the value of chlamydia trachomatis-specific igg antibody testing
TRANSCRIPT
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