The influence of overlap in classes in training and test set on face recognition performance

Several studies use an overlap in individuals (classes) between the training and test set during performance evaluation of face recognition systems, but little is known about the influence of having overlap in classes. This study investigates the influence of overlap in classes in the training and test set on recognition performance in a PCA/LDA-based log likelihood ratio classifier. 278 classes from the FRCG dataset with 20 samples per class are used to investigate overlap percentages of 0%, 25%, 50%, 75%, and 100%. The results show an equal error rate of 3.09% at 0% overlap and an equal error rate of 1.24% for 100% overlap. Additionally, no difference in performance was found between overlap percentages of 0% and 25%. The results of this study suggest that having a big overlap in classes between the training and the test set results in an overestimation of face recognition performance

Interobserver variability in the classification of appendicitis during laparoscopy

Background: The intraoperative classification of appendicitis dictates the patient's postoperative management. Prolonged antibiotic prophylaxis is recommended for complex appendicitis (gangrenous, perforated, abscess), whereas preoperative prophylaxis suffices for simple appendicitis. Distinguishing these two conditions can be challenging. The aim of this study was to assess interobserver variability in the classification of appendicitis during laparoscopy. Methods: Short video recordings taken during laparoscopy for suspected appendicitis were shown to surgeons and surgical residents. They were asked to: classify the appendix as indicative of no, simple or complex appendicitis; categorize the appendix as normal, phlegmonous, gangrenous, perforated and/or abscess; and decide whether they would prescribe postoperative antibiotics. Inter-rater reliability was evaluated using Fleiss' κ score and the S* statistic. Results: Some 80 assessors participated in the study. Video recordings of 20 patients were used. Interobserver agreement was minimal for both the classification of appendicitis (κ score 0·398, 95 per cent c.i. 0·385 to 0·410) and the decision to prescribe postoperative antibiotic treatment (κ score 0·378, 0·362 to 0·393). Agreement was slightly higher when published criteria were applied (κ score 0·552, 0·537 to 0·568). Conclusion: There is considerable variability in the intraoperative classification of appendicitis and the decision to prescribe postoperative antibiotic treatment

Gastric Cancer Screening in Low­-Income Countries: System Design, Fabrication, and Analysis for an Ultralow-Cost Endoscopy Procedure

Gastric adenocarcinoma is the fifth most common malignancy in the world and the third leading cause of cancer death in both women and men. In 2012, its estimated global incidence was 952,000 new cases with an estimated 723,000 deaths worldwide. It is projected to rise from 14th to eighth in all-cause mortality in the near term, primarily due to the growing and aging populations in high-incidence areas, such as Latin America and eastern Asia. Unlike any other major cancer, gastric cancer demonstrates marked geographic variability in regions and within countries, with more than 70% of incident cases concentrated in lowand middle-income countries (LMICs)

Two versus five days of antibiotics after appendectomy for complex acute appendicitis (APPIC): Study protocol for a randomized controlled trial

Background: Acute appendicitis is one of the most common indications for emergency surgery. In patients with a complex appendicitis, prolonged antibiotic prophylaxis is recommended after appendectomy. There is no consensus regarding the optimum duration of antibiotics. Guidelines propose 3 to 7 days of treatment, but shorter courses may be as effective in the prevention of infectious complications. At the same time, the global issue of increasing antimicrobial resistance urges for optimization of antibiotic strategies. The aim of this study is to determine whether a short course (48 h) of postoperative antibiotics is non-inferior to current standard practice of 5 days. Methods: Patients of 8 years and older undergoing appendectomy for acute complex appendicitis - defined as a gangrenous and/or perforated appendicitis or appendicitis in presence of an abscess - are eligible for inclusion. Immunocompromised or pregnant patients are excluded, as well as patients with a contraindication to the study antibiotics. In total, 1066 patients will be randomly allocated in a 1:1 ratio to the experimental treatment arm (48 h of postoperative intravenously administered (IV) antibiotics) or the control arm (5 days of postoperative IV antibiotics). After discharge from the hospital, patients participate in a productivity-cost-questionnaire at 4 weeks and a standardized telephone follow-up at 90 days after appendectomy. The primary outcome is a composite endpoint of infectious complications, including intra-abdominal abscess (IAA) and surgical site infection (SSI), and mortality within 90 days after appendectomy. Secondary outcomes include IAA, SSI, restart of antibiotics, length of hospital stay (LOS), reoperation, percutaneous drainage, readmission rate, and cost-effectiveness. The non-inferiority margin for the difference in the primary endpoint rate is set at 7.5% (one-sided test at α 0.025). Both per-protocol and intention-to-treat analyses will be performed. Discussion: This trial will provide evidence on whether 48 h of postoperative antibiotics is non-inferior to a standard course of 5 days of antibiotics. If non-inferiority is established, longer intravenous administration following appendectomy for complex appendicitis can be abandoned, and guidelines need to be adjusted accordingly

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Transanal endoscopic microsurgery is superior to transanal excision of rectal adenomas

