Multivariable Quantile Regression Models Research Articles

On function-on-function linear quantile regression

We present two innovative functional partial quantile regression algorithms designed to accurately and efficiently estimate the regression coefficient function within the function-on-function linear quantile regression model. Our algorithms utilize functional partial quantile regression decomposition to effectively project the infinite-dimensional response and predictor variables onto a finite-dimensional space. Within this framework, the partial quantile regression components are approximated using a basis expansion approach. Consequently, we approximate the infinite-dimensional function-on-function linear quantile regression model using a multivariate quantile regression model constructed from these partial quantile regression components. To evaluate the efficacy of our proposed techniques, we conduct a series of Monte Carlo experiments and analyze an empirical dataset, demonstrating superior performance compared to existing methods in finite-sample scenarios. Our techniques have been implemented in the ffpqr package in .

A censored quantile transformation model for Alzheimer’s Disease data with multiple functional covariates

Abstract Alzheimer’s disease (AD) is a progressive disease that starts from mild cognitive impairment and may eventually lead to irreversible memory loss. It is imperative to explore the risk factors associated with the conversion time to AD that is usually right-censored. Classical statistical models like mean regression and Cox models fail to quantify the impact of risk factors across different quantiles of a response distribution, and previous research has primarily focused on modelling a single functional covariate, possibly overlooking the interdependence among multiple functional covariates and other crucial features of the distribution. To address these issues, this paper proposes a multivariate functional censored quantile regression model based on dynamic power transformations, which relaxes the global linear assumption and provides more robustness and flexibility. Uniform consistency and weak convergence of the quantile process are established. Simulation studies suggest that the proposed method outperforms the existing approaches. Real data analysis shows the importance of both left and right hippocampal radial distance curves for predicting the conversion time to AD at different quantile levels.

Influence of Impaired Diffusing Capacity and Sleep-disordered Breathing on Nocturnal Hypoxemia and Health Outcomes in Men with and without Human Immunodeficiency Virus.

Rationale: Nocturnal hypoxemia is common in sleep-disordered breathing (SDB) and is associated with increased morbidity and mortality. Although impaired diffusing capacity of the lung for carbon monoxide (DlCO) is associated with daytime hypoxemia, its influence on SDB-related nocturnal hypoxemia is not known. Objectives: To characterize the effects of DlCO impairment on SDB-related nocturnal hypoxemia and associated health outcomes. Methods: Data from a multicenter cohort of men with and without human immunodeficiency virus (HIV) infection, with concomitant measures of DlCO and home-based polysomnography (n = 544), were analyzed. Multivariable quantile regression models characterized associations between DlCO and several measures of SDB-related hypoxemia (e.g., total sleep time with oxygen saturation as measured by pulse oximetry [SpO2] < 90% [T90]). Structural equation models were used to assess associations of impaired DlCO and SDB-related hypoxemia measures with prevalent hypertension and type 2 diabetes. Results: DlCO impairment (<80% predicted) was associated with sleep-related hypoxemia. Participants with severe SDB (apnea-hypopnea index ⩾ 30 events/h) and impaired DlCO had higher T90 (median difference, 15.0% [95% confidence interval (CI), 10.3% to 19.7%]) and average SDB-related desaturation (median difference, 1.0 [95% CI, 0.5 to 1.5]) and lower nadir SpO2 (median difference, -8.2% [95% CI, -11.4% to -4.9%]) and average SpO2 during sleep (median difference, -1.1% [95% CI, -2.1% to -0.01%]) than those with severe SDB and preserved DlCO. Higher T90 was associated with higher adjusted odds of prevalent hypertension (odds ratio, 1.39 [95% CI, 1.14 to 1.70]) and type 2 diabetes (odds ratio, 1.25 [95% CI, 1.07 to 1.46]). Conclusions: DlCO impairment in severe SDB was associated with sleep-related hypoxemia, prevalent hypertension, and type 2 diabetes. Assessment of SDB should be considered in those with impaired DlCO to guide testing and risk stratification strategies.

