Tag: statistics

Anesthesiology. 2021 Jul 30. doi: 10.1097/ALN.0000000000003871. Online ahead of print.

ABSTRACT

Clinical prediction models in anesthesia and surgery research have many clinical applications including preoperative risk stratification with implications for clinical utility in decision-making, resource utilization, and costs. It is imperative that predictive algorithms and multivariable models are validated in a suitable and comprehensive way in order to establish the robustness of the model in terms of accuracy, predictive ability, reliability, and generalizability. The purpose of this article is to educate anesthesia researchers at an introductory level on important statistical concepts involved with development and validation of multivariable prediction models for a binary outcome. Methods covered include assessments of discrimination and calibration through internal and external validation. An anesthesia research publication is examined to illustrate the process and presentation of multivariable prediction model development and validation for a binary outcome. Properly assessing the statistical and clinical validity of a multivariable prediction model is essential for reassuring the generalizability and reproducibility of the published tool.

PMID:34330146 | DOI:10.1097/ALN.0000000000003871

Asia Pac J Public Health. 2021 Jul 30:10105395211036275. doi: 10.1177/10105395211036275. Online ahead of print.

ABSTRACT

Tobacco smoking is a leading cause of premature death. Smoking prevalence in Vietnam ranks among the highest in Southeast Asia. Given the important role of health care workers (HCWs) in promoting and supporting smoking cessation, this project aimed to characterize the prevalence of smoking among HCWs in Vietnam, and their attitudes toward smoking cessation interventions. A cross-sectional survey was conducted among care workers in 4 levels of the health system, within 4 provinces of Vietnam. Descriptive statistics evaluated participant attitudes, perception, behaviors, and knowledge about smoking. Multivariable logistic regression models evaluated risk factors for smoking. Among 3343 HCWs, 7.5% identified as current smokers, comprising 22.2% males and 0.5% of females. Males had substantially greater odds (adjusted odds ratio = 55.3; 95% confidence interval = 29.0-105.6) of identifying as current smokers compared with females. HCWs in urban settings had higher odds of identifying as smokers compared with rural workers (adjusted odds ratio = 1.72; 95% confidence interval = 1.23-2.24). Strong support for smoking cessation policies and interventions were identified, even among staff who smoked. HCWs play an integral role in identifying smokers and supporting smoking cessation interventions for their patients. Efforts to support affordable smoking cessation interventions within health facilities are likely to contribute to a reduction in smoking prevalence in Vietnam.

PMID:34330179 | DOI:10.1177/10105395211036275

J Perinat Neonatal Nurs. 2021 Jul-Sep 01;35(3):247-257. doi: 10.1097/JPN.0000000000000556.

ABSTRACT

Benefits of skin-to-skin contact (SSC) are documented but often delayed in the extremely preterm population due to medical complexity and staff misconceptions about safety. This quality improvement initiative was designed to increase SSC utilization among infants born before 29 weeks’ gestation regardless of respiratory support by addressing nursing barriers inhibiting SSC. A pre-/postsurvey evaluated comfort level performing and perceived barriers to SSC utilization. Implementation consisted of an updated unit-specific SSC protocol and tailored education specific to identified barriers. Evaluation included SSC rates and maternal human milk usage in the first 30 days of life. In total, 81 patients (22-28 weeks, 370-1410 g) were included. SSC rates ranged from 3.3% to 17.7% at baseline and increased to 33.2% to 39.1% postintervention. Maternal human milk utilization increased above target (≥75%) postintervention for days 7 and 14, but declined towards baseline on days 21 and 30. A statistically significant increase was observed in nursing comfort level when performing SSC for intubated infants as well as infants with a peripherally inserted central catheter or umbilical venous catheter. SSC rates increased with infants younger than 29 weeks requiring intubation and central line management, possibly as a result of greater nursing comfort surrounding with SSC.

PMID:34330136 | DOI:10.1097/JPN.0000000000000556

J Perinat Neonatal Nurs. 2021 Jul-Sep 01;35(3):266-274. doi: 10.1097/JPN.0000000000000557.