Aim Comparison of transanal excision (TE) and transanal endoscopic microsurgery (TEM) of rectal adenomas (RA) has rarely been performed. Method From 1990 to 2007, the results of TE (43 RA) and TEM (216 RA) were compared. Rectal adenomas were matched for diameter and distance from the anal verge. Results Operation time was 47.5 min for TE and 35 min for TEM (P < 0.001). Morbidity was 10% after TE and 5.3% after TEM (P < 0.001). Negative resection margins were observed in 50% after TE and 88% after TEM (P < 0.001). Fragmentation of the excised specimen was observed in 23.8% after TE and 1.4% after TEM (P < 0.001). In cases of fragmentation, positive resection margins were observed more frequently. Recurrence was 28.7% after TE and 6.1% after TEM (P < 0.001). After TE, RA with a negative resection margin had a local recurrence rate of 0%, compared with 59.6% with a positive margin (P < 0.001), and after TEM these rates were 3.2 and 7.7% (P = 0.3), respectively. Conclusion Transanal endoscopic microsurgery is superior to transanal excision of RA

Implementing a clinical pathway for hip fractures; effects on hospital length of stay and complication rates in five hundred and twenty six patients

Purpose Modern management of the elderly with a hip fracture is complex and costly. The aim of this study was to compare the treatment-related hospital length of stay (HLOS) before and after implementing a clinical pathway for patients undergoing hip fracture surgery. Methods This was a retrospective, before-and-after study. The first period ranged from June 21, 2008 to November 1, 2009 (N = 212), and the second was from January 7, 2010 to July 7, 2011 (N = 314). The electronic hospital system and patients records were reviewed for demographics, HLOS, mortality, complications and readmissions. Results In the first period 53 % had a femoral neck fracture, of which 57 % were treated with hemiarthroplasty. In the second period this was 46 % and 71 %. Pertrochanteric fractures were treated with a Gamma nail in 85 % in the first period, and in 92 % in the second period. The median HLOS decreased from nine to six days (p < 0.001). For the hemiarthroplasty group HLOS decreased from nine to seven days (p < 0.001); for internal fixation there was no significant difference (five versus six days, p = 0.557) and after Gamma nailing it decreased from ten to six days (p < 0.001). For mortality no statistically significant difference was found (6 % versus 5 %, p = 0.698). Complications decreased for the Gamma nail group (44 % versus 31 %, p = 0.049). Readmissions for the total group were not different (16 % versus 17 %, p = 0.720). Conclusions Implementing a clinical pathway for hip fractures is a safe way to reduce the HLOS and it improves the quality of care

Spinal or local anesthesia in Lichtenstein hernia repair - A randomized controlled trial

Background: With established protocols lacking, the choice of anesthetic technique remains arbitrary in inguinal hernia repair. Well-designed studies in this subject are important because of the gap or discrepancy between available scientific evidence and clinical practice. Methods: Between August 2004 and June 2006, a multicenter prospective clinical trial was performed in which 100 patients with unilateral primary inguinal hernia were randomized to spinal or local anesthesia. Clinical examination took place within 2 weeks postoperatively and at 3 months in the outpatient clinic. Results: Analysis of postoperative visual analogue scale scores showed that patients operated under local anesthesia had significant less pain shortly after surgery (P = 0.021). Significantly more urinary retention (P < 0.001) and more overnight admissions (P = 0.004) occurred after spinal anesthesia. Total operating time is significantly shorter in the local anesthesia group (P < 0.001). No significant differences were found between the 2 groups with respect to the activities of daily life and quality of life. Conclusions: Our study provides evidence that local anesthesia is superior to spinal anesthesia in inguinal hernia repair. Local anesthesia in primary, inguinal hernia repairs should be the method of choice

Implementing a clinical pathway for hip fractures; Effects on hospital length of stay and complication rates in five hundred and twenty six patients

Purpose: Modern management of the elderly with a hip fracture is complex and costly. The aim of this study was to compare the treatment-related hospital length of stay (HLOS) before and after implementing a clinical pathway for patients undergoing hip fracture surgery. Methods: This was a retrospective, before-and-after study. The first period ranged from June 21, 2008 to November 1, 2009 (N=212), and the second was from January 7, 2010 to July 7, 2011 (N=314). The electronic hospital system and patients records were reviewed for demographics, HLOS, mortality, complications and readmissions. Results: In the first period 53 % had a femoral neck fracture, of which 57 % were treated with hemiarthroplasty. In the second period this was 46 % and 71 %. Pertrochanteric fractures were treated with a Gamma nail in 85 % in the first period, and in 92 % in the second period. The median HLOS decreased from nine to six days (p<0.001). For the hemiarthroplasty group HLOS decreased from nine to seven days (p<0.001); for internal fixation there was no significant difference (five versus six days, p=0.557) and after Gamma nailing it decreased from ten to six days (p<0.001). For mortality no statistically significant difference was found (6 % versus 5 %, p=0.698). Complications decreased for the Gamma nail group (44 % versus 31 %, p=0.049). Readmissions for the total group were not different (16 % versus 17 %, p=0.720). Conclusions: Implementing a clinical pathway for hip fractures is a safe way to reduce the HLOS and it improves the quality of care