Factors associated with late initiation of antiretroviral therapy in Iran’s HIV/AIDS surveillance data

Early initiation of Antiretroviral Treatment (ART) in HIV patients is essential for effectively suppressing the viral load and prognosis. This study utilized National HIV/AIDS Surveillance Data in Iran to identify factors associated factors with the duration to initiate ART. This hybrid cross-sectional historical cohort study was conducted on Iran’s National HIV/AIDS Surveillance Data from 2001 to 2019. Sociodemographic characteristics, route of transmission, HIV diagnosis date, and ART initiation date were collected. Multivariable linear and quantile regression models were employed to analyze the duration to initiate ART by considering predictor variables. This study included 17,062 patients (mean age 34.14 ± 10.77 years, 69.49% males). Multivariate quantile regression coefficients varied across different distributions of the dependent variable (i.e., duration to initiate ART) for several independent variables. Generally, male gender, injecting drug use (IDU), and having an HIV-positive spouse were significantly associated with an increased duration to initiate ART (p < 0.05). However, a significant decrease was observed in older patients, those with a university level education, men who had sex with men (MSM), and patients diagnosed after 2016 (p < 0.05). Despite improvements in the duration to initiate ART after implementing the WHO’s 2016 program in Iran, various sociodemographic groups were still vulnerable to delayed ART initiation in the region. Therefore, programs including early testing, early ART initiation, active care, educational and cultural interventions, and appropriate incentives are required for these groups.

Three approaches to assessing dietary quality in Mexican adolescents from 2006 to 2018 with data from national health and nutrition surveys.

To assess trends in the dietary quality of Mexican adolescents from 2006 to 2018, both overall and by sociodemographic indicators, using adaptations of the EAT-Lancet Planetary Health (PH) recommendations, optimal intake estimated by the Global Burden of Disease (GBD) and 2015 Mexican Dietary Guidelines (MDG) in nationally representative samples. Using dietary data from a semi-quantitative FFQ, dietary quality indexes were constructed as adaptations of three dietary intake recommendations. Trends in adherence to recommendations were evaluated with multivariate quantile regression models with survey year as the main independent variable and adjusted for age, sex, energy intake, dwelling area, geographical region, household assets condition, and student/non-student status. P values and CI were Bonferroni-corrected. Mexico. Non-pregnant or lactating adolescents aged 12-19 years (n 16 520). Adherence to the PH index was about 40 %, GBD was nearly 35 % and MDG was about 37 %. The lowest adherences were for added sugars, sugar-sweetened beverages, nuts and seeds, red meats, processed meats, and legumes (<28 %). No 2006-2018 trends in total adherence were found in any index. Nevertheless, negative adherence trends were identified for poultry (β = -2·4), and saturated fats (β = -0·93), and positive for unsaturated oils (β = 1·23), in the PH. In MDG, relevant trends were found for plain water (β = 1·63) and foods rich in fats (β = -1·24). Mexican adolescents have demonstrated poor dietary quality by these three approaches. Therefore, this population has a high-risk profile for diet-associated chronic diseases. Further research and appropriate public policies are needed.

General joint hypermobility in temporomandibular joint disease; clinical characteristics, biomarkers, and surgical aspects

ObjectivesThis study aimed at identifying biomarkers in the temporomandibular joint (TMJ) synovial tissue analysing 28 extra cellular matrix proteins in TMJ diseased patients, classified with either general joint hypermobility (GJH) or normal joint mobility (NJM), and to compile clinical and protein characterisation to reveal potential surgical predictive factors. Study designA prospective observational cohort study including 97 consecutive patients scheduled for TMJ surgery was performed. Joint mobility and several other predefined clinical variables were recorded. Synovial tissue was harvested during surgery followed by examination using multi-analytic profiling. A multivariate quantile regression model was used for analysis purposes. ResultsThe GJH/NJM ratio was 2:5. The GJH cohort were younger (P = 0.001) and more likely to be women (P = 0.026) compared to the NJM cohort. None of the protein concentrations could be correlated to joint mobility in the multivariate regression model, but often to the variable TMJ diagnosis. The surgical outcome after the six-month follow-up were equal between GJH and NJM patients. ConclusionsGJH was more common in the study cohort compared to general population frequencies, but GJH was not a negative factor for surgical outcome. Young age and female gender correlated to GJH. No TMJ biomarkers were GJH specific, and the results suggested that TMJ diagnosis more strongly correlated to the protein profile compared to GJH and the other investigated variables.

Impact of Urban Slum Residence on Coverage of Maternal, Neonatal, and Child Health Service Indicators in the Greater Accra Region of Ghana: an Ecological Time-Series Analysis, 2018-2021.

