bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and sample size considerations for Alzheimer’s disease prevention trials using multistate models
Authors: Brookmeyer Ron , Abdalla Nada 
Published: March 2019

Background/Aims Clinical trials for Alzheimer’s disease have been aimed primarily at persons who have cognitive symptoms at enrollment. However, researchers are now recognizing that the pathophysiological process of Alzheimer’s disease begins years, if not decades, prior to the onset of clinical symptoms. Successful intervention may require intervening early in the disease process. Critical issues arise in designing clinical trials for primary and secondary prevention of Alzheimer’s disease including determination of sample sizes and follow-up duration. We address a number of these issues through application of a unifying multistate model for the preclinical course of Alzheimer’s disease. A multistate model allows us to specify at which points during the long disease process the intervention exerts its effects. Methods We used a nonhomogeneous Markov multistate model for the progression of Alzheimer’s disease through preclinical disease states defined by biomarkers, mild cognitive impairment and Alzheimer’s disease dementia. We used transition probabilities based on several published cohort studies. Sample size methods were developed that account for factors including the initial preclinical disease state of trial participants, the primary endpoint, age-dependent transition and mortality rates and specifications of which transition rates are the targets of the intervention. Results We find that Alzheimer’s disease prevention trials with a clinical primary endpoint of mild cognitive impairment or Alzheimer’s disease dementia will require sample sizes of the order many thousands of individuals with at least 5 years of follow-up, which is larger than most Alzheimer’s disease therapeutic trials conducted to date. The reasons for the large trial sizes include the long and variable preclinical period that spans decades, high rates of attrition among elderly populations due to mortality and losses to follow-up and potential selection effects, whereby healthier subjects enroll in prevention trials. A web application is available to perform sample size calculations using the methods reported here. Conclusion Sample sizes based on multistate models can account for the points in the disease process when interventions exert their effects and may lead to more accurate sample size determinations. We will need innovative strategies to help design Alzheimer’s disease prevention trials with feasible sample size requirements and durations of follow-up.
A cross-sectional study to describe and explore factors associated with measles immunisation and recording among cases linked to an outbreak, South West England, 2016
Authors: McLaughlin Joanna C , Verlander Neville Q , Yates Julie , Beck Charles R 
Published: March 2019

Following an outbreak of measles across South West England in 2016, the multi-agency outbreak control team suggested that immunisation history records collected for the health protection response may not be reliable. We undertook a cross-sectional study to compare measles immunisation records collected from outbreak cases on the case management system HPZone by the Health Protection Team with the full primary care record. A total of 122 cases were reported. We identified 86.9% cases were not fully immunised and 5.7% had an unknown immunisation status. There were 14 cases whose primary care records did not match HPZone and 18 cases where primary care records were available and immunisation status was not documented in HPZone. Complex, non-linear associations were found between age and socioeconomic deprivation status of each case and having an incorrect HPZone record. Cases who resided in postcode areas of greater socioeconomic deprivation had statistically significantly higher odds of having been fully immunised. Only 13.3% of partially or unimmunised cases received an MMR immunisation following their onset of measles infection. Collecting immunisation status from the full primary care record during acute management of measles cases may support improvements in control and prevention of further cases.
Hand hygiene expectations in radiography: A critical evaluation of the opportunities for and barriers to compliance
Authors: Jeanes Annette , Henderson Fiona , Drey Nick , Gould Dinah 
Published: March 2019

Introduction: Good hand hygiene practices reduce the risk of transmission of infection in healthcare. In common with other areas of healthcare, infection control knowledge and practice in radiography has potential for improvement. Regular hand hygiene compliance (HHC) monitoring indicated poor compliance in radiology which did not accurately reflect practice in one organisation. Using a quality improvement cycle, the process and context of work undertaken in radiology were examined in order to improve the validity and utility of HHC monitoring data collection process in the department. Methods: Following examination of the evidence base and with agreement from the radiology team, the chest X-ray process was observed and actions notated. This was then scored using the organisation and the World Health Organization five moments of hand hygiene tool. An alternative risk-based scoring system was developed. Results: The HHC score of 22% was obtained using standard measurements. Achievement of 100% compliance would require the radiographer to clean their hands nine times for each X-ray. The sequence of taking a chest X-ray was examined and two points in the process were identified as key points at which hand cleaning should take place to reduce the risk of transmission of infection. Conclusions: Cleaning hands frequently to achieve compliance expectations in this short low-risk process is neither feasible nor beneficial. A pragmatic risk-based approach to hand hygiene expectations in predictable procedures such as taking a chest X-ray reduces ambiguity and potentially increases compliance.
Bilirubin encephalopathy (kernicterus) in an adult cat
Authors: Saraiva Luís HG , Andrade Maria C , Moreira Matheus VL , Oliveira Letícia B , Santos Ágna F , Ferreira Raquel S , Santos Willian HM , Ecco Roselene 
Published: March 2019

