive likelihood ratio : 2.6

Negative likelihood ratio : 0.7

DIAGNOSTIC TESTS

Laparoscopy

HSG

A B

A 11 13 24

B 5 36 41

16 49 65

SENSITIVITY : 11 / 16 = 69 %

SPECIFICITY : 36 / 49 = 73 %

Positive likelihood ratio : 2.6

Negative likelihood ratio : 0.4

PROGNOSTIC TESTS

NO STATISTICALLY SIGNIFICANT DIFFERENCE found in cumulative pregnancy rate between CtsIgG negative and positive

Hazard ratio 0.7395% CI 0.42 – 1.25p =.25

PROGNOSTIC TESTS

NO STATISTICALLY SIGNIFICANT DIFFERENCE in cumulative pregnancy rate between normal and abnormal HSG

Hazard ratio 1.3395% CI 0.73 – 2.41p =.35

CONCLUSION

Diagnostic accuracy of CAT antibody testing is comparable with HSG but both show poor performance

The prognostic value of occurrence pregnancy of both tests is also poor

Chlamydia antibody testing as screening test to estimate the risk of tubal pathology before laparoscopy is preferable to HSG owing to its simplicity and limited inconvenience.

General comment

The CAT and HSG tests provide risk estimates of tubal pathology before laparoscopy

The diagnostic accuracy of CAT and HSG compared with laparoscopy and dye is well established

The prognostic value of both studies in predicting occurrence of pregnancy is not well known

General comment

Main strength : prospective study Shortcoming : diagnostic or prognostic value of

CAT and HSG can be determined separately, but the total sample size is too small for the combination of diagnostic and prognostic value

Critical AppraisalDiagnostic study 1. Was there an independent, “blind” comparison with a gold

standard of diagnosis?there were a gold standard involved and mentioned in this study which was a laparoscopy + dye, but its blinding procedure did not clearly described

2. Did the patients sample include an appropriate spectrum of mild, severe, treated, and untreated disease, plus individuals with different but commonly confused disorders?

there were no clear definition regarding the “state” of infertility studied

Critical Appraisal

3. Was the setting for the study, as well as the filter through which study patients passed, adequately described ?

The setting took place in the Division of Reproductive Medicine, Department of Gynecology, Leiden University Medical Center

4. Was the reproducibility of the test result (precision) and site interpretation (observer variation) determined ?

maybe, in this journal we can find “clear and fixed category / interpretation” regarding every variables studied, but because there was no statement about inclusion and description of subjects somehow made it, a little bit difficult to do

Critical Appraisal

5. Was the term normal defined sensibly ?

yes both including a clear definition on its normal and abnormal, also positive and negative result

6. If the test is advocated as part of cluster or sequence test, was its contribution to the overall validity of the cluster or sequence determined ?

no, it wasnt

Critical Appraisal

7. Were the tactics for carrying out the test described in sufficient detail to permit their exact replication ?

yes, we could actually track back the result and its interpretation with this journal

8. Was the “utility” of the test determined ?

yes, its clearly stated its aim

Critical AppraisalPrognostic study1. Was an inception cohort assembled ?

this study didn’t clearly stated its “baseline” condition of their subject

2. Was the referral pattern described ?no

3. Was the complete follow up achieved ?

yes, it mentioned 0% loss to follow up

Critical Appraisal

4. Were objective outcome criteria developed and used ?

yes, it were positive urine or serum pregnancy test in association with an intact intrauterine gestation sac on ultrasound

5. Was the outcome assessment “blind” ?

didn’t state clearly

Validity its validity regarding, procedure, subjects recruitment, confounding factor and person who assessed the variables and outcome criteria didn’t mentioned clearly questionable

Expertise its results were almost similar to other study previously carried out

Applicable to clinic / practice able to be include in part of our systematic assessment of patient but cannot be done as a single examination alone due to its poor performance and predictive value