Among other focus areas, the global Sustainable Development Goals (SDGs) 3 and 11 seek to advance progress toward universal coverage of maternal, neonatal, and child health (MNCH) services and access to safe and affordable housing and basic services by 2030. Governments and development agencies have historically neglected the health and well-being associated with living in urban slums across major capital cities in sub-Saharan Africa since health policies and programs have tended to focus on people living in rural communities. This study assessed the trends and compared inequities in MNCH service utilization between slum and non-slum districts in the Greater Accra region of Ghana. It analyzed information from 29 districts using monthly time-series Health Management Information System (HMIS) data on MNCH service utilization between January 2018 and December 2021. Multivariable quantile regression models with robust standard errors were used to quantify the impact of urban slum residence on MNCH service utilization. We assessed the inequality of MNCH coverage indicators between slum and non-slum districts using the Gini index with bootstrapped standard errors and the generalized Lorenz curve. The results indicate that rates of vaccination coverage and antenatal care (ANC) attendance have declined significantly in slum districts compared to those in non-slum districts. However, skilled birth delivery and postnatal care (PNC) were found to be higher in urban slum areas compared to those in non-urban slum areas. To help achieve the SDGs' targets, it is important for the government of Ghana and other relevant stakeholders to prioritize the implementation of effective policies, programs, and interventions that will improve access to and utilization of ANC and immunization services among urban slum dwellers.

Abstract 16482: Proteomic Measures Associated With Leisure-Time Physical Activity and Heart Failure Risk in Late-Life - The Atherosclerosis Risk in Communities Study

Introduction: Leisure-time physical activity (LTPA) is associated with lower heart failure (HF) risk. However, the underlying molecular mechanisms by which LTPA impacts HF risk is unclear. Methods: We evaluated participants at Atherosclerosis Risk in Communities study visits 3 (1993-95) and 5 (2011-13) with plasma proteomics data (Somascan v4) and without HF or stroke. LTPA was assessed by the Baecke questionnaire as metabolic equivalent (MET)-minutes/week. We performed cross-sectional associations of 4,955 proteins with LTPA at visit 3 and then at visit 5 LTPA using multivariable quantile regression models at Bonferroni-corrected significance (p&lt;1e-5, p&lt;0.0004, respectively). We related these proteins to incident HF after visit 3 and then visit 5 using multivariable Cox regression models at Bonferroni-corrected significance (p&lt;0.00086, p&lt;0.003, respectively). Results: Thirty-nine proteins were associated with LTPA at visit 3 (n=10,402; age 60±6 yrs, 54% women; mean 688.6 MET-minutes/week, 773 incident HF events) and visit 5 (n=4,135; 75±5 yrs, 58% women; mean 834.8 MET-minutes/week, 362 events), of which 5 proteins were also associated with incident HF at both visits. Higher levels of THBS2, GABARAP, and BAGE2 were associated with lower LTPA and higher HF risk while higher levels of ART3 associated with higher LTPA and lower risk of incident HF (Figure). PTK7 demonstrated discordant associations with LTPA and HF risk. Levels of THBS2, GABARAP, BAGE2, and ART3 accounted for a significant proportion of the LTPA-HF association (p&lt;0.05). Conclusion: Large-scale proteomics can identify novel biomarkers potentially linking LTPA to HF risk. Further study is needed of THBS2, GABARAP, BAGE2, and ART3, which may link the association of LTPA on HF.

Fast optimization methods for high-dimensional row-sparse multivariate quantile linear regression

Sparse quantile regression is a useful tool for variable selection, robust estimation and heteroscedasticity treatment in high-dimensional data analysis. Due to the non-smooth of quantile loss, the computation is heavier than the least square models. In the literature, there are various numerical methods for linear quantile regression, such as ADMM developed in Gu et al. [Technometrics. 2017;60(3):319–331]. However, the computation of multivariate quantile regression has not yet been fully resolved, especially when the dimension is high. Motivated by this, we will focus on the design of fast numerical algorithms for row-sparse multivariate quantile regression model. By virtue of proximal operator and Majorize–Minimization, four smoothed algorithms are designed. For all the obtained algorithms, we analyse their convergence and the parameter selection. We conduct plenty of simulations and four real data sets analysis. Finally, we conclude that the smoothed method is faster than the non-smooth method, especially when the number of predictors is large.