Case summary An adult cat presented with neurological signs and marked icterus. Clinical pathology tests detected increased serum alkaline phosphatase levels, as well as alanine aminotransferase, total bilirubin, unconjugated bilirubin and conjugated bilirubin above the normal reference intervals. Ultrasonography showed hepatomegaly and a dilated gall bladder. Following these results, the cat was referred for a cholecystectomy owing to a clinical suspicion of obstructive cholecystitis. The animal died in the postoperative period and was referred for necropsy. Grossly, the animal had marked icterus. On the cortical surface and in the brain parenchyma there were marked yellowish areas. The liver was diffusely reddish-orange, enlarged and the capsular surface was slightly irregular. The gall bladder was absent. At its anatomical site and surrounding the common hepatic duct, a whitish nodular neoplasia of 2.0 cm was found. Microscopically, a cholangioma was diagnosed in the region of the common hepatic duct. In the white matter of the cerebellar vermis, there was axonal degeneration associated with gliosis. In the Purkinje neuron layer there was slight multifocal necrosis. Some neurons contained amorphous and brownish pigment (bilirubin) in the cytoplasm. Clinical and pathological findings indicated hepatic and post-hepatic icterus from obstructive cholangioma, resulting in kernicterus. Relevance and novel information Kernicterus is a neurological disorder that is rarely diagnosed in animals, especially in adults. This report provides evidence that kernicterus can occur in adult cats, secondary to increased unconjugated and conjugated bilirubin concentrations.
An increase in the risk of excessive femoral anteversion for relatively younger age and types of femoral morphology in total hip arthroplasty with direct anterior approach
Authors: Watanabe Kenya , Mitsui Katsuhiro , Usuda Yu , Nemoto Kazuaki 
Published: March 2019

Background: Direct anterior approach (DAA) is known to diminish a dislocation risk and widely used for total hip arthroplasty (THA). On the other hand, anterior dislocation due to increasing stem anteversion and cup anteversion is an important complication. Methods: A retrospective analysis of 140 (male/female: 10/130) consecutive patients with 149 hips who had undergone primary THA in the period between 2011 and 2015 was conducted. Factors including age, gender, body mass index (BMI), and primary diagnosis were examined. Radiographic parameters including the Dorr proximal femoral types, cortical thickness index (CTI), canal flare index (CFI), and canal to calcar index were measured. To investigate relationships of combined anteversion (CA) with other factors, a stepwise regression analysis was performed. Results: The mean age, BMI, and the follow-up period were 69.5 ± 10.3 years old, 23.4 ± 3.4 kg/m2, and 48.2 ± 13.6 months, respectively. The proximal femurs of the 149 hips were categorized as Dorr type A ( n = 33), type B ( n = 110), and type C ( n = 6). The mean CTI, CFI, and canal to calcar index were 0.56 ± 0.08, 4.15 ± 0.83, and 0.46 ± 0.09, respectively. The mean stem varus angle, radiographic inclination, and radiographic anteversion of the cup were 0.19 ± 1.63, 40.9 ± 6.0°, and 12.7 ± 3.5°, respectively. Stem anteversion measured by computed tomography (CT) axial image was 17.7 ± 12.0°. The mean radiographic inclination, radiographic anteversion (CTRA), and anatomical anteversion analyzed by Kyocera 3-D template were 40.8 ± 7.2°, 19.8 ± 6.6°, and 28.8 ± 10.0°, respectively. Mean CA defined as the sum of stem anteversion and CTRA was 37.5 ± 14.5°. To investigate relationships of CA with other factors, a stepwise regression analysis was performed and resulted in a model with age ( p < 0.001). In the same way, stem anteversion and CTRA were analyzed; only for the stem anteversion, the stepwise selection process resulted in a model with age ( p < 0.001) and the Dorr types ( p = 0.047). Conclusion: The risk of excessive femoral anteversion increases for relatively younger age and for types of femoral morphology according to the Dorr classification, moreover with an increase of CA in DAA-THA with cementless tapered-wedge stem.
The relationship between the clinical results and the remnant type following anterior cruciate ligament reconstruction using a hamstring tendon
Authors: Yanagisawa Shinya , Kimura Masashi , Hagiwara Keiichi , Ogoshi Atsuko , Nakagawa Tomoyuki , Shiozawa Hiroyuki , Ohsawa Takashi , Chikuda Hirotaka 
Published: March 2019

