Category: Statistics

Int J Cancer. 2021 Aug 27. doi: 10.1002/ijc.33779. Online ahead of print.

ABSTRACT

Epidemiological evidence is consistent with a protective effect of vitamin D against colorectal cancer (CRC), but the observed strong associations are open to confounders and potential reverse causation. Previous Mendelian randomisation (MR) studies were limited by poor genetic instruments and inadequate statistical power. Moreover, whether genetically higher CRC risk can influence vitamin D level, namely the reverse causation, still remains unknown. Herein, we report the first bi-directional MR study. We employed 110 newly-identified genetic variants as proxies for vitamin D to obtain unconfounded effect estimates on CRC risk in 26 397 CRC cases and 41 481 controls of European ancestry. To test for reserve causation, we estimated effects of 115 CRC-risk variants on vitamin D level amongst 417 580 participants from the UK Biobank. The causal association was estimated using the random-effect inverse-variance weighted (IVW) method. We found no significant causal effect of vitamin D on CRC risk (IVW estimate OR: 0.97, 95%CI: 0.88-1.07, P = 0.565). Similarly, no significant reverse causal association was identified between genetically increased CRC risk and vitamin D levels (IVW estimate β: -0.002, 95% CI: -0.008 to 0.004, P = 0.543). Stratified analysis by tumour sites did not identify significant causal associations in either direction between vitamin D and colon or rectal cancer. Despite the improved statistical power of this study, we found no evidence of causal association of either direction between circulating vitamin D and CRC risk. Significant associations reported by observational studies may be primarily driven by unidentified confounders.

PMID:34449871 | DOI:10.1002/ijc.33779

Med J (Ft Sam Houst Tex). 2021 Jul-Sep;(PB 8-21-07/08/09):50-56.

ABSTRACT

BACKGROUND: Sports injuries are an important non-battle cause of attrition and morbidity among deployed US service members (SMs). Injuries secondary to sport may cause physical disability and prolonged periods of limited duty days. Our objective was to provide a descriptive analysis of sports injuries sustained by US SMs which may assist in the preventive strategies and thereby decrease their burden on the deployed force.

METHODS: Using the Department of Defense Trauma Registry’s (DoDTR) data between October 2001 and December 2018, a retrospective cross-sectional analysis was conducted. We reported summary statistics of injury characteristics and care provided, stratified by geographic location.

RESULTS: We found 1,578 causalities with sport injuries (4.9% of DoDTR); 1,081 (68.5%) in Iraq and Syria and 497 (31.5%) in Afghanistan. Most casualties had mild injuries (injury severity score: 1-9; n=1,514; 95.9%) and most sustained injuries in the lower extremities (n=741; 47%) followed by upper extremities (n=430; 27.2%). Most injuries were caused by a striking force (n=827; 52.4%) followed by overexertion (n=444; 28.2%), and 512 casualties (32.4%) had a fall incident. About 833 casualties (52.8%) received at least one surgery, and 931 casualties (59%) were hospitalized for two days or more. One casualty died of wound (0.1%).

CONCLUSIONS: Sports injuries continue to be an important source of morbidity and attrition and require disproportional medical attention, relative to their mild severity, representing a significant burden to the deployed health care system and impact combat readiness. Further research addressing the prevention of sports injury among deployed US SMs is needed.

PMID:34449861

Int J Cancer. 2021 Aug 27. doi: 10.1002/ijc.33780. Online ahead of print.

