Tag: statistics

Expert Syst Appl. 2023 Sep 1;225:120103. doi: 10.1016/j.eswa.2023.120103. Epub 2023 Apr 17.

ABSTRACT

The sanitary emergency caused by COVID-19 has compromised countries and generated a worldwide health and economic crisis. To provide support to the countries’ responses, numerous lines of research have been developed. The spotlight was put on effectively and rapidly diagnosing and predicting the evolution of the pandemic, one of the most challenging problems of the past months. This work contributes to the existing literature by developing a two-step methodology to analyze the transmission rate, designing models applied to territories with similar pandemic behavior characteristics. Virus transmission is considered as bacterial growth curves to understand the spread of the virus and to make predictions about its future evolution. Hence, an analytical clustering procedure is first applied to create groups of locations where the virus transmission rate behaved similarly in the different outbreaks. A curve decomposition process based on an iterative polynomial process is then applied, obtaining meaningful forecasting features. Information of the territories belonging to the same cluster is merged to build models capable of simultaneously predicting the 14-day incidence in several locations using Evolutionary Artificial Neural Networks. The methodology is applied to Andalusia (Spain), although it is applicable to any region across the world. Individual models trained for a specific territory are carried out for comparison purposes. The results demonstrate that this methodology achieves statistically similar, or even better, performance for most of the locations. In addition to being extremely competitive, the main advantage of the proposal lies in its complexity cost reduction. The total number of parameters to be estimated is reduced up to 93.51% for the short term and 93.31% for the mid-term forecasting, respectively. Moreover, the number of required models is reduced by 73.53% and 58.82% for the short- and mid-term forecasting horizons.

PMID:37090447 | PMC:PMC10108563 | DOI:10.1016/j.eswa.2023.120103

Spat Stat. 2023 Jun;55:100729. doi: 10.1016/j.spasta.2023.100729. Epub 2023 Mar 14.

ABSTRACT

The basic homogeneous SEIR (susceptible-exposed-infected-removed) model is a commonly used compartmental model for analysing infectious diseases such as influenza and COVID-19. However, in the homogeneous SEIR model, it is assumed that the population of study is homogeneous and, one cannot incorporate individual-level information (e.g., location of infected people, distance between susceptible and infected individuals, vaccination status) which may be important in predicting new disease cases. Recently, a geographically-dependent individual-level model (GD-ILM) within an SEIR framework was developed for when both regional and individual-level spatial data are available. In this paper, we propose to use an SEIR GD-ILM for each health region of Manitoba (central Canadian province) population to analyse the COVID-19 data. As different health regions of the population under study may act differently, we assume that each health region has its own corresponding parameters determined by a homogeneous SEIR model (such as contact rate, latent period, infectious period). A Monte Carlo Expectation Conditional Maximization (MCECM) algorithm is used for inference. Using estimated parameters we predict the infection rate at each health region of Manitoba over time to identify highly risk local geographical areas. Performance of the proposed approach is also evaluated through simulation studies.

PMID:37089455 | PMC:PMC10103593 | DOI:10.1016/j.spasta.2023.100729

J Cataract Refract Surg. 2023 May 1;49(5):499-503. doi: 10.1097/j.jcrs.0000000000001138.

ABSTRACT

PURPOSE: To assess whether there are added risks when performing intraocular lens (IOL) exchange in the setting of an open posterior capsule (OPC) when compared with a closed posterior capsule (CPC) IOL exchange.

SETTING: Private practice, Los Angeles, California.

DESIGN: Nonrandomized and unmasked retrospective chart review.

METHODS: Eyes undergoing IOL exchange solely to relieve optical symptoms, with open or intact posterior capsules, were included. Eyes undergoing IOL exchange due to IOL malposition or dislocation were excluded. Eyes with preexisting, uncontrolled glaucoma and inflammation and eyes with a visual potential worse than 20/40 (Snellen) were also excluded. The main outcome measures were the postoperative complications compared between the OPC and CPC groups.

RESULTS: 90 eyes of 75 patients undergoing IOL exchange were included in this study; 38/90 eyes had an OPC, and 52/90 eyes had a CPC. 3/38 in the OPC group and 2/52 in the CPC group experienced worsening intraocular pressure control. 1/38 in the OPC group experienced chronic inflammation. 2/38 in the OPC group and 2/52 in the CPC group experienced cystoid macular edema. 1/52 in the CPC group experienced a retinal tear. Statistically or clinically significant differences in postoperative complications between the OPC and CPC groups were not found.