Purpose: The aim of the present study was to investigate the correlations among the preoperative and postoperative knee laxity, the clinical results, and the type of remnant tissue following the anterior cruciate ligament (ACL) reconstruction. Methods: One hundred ninety-two patients (male, n = 101; female, n = 91; mean age, 27.1 years) with ACL-deficient knees who had undergone double-bundle reconstruction were included. The time between injury and surgery (TBIS) was 34.7 weeks (range, 1–504 weeks). The subjects were divided into four groups according to the Crain’s classifications and factors such as the age at surgery, gender, TBIS, side-to-side difference (SSD), Tegner activity score (TAS), and Lysholm score were compared. Results: The percentage of patients with ACL remnant pattern types 1, 2, 3, 4 was 19% (37 knees), 52% (101 knees), 9% (19 knees), and 18% (35 knees), respectively. The TBIS of the patients with Crain type 4 was significantly longer in comparison to the other groups ( p < 0.01). A significant difference was observed in the preoperative SSD of the Crain type 3 and Crain type 4 (6.2 ± 3.4 mm, 9.3 ± 3.6, respectively) groups. The TBIS in patients with Crain type 4 was significantly longer in comparison to the other groups ( p < 0.01). There were no significant differences between the groups in terms of the postoperative SSD, TAS, or Lysholm score. Conclusion: This study suggests that a Crain type 3 remnant was associated with a significantly lower preoperative SSD. In addition, the TBIS in patients with Crain type 4 was found to be significantly longer in comparison to the other groups. Level of Evidence: Level III, case–control study.
YOUTH MARATHON TRAINING: INJURY EPIDEMIOLOGY & RISK FACTORS
Authors: Goldman Joshua , Beck Jennifer 
Published: March 2019

Background Youth participation in long distance running has increased yet little data exist about the injury patterns and safety of such activity. There are inherent training challenges in youth athletes that theoretically increase their risk of injury relative to their adult counterparts. These include their ongoing neuromuscular development and evolving gait, vulnerable growth open plates, increasing limb length that outpaces muscle growth, and reduced heat tolerance. Students Run LA (SRLA), now in its 30th year of operation, is a non-profit organization that mentors youth during an eight-month marathon training program. While there are many program benefits, little is known about the safety of distance running in adolescent athletes. This study sought to determine the types and rates of injuries in a subset of SRLA participants. Methods & Study Design From August 2017 - March 2018, weekly injury reports were digitally collected by volunteer coaches. Data collection included demographics, injury type, severity, acuity, time off and training mileage. Results 50 high schools and 34 middle schools participated, representing 1930/2750 (70.2%) of total SRLA participants. Mean age was 15 (SD 1.9). 1922/1930 (99.6%) completed the marathon. 411 injuries occurred in 353/1930 (18%) runners during the training program. HS runners were more likely to be injured than MS runners (20.8% vs. 14.2%, p<0.001). There was no difference in injury rates between male and female runners (46.7% vs. 53.2%, p=0.153). 72% of injuries were acute, 16% were subacute, 3% chronic, and 9% unspecified. 60.1% of injuries were associated with time off with a mean time off of 4.8 days (SD 4.8). The most frequent sites of injury were the knee (33%), leg (19%), ankle (15%), and foot (14%). Overall, runners with injuries ran significantly more miles per week than uninjured runners (14.6 vs. 12 .0, p<0.001), a pattern that was consistent at the MS (14.1 vs. 11.6, p<0.001) and HS levels (15 vs. 12.1, p<0.001). Conclusions 18% of youth marathon participants reported an injury over the course of an 8-month training program. The majority of injuries were acute. There was no significant difference in injury rates between males & females but HS runners were more likely to be injured than MS runners. 99.6% of study participants successfully completed the marathon, a higher completion rate than seen in adults. Significance This study represents one of the largest descriptions of injury prevalence in youth distance running. The results highlight an injury rate in youth runners comparable to adults during a marathon training program and a race completion rate that is higher than adults. These findings may lead to changes in the current Position Statement with regard to youth marathon participation. Acknowledgements Orthopedic Institute for Children Students Run LA
THE RELATIONSHIP BETWEEN PERCEIVED SOCIAL SUPPORT AND PSYCHOLOGICAL FACTORS RELATED TO RETURNING TO SPORT IN ADOLESCENTS FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION
Authors: Armento Aubrey , Albright Jay , Skelton Anne , Gagliardi Alexia G. , Howell David R. , Daoud Ariel Kiyomi , Mayer Stephanie W. 
Published: March 2019