ABSTRACT

It is very important that infants are exclusively breastfed for the first 6 months of life and then that breastfeeding is continued until 2 years of age. In this study, we aimed to determine the rate of exclusive breastfeeding for the first 6 months of life following birth and the factors associated with continuation of exclusive breastfeeding. The study was a retrospective cohort study. The study population consists of infants born in Akdeniz University Hospital. Infants born between June 1, 2016, and June 1, 2017 (n = 1402) were included in the sample. For analysis of data, descriptive statistics, χ2 test, t test, and logistic regression test were employed. The rate of exclusive breastfeeding for the first 6 months was 29.8%. Further analysis revealed that chances of breastfeeding exclusivity for the first 6 months were increased by 1.6-fold if the father had higher education, by 1.4-fold if the infant was not given formula in the hospital, by approximately 4-fold if feeding bottle was not used, and by 1.7-fold in the absence of problems related to breastfeeding. The study results showed that success in exclusive breastfeeding was influenced by several factors. We recommended that modifiable factors associated with the success of exclusive breastfeeding be well managed.

PMID:34330139 | DOI:10.1097/JPN.0000000000000557

J Neurosurg Pediatr. 2021 Jul 30:1-7. doi: 10.3171/2021.2.PEDS2115. Online ahead of print.

ABSTRACT

OBJECTIVE: Given concerns about the potential long-term effects of concussion in young athletes, concussion prevention has become a major focus for amateur sports leagues. Athletes have been known to frequently use anti-inflammatory medications to manage injuries, expedite return to play, and treat concussion symptoms. However, the effects of baseline nonsteroidal anti-inflammatory drug (NSAID) use on the susceptibility to head injury and concussion remain unclear. This study aims to assess the effects of preinjury NSAID use on concussion incidence, severity, and recovery in young athletes.

METHODS: Data from 25,815 ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) tests were obtained through a research agreement with ImPACT Applications Inc. Subjects ranged in age from 12 to 22 years old. Those who reported NSAID use at baseline were assigned to one (anti-inflammatory [AI]) cohort, whereas all others were assigned to the control (CT) cohort. Differences in head trauma and concussion incidence, severity, and recovery were assessed using chi-square tests, unpaired t-tests, and Kaplan-Meier plots.

RESULTS: The CT cohort comprised a higher percentage (p < 0.0001) of males (66.30%) than the AI cohort (44.16%) and had a significantly greater portion of athletes who played football (p = 0.004). However, no statistically significant differences were found between the two cohorts in terms of the incidence of head trauma (CT = 0.489, AI = 0.500, p = 0.9219), concussion incidence (CT = 0.175, AI = 0.169, p = 0.7201), injury severity, or median concussion recovery time (CT = 8, AI = 8, p = 0.6416). In a multivariable analysis controlling for baseline differences between the cohorts, no association was found between NSAID use and concussion incidence or severity.

CONCLUSIONS: In this analysis, the authors found no evidence that preinjury use of NSAIDs affects concussion risk in adolescent athletes. They also found no indication that preinjury NSAID use affects the severity of initial injury presentation or concussion recovery.

PMID:34330088 | DOI:10.3171/2021.2.PEDS2115

Phys Med Biol. 2021 Jul 30. doi: 10.1088/1361-6560/ac195b. Online ahead of print.