ABSTRACT

Chronic inflammation has been associated with the development of lung cancer. In this study, we examined the association between CRP and lung cancer in a prospective cohort study and used Mendelian randomization (MR) to clarify the causality. We included 420 977 participants from the UK Biobank in the analyses; 1892 thereof were diagnosed with lung cancer during the follow-up. Hazards ratios (HRs) of CRP concentrations were estimated by Cox proportional hazard models and two approaches of MR analysis were performed. Besides, we added CRP concentrations to epidemiological model of lung cancer to evaluate its pre-diagnostic role through time-dependent ROC analysis. Elevated CRP levels were associated with a 22% increased lung cancer risk per 1 standard deviation increase (HR=1.22, 95%CI: 1.18 to 1.26). Positive associations were observed in small cell lung cancer (HR= 1.21, 95%CI: 1.10 to 1.33), lung adenocarcinoma (HR=1.17, 95%CI: 1.11 to 1.23) and lung squamous cell carcinoma (HR=1.22, 95%CI: 1.14 to 1.31). No genetical association of circulating CRP levels and lung cancer risk was observed in MR analysis. When added to a risk model of lung cancer, CRP improved the performance of model as long as 8 years among current smokers (basic model: C-statistic=0.78 [95%CI: 0.75 to 0.80]; CRP model: C-statistic=0.79 [95%CI: 0.76 to 0.81]; P_non-adjusted =0.003, P_adjusted =0.014). Our results did not support the causal association of circulating CRP with lung cancer risk. However, circulating CRP could be a pre-diagnostic marker of lung cancer as long as 8 years in advance for current smokers. This article is protected by copyright. All rights reserved.

PMID:34449869 | DOI:10.1002/ijc.33780

Med J (Ft Sam Houst Tex). 2021 Jul-Sep;(PB 8-21-07/08/09):13-19.

ABSTRACT

BACKGROUND: Correct diagnosis of pneumothorax in trauma patients is essential. Under-diagnosis can lead to development of life-threatening tension pneumothorax, but overdiagnosis leads to placement of unnecessary chest tubes with potential related morbidity and pain. It is unclear from previous work if there is a benefit to switching from the phased array (low frequency) probe to the linear (high frequency) probe. Is the improvement in image quality worth the time lost changing probes?

METHODS: We compared the sensitivity and specificity of a low frequency and high frequency ultrasound probe for the detection of pneumothorax. Images were obtained using swine models and were interpreted by Emergency Medicine residents, attendings, and physician assistants.

RESULTS: We found a specificity of 89% and sensitivity of 99% for the low frequency probe and specificity of 96% and sensitivity of 99% for the high frequency probe. There was a statistically different specificity between the two probes, suggesting that the linear probe may be the superior probe for confirming the presence of pneumothorax.

CONCLUSION: We conclude switching to the linear probe for the thoracic portion of the Extended-Focused Assessment in Trauma will lead to more accurate diagnosis of pneumothorax and decreased false-positive exams.

PMID:34449855

Med J (Ft Sam Houst Tex). 2021 Jul-Sep;(PB 8-21-07/08/09):44-49.

ABSTRACT

BACKGROUND: Most battlefield deaths occur in the prehospital setting prior to reaching surgical and hospital care. Described are casualties captured by the Joint Trauma System (JTS) in the Prehospital Trauma Registry (PHTR) module of the Department of Defense Trauma Registry (DoDTR), from inception through May 2019.

METHODS: The JTS was queried for all PHTR encounters and associated data from inception (January 2003) through May 2019. The PHTR captures data on Role 1 prehospital care which encompasses treatment prior to arrival at a Role 2 with or without forward surgical team or Role 3 combat support hospital. Two unique patient identifiers were used to link DODTR outcome data to each PHTR encounter. Descriptive statistics were used to analyze the data.

RESULTS: We obtained a total of 1,357 encounters from the PHTR. Of these encounters, we successfully linked 52.2% (709/1357) to the DODTR for outcome data. Encounters spanned from 2003 to 2019, with most (69.5%) occurring from 2012 to 2014. Many casualties were in the 18-25 (25.5%) or 26-33 (27.0%) age ranges, male (99.2%), injured by explosive (47.1%) or firearm (34.8%), enlisted (44.8%), and US military conventional (24.1%) and special operations (23.9%) forces. Of those linked to the DODTR, demographics were similar, most casualties sustained battle injuries (87.1%), the majority of which survived (99.1%).

CONCLUSIONS: We described 1,357 encounters within the PHTR, most of which were US casualties and casualties injured by explosives. This renewed effort by the JTS to capture more casualties for inclusion into the registry has nearly doubled the proportion of available encounters for analysis. This analysis lays the foundation for in-depth analyses targeting areas for optimizing Role 1 prehospital combat casualty care.

PMID:34449860

PLoS One. 2021 Aug 27;16(8):e0256448. doi: 10.1371/journal.pone.0256448. eCollection 2021.

