Category: Statistics

Aerosp Med Hum Perform. 2021 Oct 1;92(10):815-824. doi: 10.3357/AMHP.5824.2021.

ABSTRACT

BACKGROUND: Neck pain (NP) is common among high performance aircrew, yet evidence remains insufficient to guide examination, treatment, and prevention. The purpose of this randomized pilot study was to collect baseline data for neck function for F-15E aircrew and determine efficacy and feasibility of two separate exercise protocols in measuring short-term outcomes of subjective and objective neck function in order to inform future study design. METHODS: Randomized to either progressive (PRO) or general (GEN) exercise groups were 41 F-15E aircrew. Data collection occurred at baseline, 3 wk, and 3 mo. RESULTS: At baseline, 39% of the subjects reported current NP, 79.5% reported a history of NP attributed to flying, 12.8% reported being removed from flying duties due to NP, and 10% reported receiving medical care for NP. PRO and GEN group randomization showed similar baseline assessment data. Blinding was successful and exercise logs showed 31.6% compliance with prescribed exercise regimens. There were small but statistically significant increases in neck range of motion in both groups over the course of the study. Aircrew with current NP had significantly higher F-15E flight hours. DISCUSSION: This study supports the high prevalence of NP in aircrew, yet low frequency of seeking care for NP. Future studies to assess NP prevention and treatment in aircrew require an integrated approach that includes operational exercise policy and long-term data collection in flying units with dedicated resources for assessment and analysis. Lee MS, Briggs R, Scheirer V, Kearby G, Young BA. Exercise effects on neck function among F-15E aircrew. Aerosp Med Hum Perform. 2021; 92(10):815824.

PMID:34642002 | DOI:10.3357/AMHP.5824.2021

Aerosp Med Hum Perform. 2021 Oct 1;92(10):780-785. doi: 10.3357/AMHP.5859.2021.

ABSTRACT

BACKGROUND: A growing number of symptom reports suggestive of acceleration atelectasis in fast jet aircrew have raised the question as to whether traditional guidelines on inspired gas composition remain valid. The aim of this study was to assess the effects of inspired O₂ concentration on the development of acceleration atelectasis when wearing modern anti-G garments. METHODS: There were 14 nonaircrew subjects who completed 5 centrifuge exposures to +5 G_z lasting 90 s. During exposures subjects breathed a gas mixture containing 21, 35, 45, 60, or 75% O₂. To assess the extent of atelectasis post-G_z, forced inspiratory vital capacity (FIVC), regional FIVC (EIT_FIVC), shunt, respiratory resistance, reactance, and compliance and peripheral O₂ saturation during a hypoxic exposure were measured. RESULTS: Compared with baseline, FIVC was not statistically significantly altered. EIT_FIVC was 14.4% lower after the 75% O₂ exposure only with a greater symptom reporting with higher F_IO₂ in some individuals. A significantly greater shunt (3>6%) followed the 60 and 75% O₂ exposures. O₂ concentration during G_z had no effect on respiratory resistance, reactance, compliance, or hypoxemia. DISCUSSION: There is evidence of mild acceleration atelectasis present when breathing 60% O₂, particularly in susceptible individuals, with 75% O₂ causing more obvious physiological compromise. An inspired oxygen concentration of <60% will prevent the majority of individuals from developing acceleration atelectasis. Pollock RD, Gates SD, Radcliffe JJ, Stevenson AT. Indirect measurements of acceleration atelectasis and the role of inspired oxygen concentrations. Aerosp Med Hum Perform. 2021; 92(10):780785.

PMID:34641998 | DOI:10.3357/AMHP.5859.2021

Aerosp Med Hum Perform. 2021 Oct 1;92(10):773-779. doi: 10.3357/AMHP.5876.2021.

