Tag: statistics

Horm Behav. 2021 Nov 16;137:105082. doi: 10.1016/j.yhbeh.2021.105082. Online ahead of print.

ABSTRACT

Salivary hormone analyses provide a useful alternative to fecal and urinary hormone analyses in non-invasive studies of behavioral endocrinology. Here, we use saliva to assess cortisol levels in a wild population of spotted hyenas (Crocuta crocuta), a gregarious carnivore living in complex social groups. We first describe a novel, non-invasive method of collecting saliva from juvenile hyenas and validate a salivary cortisol assay for use in this species. We then analyze over 260 saliva samples collected from nearly 70 juveniles to investigate the relationships between cortisol and temporal and social variables in these animals. We obtain some evidence of a bimodal daily rhythm with salivary cortisol concentrations dropping around dawn and dusk, times at which cub activity levels are changing substantially. We also find that dominant littermates have lower cortisol than singleton juveniles, but that cortisol does not vary with age, sex, or maternal social rank. Finally, we examine how social behaviors such as aggression or play affect salivary cortisol concentrations. We find that inflicting aggression on others was associated with lower cortisol concentrations. We hope that the detailed description of our methods provides wildlife researchers with the tools to measure salivary cortisol in other wild carnivores.

PMID:34798449 | DOI:10.1016/j.yhbeh.2021.105082

Neuroimage. 2021 Nov 16;245:118715. doi: 10.1016/j.neuroimage.2021.118715. Online ahead of print.

ABSTRACT

Normative modelling is becoming more popular in neuroimaging due to its ability to make predictions of deviation from a normal trajectory at the level of individual participants. It allows the user to model the distribution of several neuroimaging modalities, giving an estimation for the mean and centiles of variation. With the increase in the availability of big data in neuroimaging, there is a need to scale normative modelling to big data sets. However, the scaling of normative models has come with several challenges. So far, most normative modelling approaches used Gaussian process regression, and although suitable for smaller datasets (up to a few thousand participants) it does not scale well to the large cohorts currently available and being acquired. Furthermore, most neuroimaging modelling methods that are available assume the predictive distribution to be Gaussian in shape. However, deviations from Gaussianity can be frequently found, which may lead to incorrect inferences, particularly in the outer centiles of the distribution. In normative modelling, we use the centiles to give an estimation of the deviation of a particular participant from the ‘normal’ trend. Therefore, especially in normative modelling, the correct estimation of the outer centiles is of utmost importance, which is also where data are sparsest. Here, we present a novel framework based on Bayesian linear regression with likelihood warping that allows us to address these problems, that is, to correctly model non-Gaussian predictive distributions and scale normative modelling elegantly to big data cohorts. In addition, this method provides likelihood-based statistics, which are useful for model selection. To evaluate this framework, we use a range of neuroimaging-derived measures from the UK Biobank study, including image-derived phenotypes (IDPs) and whole-brain voxel-wise measures derived from diffusion tensor imaging. We show good computational scaling and improved accuracy of the warped BLR for certain IDPs and voxels if there was a deviation from normality of these parameters in their residuals. The present results indicate the advantage of a warped BLR in terms of; computational scalability and the flexibility to incorporate non-linearity and non-Gaussianity of the data, giving a wider range of neuroimaging datasets that can be correctly modelled.

PMID:34798518 | DOI:10.1016/j.neuroimage.2021.118715

Sleep Med. 2021 Oct 30;88:241-246. doi: 10.1016/j.sleep.2021.10.029. Online ahead of print.

ABSTRACT

BACKGROUND: There is possibly an association between migraine, tension-type headache, anxiety, depression and insomnia. These conditions are prevalent among university students. Our primary objective was to verify whether students with primary headaches (migraine and tension-type headache) have a higher prevalence of insomnia. Our secondary objective was to assess whether the impact of headaches was associated with greater severity of insomnia.

METHODS: Cross-sectional study. 440 students out of 3030 were randomly selected. A semi-structured questionnaire containing information about the characteristics of the headaches, including their frequencies in the last 3 months; the Headache Impact Test (HIT-6); the Hospital Anxiety Depression Scale; and the Insomnia Severity Index were used.