CONCLUSIONS: In the hands of an experienced surgeon, IOL exchange with an OPC appear red to be just as safe as IOL exchange with a CPC; when deemed necessary, experienced surgeons may perform an IOL exchange safely in the presence of an OPC.

PMID:37088935 | DOI:10.1097/j.jcrs.0000000000001138

Orthop Surg. 2023 Apr 24. doi: 10.1111/os.13727. Online ahead of print.

ABSTRACT

OBJECTIVE: Free flaps are widely used for the repair of soft tissue defects in the lower limbs, but there is still a specific rate of necrosis. Few clinical retrospective studies have analyzed the nontechnical risk factors for lower limb free flap necrosis. This study aimed to analyze the nontechnical causes of flap necrosis in lower limb soft tissue reconstruction in order to identify risk factors and improve the survival rate of free flaps.

METHODS: Clinical data from 244 cases of soft tissue defects of the leg or foot that were repaired with a free flap from January 2011 to June 2020 were retrospectively analyzed. The flap results were divided into complete survival and necrosis groups. The patients’ general information, smoking history, soft tissue defect site, Gustilo-Anderson classification, shock after injury, type and size of the flap, and time from injury to flap coverage were recorded. A logistic regression model was used to analyze the correlations between flap necrosis and possible risk factors.

RESULTS: Of the 244 flaps, 32 suffered from partial or total necrosis, and 212 completely survived. Univariate analysis showed that age, smoking history, soft tissue defect site, and time from injury to flap coverage were significantly correlated with flap necrosis (p ≤ 0.2). Multivariate logistic regression analysis showed that moderate-to-severe smoking history (p < 0.001, odds ratio [OR] = 10.259, 95% confidence interval [CI] = 2.886-36.468), proximal leg defect (p = 0.006, OR = 7.095, 95% CI = 1.731-29.089), and time from injury to flap coverage >7 days (p = 0.003, OR = 12.351, 95% CI = 2.343-65.099) were statistically significant risk factors for flap necrosis (p < 0.05), and age was excluded (p = 0.666; p = 0.924).

CONCLUSION: The risk of flap necrosis was significantly increased when the soft tissue defect was located in the proximal leg, the time from injury to flap coverage was >7 days, and the patient had a moderate-to-severe smoking history. These three risk factors have an increased influence on flap necrosis and have guiding significance in predicting flap prognosis.

PMID:37092532 | DOI:10.1111/os.13727

Orthop Surg. 2023 Apr 24. doi: 10.1111/os.13700. Online ahead of print.

ABSTRACT

OBJECTIVE: Bone cement releases a large amount of heat as it polymerizes. Skin burns caused by discarded bone cement are not well understood during arthroplasty. It is important to study the correlates and mechanisms of scalding and to accurately evaluate the severity of burns to guide treatment decisions.

METHODS: Standardized burns were created in eight anesthetized rabbits using different thicknesses of bone cement. Bone cement was uniformly stirred to make thicknesses of 1 mm, 4 mm, 8 mm, 12 mm, 16 mm, and 20 mm and a 20 × 40 mm cuboid. Bone cement samples were then placed on the back of a rabbit, and the temperature changes were recorded with an industrial digital thermometer. One hour later, the appearance of scalded skin was observed, and the rabbits were euthanized. The scalded parts were cut to make pathological sections and stained with HE, and the differences in the depth of the scalded skin caused by different thicknesses of bone cement were observed under a light microscope.

RESULTS: Damage caused by 1 mm-, 4 mm-, 8 mm-, 12 mm-, 16 mm-, and 20 mm-thick bone cement samples mainly involved the epidermis, the papillary dermis, the reticular dermis layer, and the full thickness of the skin and the subcutaneous tissue. The maximum temperature of 1 mm, 4 mm, 8 mm, and 12 mm bone cementation had a statistically significant difference (p < 0.001), while there was no significant difference between 12 mm, 16 mm, and 20 mm samples (p = 0.856). The time to severe scalding with bone cement at temperatures above 70°C was significantly different between different thicknesses (p < 0.001).