ABSTRACT

BACKGROUND/OBJECTIVE: The COVID-19 virus has caused over 582,000 deaths in the United States to date. However, the pandemic has also afflicted the mental health of the population at large in the domains of anxiety and sleep disruption, potentially interfering with cognitive function. From an aviation perspective, safely operating an aircraft requires an airmans cognitive engagement for: 1) situational awareness, 2) spatial orientation, and 3) avionics programming. Since impaired cognitive function could interfere with such tasks, the current study was undertaken to determine if flight safety for a cohort of single engine, piston-powered light airplanes was adversely affected during a period of the pandemic (MarchOctober 2020) prior to U.S. approval of the first COVID-19 vaccine. METHODS: Airplane accidents were per the National Transportation Safety Board Access<sup/> database. Fleet times were derived using Automatic Dependent Surveillance-Broadcast. Statistics used Poisson distributions, Chi-squared/Fisher, and Mann-Whitney tests. RESULTS: Little difference in accident rate was evident between the pandemic period (MarchOctober 2020) and the preceding (JanuaryFebruary) months (19 and 22 mishaps/100,000 h, respectively). Similarly, a proportional comparison of accidents occurring in 2020 with those for the corresponding months in 2019 failed to show over-representation of mishaps during the pandemic. Although a trend to a higher injury severity (43% vs. 34% serious/fatal injuries) was evident for pandemic-period mishaps, the proportional difference was not statistically significant when referencing the corresponding months in 2019. CONCLUSION: Surprisingly, using accidents as an outcome, the study herein shows little evidence of diminished flight safety for light aircraft operations during the COVID-19 pandemic. Boyd DD. General aviation flight safety during the COVID-19 pandemic. Aerosp Med Hum Perform. 2021; 92(10):773779.

PMID:34641997 | DOI:10.3357/AMHP.5876.2021

BDJ Open. 2020 Oct 12;6(1):19. doi: 10.1038/s41405-020-00047-0.

ABSTRACT

OBJECTIVES: This study aimed to evaluate the fear of infection among Egyptian dentists practicing during the current coronavirus disease 2019 (COVID-19) pandemic and to explore the dentist’s knowledge about guidelines to fight the virus and to assess various modifications in dental practice.

METHODS: An online survey was submitted to dental professionals. Data were collected through a validated questionnaire consisting of 23 closed-ended questions. The gathered data were statistically analyzed.

RESULTS: An overall 216 dentists completed the survey. A total of 200 (92.6%) dental professionals were afraid of becoming infected with COVID-19 while 196 (90.7%) became anxious to treat patients showing suspicious symptoms. The majority of the participants were aware of the mode of transmission of COVID-19 and a lot of them were updated with the current Disease Control and Prevention (CDC) or World Health Organization (WHO) guidelines for cross-infection control.

CONCLUSIONS: COVID-19 pandemic has a significant impact on dental professionals.

PMID:34635638 | DOI:10.1038/s41405-020-00047-0

Transl Psychiatry. 2021 Oct 11;11(1):520. doi: 10.1038/s41398-021-01649-4.

ABSTRACT

Polygenic risk for schizophrenia has been associated with lower cognitive ability and age-related cognitive change in healthy individuals. Despite well-established neuropsychological sex differences in schizophrenia patients, genetic studies on sex differences in schizophrenia in relation to cognitive phenotypes are scarce. Here, we investigated whether the effect of a polygenic risk score (PRS) for schizophrenia on childhood, midlife, and late-life cognitive function in healthy individuals is modified by sex, and if PRS is linked to accelerated cognitive decline. Using a longitudinal data set from healthy individuals aged 25-100 years (N = 1459) spanning a 25-year period, we found that PRS was associated with lower cognitive ability (episodic memory, semantic memory, visuospatial ability), but not with accelerated cognitive decline. A significant interaction effect between sex and PRS was seen on cognitive task performance, and sex-stratified analyses showed that the effect of PRS was male-specific. In a sub-sample, we observed a male-specific effect of the PRS on school performance at age 12 (N = 496). Our findings of sex-specific effects of schizophrenia genetics on cognitive functioning across the lifespan indicate that the effects of underlying disease genetics on cognitive functioning is dependent on biological processes that differ between the sexes.

PMID:34635642 | DOI:10.1038/s41398-021-01649-4

Ann Lab Med. 2022 Mar 1;42(2):249-257. doi: 10.3343/alm.2022.42.2.249.

ABSTRACT

BACKGROUND: Non-invasive clinical algorithms for the detection of liver fibrosis (LF) can reduce the need for liver biopsy (LB). We explored the implementation of two serum biomarkers, enhanced liver fibrosis (ELF) and Mac-2 binding protein glycosylation isomer (M2BPGi), in clinical algorithms for LF in chronic hepatitis B (CHB) patients.