RESULTS: 420 students (95.5%) agreed to participate; 51.4% men; median age of 21 (19, 23); 95 (22.6%) had insomnia; 265 (63.1%), migraine; 152 (36.2%), tension-type headache; 201 (47.9%) suffered from anxiety and 108 (25.7%), from depression. The severe impact of headache (HIT-6>55 points; OR = 3.9; p = 0.003) and anxiety (OR = 3.6; p = 0.003) were associated with insomnia (logistic regression). The severity of insomnia was positively and significantly correlated with the impact (HIT-6 score), with frequency of headache, and with having anxiety (multiple linear regression).

CONCLUSIONS: The diagnoses of migraine and tension-type headache are not associated with the presence of insomnia. The severity of insomnia is associated with the impact and the frequency of the headaches.

PMID:34798440 | DOI:10.1016/j.sleep.2021.10.029

J Stroke Cerebrovasc Dis. 2021 Oct 14;31(1):106177. doi: 10.1016/j.jstrokecerebrovasdis.2021.106177. Online ahead of print.

ABSTRACT

BACKGROUND AND PURPOSE: During the coronavirus disease 2019 (COVID-19) pandemic, we instituted virtual inpatient stroke rounds and acute stroke evaluations via telemedicine in the emergency department. We sought to explore trainees’ and experienced providers’ views on stroke care and education.

METHODS: The implementation and the survey took place at a single academic comprehensive stroke center in northeast Ohio in the United States. “Virtual rounding” consisted of patient presentation and discussion in the morning in on-line virtual team format followed by in-person patient rounds in small groups. Acute stroke evaluations in the emergency department included direct in-person evaluation by neurology residents with supervision over telemedicine.The neurology residents, stroke fellows, stroke nurse practitioners, and stroke staff physicians were surveyed 2 months after implementation. Quantitative data was analyzed using descriptive statistical analysis, written responses in comment sections were analyzed using content analysis.

RESULTS: Thirty-two of 42 (73%) surveys were completed. Nine (45%) residents and 5 (42%) experienced providers responded that virtual rounds did not compromise learning and education on stroke service. Fifteen (75%) residents and all experienced providers agreed that virtual rounds protected caregivers from exposure to the virus. While more than a third of residents (37%) did not feel comfortable utilizing telemedicine in ED, the majority of experienced providers (89%) were at ease with it. A total of 58% of residents and 67% of experienced providers felt that they were spending less time at the bedside, and 42% of residents and 58% of experienced providers felt less connected to patients during the pandemic.

CONCLUSION: Majority of neurology residents’ experience was not positive utilising telemedicine as compared to other staff providers. This is likely attributed to lack of prior exposure and unpreparedness. Incorporation of telemedicine curricula in medical school and residency training could prepare the next generation physicians to effectively use these technologies and meet the growing need for telehealth services for current and future pandemics.

PMID:34798435 | DOI:10.1016/j.jstrokecerebrovasdis.2021.106177

Gait Posture. 2021 Nov 6;91:290-296. doi: 10.1016/j.gaitpost.2021.10.030. Online ahead of print.

ABSTRACT

BACKGROUND: Stair climbing is a complex and demanding daily activity with increased physical loads. Therefore, analyzing stair climbing abilities is a frequently used diagnostic tool. Leg length inequalities (LLIs) are a common condition in the population, with individual consequences like lower back pain, scoliosis, and osteoarthritis. Despite its high prevalence, the necessary treatment, for mild LLIs, is still controversial. Previously, the focus was to analyze the effects of LLIs during static standing and walking. To create a holistic view on the dynamic effects of LLIs, and since climbing stairs produces a similar biomechanical imbalance as LLIs, the compensation mechanics during stair climbing are of special interest.

RESEARCH QUESTION: What are the biomechanical compensation mechanisms of (simulated) LLIs during ascending and descending stairs?

METHODS: Thirty-five healthy participants were measured with the inertial measurement system MyoMotion during stair climbing with simulated LLIs of 0-3 cm. The maximum estimated lower limb joint angles of the long and short leg were analyzed with statistically repeated measurement models.

