Implications of resampling data to address the class imbalance problem (IRCIP): an evaluation of impact on performance between classification algorithms in medical data

Objective When correcting for the "class imbalance" problem in medical data, the effects of resampling applied on classifier algorithms remain unclear. We examined the effect on performance over several combinations of classifiers and resampling ratios. Materials and Methods Multiple classification algorithms were trained on 7 resampled datasets: no correction, random undersampling, 4 ratios of Synthetic Minority Oversampling Technique (SMOTE), and random oversampling with the Adaptive Synthetic algorithm (ADASYN). Performance was evaluated in Area Under the Curve (AUC), precision, recall, Brier score, and calibration metrics. A case study on prediction modeling for 30-day unplanned readmissions in previously admitted Urology patients was presented. Results For most algorithms, using resampled data showed a significant increase in AUC and precision, ranging from 0.74 (CI: 0.69-0.79) to 0.93 (CI: 0.92-0.94), and 0.35 (CI: 0.12-0.58) to 0.86 (CI: 0.81-0.92) respectively. All classification algorithms showed significant increases in recall, and significant decreases in Brier score with distorted calibration overestimating positives. Discussion Imbalance correction resulted in an overall improved performance, yet poorly calibrated models. There can still be clinical utility due to a strong discriminating performance, specifically when predicting only low and high risk cases is clinically more relevant. Conclusion Resampling data resulted in increased performances in classification algorithms, yet produced an overestimation of positive predictions. Based on the findings from our case study, a thoughtful predefinition of the clinical prediction task may guide the use of resampling techniques in future studies aiming to improve clinical decision support tools.Orthopaedics, Trauma Surgery and Rehabilitatio

Clockwise torque results in higher reoperation rates in left-sided femur fractures

Purpose: Effects of clockwise torque rotation onto proximal femoral fracture fixation have been subject of ongoing debate: fixated right-sided trochanteric fractures seem more rotationally stable than left-sided fractures in the biomechanical setting, but this theoretical advantage has not been demonstrated in the clinical setting to date. The purpose of this study was to identify a difference in early reoperation rate between patients undergoing surgery for left-versus right-sided proximal femur fractures using cephalomedullary nailing (CMN). Materials and methods: The American College of Surgeons National Surgical Quality Improvement Program was queried from 2016-2019 to identify patients aged 50 years and older undergoing CMN for a proximal femoral fracture. The primary outcome was any unplanned reoperation within 30 days following surgery. The difference was calculated using a Chi-square test, and observed power calculated using post-hoc power analysis. Results: In total, of 20,122 patients undergoing CMN for proximal femoral fracture management, 1.8% (n=371) had to undergo an unplanned reoperation within 30 days after surgery. Overall, 208 (2.0%) were left-sided and 163 (1.7%) right-sided fractures (p=0.052, risk ratio [RR] 1.22, 95% confidence interval [CI] 1.00-1.50), odds ratio [OR] 1.23 (95%CI 1.00-1.51), power 49.2% (& alpha;=0.05). Conclusion: This study shows a higher risk of reoperation for left-sided compared to right-sided proximal femur fractures after CMN in a large sample size. Although results may be underpowered and statistically insignificant, this finding might substantiate the hypothesis that clockwise rotation during implant insertion and (post-operative) weightbearing may lead to higher reoperation rates. Level of evidence: Therapeutic level II.Orthopaedics, Trauma Surgery and Rehabilitatio