METHODS: Two clinical algorithms were applied to 152 CHB patients: (1) transient elastography (TE) followed by biomarkers (TE/ELF and TE/M2GPGi); (2) biomarker test followed by TE (ELF/TE and M2BPGi/TE). Using the cut-off value or index for the detection of advanced LF (TE≥F3; 9.8 in ELF and 3.0 in M2BPGi), LB was expected to be performed in cases with discordant TE and biomarker results.

RESULTS: In both algorithms, the expected number of LBs was lower when using M2BPGi than when using ELF (TE/ELF or ELF/TE, 13.2% [N=20]; TE/M2BPGi or M2BPGi/TE, 9.9% [N=15]), although there was no statistical difference (P=0.398). In the TE low-risk group (TE≤F2), the discordance rate was significantly lower in the TE/M2BPGi approach than in the TE/ELF approach (1.5% [2/136] vs. 11.0% [15/136], P=0.002). In the biomarker low-risk group, there was no significant difference between the ELF/TE and M2BPGi/TE approaches (3.9% [5/126] vs. 8.8% [13/147], P=0.118).

CONCLUSIONS: Both ELF and M2BPGi can be implemented in non-invasive clinical algorithms for assessing LF in CHB patients. Given the lowest possibility of losing advanced LF cases in the low-risk group when using the TE/M2BPGi approach, this combination seems useful in clinical practice.

PMID:34635616 | DOI:10.3343/alm.2022.42.2.249

Gut Liver. 2021 Oct 12. doi: 10.5009/gnl210167. Online ahead of print.

ABSTRACT

BACKGROUND/AIMS: We investigated the effect of metabolic dysfunction-associated fatty liver disease (MAFLD) on future mortality and cardiovascular disease (CVD) using a prospective community-based cohort study.

METHODS: Individuals from two community-based cohorts who were 40 to 70 years old were prospectively followed for 16 years. MAFLD was defined as a high fatty liver index (FLI ≥60) plus one of the following conditions: overweight/obesity (body mass index ≥23 kg/m²), type 2 diabetes mellitus, or ≥2 metabolic risk abnormalities. Nonalcoholic fatty liver disease (NAFLD) was defined as FLI ≥60 without any secondary cause of hepatic steatosis.

RESULTS: Among 8,919 subjects (age 52.2±8.9 years, 47.7% of males), 1,509 (16.9%) had MAFLD. During the median follow-up of 15.7 years, MAFLD independently predicted overall mortality after adjustment for confounders (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.05 to 1.69) but NAFLD did not (HR, 1.20; 95% CI, 0.94 to 1.53). MAFLD also predicted CVD after adjustment for age, sex, and body mass index (HR, 1.35; 95% CI, 1.13 to 1.62), which lost its statistical significance by further adjustments. Stratified analysis indicated that metabolic dysfunction contributed to mortality (HR, 1.51; 95% CI, 1.21 to 1.89) and CVD (HR, 1.27; 95% CI, 1.02 to 1.59). Among metabolic dysfunctions used for defining MAFLD, type 2 diabetes mellitus in MAFLD increased the risk of both mortality (HR, 2.07; 95% CI, 1.52 to 2.81) and CVD (HR, 1.42; 95% CI, 1.09 to 1.85).

CONCLUSIONS: MAFLD independently increased overall mortality. Heterogeneity in mortality and CVD risk of subjects with MAFLD may be determined by the accompanying metabolic dysfunctions.

PMID:34635626 | DOI:10.5009/gnl210167

Proc Natl Acad Sci U S A. 2021 Oct 19;118(42):e2105570118. doi: 10.1073/pnas.2105570118.

ABSTRACT

The reintegration of former members of violent extremist groups is a pressing policy challenge. Governments and policymakers often have to change minds among reticent populations and shift perceived community norms in order to pave the way for peaceful reintegration. How can they do so on a mass scale? Previous research shows that messages from trusted authorities can be effective in creating attitude change and shifting perceptions of social norms. In this study, we test whether messages from religious leaders-trusted authorities in many communities worldwide-can change minds and shift norms around an issue related to conflict resolution: the reintegration of former members of violent extremist groups. Our study takes place in Maiduguri, Nigeria, the birthplace of the violent extremist group Boko Haram. Participants were randomly assigned to listen to either a placebo radio message or to a treatment message from a religious leader emphasizing the importance of forgiveness, announcing the leader’s forgiveness of repentant fighters, and calling on followers to forgive. Participants were then asked about their attitudes, intended behaviors, and perceptions of social norms surrounding the reintegration of an ex-Boko Haram fighter. The religious leader message significantly increased support for reintegration and willingness to interact with the ex-fighter in social, political, and economic life (8 to 10 percentage points). It also shifted people’s beliefs that others in their community were more supportive of reintegration (6 to 10 percentage points). Our findings suggest that trusted authorities such as religious leaders can be effective messengers for promoting peace.

