Can Machine Learning Methods Produce Accurate and Easy-to-Use Preoperative Prediction Models of One-Year Improvements in Pain and Functioning After Knee Arthroplasty?

BackgroundApproximately 15%-20% of total knee arthroplasty (TKA) patients do not experience clinically meaningful improvements. We sought to compare the accuracy and parsimony of several machine learning strategies for developing predictive models of failing to experience minimal clinically important differences in patient-reported outcome measures (PROMs) 1 year after TKA.MethodsPatients (N = 587) in 3 large Veteran Health Administration facilities completed PROMs before and 1 year after TKA (92% follow-up). Preoperative PROMs and electronic health record data were used to develop and validate models to predict failing to experience at least a minimal clinically important difference in Knee Injury and Osteoarthritis Outcome Score (KOOS) Total, KOOS JR, and KOOS subscales (Pain, Symptoms, Activities of Daily Living, Quality of Life, and recreation). Several machine learning strategies were used for model development. Ten-fold cross-validation and bootstrapping were used to produce measures of overall accuracy (C-statistic, Brier Score). The sensitivity and specificity of various predicted probability cut-points were examined.ResultsThe most accurate models produced were for the Activities of Daily Living, Pain, Symptoms, and Quality of Life subscales of the KOOS (C-statistics 0.76, 0.72, 0.72, and 0.71, respectively). Strategies varied substantially in terms of the numbers of inputs required to achieve similar accuracy, with none being superior for all outcomes.ConclusionModels produced in this project provide estimates of patient-specific improvements in major outcomes 1 year after TKA. Integrating these models into clinical decision support, informed consent and shared decision making could improve patient selection, education, and satisfaction.Level of EvidenceLevel III, diagnostic study.     

Timing of parathyroidectomy for tertiary hyperparathyroidism with end-stage renal disease: A cost-effectiveness analysis

BackgroundTertiary hyperparathyroidism associated with end-stage renal disease is characterized by progression from secondary hyperparathyroidism to an autonomous overproduction of parathyroid hormone that leads to adverse health outcomes. Rates of parathyroidectomy (PTX) have decreased with the use of calcimimetics. Optimal timing of PTX in relation to kidney transplant remains controversial. We aimed to identify the most cost-effective strategy for patients with tertiary hyperparathyroidism undergoing kidney transplant.MethodsWe constructed a patient level state transition microsimulation to compare 3 management schemes: cinacalcet with kidney transplant, cinacalcet with PTX before kidney transplant, or cinacalcet with PTX after kidney transplant. Our base case was a 55-year-old on dialysis with tertiary hyperparathyroidism awaiting kidney transplant. Outcomes, including quality-adjusted life years, surgical complications, and mortality, were extracted from the literature, and costs were estimated using Medicare reimbursement data.ResultsOur base case analysis demonstrated that cinacalcet with PTX before kidney transplant was dominant, with a lesser cost of $399,287 and greater quality-adjusted life years of 10.3 vs $497,813 for cinacalcet with PTX after kidney transplant (quality-adjusted life years 9.4) and $643,929 for cinacalcet with kidney transplant (quality-adjusted life years 7.4).ConclusionCinacalcet alone with kidney transplant is the least cost-effective strategy. Patients with end-stage renal disease-related tertiary hyperparathyroidism should be referred for PTX, and it is most cost-effective if performed prior to kidney transplant.     

Optimizing the fellowship interview process: Perspectives from applicants and program directors of the comprehensive endocrine surgery fellowship program

BackgroundApproximately 80% of general surgery residents undertake some form of fellowship training. Our objective was to characterize goals and burdens of the interview process among applicants to Comprehensive Endocrine Surgery Fellowship programs.MethodsParticipants included trainees from 2013 to 2019. Results for ranking questions are presented as a mean rank reported out of the total number of selections.ResultsResponse rate was 54% (n = 75). The most important goal for interviews was meeting the faculty (mean rank 2.4/9), followed by “behind the scenes information” and “make a good impression” (mean rank 3.6 and 3.7, respectively). The most substantial burden for the applicant was expense (mean rank 2.1/7), followed by time away from residency (mean rank 3.1/7). The economic burden of 51% of the applicants was $2,500 to $7,500. Geographic location and expense were the top 2 reasons applicants declined offers of interviews. Despite the process, 76% of respondents indicated that no improvements to the interview process are necessary. Alternative strategies such as videoconferencing or centralized interviews received little support (<10%).ConclusionDespite identifying several burdens, survey respondents believed that in-person interviews are an integral component of the fellowship application process. Indeed, 70% of applicants do not have a first-choice program before interviews, and meeting the faculty is ranked as the greatest priority goal. Our data illustrate the importance of individual specialties evaluating and optimizing their own processes for fellowship interviews.     

