Does vertical incomitance predict the diplopia outcome in orbital fracture patients? A prospective study of 188 patients.

OBJECTIVE: To determine the predictive value of vertical incomitance for diplopia outcome in orbital fracture patients. PATIENTS AND METHODS: A prospective cohort study composed of patients with orbital fractures was designed. The predictor variable was vertical incomitance, and the primary outcome variable was diplopia. Incomitance was calculated in prism diopters (Δ) as the difference of the maximum absolute deviation between the upper and lower three gaze directions. Standard statistics for patient characteristics, the Fisher exact test for categorical variables and the Wilcoxon rank sum test for continuous variables were computed. RESULTS: The sample was composed of 188 patients grouped as follows: non-operated (n = 124) and operated (n = 64). Fifty-one patients showed vertical incomitance of whom 10 (19.6%) had persistent diplopia at the 1-year follow-up. The mean incomitance was 9.6Δ in the diplopia group versus 2Δ in the non diplopia group (OR = 1.13; p < 0.001). There was a statistically significant association between vertical incomitance of >2Δ and persistent diplopia at 1 year after adjusting for the surgery variable (OR = 1.07; p < 0.04). CONCLUSION: The present study has demonstrated that in orbital fracture patients, vertical incomitance was associated with (1) persistence of long-term diplopia, (2) the decision to perform surgery, and (3) the severity of the fracture.

Tissue eosinophilia in oral intraepithelial neoplasia as a probable indicator of invasion.

OBJECTIVE: To investigate the presence of eosinophils in oral intraepithelial neoplasia (OIN) and oral squamous cell carcinoma (OSCC) lesions and its relation to invasion. SUBJECTS AND METHODS: Ninety-nine oral biopsies were selected and subdivided into the following: OIN-1(16 cases), OIN-2 (18 cases), OIN-3 (17 cases), microinvasive OSCC (10 cases), non-metastatic OSCC (22 cases) and metastatic OSCC (16 cases). The tissue eosinophilia was evaluated histologically in slices stained with haematoxylin and eosin. RESULTS: Eosinophil distribution was associated with diagnosis severity (p < .01). A significant difference was found between OIN-3 or microinvasive OSCC and non-metastatic or metastatic OSCC. Stromal invasion threshold was 7 eos/10 high power field (hpf) (96.1% specificity and 62.5% sensitivity). Eosinophils were absent in OIN-1; in OIN-2, two cases were positive. In OIN-3, five cases showed tissue eosinophilia, four of which had ≥3 eos/hpf or ≥7 eos/10 hpf. Three cases were suspected of invasion; two had a previous history of OSCC with elevated eosinophil infiltrate. In microinvasive OSCC, the four positive cases presented ≥3 eos/hpf and ≥7 eos/10 hpf. Although not significantly different, non-metastatic invasive OSCC had a higher number of cases (68.2%) with ≥22 eos/10 hpf contrasting with 50% in metastatic OSCC. CONCLUSION: Our results suggest that eosinophils can be considered an indicator of invasion in OIN, helping in cases of difficult diagnosis.

Meta-analysis of two-arm studies: Modeling the intervention effect from survival probabilities.

Pooling the hazard ratios is not always feasible in meta-analyses of two-arm survival studies, because the measure of the intervention effect is not systematically reported. An alternative approach proposed by Moodie et al. is to use the survival probabilities of the included studies, all collected at a single point in time: the intervention effect is then summarised as the pooled ratio of the logarithm of survival probabilities (which is an estimator of the hazard ratios when hazards are proportional). In this article, we propose a generalization of this method. By using survival probabilities at several points in time, this generalization allows a flexible modeling of the intervention over time. The method is applicable to partially proportional hazards models, with the advantage of not requiring the specification of the baseline survival. As in Moodie et al.'s method, the study-level factors modifying the survival functions can be ignored as long as they do not modify the intervention effect. The procedures of estimation are presented for fixed and random effects models. Two illustrative examples are presented.