ABSTRACT

The construction of photon propagation has a close relationship with the quality of reconstructed images. The classical Monte Carlo (MC) based method can model the photon propagation precisely, but it is time-consuming. The analytical method can often quickly construct a model, but its precision is a problem. How to fully exploit the advantages of the MC simulation and analytical model is an open problem. Inspired by the characteristics of the depth of interaction (DOI) detectors, which can help confirm the deposited position of a photon with DOI-encoding technology, we virtually discretize each crystal into several subcrystals to obtain the statistical distribution by MC-based simulation. Then, the statistical distribution is combined with a spatially variant solid-angle model. This combination strategy provides a hybrid model to describe photon propagation with relatively high accuracy and low computational cost. Three discretization schemes are compared to optimize the constructed photon propagation model. Several experiments are carried out to evaluate the performance of the proposed hybrid method. The metrics of Full Width at Half Maximum (FWHM), Contrast Recovery (CR), and Coefficient of Variation (COV) are adopted to quantitate the imaging results. The classical Monte Carlo (MC)-based method is compared as a gold-standard reference. When a crystal is divided into two discretized positions, the convergent tendencies of CRs and COVs are consistent with that based on MC simulation method, respectively. In terms of FWHMs, the resolutions of using the MC-based model and the proposed hybrid model are 0.71 mm and 0.68 mm in the direction parallel to the detector head, respectively. This indicates the potential of the proposed method in PET imaging.

PMID:34330106 | DOI:10.1088/1361-6560/ac195b

Neuroimage Clin. 2021 Jul 24;31:102767. doi: 10.1016/j.nicl.2021.102767. Online ahead of print.

ABSTRACT

Maintaining high levels of daily activity and physical capability have been proposed as important constituents to promote healthy brain and cognitive aging. Studies investigating the associations between brain health and physical activity in late life have, however, mainly been based on self-reported data or measures designed for clinical populations. In the current study, we examined cross-sectional associations between physical activity, recorded by an ankle-positioned accelerometer for seven days, physical capability (grip strength, postural control, and walking speed), and neuroimaging based surrogate markers of brain health in 122 healthy older adults aged 65-88 years. We used a multimodal brain imaging approach offering complementary structural MRI based indicators of brain health: global white matter fractional anisotropy (FA) and mean diffusivity (MD) based on diffusion tensor imaging, and subcortical and global brain age based on brain morphology inferred from T1-weighted MRI data. In addition, based on the results from the main analysis, follow-up regression analysis was performed to test for association between the volume of key subcortical regions of interest (hippocampus, caudate, thalamus and cerebellum) and daily steps, and a follow-up voxelwise analysis to test for associations between walking speed and FA across the white matter Tract-Based Spatial Statistics (TBSS) skeleton. The analyses revealed a significant association between global FA and walking speed, indicating higher white matter integrity in people with higher pace. Voxelwise analysis supported widespread significant associations. We also found a significant interaction between sex and subcortical brain age on number of daily steps, indicating younger-appearing brains in more physically active women, with no significant associations among men. These results provide insight into the intricate associations between different measures of brain and physical health in old age, and corroborate established public health advice promoting physical activity.

PMID:34330086 | DOI:10.1016/j.nicl.2021.102767

Placenta. 2021 Jul 23;112:89-96. doi: 10.1016/j.placenta.2021.07.291. Online ahead of print.

ABSTRACT

INTRODUCTION: Maternal alloimmunization against human platelet antigen (HPA)-1a has been implied to mediate both reduced birth weight and chronic placental inflammation. Fetal growth restriction is associated with different types of chronic inflammation in the placenta, mainly chronic histiocytic intervillositis and chronic villitis. The aim of this prospective study was to do a systematic examination of placentas from HPA-1a alloimmunized pregnancies, with focus on the histopathological and immunohistochemical diagnosis of variants of chronic inflammation.

MATERIAL AND METHODS: In a Polish-Norwegian study, 48 placentas were examined. The histopathology of placentas from 27 HPA-1a immunized women was compared with 21 placentas from non-immunized HPA-1a negative women (controls). In the group of alloimmunized women, ten received antenatal intravenous immunoglobulin G (IVIg). Tissue sections from formalin fixed paraffin embedded placental tissue were stained with hematoxylin and eosin and microscopically examined with focus on various types of chronic placental inflammations.

RESULTS: Chronic histiocytic intervillositis was observed in 40.7% of placentas from HPA-1a alloimmunized pregnancies, compared to none in the control group (p = 0.001). Chronic villitis of unknown etiology was more frequently found in the alloimmunized group, however this difference was not statistically significant. Maternal administration of IVIg did not seem to protect against chronic inflammatory lesions.