CONCLUSION: The heat released by different thicknesses of bone cement leads to different maximum temperatures and the duration of severe burns, resulting in different degrees of skin burns. Attention should be paid to discarded bone cement to prevent this potential complication in knee arthroplasty.

PMID:37092381 | DOI:10.1111/os.13700

Scand J Psychol. 2023 Apr 24. doi: 10.1111/sjop.12917. Online ahead of print.

ABSTRACT

To create healthy workplaces, organizations need tools for assessing factors contributing to employee well-being. Psychosocial safety climate (PSC) refers to shared perceptions regarding the extent to which psychological health and safety are prioritized in organizations; it is operationalized in the PSC scale. We evaluated the factor structure of the Finnish version of the PSC-4 scale, its invariance across time and concurrent and predictive relationships with perceived stress, job exhaustion, and work engagement. Moreover, the mean-level changes in PSC and well-being during enforced remote work were studied. Participants were 442 higher education employees who completed a well-being survey four times between April 2020 and February 2021. The longitudinal factor structure of the PSC-4 and well-being indicators were investigated using confirmatory factor analysis and structural equation modeling. The statistical analyses supported the one-factor structure of the PSC-4 and its measurement invariance across time. PSC was negatively associated with concurrent stress and job exhaustion and positively associated with concurrent work engagement at each measurement. Moreover, PSC predicted subsequent stress between each time point. Cross-lagged effects were also evident for job exhaustion at T2-T3 and T3-T4 and for work engagement at T1-T2. The mean level of PSC decreased during enforced remote work. To conclude, the Finnish PSC-4 is a valid tool for evaluating perceived psychosocial safety climate in organizations. PSC predicted well-being over time and showed subsequent relationships with job exhaustion and work engagement, which is a new contribution to PSC theory and literature. Organizations need to design interventions to improve it, especially during stressful times.

PMID:37092361 | DOI:10.1111/sjop.12917

Eval Health Prof. 2023 Apr 24:1632787231172277. doi: 10.1177/01632787231172277. Online ahead of print.

ABSTRACT

The impact of multi-point nursing strategies drawing on a problem-solving clinical framework to examine adverse events associated with thyroid nodule resection was investigated. Patients (n = 98) who underwent thyroid nodule resection were divided into observation and control groups. Patients in the control group received conventional care, and patients in the observation group received a multi-point care strategy under a clinical problem-solving framework. The length of stay (p < .001), hospitalization cost (p < .001), nursing satisfaction scores (p < .001) of the observation group were longer or higher and statistically significant. The incidence of complications in the observation group (8.16%) was lower than that in the control group (22.45%). The incidence of adverse events in the observation group (2.04%) was lower than that in the control group (14.29%), and statistically significant (p < .05). The multi-point nursing strategy using a clinical problem-solving framework provided evidence that it shortened the length of stay, reduce hospitalization costs, improve psychological status, increase nursing satisfaction, and reduce complications and adverse events in patients undergoing thyroid nodule resection.

PMID:37092358 | DOI:10.1177/01632787231172277

Eur J Heart Fail. 2023 Apr 24. doi: 10.1002/ejhf.2870. Online ahead of print.

ABSTRACT

AIMS: In the SHIFT (Systolic Heart failure treatment with the If inhibitor ivabradine Trial, ISRCTN70429960) study, ivabradine reduced cardiovascular death or heart failure (HF) hospitalizations in patients with heart failure and reduced ejection fraction (HFrEF) in sinus rhythm and with a heart rate (HR) ≥70 bpm. In this study, we sought to determine the clinical significance of the time durations of heart rate reduction and the significant treatment effect on outcomes among patients with HFrEF.

METHODS AND RESULTS: The time to statistically significant reduction of the primary outcome (HF hospitalization and cardiovascular death) and its components, all-cause death, and HF death, were assessed in a post-hoc analysis of the SHIFT trial in the overall population (HR ≥70 bpm) and at HR ≥75 bpm, representing the approved label in many countries. Compared to placebo, the primary outcome and HF hospitalizations were significantly reduced at 102 days, while there was no effect on cardiovascular death, all-cause death, and HF death at HR ≥70 bpm. In the population with a baseline HR ≥75 bpm, a reduction of the primary outcome occurred after 67 days, HF hospitalization after 78 days, cardiovascular death after 169 days, death from HF after 157 days and all-cause death after 169 days.