ABSTRACT

INTRODUCTION: Physical activity (PA) plays an important role in the prevention of cardiovascular diseases, especially in children. Previous studies which investigated the role of PA and sedentary time (ST) in cardiovascular disease used different measurements and found inconsistent results. The current study used recommended standardized measures and provides an overview of PA and ST among Dutch primary school children and their associations with cardiovascular risk factors.

METHODS: 503 children (55% girls, mean age (± SD) 10 ± 1y) were included. PA (total PA, lightPA and moderate to vigorous PA (MVPA)) and ST were measured with the Actigraph GT3X accelerometer. PA in different domains was measured with the BAECKE questionnaire. Cardiovascular risk factors included BMI z-score, waist circumference, blood pressure (z-score) and estimated cardiorespiratory fitness (CRF) as measured with the 20 meter shuttle run test.

RESULTS: Children spent 57 ± 20 min/day (8%) on MVPA and 42% of the children reached the MVPA guideline of 60 min/day. Total PA and MVPA (h/day) were negatively associated with BMI z-score (B = -0.452, p = 0.011) and waist circumference (B = -3.553, p = 0.011) and positively associated with CRF (B = 2.527, p = <0.001). ST was positively associated with BMI z-score (B = 0.108, p = 0.048) and waist circumference (B = 0.920, p = 0.033). No significant associations were found between total PA or PA intensities and blood pressure.

CONCLUSION: This study used standardized measures of PA and therefore created an accurate overview of PA, ST and their associations with cardiovascular risk factors. PA and ST were associated with BMI z-score, waist circumference and CRF. The findings emphasize the importance of promoting MVPA in children, but also highlight the potential benefits of reducing ST to improve cardiovascular risk factors.

TRIAL REGISTRATION: ClinicalTrials.gov NCT03440580.

PMID:34449807 | DOI:10.1371/journal.pone.0256448

PLoS One. 2021 Aug 27;16(8):e0256866. doi: 10.1371/journal.pone.0256866. eCollection 2021.

ABSTRACT

BACKGROUND: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a common undesirable event associated with significant morbidity and mortality. Several clinical prediction tools for predicting in-hospital mortality in patients with AECOPD have been developed in the past decades. However, some issues concerning the validity and availability of some predictors in the existing models may undermine their clinical applicability in resource-limited clinical settings.

METHODS: We developed a multivariable model for predicting in-hospitality from a retrospective cohort of patients admitted with AECOPD to one tertiary care center in Thailand from October 2015 to September 2017. Multivariable logistic regression with fractional polynomial algorithms and cluster variance correction was used for model derivation.

RESULTS: During the study period, 923 admissions from 600 patients with AECOPD were included. The in-hospital mortality rate was 1.68 per 100 admission-day. Eleven potential predictors from the univariable analysis were included in the multivariable logistic regression. The reduced model, named MAGENTA, incorporated seven final predictors: age, body temperature, mean arterial pressure, the requirement of endotracheal intubation, serum sodium, blood urea nitrogen, and serum albumin. The model discriminative ability based on the area under the receiver operating characteristic curve (AuROC) was excellent at 0.82 (95% confidence interval 0.77, 0.86), and the calibration was good.

CONCLUSION: The MAGENTA model consists of seven routinely available clinical predictors upon patient admissions. The model can be used as an assisting tool to aid clinicians in accurate risk stratification and making appropriate decisions to admit patients for intensive care.

PMID:34449823 | DOI:10.1371/journal.pone.0256866

PLoS One. 2021 Aug 27;16(8):e0256561. doi: 10.1371/journal.pone.0256561. eCollection 2021.

ABSTRACT

An impaired joint position sense (JPS) causes activity limitations, postural imbalance, and falls. This study compares the reliability of knee JPS measurements between the iPhone’s “Measure” application and VICON motion capture system. Eleven healthy participants were recruited for the study. To conduct the study measures, the blindfolded participant, with an iPhone fixed to the lower non-dominant leg, was seated with their lower limbs in a relaxed position. The examiner held the participant’s leg at the target angle (30°/60° from initial position) for 5 s before releasing it. The participant was then instructed to move the leg to the same target angle and hold it for 5 s (replicated angle). Absolute angular error (AAE), i.e., the difference between the target and replicated angles, was measured. Intraclass and Pearson correlation coefficients established statistically significant relationships. The study comprised 6 males and 5 females of mean age 27.6±5.6 years, mean height 1.67±0.10 m, and mean body weight 60.7±10.3 kg. Strong correlations existed between iPhone and VICON 30° (ICC = 0.969, r = 0.960, P < 0.001) and 60° AAEs (ICC 0.969, r = 0.960, P < 0.001). Bland-Altman plots showed a mean difference of 0.43° and 0.20° between the AAE measurements at 30° and 60°, respectively. The iPhone’s “Measure” application is a simple and reliable method for measuring JPS in clinical practice and sports/fitness settings.