Objectives: “Return-to-sport” (RTS) criteria following anterior cruciate ligament (ACL) reconstruction lacks standardization. In addition to functional strength and knee joint stability, psychological factors may also affect readiness to RTS. The present study aimed to assess the association between perceived levels of social support and confidence in RTS among adolescent athletes prior to undergoing ACL reconstruction. We hypothesized that athletes who perceived higher levels of social support would have greater confidence in their ultimate ability to return to their previous level of play after ACL reconstruction. Methods: Fifty-three subjects completed two questionnaires prior to undergoing ACL reconstruction: the Multidimensional Scale of Perceived Social Support (MSPSS) and a psycho-vitality (PV) questionnaire. We performed a multiple linear regression to assess if MSPSS score was associated with confidence in returning to sport (PV score), while controlling for the independent effects of age and gender. Independent sample t-tests were also used to compare MSPSS scores between those who did and did not state that they had doubts in their ability to RTS and those who were and were not willing to settle for a less strenuous sporting activity than previously, based on the PV questionnaire responses. Results: The mean age of participants was 15.6±1.7 years (range 9-18 years) with 42% males. There was no significant association between MSPSS total score (mean= 6.22±0375, range= 4-7) and PV total score (mean= 13.8±3.0, range= 8-18; ß coefficient= -0.63, 95% CI= -1.77, 0.52, p = 0.28). Those who reported doubts in returning to sport did not significantly differ than those who reported no doubts (n=19) in MSPSS total score (6.07±0.82 vs. 6.30±0.70; p = 0.29; Cohen’s d= 0.31). Similarly, those who did and did not respond that they were willing to settle for a less strenuous sporting activity had similar MSPSS scores (6.14±0.81 vs. 6.47±0.45; p= 0.17; Cohen’s d= 0.44). Conclusion: Previous studies suggest that psychological factors play a role in successful RTS, yet the specifics of how this pertains to adolescent athletes remain unknown. The present study suggests that prior to ACL reconstruction, perceived social support does not significantly influence confidence in the ability to ultimately RTS following surgery and subsequent rehabilitation in young athletes. Future studies will aim to correlate these variables between pre-operative and actual RTS time points, as well as to investigate how other factors, such as motivation and self-esteem, are influenced by social support and affect ultimate RTS success.
SEX DIFFERENCES IN ANTERIOR CRUCIATE LIGAMENT INJURIES AMONG US HIGH SCHOOL SOCCER PLAYERS: AN EPIDEMIOLOGIC STUDY
Authors: Gupta Andrew , Pierpoint Lauren , Comstock Dawn , Saper Michael 
Published: March 2019