The direct and mediating effect of social support on health-related quality of life during pregnancy among Australian women

BackgroundPrenatal stress can have a negative effect on the quality of life (QoL) of pregnant women. Social support plays a vital role in improving the psychological well-being of pregnant women by enhancing their stress-coping ability. The current study assessed the association between social support and health-related quality of life (HRQoL) as well as the mediating role of social support in the linkage between perceived stress and HRQoL among pregnant Australian women.MethodsSecondary data was obtained from 493 women who reported being pregnant in survey six of the 1973–78 cohort of the Australian Longitudinal Study on Women’s Health (ALSWH). Social support and perceived stress were assessed using the Medical Outcomes Study Social Support Index (MOS-SSS-19) and the Perceived Stress Scale, respectively. The Mental Component Scale (MCS) and Physical Component Scale (PCS) of the SF-36 were used to examine the mental and physical HRQoL. A mediation model was used to examine the mediating effect of social support in the relationship between perceived stress and HRQoL. A multivariate quantile regression (QR) model was used to assess the association between social support and HRQoL after adjusting for potential confounders.ResultThe mean age of the pregnant women was 35.8 years. The mediational analysis revealed that emotional/informational support (β= -1.53; 95% CI: -2.36, -0.78), tangible support (β= -0.64; 95% CI: -1.29, -0.09), and affectionate support/positive social interaction (β= -1.33; 95% CI: -2.25, -0.48), played a significant mediating role in the relationship between perceived stress and mental health-related QoL. In addition, perceived stress had a significant indirect effect on mental health-related QoL through overall social support (β = -1.38; 95% CI: -2.28, -0.56), and the mediator accounted for approximately 14.3% of the total effect. The multivariate QR analysis indicated that all the domains of social support and overall social support scores were positively associated with higher MCS scores (p < 0.05). However, social support was found to have no significant association with PCS (p > 0.05).ConclusionSocial support plays a direct and mediating role in improving the HRQoL of pregnant Australian women. Maternal health professionals need to consider social support as an essential tool to improve the HRQoL of pregnant women. Further, as part of routine antenatal care activity, assessing pregnant women’s level of social support is beneficial.

Prevalence and risk factors of underweight among under-5 children in Bangladesh: Evidence from a countrywide cross-sectional study.

Underweight is one of the important anthropometric components of malnutrition among under-five children and is a major public health concern in Bangladesh because it contributes to mortality as well as morbidity. In designing suitable health programs and policies with the goal of attaining UN SDG Goals, it is necessary to identify the critical risk factors of under-five malnutrition. It is evident that the quantile regression produces robust estimates in the presence of outliers. However, in the context of Bangladesh, no study has been conducted considering the sequential quantile regression on this topic. Therefore, the authors aimed to find the determinants of underweight among under-5 children in Bangladesh considering the latest country representative dataset. The paper considers a weighted sample of size 7762 children are used and data were extracted from the latest Bangladesh Demographic and Health Survey (BDHS) 2017-18 data. Multivariable simultaneous quantile regression models were used to fulfill the objectives of this study. Findings depict that undernutrition affects the majority of children in the population as compared to the reference population. The WAZ-score of the child increases by 0.202 points at the 10th quantile of the conditional distribution, and by 0.565 points at the 90th quantile as we move from children of underweight to overweight women. Moreover, the WAZ scores of children from the richest families in the 10th, 50th, and 75th quantiles, respectively, are increased by 0.171, 0.016, and 0.084 points. Quantile regression revealed the results of several socioeconomic and demographic factors acting differently across the WAZ distribution. Therefore, policymakers may consider the identified risk factors to lessen malnutrition among under-5 children in Bangladesh.