Effects of neonatal cortical lesions upon retinocollicular projections in the hamster

Autoradiography and anterograde horseradish peroxidase transport were used to examine retinocollicular projections in normal hamsters and in animals subjected to ablation of the ipsilateral, posterior neocortex at 1, 3, 6, 10 or 120 days of age. The crossed retinotectal projections of all groups were quite similar. There did, however, appear to be a slight increase in the density of the projection to the lower portion of the stratum griseum superficiale in the neonatally brain-damaged hamsters.The uncrossed pathway, on the other hand, was quite abnormal in the neonatally lesioned animals. In normals, the ipsilateral retinocollicular projection consisted almost entirely of a series of patches along the stratum yriseum superficiale-stratum opticum border in the rostral one-third of the colliculus. Only a few axons from the ipsilateral eye were observed in the caudal two-thirds of the tectum and these could only be visualized when horseradish peroxidase was used as the tracer. In all of the neonatally brain-damaged hamsters both autoradiography and horseradish peroxidase tracing demonstrated that the ipsilateral retina densely innervated the entire rostrocaudal extent of the colliculus.Retrograde tracing experiments demonstrated that the portion of the temporal retina which gave rise to the uncrossed retinocollicular projection in the normal hamsters was also the source of the expanded projection in the neonatally brain-damaged animals; and, further, that the numbers and areal distributions of ipsilaterally projecting retinal and retinocollicular ganglion cells were similar in the two groups.These findings suggest that, at least in the hamster, normal inputs from the two eyes may not be a sufficient condition for the development of the largely complementary pattern of collicular innervation by the two retinae.     

A new cardiothoracic centre: 'how to do it?'

All cardiac surgical patients, emergency and routine, from the South West peninsula of England had to travel long distances until 19 months ago, a stressful if not dangerous situation. This paper describes the planning, commissioning and start-up of a brand new cardiac surgical facility. The lessons learnt may help similar projects as provision of specialist health care decentralizes.     

Efficacy of a pure compound H1-A extracted from Cordyceps sinensis on autoimmune disease of MRL lpr/lpr mice

Cordyceps sinensis (CS) is a traditional Chinese medicine with immunomodulatory effect and is effective in improving the survival of lupus mice. In the present study we isolated a pure compound (H1-A) from CS and investigated its effect on inhibiting autoimmune disease progression in MRL Ipr/Ipr mice. Our results demonstrated that MRL Ipr/Ipr mice treated daily with H1-A (40 microg/kg/d orally) for 8 weeks had a progressive reduction in anti-ds-DNA production (optical density value decreased from 0.172 +/- 0.009 to 0.112 +/- 0.015) when compared with the control group (optical density value increased from 0.141 +/- 0.036 to 0.198 +/- 0.047). In clinical presentation, the treated group had a reduction in lymphadenopathy, a delayed progression of proteinuria, and an improvement in kidney function. Histologic analysis of kidney tissue indicated that H 1-A could inhibit the mesangial proliferation that was evident in lupus nephritis. However, there was no significant change in immune complex deposition. The studies reveal that the pure compound (H1-A) may be potentially useful for treating systemic lupus erythematosus in human patients, and they provide some questions for further investigation of the pathogenesis of systemic lupus erythematosus and lupus nephritis.     

三氟氯氰菊酯在不同载体上杀灭3种卫生害虫持续效果观察

目的:观察三氟氯氰菊酯微胶囊悬浮剂在不同载体表面杀虫活性持续时间。方法:在4种载体表面,按不同剂量(mgai/m~2)喷涂一定药液,采用强迫接触法观察其持续效果。结果:1.在玻璃板面按20mgai/m~2给药,对家蝇持续效果为90天;淡色库蚊及德国小蠊为100天。2.在油漆板面剂量同上对家蝇、淡色库蚊及德国小蠊的持续效果均有90天。3.在水泥板面按25mgai/m~2,对家蝇和淡色库蚊的持续效果为90天,对德国小蠊为80天。4.在石灰墙面按25mgai/m~2,对家蝇持续效果为50天,淡色库蚊和德国小蠊均为60天。