PMID:34449787 | DOI:10.1371/journal.pone.0256561

PLoS One. 2021 Aug 27;16(8):e0256535. doi: 10.1371/journal.pone.0256535. eCollection 2021.

ABSTRACT

EUROCAT is a European network of population-based congenital anomaly (CA) registries. Twenty-one registries agreed to participate in the EUROlinkCAT study to determine if reliable information on the survival of children born with a major CA between 1995 and 2014 can be obtained through linkage to national vital statistics or mortality records. Live birth children with a CA could be linked using personal identifiers to either their national vital statistics (including birth records, death records, hospital records) or to mortality records only, depending on the data available within each region. In total, 18 of 21 registries with data on 192,862 children born with congenital anomalies participated in the study. One registry was unable to get ethical approval to participate and linkage was not possible for two registries due to local reasons. Eleven registries linked to vital statistics and seven registries linked to mortality records only; one of the latter only had identification numbers for 78% of cases, hence it was excluded from further analysis. For registries linking to vital statistics: six linked over 95% of their cases for all years and five were unable to link at least 85% of all live born CA children in the earlier years of the study. No estimate of linkage success could be calculated for registries linking to mortality records. Irrespective of linkage method, deaths that occurred during the first week of life were over three times less likely to be linked compared to deaths occurring after the first week of life. Linkage to vital statistics can provide accurate estimates of survival of children with CAs in some European countries. Bias arises when linkage is not successful, as early neonatal deaths were less likely to be linked. Linkage to mortality records only cannot be recommended, as linkage quality, and hence bias, cannot be assessed.

PMID:34449798 | DOI:10.1371/journal.pone.0256535

PLoS One. 2021 Aug 27;16(8):e0256609. doi: 10.1371/journal.pone.0256609. eCollection 2021.

ABSTRACT

OBJECTIVES: Although, pre-operative inspiratory muscle training has been investigated and reported to be an effective strategy to reduce postoperative pulmonary complications, the efficacy of postoperative inspiratory muscle training as well as the proper load, frequency, and duration necessary to reduce the postoperative pulmonary complications has not been fully investigated. This study was designed to investigate the effect of postoperative high-load long-duration inspiratory muscle training on pulmonary function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.

DESIGN: Prospective randomized controlled trial.

METHODS: A total of one hundred patients (mean age 38.3±3.29years) underwent mitral valve replacement surgery were randomized into experimental (n = 50) and control (n = 50) groups. The control group received conventional physiotherapy care, while experimental group received conventional care in addition to inspiratory muscle training, with 40% of the baseline maximal inspiratory pressure targeting a load of 80% by the end of the 8 weeks intervention protocol. Inspiratory muscle training started on the patient’s first day in the inpatient ward. Lung functions, inspiratory muscle strength, and functional capacity were evaluated using a computer-based spirometry system, maximal inspiratory pressure measurement and 6MWT respectively at 5 time points and a follow-up assessment was performed 6 months after surgery. Repeated measure ANOVA and post-hoc analyses were used (p <0.05).

RESULTS: Group-time interactions were detected for all the studied variables (p<0.001). Between-group analysis revealed statistically significant postoperative improvements in all studied variables in the experimental group compared to the control group (p <0.001) with large effect size of η2 ˃0.14. Within-group analysis indicated substantial improvements in lung function, inspiratory pressure and functional capacity in the experimental group (p <0.05) over time, and these improvements were maintained at follow-up.

CONCLUSION: High intensity, long-duration postoperative inspiratory muscle training is highly effective in improving lung function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.

PMID:34449776 | DOI:10.1371/journal.pone.0256609