BACKGROUND Anterior cruciate ligament (ACL) injuries are common among adolescent athletes, with soccer being the sport most frequently implicated in girls’ ACL injuries. The current literature on ACL injuries, while extensive, lacks a comprehensive study of ACL injuries in United States (US) high school soccer players. The objective of this study was to describe the epidemiology of ACL injuries among US high school soccer players. METHODS ACL injury and athlete exposure (AE) data for US high school soccer players were obtained from the internet-based National High School Sports-Related Injury Surveillance System, High School RIO (Reporting Information Online) dataset collected from school years 2007-2008 through 2016-2017. Injury rates were calculated as the number of ACL injuries per 100,000 AEs. Subgroup differences were evaluated with rate ratios (RRs) or injury proportion ratios (IPRs) and 95% Confidence Intervals (CIs). Subgroup differences were examined with independent t-tests. Comparisons of categorical data (i.e., mechanism of injury) were performed using Pearson’s?2 tests. RESULTS The number of ACL injuries reported to High School RIO corresponded to weighted national estimates of 41,205 (95% CI = 33,321 – 48,730) ACL injuries in boys’ soccer and 110,029 (95% CI = 95,349 – 124,709) in girls’ soccer during the study period. ACL injury rates were significantly higher in girls’ soccer (13.23 per 100,000 AEs) than boys’ soccer (4.35 per 100,000 AEs) (RR = 3.04, 95% CI = 2.35 – 3.98) and were significantly higher in competition compared to practice for both girls (RR = 14.77, 95% CI = 9.85 – 22.15) and boys (RR = 8.69, 95% CI = 5.01 – 15.08). A greater proportion of ACL injuries were due to player-player contact in boys (48.6%) compared to girls (30.1%) (IPR = 1.62, 95% CI = 1.08 – 2.42). There was no statistical difference in the proportion of ACL injuries managed surgically in boys and girls (84% vs. 78%, respectively). CONCLUSIONS There are sex-based differences in mechanism of injury and ACL injury rate in high school soccer players. In addition, boys and girls showed higher rates of injury during competition. This study suggests several areas for targeted evidence-based ACL injury prevention strategies in US high school soccer players.
FEMOROACETABULAR IMPINGEMENT INSURANCE COVERAGE TRENDS IN RECENT YEARS: A COHORT BASED ANALYSIS
Authors: Nepple Jeffrey J. , Minaie Arya , Ross James , Bogunovic Ljiljana , Clohisy John 
Published: March 2019

Background: The diagnostic criteria for surgical indication of femoroacetabular impingement (FAI) remain controversial. With a growing body of literature investigating the quality of these criteria, little is known about the direction that these have had on changes of third-party policies. The purpose of this study was to measure how these changes in policy would affect the exclusion of a cohort of previously identified FAI patients who were treated operatively. Methods: Four insurance companies’ coverage policies with specific criteria for the surgical treatment of FAI were applied to this population at two time points, 2012 and 2018, to determine whether these third-party payer criteria for FAI surgery were met. The insurance criteria were assessed in a prospective multicenter cohort of 712 patients undergoing primary FAI surgery. The policies listed various combinations of age, symptom duration, positive impingement test, radiographic osteoarthritis, radiographic sign of CAM and/or pincer impingement, and physical exam findings. Results: The cohort of 712 hips included 324 men [45.5%] and 388 females [54.5] with a mean age of 28.7 years. Overall, insurance criteria were not met in: Insurance #1 old 30.1%, new 25.7%; Insurance #2 old and new 17.8%, Insurance #3 old 21.9%, new 21.1%; and Insurance #4 old 17.8%, new 14.9%-20.6%. In 2012, the average percent exclusion of the four companies was 21.9%, this number decreased slightly to 20.6% overall in 2018. The most likely reason to be excluded was found to be failure to meet imaging criteria. The second most likely failed characteristic was a negative impingement test (65 patients excluded). Several insurance companies continue to utilize Outerbridge criteria for cartilage lesions which cannot be assessed preoperatively. Discussion and Conclusion: The diagnosis of FAI and its surgical indications have no definitive set criteria. Our study shows that with a six-year span of growing literature and updated policies, nearly 1 in 5 patients deemed to need surgical intervention by experienced hip preservation surgeons would still be denied coverage. There is a need for continued improvement of consensus regarding the diagnosis of FAI and appropriate indications for surgical intervention based on the available literature.