Using virtual-reality simulation to ensure basic competence in hysteroscopy.

BACKGROUND: Hysteroscopy is a technically challenging procedure. Specialty curricula of obstetrics and gynaecology appraise hysteroscopy for trainees but there is no present evidence-based training program that certifies the fundamental technical skills before performance on patients. The objectives of this study were to develop and gather validity evidence for a simulation-based test that can ensure basic competence in hysteroscopy. METHODS: We used the virtual-reality simulator HystMentor™. Six experts evaluated the feasibility and clinical relevance of the simulator modules. Six modules were selected for the test and a pilot study was carried out. Subsequently, medical students, residents, and experienced gynaecologists were enrolled for testing. Outcomes were based on generated simulator metrics. Validity evidence was explored for all five sources of evidence (content, response process, internal structure, relations to other variables, consequences of testing). RESULTS: Inter-case reliability was high for four out of five metrics (Cronbach's alpha ≥ 0.80). Significant differences were identified when comparing the three groups' performances (p values < 0.05). Participants' clinical experience was significantly correlated to their simulator test score (Pearson's r = 0.49, p < 0.001). A single medical student managed to achieve the established pass/fail score (6.7% false positive) and three experienced gynaecologists failed the test (27.3% false negative). CONCLUSIONS: We developed a virtual-reality simulation-based test in hysteroscopy with supporting validity evidence. The test is intended to ensure competency in a mastery learning program where trainees practise on the simulator until they are able to pass before they proceed to supervised training on patients.

Polymerase chain reaction for Group B Streptococci (GBS) at labor highly correlates with vaginal GBS load.

OBJECTIVE: To explore factors associated with a high vaginal GBS load during labor considering (1) the recto-vaginal GBS load at 35-37 weeks' gestation determined by culture and (2) the vaginal GBS colonization determined by a polymerase chain reaction (PCR) assay during labor. METHODS: From an unselected cohort of 902 pregnant women, we obtained (1) recto-vaginal swabs for culture of GBS at 35-37 weeks' gestation (GBSrectovag-36), (2) vaginal swabs for GBS PCR detection at labor (PCRvag-labor), and (3) vaginal swabs for culture of GBS at labor (GBSvag-labor). The GBS load was classified semi quantitatively according to a culture protocol without prior broth enrichment of the swab samples: none (0), few (+), some (++), or many (+++) GBS colonies. RESULTS: Among 902 unselected pregnant women, 859 (95%) had a vaginal swab culture taken at labor, which was classified semi quantitatively. High load GBSvag-labor (+++) were found in 31 participants. GBSrectovag-36 showed a sensitivity of 90% (28/31) and a PPV of 23% (28/121), whereas PCRvag-labor had a sensitivity of 98% (30/31, non-significant difference) and a PPV of 42% (30/71, p < .01). PCR at labor had a lower sensitivity (78%) for detection of vaginal colonization with GBS at labor (any load) compared to recto/vaginal colonization with GBS at 36 weeks (92%). Vaginal colonization with GBS at 36 weeks seemed to have a lower sensitivity for detecting GBS in vagina at labor for high load (48%) and for any load (39%). CONCLUSION: PCR at labor has higher detection rate (non-significant) and PPV in identification of laboring women with a high load of vaginal GBS compared with recto-vaginal culture at 36 weeks' gestation.

Urine dipstick for predicting intrapartum recto-vaginal colonisation by group B streptococci.

INTRODUCTION: In pregnant women, bacteriuria with group B streptococci (GBS) may be associated with a high degree of recto-vaginal GBS colonisation and therefore an increased risk of early-onset GBS disease. The aim of this study was to assess the performance of routine use of dipstick urine analysis during pregnancy for prediction of recto-vaginal GBS colonisation at the time of labour. METHODS: Among 902 unselected Danish pregnant women, we obtained results from 1) dipstick urine analysis, 2) urine culture carried out during pregnancy, if indicated, and 3) recto-vaginal culture at labour. The inclusion criteria were age > 18 years and gestational age ≥ 37 weeks. RESULTS: Intrapartum recto-vaginal GBS colonisation was predicted by a positive urine dipstick with 5% sensitivity only. CONCLUSION: Dipstick urine analysis had a low sensitivity for predicting intrapartum recto-vaginal colonisation with GBS. FUNDING: none. TRIAL REGISTRATION: not relevant.

Number of colony forming units in urine at 35-37 weeks' gestation as predictor of the vaginal load of Group B Streptococci at birth.

OBJECTIVE: To evaluate GBS colony numbers in the urine at 35-37 weeks' gestation to predict the load of GBS-colonization of the vagina at birth. STUDY DESIGN: In this prospective observational study, we included 902 unselected pregnant women. Exposure was GBS colony forming units (CFU) per mL urine at 35-37 weeks' gestation. Outcome was vaginal GBS colonization at birth as assessed by a semi-quantitative culture of a vaginal swab sample (negative, +1, +2, +3). RESULTS: Bacteriuria with GBS at 35-37 weeks' gestation performed with a sensitivity of 30% concerning any degree of vaginal GBS colonization at birth (31 of 104 cases); 19% for light (+1), 17% for medium (+2), and 52% for high load (+3) vaginal GBS colonization. The colony count in case of GBS bacteriuria at 35-37 weeks' gestation performed with positive predictive values of 35% for <104 CFU/mL, 70% for 104 CFU/mL, and 67% for >104 CFU/mL. CONCLUSION: Even though the urinary GBS CFU at 35-37 weeks' gestation is strongly associated with a high load of vaginal GBS colonization intrapartum, it may not perform satisfactorily as a standalone-screening marker for risk of early-onset GBS disease.

Intrapartum PCR assay versus antepartum culture for assessment of vaginal carriage of group B streptococci in a Danish cohort at birth.

The aim of this study was to compare the performances of two strategies for predicting intrapartum vaginal carriage of group B streptococci (GBS). One strategy was based on an antepartum culture and the other on an intrapartum polymerase chain reaction (PCR). We conducted a prospective observational study enrolling 902 pregnant women offered GBS screening before delivery by two strategies. The Culture-strategy was based on vaginal and rectal cultures at 35-37 weeks' gestation, whereas the PCR-strategy was based on PCR assay on intrapartum vaginal swab samples. An intrapartum vaginal culture for GBS was used as the reference standard from which the performances of the 2 strategies were evaluated. The reference standard showed a GBS-prevalence of 12%. The culture-strategy performed with a sensitivity of 82%, specificity of 91%, positive predictive value (PPV) of 55%, negative predictive value (NPV) of 98%, and Likelihood ratio (LH+) of 9.2. The PCR-strategy showed corresponding values as sensitivity of 83%, specificity of 97%, PPV of 78%, NPV of 98%, and LH+ of 27.5. We conclude that in a Danish population with a low rate of early-onset neonatal infection with GBS, the intrapartum PCR assay performs better than the antepartum culture for identification of GBS vaginal carriers during labor.