DISCUSSION: Placentas with detectable maternal anti-HPA-1a antibodies are associated with highly increased risk of low-grade chronic histiocytic intervillositis.

PMID:34329972 | DOI:10.1016/j.placenta.2021.07.291

J Affect Disord. 2021 Jul 22;294:513-520. doi: 10.1016/j.jad.2021.07.062. Online ahead of print.

ABSTRACT

BACKGROUND: We primarily aimed to explore the associations between duration of untreated illness (DUI), treatment response, and functioning in a cohort of patients with bipolar disorder (BD).

METHODS: 261 participants with BD were recruited. DUI was defined as months from the first affective episode to the start of a mood-stabilizer. The functioning assessment short test (FAST) scores and treatment response scores for lithium, valproate, or lamotrigine according to the Alda Scale Total Score (TS) were compared between patients with short (<24 months) or long DUI. Differences in FAST scores among good (GR; TS≥7), poor (PR; TS=2-6), or non-responders (NR; TS<2) to each mood-stabilizer were analyzed. Linear regression was computed using the FAST global score as the dependent variable.

RESULTS: DUI and FAST scores showed no statistically significant correlation. Patients with a longer DUI showed poorer response to lithium (Z=-3.196; p<0.001), but not to valproate or lamotrigine. Response to lithium (β=-1.814; p<0.001), number of hospitalizations (β=0.237; p<0.001), and illness duration (β=0.160; p=0.028) were associated with FAST total scores. GR to lithium was associated with better global functioning compared to PR or NR [H=27.631; p<0.001].

LIMITATIONS: The retrospective design could expose our data to a recall bias. Also, only few patients were on valproate or lamotrigine treatment.

CONCLUSIONS: Poor functioning in BD could be the result of multiple affective relapses, rather than a direct effect of DUI. A timely diagnosis with subsequent effective prophylactic treatment, such as lithium, may prevent poor functional outcomes in real-world patients with BD.

PMID:34330047 | DOI:10.1016/j.jad.2021.07.062

Eur J Obstet Gynecol Reprod Biol. 2021 Jul 22;264:206-211. doi: 10.1016/j.ejogrb.2021.07.033. Online ahead of print.

ABSTRACT

OBJECTIVE: To explore the development and pregnancy potential of non-pronuclear (0PN) zygote-derived embryos in conventional in vitro fertilization (IVF) cycles.

STUDY DESIGN: Embryonic development in 1039 oocyte retrieval cycles and clinical outcomes of 659 frozen-thawed blastocyst transfer cycles were retrospectively studied.

RESULTS: Developmental potential of embryos with different blastomere numbers on day 3 were inconsistent in 0PN and 2PN groups. For 0PN-derived embryos, blastocyst rate of fast developing embryos (75.4%) was similar to that of intermediately developing embryos (72.9%), but good quality blastocyst rate of the former (49.2%) was significantly higher than that of the later (39.6%). In 2PN group, intermediately developing embryos had the highest blastocyst rate (77.9%) and good quality blastocyst rate (51.5%) (statistically significant). Comparison of frozen-thawed transfer was carried out between 0PN- and 2PN-derived blastocysts. For both single (SBT) and double blastocyst transfer (DBT) groups, no statistical differences existed between 0PN- and 2PN-derived blastocysts in clinical pregnancy rates (45.2% and 49.1% in SBT group, 64.7% and 66.4% in DBT group), implantation rates (45.2% and 49.1% in SBT group, 41.2% and 47.7% in DBT group) and live birth rates (35.5% and 36.8% in SBT group, 52.9% and 51.2% in DBT group).

CONCLUSION: The developmental characteristic of 0PN-derived embryos was different from that of 2PN-derived embryos in IVF cycles. 0PN-derived blastocysts could obtain acceptable clinical pregnancy and live birth, but more studies are needed to confirm the safety..

PMID:34329946 | DOI:10.1016/j.ejogrb.2021.07.033