MP13-05 COMPARING COSTS AND BENEFITS OF OPEN VS ROBOTIC SIMPLE PROSTATECTOMY

You have accessJournal of UrologyCME1 Apr 2023MP13-05 COMPARING COSTS AND BENEFITS OF OPEN VS ROBOTIC SIMPLE PROSTATECTOMY Catherine Gu, Martin Kathrins, and Steven Chang Catherine GuCatherine Gu More articles by this author , Martin KathrinsMartin Kathrins More articles by this author , and Steven ChangSteven Chang More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003233.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: With the rise of robotic surgery, there has been much debate on the cost/benefit of robotic vs open surgery. Most studies examining the outcomes and costs of robotic surgery have been done in the context of robotic-assisted laparoscopic radical prostatectomy with limited studies of the cost/benefit for other indications such as simple prostatectomy or cystectomy. We sought to examine the monetary costs, hospital resource utilization, and short-term complications of robotic vs open simple prostatectomy in a national cohort. METHODS: We performed a retrospective cohort study of adult men undergoing elective open and robotic simple prostatectomy from 2011 to 2020 using data from the Premier Hospital Database (PHD), a national hospital discharge dataset representing approximately 20% of non-federal hospital discharges in the United States. We assessed for associations between surgical approach and postoperative outcomes including surgical complications, operating room time, need for blood transfusion, length of stay, readmissions and overall costs. All multivariable logistic and quantile regression models were controlled for clinical, demographic, and hospital factors. Analyses used sampling weights to achieve a nationally representative estimation. RESULTS: A total of 7,119 men in PHD, representing a weighted sample of 27,232 patients, underwent simple prostatectomy during 2011-2020. In the study period, the portion of robotic procedures increased from 5.1% to 26.4% of annual cases. There were no differences in the 90-day minor (Clavien grade 1-2) and major (Clavien grade 3-5) complications, although the open approach was more commonly associated with intraoperative and postoperative hemorrhage (OR: 1.90, 95% CI: 1.25 to 2.90, p=0.003). The robotic approach was associated with longer median operating room time (+135 min, 95% CI: 120 to 151 min, p<0.0001), shorter hospitalization (-1.5 day, 95% CI: -1.71 to -1.29 days, p<0.0001), and no difference in the odds for 90-day readmission. The 90-day cost was significantly higher for robotic simple prostatectomy (+US $3,550, 95% CI: $3,044 to $4,057, p<0.0001). CONCLUSIONS: There is a gradual increase in the proportion of simple prostatectomies in the United States performed via the robotic approach. The 90-day cost of robotic simple prostatectomy was significantly higher despite the shorter hospital length of stay—likely due to higher equipment costs and longer operative times—with no differences in major or minor complications. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e174 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Catherine Gu More articles by this author Martin Kathrins More articles by this author Steven Chang More articles by this author Expand All Advertisement PDF downloadLoading ...

Joint Food and Water Insecurity Had a Multiplicative Effect on Women’s Depression in Urban Informal Settlements in Makassar, Indonesia during the COVID-19 Pandemic

BackgroundWomen living in urban informal settlements may be particularly vulnerable to the detrimental effects of the COVID-19 pandemic because of increased economic and psychosocial stressors in resource-limited environments. ObjectivesThe objective of this study was to assess the associations between food and water insecurity during the pandemic and depression among women living in the urban informal settlements in Makassar, Indonesia. MethodsWe implemented surveys at 3 time points among women enrolled in the Revitalizing Informal Settlements and their Environments trial. Depression was measured using the Center for Epidemiologic Studies Depression Scale—10 (CESD-10) between November and December 2019 and again between February and March 2021. Food insecurity was measured using questions from the Innovation for Poverty Action’s Research for Effective COVID-19 Reponses survey and water insecurity was measured using the Household Water Insecurity Experiences Short Form. Both were measured between August and September 2020. We built 3 multivariate quantile linear regression models to assess the effects of water insecurity, food insecurity, and joint food and water insecurity during the COVID-19 pandemic on CESD-10 score. ResultsIn models with the full sample (n = 323), food insecurity (β: 1.48; 95% CI: 0.79, 2.17), water insecurity (β: 0.13; 95% CI: −0.01, 0.26), and joint food and water insecurity (β: 2.40; 95% CI: 1.43, 3.38) were positively associated with CESD-10 score. In subgroup analyses of respondents for whom we had prepandemic CESD-10 scores (n = 221), joint food and water insecurity (β: 1.96; 95% CI: 0.78, 3.15) maintained the strongest relationship with CESD-10 score. A limitation of this study is that inconsistency in respondents from households across the survey waves reduced the sample size used for this study. ConclusionsOur results find a larger association between depression and joint resource insecurity than with water or food insecurity alone, underlining the importance of addressing food and water insecurity together, particularly as they relate to women’s mental health and well-being.

Association of SARS-CoV-2 viral load distributions with individual demographics and suspected variant type: results from the Liverpool community testing pilot, England, 6 November 2020 to 8 September 2021.