PMID:34635594 | DOI:10.1073/pnas.2105570118

Aging (Albany NY). 2021 Oct 11;13(undefined). doi: 10.18632/aging.203622. Online ahead of print.

ABSTRACT

Metabolic syndrome (MetS) is a significant factor for cardiometabolic comorbidities in people living with HIV (PLWH) and a barrier to healthy aging. The long-term consequences of HIV-infection and combination antiretroviral therapy (cART) in metabolic reprogramming are unknown. In this study, we investigated metabolic alterations in well-treated PLWH with MetS to identify potential mechanisms behind the MetS phenotype using advanced statistical and machine learning algorithms. We included 200 PLWH from the Copenhagen Comorbidity in HIV-infection (COCOMO) study. PLWH were grouped into PLWH with MetS (n = 100) defined according to the International Diabetes Federation (IDF) consensus worldwide definition of the MetS or without MetS (n = 100). The untargeted plasma metabolomics was performed using ultra-high-performance liquid chromatography/mass spectrometry (UHPLC/MS/MS) and immune-phenotyping of Glut1 (glucose transporter), xCT (glutamate/cysteine transporter) and MCT1 (pyruvate/lactate transporter) by flow cytometry. We applied several conventional approaches, machine learning algorithms, and linear classification models to identify the biologically relevant metabolites associated with MetS in PLWH. Of the 877 identified biochemicals, 9% (76/877) differed significantly between PLWH with and without MetS (false discovery rate < 0.05). The majority belonged to amino acid metabolism (43%). A consensus identification by combining supervised and unsupervised methods indicated 11 biomarkers of MetS phenotype in PLWH. A weighted co-expression network identified seven communities of positively intercorrelated metabolites. A single community contained six of the potential biomarkers mainly related to glutamate metabolism. Transporter expression identified altered xCT and MCT in both lymphocytic and monocytic cells. Combining metabolomics and immune-phenotyping indicated altered glutamate metabolism associated with MetS in PLWH, which has clinical significance.

PMID:34635603 | DOI:10.18632/aging.203622

Open Heart. 2021 Oct;8(2):e001835. doi: 10.1136/openhrt-2021-001835.

ABSTRACT

INTRODUCTION: Incomplete cardiac revascularisation (ICR) assessed by residual SYNTAX score (rSs) is associated with increased 5-year mortality. Furthermore, in the general population, our group has demonstrated that impaired autonomic function determined by heart rate recovery time between 10 and 20 s (HRR_10-20) following an active stand is associated with increased all-cause mortality.

PURPOSE: We hypothesised that ICR would be associated with impaired autonomic function determined by HRR_10-20.

METHODS: After ethical approval and informed consent, consecutive patients attending cardiac rehabilitation in a tertiary referral centre were enrolled. All patients had percutaneous coronary revascularisation. During an active stand, real-time heart rate, blood pressure and ECG recordings were taken using non-invasive digital photoplethysmography and HRR_10-20 determined. Assessment of autonomic function was performed by determining speed of HRR_10-20 post-orthostatic challenge.Patients with an rSs >0 were considered incompletely revascularised and those with an rSs of 0 fully revascularised. Demographic data were recorded and statistical analysis performed.

RESULTS: Patients (n=53) comprised those with complete revascularisation (CR) (n=37) and ICR (n=16). In the ICR group, mean rSs was 9.4.HRR_10-20 was impaired in the ICR group (-3±0.60) compared with the CR cohort (-6.56±0.52) (p<0.0001). Completeness of revascularisation was strongly associated with HRR_10-20 (Pearson’s correlation coefficient 0.529; p<0.0001). Baseline demographics did not differ significantly. Use of rate-limiting medication was similar between cohorts (beta blockers, calcium channel blockers, ivabradine).

CONCLUSIONS: Our data confirm significant correlation between ICR and impaired autonomic function determined by speed of heart rate recovery. Thus, determining autonomic dysfunction post-ICR may identify those at increased mortality risk.

PMID:34635578 | DOI:10.1136/openhrt-2021-001835