RESULTS: The long leg showed significantly increased hip and knee flexion, while the short leg showed decreased hip and knee flexion, decreased dorsiflexion, and significantly increased plantarflexion. Different mechanisms were found in the case of 1 cm LLI when compared to greater LLIs. In the former, increased hip and knee flexion in the short leg accompanied by increased dorsiflexion in the long leg was observed. In the latter, the dorsiflexion of the long leg was reduced.

SIGNIFICANCE: Except for the reduced dorsiflexion of the long leg (LLI >1 cm), during stair climbing compared compensation mechanisms as during walking were presented, with the long leg functionally shortened and the short leg lengthened. Although the feet were already on different levels, during stair climbing with the step-over-step technique, significant compensation mechanisms were found as a consequence of LLIs.

PMID:34798420 | DOI:10.1016/j.gaitpost.2021.10.030

Aten Primaria. 2021 Nov 16;54(2):102171. doi: 10.1016/j.aprim.2021.102171. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the incidence of hip fracture in patients with antipsychotic treatment, comparing it with that of individuals who have not been treated with antipsychotics.

DESIGN: Retrospective cohort study of patients treated with antipsychotic drugs (TAP) and patients without known treatment (non-TAP). The observation period was 2006-2014. SITE: All primary care teams in Catalonia of the Catalan Health Institute (ICS).

PARTICIPANTS: Patients older than 44 years with TAP lasting at least 3 months. Control cohort: random selection of non-TAP patients matching for baseline comorbidities and other variables. A total of 22,010 are analyzed. Main measurements Incidence rate (1000× person-years: PY) of hip fracture in each group (TAP and non-TAP). Cox regression models to estimate adjusted risks (hazard ratio: HR).

RESULTS: The hip fracture incidence rate was higher in TAP patients (5.83 vs 3.58 fractures per 1000 PY), and is higher in all strata according to sex, age and type of diagnosis. The risk of suffering a hip fracture was 60% higher (HR: 1.60 95% CI: 1.34-1.92) in the TAP group than in the non-TAP group. The risk was higher in the group with schizophrenia (HR: 3.57 95% CI: 1.75-7.30), followed by bipolar disorder (HR: 2.61; 95% CI: 1.39-4.92) and depression (HR: 1.51; 95% CI: 1.21-1.88).

CONCLUSIONS: Patients with antipsychotic treatment have a higher risk of hip fracture than those who have not been treated with antipsychotics.

PMID:34798403 | DOI:10.1016/j.aprim.2021.102171

Aten Primaria. 2021 Nov 16;54(2):102194. doi: 10.1016/j.aprim.2021.102194. Online ahead of print.

ABSTRACT

OBJECTIVE: To develop a valid and reliable scale to measure the role of the nursing professional in the community (REFCO).

DESIGN: Observational with cross-sectional and instrumental design. SITE: Populated centers and communities of the coast, highlands and jungle from Peru.

PARTICIPANTS: The validation phase of the questionnaire had the voluntary participation of 402 Peruvian adults (50.7% from the coast, 40.5% from the highlands and 8.8% from the jungle).

INTERVENTIONS: The elaborated questionnaire that measures perceptions about the role of the nursing professional in the community was applied.

MAIN MEASUREMENTS: The psychometric properties of the REFCO scale were analyzed, such as content validation and internal consistency through the calculation of Aiken’s V, exploratory factor analysis (EFA) and later confirmatory factor analysis (CFA), respectively. Finally, the reliability of the scale was calculated.

RESULTS: Overall, all values were statistically significant when evaluated with the V-Aiken coefficient. Likewise, the skewness and kurtosis values of all the items of the instrument did not exceed the range >±1.5. The correlations between factors 1 and 2 were significant (p < .05). The reliability of the scale presents a Cronbach’s α coefficient = 0.865.

CONCLUSIONS: The REFCO scale has 9 items and 2 dimensions; outreach and education; with content and construct validity that provide evidence for community nursing categories, which is useful for measuring nursing work in the community field.

PMID:34798404 | DOI:10.1016/j.aprim.2021.102194

Asian J Psychiatr. 2021 Nov 6;67:102918. doi: 10.1016/j.ajp.2021.102918. Online ahead of print.

