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To properly assess the risk induced by vestibular and sensorimotor adaptation during exploration missions, we examined how long-duration stays on the International Space Station affect functional performance after gravity transitions. Mission-critical tasks that challenge the balance and the locomotion control systems were assessed: i.e., sit-to-stand, recovery-from-fall, tandem-walk, and walk-and-turn. We assessed 19 astronauts, including 7 first-time flyers and 12 experienced flyers, before their flight, a few hours after landing, and then 1 day and 6–11 days later. Results show that adaptation to long-term weightlessness causes deficits in functional performance immediately after landing that can last for up to 1 week. No differences were observed between first-time and experienced astronaut groups. These data suggest that additional sensorimotor-based countermeasures may be necessary to maintain functional performance at preflight levels when landing on planetary surfaces after a long period in weightlessness.

Background Opioid use has increased to epidemic levels over the past decade within the United States, particularly among vulnerable populations. This retrospective study aimed to evaluate rates of prolonged opioid use in the Veteran population after thoracic surgery and identify specific risk clusters. Methods Veterans Administration data on patients who underwent thoracic surgery between January 1, 2006 and September 30, 2015 included preoperative opioid use information for stratification of patients to preoperative chronic opioid use (PCOU; nPCOU = 16,612) versus patients without preoperative chronic opioid use (WPCOU; nWPCOU = 2,328). A Poisson regression model and prior literature were used to identify variables for use in a Latent Class Analysis (LCA) model for each stratum. Three-cluster models were selected, and identified as 'low-', 'intermediate-' and 'high-' risk groups. Results Cluster interpretations included: (a) Low risk: no psychiatric diagnoses, preoperative medication use, or preoperative chronic pain, (b) Intermediate risk: no psychiatric diagnoses, but had preoperative medication use and some preoperative chronic pain and (c) High risk: psychiatric diagnoses, preoperative medication use and preoperative chronic pain. For the PCOU stratum, rates of prolonged opioid use 1 year after surgery were as follows: 46.3%, 61.9% and 66.0%. For the WPCOU stratum, the observed rates were 4.7%, 8.3% and 9.2%. Conclusions Prolonged opioid use trajectories obviously differ by PCOU status, as well as preoperative psychosocial diagnoses, medication use and chronic pain. This is a first step in population-level research to curb the rate of prolonged opioid use in Veterans following thoracic surgery. Significance This article presents population-level chronic opioid use trajectories after thoracic surgery, using latent class structures. Demographics, preoperative psychological diagnoses, medication usage and chronic pain variables were utilized to identify population-level clusters. The cluster identified as highest risk had preoperative chronic opioid use, psychological diagnoses, other medication prescriptions and chronic pain.

Background: A better understanding of how vestibular asymmetry manifests across tests is important due to its potential implications for balance dysfunction, motion sickness susceptibility, and adaptation to new environments. Objective: We report the results of multiple tests for vestibular asymmetry in 32 healthy participants. Methods: Asymmetry was measured using perceptual reports during unilateral centrifugation, oculomotor responses during visual alignment tasks, vestibulo-ocular reflex gain during head impulse tests, and body rotation during stepping tests. Results: A significant correlation was observed between asymmetries of subjective visual vertical and verbal report during unilateral centrifugation. Another significant correlation was observed between the asymmetries of ocular alignment, vestibulo-ocular reflex gain, and body rotation. Conclusions: These data suggest that there are underlying vestibular asymmetries in healthy individuals that are consistent across various vestibular challenges. In addition, these findings have value in guiding test selection during experimental design for assessing vestibular asymmetry in healthy adults.

Background The goal of surgical education is to prepare the trainee for independent practice; however, the relevance of the current residency experience to practice remains uncertain. The purpose of this study was to identify the surgical procedures most frequently performed in orthopaedic residency and in early surgical practice and to identify surgical procedures performed more often or less often in orthopaedic residency compared with early surgical practice. Methods This retrospective cohort study included American Medical Association (AMA) Current Procedural Terminology (CPT) codes (n = 4,329,561 procedures) reported by all U.S. orthopaedic surgery residents completing residency between 2010 and 2012 (n = 1,978) and AMA CPT codes for all procedures (n = 413,370) reported by U.S. orthopaedic surgeons who took the American Board of Orthopaedic Surgery Part II certifying examination between 2013 and 2015 (n = 2,205). Relative rates were determined for AMA CPT codes and AMA CPT code categories for adult and pediatric surgeries that had frequencies of ≥0.1% for both practitioners and residents. Results The top 25 adult AMA CPT code categories contributed 82.1% of the total case volume for residents and 82.4% for practitioners. Knee and shoulder arthroscopy were the most frequently performed procedures in adults in both residency and early practice. Humerus/elbow fracture and/or dislocation procedures and "other musculoskeletal-introduction or removal" procedures were the most frequently performed procedures in pediatric cases in both residency and early practice. Of the total 78 adult and 82 pediatric code categories included in our analysis that had a frequency of >1% in residency or early practice, there were 4 adult and 6 pediatric code categories demonstrating 44% to 1,164% greater frequency in residency than in early practice, and there were 8 adult and 7 pediatric code categories demonstrating 26% to 73% less frequency in residency than in early practice. Conclusions Similarity between residency and early practice experience is generally strong. However, we identified several AMA CPT code categories and individual CPT codes for which the level of exposure during residency varied substantially from early practice experience. These findings can help residencies ensure adequate trainee exposure to procedures performed commonly in early practice.