Evaluation of condylar morphology following orthognathic surgery on digital panoramic radiographs. Could methodology influence the range of "normality" in condylar changes?

OBJECTIVES: To evaluate the morphological condylar changes following orthognathic surgery by using a rapid and reliable computational method on panoramic radiographs. METHODS: Digital panoramic radiographs of 45 patients who underwent bilateral sagittal split osteotomy (alone or associated with a Le Fort I osteotomy) between 2007 and 2010 were analysed. Calculation of the area, perimeter and height of 90 condyles was performed by using a specific computational method. Measurements were taken before surgery (m1), 1 day after surgery (m2) and 1 year after surgery (m3). The evolution of each index was analysed using paired t-tests between measures before and 1 day after surgery (m1 - m2) and measures before and 1 year after surgery (m1 - m3). The changes in the condylar area, perimeter and height were examined using the Bland and Altman plotting method. RESULTS: There were no statistically significant changes in the mean condylar area, perimeter or height between m1 and m2 or between m1 and m3. The Bland and Altman plots for each index showed that a very limited number of condyles increased or decreased in area, perimeter and/or height outside the boundaries of the measurement error. Given the impossibility for a condyle to increase in size, these results are considered to represent the limits of the computational method used. CONCLUSIONS: This study demonstrated that there were no significant morphological condylar changes at the 1-year follow-up following surgery and that the range of normality in condylar changes could be influenced by the methodology used.

Clinical factors associated with the non-utilization of an anaesthesia incident reporting system.

BACKGROUND: Incident reporting is a widely recommended method to measure undesirable events in anaesthesia. Under-utilization is a major weakness of voluntary incident reporting systems. Little is known about factors influencing reporting practices, particularly the clinical environment, anaesthesia team composition, severity of the incident, and perceived risk of litigation. The purpose of this study was to assess each of these, using an existing anaesthesia database. METHODS: We performed a retrospective cohort study and analysed 46 207 surgical patients. We used multivariate analysis to identify factors associated with the non-utilization of the reporting system. RESULTS: We found that in 7022 (15.1%) of the procedures performed, the incident reporting system was not used. Factors associated with the non-use of the system were regional anaesthesia/local anaesthesia, odds ratio (OR) 1.64 [95% confidence interval (CI) 1.03-2.62], emergency procedures OR 1.15 (95% CI: 1.05-1.27), and a consultant anaesthetist working without a trainee, OR 1.71 (95% CI: 1.03-2.82). In contrast, factors such as longer duration of surgery, OR 0.85 (95% CI: 0.76-0.94), the presence of a senior anaesthesia trainee, OR 0.86 (95% CI: 0.81-0.92), and the occurrence of severe complications with a high risk of litigation (i.e. death, nerve injuries) were less associated with a non-use of the reporting system, OR 0.65 (95% CI: 0.44-0.97). Team composition and time of day had no measurable impact on reporting practices. CONCLUSIONS: Clinical factors play a significant role in the utilization of an anaesthesia incident reporting system and more particularly, severity of complications and higher liability risks which appear more as incentives than barriers to incident reporting.

Meta-analysis of binary outcomes from two-by-two tables when the length of follow-up varies and hazards are proportional.

Odds ratios (ORs) and relative risks (RRs) are sensitive to the length of follow-up. In meta-analyses, pooling such results from studies with different lengths of follow-up may lead to an artificial heterogeneity and discrepancy caused by the choice of the summary index. In this article, we explore the utility of a meta-analysis method that uses the ratio of logarithms of survival probability as the measure of association, and that avoids the problems mentioned above when hazards are proportional. Meta-analyses of ORs, RRs and ratios of logarithms of survival probability are compared through a simulation study, in which data are simulated from a proportional hazard model and the length of follow-up varies across studies using realistic patterns of variability. Results show that the heterogeneity increases with the variability of length of follow-up for OR and RR, but not for the ratio of the logarithms of survival probability. A published meta-analysis is used to illustrate the method.