CONCLUSION: Treatment with ivabradine should not be deferred in patients in sinus rhythm with a HR of ≥70 bpm to reduce the primary outcome and HF hospitalizations, in particular in patients with HR ≥75 bpm. At HR ≥75 bpm, the time to risk reduction was shorter for reduction of hospitalization and mortality outcomes in patients with HFrEF after initiation of guideline-directed medication, including beta blockers at maximally tolerated doses.

PMID:37092340 | DOI:10.1002/ejhf.2870

Neurogastroenterol Motil. 2023 Apr 24:e14573. doi: 10.1111/nmo.14573. Online ahead of print.

ABSTRACT

BACKGROUND: Irritable bowel syndrome (IBS), a disorder of the gut-brain axis, is affected by the microbiome. Microbial studies in pediatric IBS, especially for centrally mediated treatments, are lacking. We compared the microbiome between pediatric IBS patients and healthy controls (HC), in relation to symptom severity, and with percutaneous electrical nerve field stimulation (PENFS), a non-invasive treatment targeting central pain pathways.

METHODS: We collected a stool sample, questionnaires and a 1-2 week stool and pain diary from 11 to 18 years patients with IBS. A patient subset completed 4 weeks of PENFS and repeated data collection immediately after and/or 3 months after treatment. Stool samples were collected from HC. Samples underwent metagenomic sequencing to evaluate diversity, composition, and abundance of species and MetaCyc pathways.

KEY RESULTS: We included 27 cases (15.4 ± 2.5 year) and 34 HC (14.2 ± 2.9 year). Twelve species including Firmicutes spp., and carbohydrate degradation/long-chain fatty acid (LCFA) synthesis pathways, were increased in IBS but not statistically significantly associated with symptom severity. Seventeen participants (female) who completed PENFS showed improvements in pain (p = 0.012), disability (p = 0.007), and catastrophizing (p = 0.003). Carbohydrate degradation and LCFA synthesis pathways decreased post-treatment and at follow-up (FDR p-value <0.1).

CONCLUSIONS AND INFERENCES: Firmicutes, including Clostridiaceae spp., and LCFA synthesis pathways were increased in IBS patients suggesting pain-potentiating effects. PENFS led to marked improvements in abdominal pain, functioning, and catastrophizing, while Clostridial species and LCFA microbial pathways decreased with treatment, suggesting these as potential targets for IBS centrally mediated treatments.

PMID:37092330 | DOI:10.1111/nmo.14573

J Clin Apher. 2023 Apr 24. doi: 10.1002/jca.22054. Online ahead of print.

ABSTRACT

BACKGROUND: Isovolemic hemodilution red cell exchange (IHD-RCE) is a modified form of the standard red cell exchange (STD-RCE), intended to reduce red cell requirements in patients with sickle cell disease (SCD). This retrospective crossover analysis of nine patients aims to add to the limited existing literature on IHD-RCE and address the equipoise regarding whether the benefits of (a) decreased RBC usage per exchange and (b) increased interprocedure interval (via lower fraction of cells remaining, FCR) can be observed at the same time, in the same patient.

METHODS: At a single center, we identified 37 patients with SCD undergoing chronic RCE between 2014 and 2021. We excluded those patients who did not have at least six consecutive procedures of each type (STD- and IHD-RCE), arriving at nine patients for analysis.

RESULTS: When using greater decreases in hematocrit than previously published, we did not find that IHD-RCE resulted in any clinically apparent adverse events. We did find greater decreases in diastolic blood pressure and increases in heart rate in some patients, as compared to STD-RCE. After correcting for total blood volume, seven of the nine patients had significantly reduced red cell requirements with each IHD-RCE. Because the pattern of achieving a lower FCR than programmed was seen to an equal extent with both IHD-RCE and STD-RCE, none of the nine patients showed any statistical difference in actual FCR between procedure types.

DISCUSSION: Our data do not support the observation of both IHD-RCE benefits, decreased red cell usage per exchange and lower FCR/increased interprocedure interval, simultaneously.

PMID:37092306 | DOI:10.1002/jca.22054