Surgical Compared with Conservative Treatment for Acute Nondisplaced or Minimally Displaced Scaphoid Fractures A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: There is a current trend in orthopaedic practice to treat nondisplaced or minimally displaced fractures with early open reduction and internal fixation instead of cast immobilization. This trend is not evidence-based. In this systematic review and meta-analysis, we pool data from trials comparing surgical and conservative treatment for acute nondisplaced and minimally displaced scaphoid fractures, thus aiming to summarize the best available evidence. Methods: A systematic literature search of the medical literature from 1966 to 2009 was performed. We selected eight randomized controlled trials comparing surgical with conservative treatment for acute nondisplaced or minimally displaced scaphoid fractures in adults. Data from included studies were pooled with use of fixed-effects and random-effects models with standard mean differences and risk ratios for continuous and dichotomous variables, respectively. Heterogeneity across studies was assessed with calculation of the 12 statistic. Results: Four hundred and nineteen patients from eight trials were included. Two hundred and seven patients were treated surgically, and 212 were treated conservatively. Most trials lacked scientific rigor. Our primary outcome parameter, standardized functional outcome, which was assessed for 247 patients enrolled in four trials, significantly favored surgical treatment (p < 0.01). With regard to our secondary parameters, we found heterogeneous results that favored surgical treatment in terms of satisfaction (assessed in one study), grip strength (six studies), time to union (three studies), and time off work (five studies). In contrast, we found no significant differences between surgical and conservative treatment with regard to pain (two studies), range of motion (six studies), the rates of nonunion (six studies) and malunion (seven studies), and total treatment costs (two studies). The rate of complications was higher in the surgical treatment group (23.7%) than in the conservative group (9.1%), although this difference was not significant (p = 0.13). There was a nearly significantly higher rate of scaphotrapezial osteoarthritis in the surgical treatment group (p = 0.05). Conclusions: Based on primary studies with limited methodological quality, this study suggests that surgical treatment is favorable for acute nondisplaced and minimally displaced scaphoid fractures with regard to functional outcome and time off work; however, surgical treatment engenders more complications. Thus, the long-term risks and short-term benefits of surgery should be carefully weighed in clinical decision-makin

Biomechanical studies: Science (f)or common sense?

Optimising joint reconstruction management in arthritis and bone tumour patient

Long-Term Outcomes of Fractures of Both Bones of the Forearm

Background: Previous studies identified limited impairment and disability several years after diaphyseal fractures of both the radius and ulna, although the relationship between impairment and disability was inconsistent. This investigation studied skeletally mature and immature patients more than ten years after injury and addressed the hypotheses that (1) objective measurements of impairment correlate with disability, (2) depression and misinterpretation of nociception correlate with disability, and (3) patients injured when skeletally mature or immature have comparable impairment and disability. Methods: Seventy-one patients with diaphyseal fractures of the radius and ulna were evaluated at an average of twenty-one years after injury. Twenty-five of the thirty-five patients who were skeletally immature at the time of injury were treated nonoperatively, and thirty-one of the thirty-six skeletally mature patients were treated operatively. Objective evaluation included radiographs, functional assessment, and grip strength. Validated questionnaires were used to measure arm-specific disability (the Disabilities of the Arm, Shoulder and Hand [DASH] score), misinterpretation of pain (Pain Catastrophizing Scale [PCS]), and depression (the validated Dutch form of the Center for Epidemiologic Studies-Depression scale [CES-D]). Results: The average DASH score was 8 points (range, 0 to 54); 97% of patients had excellent or satisfactory results according to the criteria of Anderson et al., and 72% reported no pain. Both the forearm rotation and the writ flexion/extension arc was 91% of that seen on the uninjured side; grip strength was 94%. There were small but significant differences in rotation (151 versus 169, p = 0.004) and wrist flexion-extension (123 degrees versus 142 degrees, p = 0.002) compared with the results in the uninjured arm. There was no difference in disability between patients who were skeletally mature or immature at the time of injury. Pain, pain catastrophizing (misinterpretation of nociception), and grip strength were the most important predictors of disability. Conclusions: An average of twenty-one years after sustaining diaphyseal fractures of both the radius and the ulna, patients who were skeletally immature or mature at the time of fracture have comparable disability. Disability correlates better with subjective and psychosocial aspects of illness, such as pain and pain catastrophizing, than with objective measurements of impairmen

The Use of Eponyms for Surgical Approaches and Fractures in Elbow Surgery: Accuracy and Reliability Pre- and Post-Training

Trauma Surger