Hui and Walter's latent-class reference-free approach may be more useful in assessing agreement than diagnostic performance.

BACKGROUND AND OBJECTIVE: Hui and Walter developed a latent class approach to assess the accuracy of a diagnostic procedure when no reference test is available. Our objective was to compare sensitivity and specificity estimates obtained with this reference-free approach and standard approaches, and to examine how and why they differed on a computerized tomography (CT) scan case study. STUDY DESIGN AND SETTING: We compared two sets of sensitivity and specificity estimates from four radiologists independently assessing tumoral and lymph node extension of 85 lung cancer patients with preoperative thoracic CT scan, those obtained relative to pathology findings from surgical specimens (reference set), and those derived from Hui and Walter's approach. RESULTS: The two sets of estimates significantly and markedly differed from each other. From simulations, we found that small-sample bias in Hui and Walter's estimates could be a major factor in explaining this difference. Furthermore, errors in pathology findings could account for part of this difference. Finally, our analyses revealed that the latent classes may differ intrinsically from the reference classes as defined from pathology findings and may have a different interpretation. CONCLUSION: Diagnostic parameters estimated with respect to latent classes may be more useful in providing a complete assessment of interobserver agreement than in assessing diagnostic performance.

Comparison of digital and ultrasonographic examination of the cervix in predicting time interval from induction to delivery in women with a low Bishop score.

OBJECTIVE: To compare pre-induction ultrasonographic cervical length and Bishop score in predicting time to delivery after labour induction with prostaglandins. DESIGN: Prognostic cohort study. SETTING: Tertiary referral maternity unit in a teaching hospital. POPULATION: Two hundred and sixty-six women with singleton pregnancies at between 34(+0) and 41(+3) weeks of gestation requiring induction of labour with prostaglandins for medical indications. METHODS: A secondary analysis of a trial comparing two prostaglandins. Assessment of the Bishop score and measurement of the cervical length by transvaginal sonography were performed by two operators, blinded to each other's results. We estimated the predictive effects on the outcomes of ultrasonographic cervical length and Bishop score. MAIN OUTCOME MEASURE: Time intervals from induction to delivery and to vaginal delivery. RESULTS: Cervical length and Bishop score were associated with the time interval from induction to delivery, based on univariable analyses. When considered jointly in a multivariable model, only the Bishop score was significantly related to the outcome: The higher the Bishop score, the higher the hazard to delivery [hazard ratio (HR): 1.2, 95% confidence interval (CI): 1.1-1.3], illustrating that once the Bishop score is taken into account, further knowledge of cervical ultrasound length (HR: 0.99, 95% CI: 0.98-1.0) did not add any predictive information. Also, Bishop score was predictive of time interval between induction and vaginal delivery (HR: 1.2, 95% CI: 1.1-1.4) while cervical length had no additional predictive value (HR: 0.99, 95% CI: 0.98-1.0) when both cervical length and Bishop score were introduced in the model. CONCLUSIONS: The Bishop score appears to be a better predictor of the time interval from induction to delivery and to vaginal delivery than cervical length after induction of labour for medical reasons.

DECOPI (DEsobstruction COronaire en Post-Infarctus): a randomized multi-centre trial of occluded artery angioplasty after acute myocardial infarction.

AIM: To determine whether late recanalization of an occluded infarct artery after acute myocardial infarction is beneficial. METHODS AND RESULTS: Two hundred and twelve patients with a first Q-wave myocardial infarction (MI) and an occluded infarct vessel were enrolled. After coronary and left ventricular contrast angiography, patients were randomized to percutaneous revascularization (PTCA, n=109), carried out 2-15 days after symptom onset or medical therapy (n=103). The primary endpoint was a composite of cardiac death, non-fatal MI, or ventricular tachyarrhythmia. The majority had single-vessel disease and less than one-third had involvement of the left anterior descending artery. The use of pharmacological therapy was high in both groups. At six months, left ventricular ejection fraction was 5% higher in the invasive compared with the medical group (P=0.013) and more patients had a patent artery (82.8% vs 34.2%, P<0.0001). Restenosis was seen in 49.4% of patients in the PTCA group. At a mean of 34 months of follow-up, the occurrence of the primary endpoint was similar in the medical and PTCA groups (8.7% vs 7.3% respectively, P=0.68), but the overall costs were higher for PTCA. The secondary endpoint combining the primary endpoint with admission for heart failure was also similar between groups (12.6% vs 10.1% in the medical and PTCA groups, respectively, P=0.56). CONCLUSIONS: Systematic late PTCA of the infarct vessel was associated with a higher left ventricular ejection fraction at six months, no difference in clinical outcomes, and higher costs than medical therapy. These results must be interpreted with caution given the small size and low risk of the population.

Interobserver and intraobserver reproducibility in the histopathology of follicular thyroid carcinoma.