In on-road driving behavior studies, vehicle acceleration is sampled at high frequencies and then reduced to meaningful metrics over short driving segments. We examined road test data from 65 subjects driving over a common route, as well as driving in naturalistic situations using their own vehicle. We isolated 24-second segments, then reduced the accelerometer data via two methods: 1) standard deviation (SD) within a segment, and 2) re-centering parameter from a time series model previously developed for driving simulator data. We analyzed the data via random effects models to ascertain the intraclass correlations (ICC’s) of the metrics. With and without adjusting for speed, the ICC of SD within a segment tended to be much greater than the ICC of the re-centering parameter for the segment (range: 0–30% vs. 0–1%). Also, ICC’s from the naturalistic driving data tended to be greater than the fixed-route data (range: 0–27% vs. 0–9%), which could reflect individuals exhibiting their more usual driving behavior in naturalistic environments. Findings illustrate the challenges of identifying meaningful driving metrics and comparing these across different epochs, road segments and research platforms.

Objective: In an era of controlling cost and improving care, 30-day readmission rates have become an important quality measure. The purpose of this study was to identify the rates of 30-day unplanned readmission and the associated risk factors in patients undergoing outpatient hand surgery. Methods: The 2011-2014 National Surgical Quality Improvement Project data were queried for patients who met 368 hand-specific Current Procedural Terminology codes. Univariable and multivariable analyses were performed to identify patient- and surgery-specific risk factors associated with unplanned readmission within 30 days. Results: Of the 368 Current Procedural Terminology codes queried, 208 were represented in the data, for a total of 23,613 patients. The overall unplanned readmission rate was 0.88% (207/23,613). On both univariable and multivariable analyses, operative year (2012), increasing age, obesity, smoking status, chronic obstructive pulmonary disease, preoperative steroid use, preoperative anemia, increasing American Society of Anesthesiologists classification, increasing operative time, and a procedure performed by a surgeon other than a plastic or orthopedic surgeon were associated with increased readmission rates. Diabetes, hypertension, low albumin levels, elevated international normalized ratio, and dirty/infected wound classification were only significant in univariable analysis. Current Procedural Terminology codes associated with the highest readmission rates were related to amputations. The most common readmission diagnoses were wound complications, followed by uncontrolled postoperative pain. Conclusions: The incidence of unplanned readmission is low in patients undergoing outpatient hand surgery. Specific patient comorbidities are associated with increased unplanned readmission rates. This information may be useful in identifying patients at higher risk for unplanned readmission and in counseling of high-risk patients preparing for surgery.

The incidence of chronic pain following thoracic surgery (∼50%) is greater than most other surgeries. The goal of this retrospective study was to detect the incidence of prolonged opioid use at 1 year after surgery among those veterans who were chronic opioid users versus not chronic users during the one year prior to their thoracic surgery, separately. In addition, predictors of prolonged opioid use at 1 year after surgery from demographic, surgical, and comorbid medical and psychiatric factors were assessed for each of the two groups separately. Veterans Health Administration sample of 19,240 patients who had thoracotomy or video assisted thoracoscopy between 2006 and 2015 and were alive at one year after surgery were included. “Chronic opioid use” was defined as consistent opioid prescription for more than 90 days during the year (1). Veterans’ opioid use during the 1-year prior to surgery was used to determine whether they were “preoperative chronic opioid users” at the time of surgery. Similarly, the opioid use information during the first year after the surgery was used to determine whether they become “prolonged opioid users” during the 1-year following surgery. Out of 2,370 preoperative opioid users at the time of surgery, 61% (95% CI: 59% to 63%) continued prolonged opioid use at 1 year after their thoracic surgery. Only younger age and the presence of pre-existing chronic pain were associated with the prolonged opioid use at 1 year after surgery. Out of 16,870 patients who were not preoperative chronic opioid users during the year prior to their surgery, 6.8% (95% CI: 6.4% to 7.2%) became prolonged opioid users. At the 0.01 type I error level, the presence of pre-existing chronic pain, longer duration of hospital stay, antidepressant use and benzodiazepine use were associated with prolonged opioid use at one year after thoracic surgery.