ABSTRACT

Although many screening tools for delirium are available, delirium is still occasionally overlooked or misdiagnosed. One of the reasons for this is the lack of brief screening tools that do not require specialized training to use. The 4 ‘A’s test (the 4AT) is a validated screening tool for delirium that can be administered in a very short time without specialized training. Herein, we evaluated the reliability and validity of the Japanese version of the 4AT (the 4AT-J). A total of 150 patients aged ≥ 65 years were enrolled. Their demographics and clinical characteristics were obtained within 24 hr of their hospitalization. On each patient’s high-risk day of developing delirium, the 4AT-J was administered by a nurse, and the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-Ⅴ) and the Japanese version of Delirium Rating Scale-Revised-98 (DRS-98-J) were administered by a psychiatrist. Our analyses revealed that when a cut-off score of 4, the 4AT-J showed high sensitivity and specificity. The Cronbach’s α-coefficient was similar to that of the original version. A receiver operating curve analysis showed sufficient power of the 4AT-J to discriminate delirium. The 4AT-J showed adequate reliability and validity for delirium screening in elderly patients.

PMID:34798384 | DOI:10.1016/j.ajp.2021.102918

J Crit Care. 2021 Nov 16;67:149-156. doi: 10.1016/j.jcrc.2021.11.005. Online ahead of print.

ABSTRACT

BACKGROUND: New-onset atrial fibrillation (NOAF) is common in patients on an intensive care unit (ICU). Evidence guiding treatments is limited, though recent reports suggest beta blocker (BB) therapy is associated with reduced mortality.

METHODS: We conducted a multicentre cohort study of adult patients admitted to 3 ICUs in the UK and 5 ICUs in the USA. We analysed the haemodynamic changes associated with NOAF. We analysed rate control, rhythm control, and hospital mortality associated with common NOAF treatments. We balanced admission and post-NOAF, pre-treatment covariates across treatment groups.

RESULTS: NOAF was followed by a systolic blood pressure reduction of 5 mmHg (p < 0.001). After adjustment, digoxin therapy was associated with inferior rate control versus amiodarone (adjusted hazard ratio (aHR) 0.56, [95% CI 0.34-0.92]). Calcium channel blocker (CCB) therapy was associated with inferior rhythm control versus amiodarone (aHR 0.59 (0.37-0.92). No difference was detected between BBs and amiodarone in rate control (aHR 1.15 [0.91-1.46]), rhythm control (aHR 0.85, [0.69-1.05]), or hospital mortality (aHR 1.03 [0.53-2.03]).

CONCLUSIONS: NOAF in ICU patients is followed by decreases in blood pressure. BBs and amiodarone are associated with similar cardiovascular control and appear superior to digoxin and CCBs. Accounting for key confounders removes previously reported mortality benefits associated with BB treatment.

PMID:34798373 | DOI:10.1016/j.jcrc.2021.11.005

J Crit Care. 2021 Nov 16;67:157-165. doi: 10.1016/j.jcrc.2021.10.022. Online ahead of print.

ABSTRACT

PURPOSE: We aimed to provide an extended analysis of the physiological handling of of the sodium burden induced by maintenance fluids.

MATERIALS AND METHODS: We revisited two studies that demonstrated, in healthy volunteers and in surgical patients, that maintenance fluids with 154 mmol/L of sodium lead to a more positive fluid balance than a regimen containing 54 mmol/L. We report different unpublished data on the renal handling of the imposed sodium burdens with specific attention to the resulting fluid and sodium balances.

RESULTS: The kidneys adapt to the sodium-rich fluids not only by altering sodium excretion, but also by retaining extra free water by concentrating urine. Realigning urinary sodium excretion with an increased administration takes around one day in health and much longer in the clinical setting. This difference may be explained by the presence of hypovolemia-induced aldosterone secretion in the latter group. Non-osmotic storage of sodium limits an unrestrained fluid retention even when very high amounts of sodium are administered but fluid accumulation will inevitably be further prolonged.

CONCLUSIONS: Sodium administration induced by sodium-rich maintenance fluids leads, especially in the clinical setting, to prolonged fluid retention when compared with a regimen that resembles a healthy dietary sodium intake, even when kidney function is normal.

PMID:34798374 | DOI:10.1016/j.jcrc.2021.10.022