We evaluated the interobserver and intraobserver reproducibility in the histopathology of follicular thyroid carcinoma (FTC). Forty-one anonymous FTC pathology slides were independently reviewed by 5 pathologists, and 31 of them were also evaluated twice by the same pathologist. A final consensus diagnosis (FCD) was made at the end of the study. Interobserver and intraobserver agreement was determined as the kappa statistic for qualitative data and intraclass correlation coefficient for quantitative data. The agreement between the 5 observers' initial diagnosis and the FCD was 0.69, 0.41, 0.35, 0.28 and 0.11, respectively, strongly suggesting a leadership phenomenon. The FCD classified 30 cases as malignant, including 24 cases diagnosed as FTC. There was unanimous agreement about 13 of the 24 FTCs. Diagnostic reproducibility was found to be acceptable for the nonminimally invasive FTC. Diagnostic discrepancies occurred in 57% of the seven cases classified as minimally invasive FTC by the FCD. FCD excluded malignancy in 11 cases including 6 atypical adenomas. Interobserver and intraobserver agreement for FTC diagnosis was 0.23 (standard error [SE], 0.04) and 0.68, respectively. Interobserver and intraobserver agreement for the presence of vascular invasion was 0.20 (SE, 0.04) and 0.51, respectively, contrasting with a moderate to substantial level of agreement when considering the number of vascular invasion. Interobserver and intraobserver agreement for nucleus optical clearing were slight and moderate, respectively. The importance of the study is the confirmation that diagnostic reproducibility of minimally invasive FTC is low and that this has clinical implications, and also implications for the design of studies into the treatment and outcome of FTC.

Prevalence and risk factors for carriage of methicillin-resistant Staphylococcus aureus at admission to the intensive care unit: results of a multicenter study.

BACKGROUND: Detection of methicillin-resistant Staphylococcus aureus (MRSA) carriers on admission to the intensive care unit (ICU) is an important component of strategies for controlling the spread of MRSA. METHODS: A prospective multicenter study was conducted in 14 French ICUs for 6 months. All patients were screened within 24 hours after admission, using nasal and cutaneous swabs In addition, clinical samples were obtained. Patient data collected on ICU admission included presence of immunosuppression; history of hospital stay, surgery, antimicrobial treatments, or previous colonization with MRSA; chronic health evaluation and McCabe scores; reason for admission; whether the patient was transferred from another ward; severity of illness; presence of skin lesions; and invasive procedures. Risk factors for MRSA carriage at ICU admission were estimated, and significantly associated variables were used to develop a predictive score for MRSA carriage. A cost-benefit analysis was then performed. RESULTS: Of the 2347 admissions with MRSA screening, 162 (6.9%; range, 3.7%-20.0% among ICUs) were positive for MRSA, of whom 54.3% were detected through screening specimens only. Of the 2310 first admissions (vs repeat admissions) to the ICU, 96 were newly identified MRSA carriers. Factors associated with MRSA carriage in the multivariate analysis were age older than 60 years, prolonged hospital stay in transferred patients, history of hospitalization or surgery, and presence of open skin lesions in directly admitted patients. Only universal screening detected MRSA carriage with acceptable sensitivity. A cost-benefit analysis confirmed that universal screening and preventive isolation were beneficial. CONCLUSIONS: The prevalence of MRSA carriage on admission to the ICU is high in this endemic setting. Screening for MRSA on admission is useful to identify the imported cases and should be performed in all ICU-admitted patients.

Preoperative chemotherapy followed by surgery compared with primary surgery in resectable stage I (except T1N0), II, and IIIa non-small-cell lung cancer.

PURPOSE: To evaluate whether preoperative chemotherapy (PCT) could improve survival in resectable stage I (except T1N0), II, and IIIA non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: A randomized trial compared PCT to primary surgery (PRS). PCT consisted of two cycles of mitomycin (6 mg/m(2), day 1), ifosfamide (1.5 g/m(2), days 1 to 3) and cisplatin (30 mg/m(2), days 1 to 3), and two additional postoperative cycles for responding patients. In both arms, patients with pT3 or pN2 disease received thoracic radiotherapy. RESULTS: Three hundred fifty-five eligible patients were randomized. Overall response to PCT was 64%. There were two preoperative toxic deaths. Postoperative mortality was 6.7% in the PCT arm and 4.5% in the PRS arm (P =.38). Median survival was 37 months (95% confidence interval [CI], 26.7 to 48.3) for PCT and 26.0 months (95% CI, 19.8 to 33.6) for PRS (P =.15). Survival differences between both arms increased from 3.8% (95% CI, 1.3% to 25.1%) at 1 year to 8.6% (95% CI, 2.64% to 24.4%) at 4 years. A quantitative interaction between N status and treatment was observed, with benefit confined to N0 to N1 disease (relative risk [RR], 0.68; 95% CI, 0.49 to 0.96; P =.027). After a nonsignificant excess of deaths during treatment, the effect of PCT was significantly favorable on survival (RR, 0.74; 95% CI, 0.56 to 0.99; P =.044). Disease-free survival time was significantly longer in the PCT arm (P =.033). CONCLUSION: Although impressive differences in median, 3-year, and 4-year survival were observed, they were not statistically significant, except for stage I and II disease.