BackgroundThe PCR quantification cycle (Cq) is a proxy measure of the viral load of a SARS-CoV-2-infected individual.AimTo investigate if Cq values vary according to different population characteristics, in particular demographic ones, and within the COVID-19 pandemic context, notably the SARS-CoV-2 type/variant individuals get infected with.MethodsWe considered all positive PCR results from Cheshire and Merseyside, England, between 6 November 2020 and 8 September 2021. Cq distributions were inspected with Kernel density estimates. Multivariable quantile regression models assessed associations between people's features and Cq.ResultsWe report Cq values for 188,821 SARS-CoV-2 positive individuals. Median Cqs increased with decreasing age for suspected wild-type virus and Alpha variant infections, but less so, if not, for Delta. For example, compared to 30-39-year-olds (median age group), 5-11-year-olds exhibited 1.8 (95% CI: 1.5 to 2.1), 2.2 (95% CI: 1.8 to 2.6) and 0.8 (95% CI: 0.6 to 0.9) higher median Cqs for suspected wild-type, Alpha and Delta positives, respectively, in multivariable analysis. 12-18-year-olds also had higher Cqs for wild-type and Alpha positives, however, not for Delta. Overall, in univariable analysis, suspected Delta positives reported 2.8 lower median Cqs than wild-type positives (95% CI: 2.7 to 2.8; p < 0.001). Suspected Alpha positives had 1.5 (95% CI: 1.4 to 1.5; p < 0.001) lower median Cqs than wild type.ConclusionsWild-type- or Alpha-infected school-aged children (5-11-year-olds) might transmit less than adults (> 18 years old), but have greater mixing exposures. Smaller differences in viral loads with age occurred in suspected Delta infections. Suspected-Alpha- or Delta-infections involved higher viral loads than wild type, suggesting increased transmission risk. COVID-19 control strategies should consider age and dominant variant.

Serum neurofilament light chain: a novel biomarker for early diabetic sensorimotor polyneuropathy

Aims/hypothesisNo established blood-based biomarker exists to monitor diabetic sensorimotor polyneuropathy (DSPN) and evaluate treatment response. The neurofilament light chain (NFL), a blood biomarker of neuroaxonal damage in several neurodegenerative diseases, represents a potential biomarker for DSPN. We hypothesised that higher serum NFL levels are associated with prevalent DSPN and nerve dysfunction in individuals recently diagnosed with diabetes.MethodsThis cross-sectional study included 423 adults with type 1 and type 2 diabetes and known diabetes duration of less than 1 year from the prospective observational German Diabetes Study cohort. NFL was measured in serum samples of fasting participants in a multiplex approach using proximity extension assay technology. DSPN was assessed by neurological examination, nerve conduction studies and quantitative sensory testing. Associations of serum NFL with DSPN (defined according to the Toronto Consensus criteria) were estimated using Poisson regression, while multivariable linear and quantile regression models were used to assess associations with nerve function measures. In exploratory analyses, other biomarkers in the multiplex panel were also analysed similarly to NFL.ResultsDSPN was found in 16% of the study sample. Serum NFL levels increased with age. After adjustment for age, sex, waist circumference, height, HbA1c, known diabetes duration, diabetes type, cholesterol, eGFR, hypertension, CVD, use of lipid-lowering drugs and use of non-steroidal anti-inflammatory drugs, higher serum NFL levels were associated with DSPN (RR [95% CI] per 1-normalised protein expression increase, 1.92 [1.50, 2.45], p<0.0001), slower motor (all p<0.0001) and sensory (all p≤0.03) nerve conduction velocities, lower sural sensory nerve action potential (p=0.0004) and higher thermal detection threshold to warm stimuli (p=0.023 and p=0.004 for hand and foot, respectively). There was no evidence for associations between other neurological biomarkers and DSPN or nerve function measures.Conclusions/interpretationOur findings in individuals recently diagnosed with diabetes provide new evidence associating higher serum NFL levels with DSPN and peripheral nerve dysfunction. The present study advocates NFL as a potential biomarker for DSPN.Graphical abstract

Associations between serum 25-hydroxyvitamin D, body mass index and body fat composition among Emirati population: Results from the UAE healthy future study.

IntroductionVitamin D deficiency and insufficiency are highly prevalent among several populations across the globe. Numerous studies have shown a significant correlation between body-mass-index (BMI) and Vitamin D status, however, some results differed according to ethnicity. Despite the abundance of sunshine throughout the year, vitamin D deficiency is prominent in the United Arab Emirates (UAE). In this study, we analyzed the UAE Healthy Future Study (UAEHFS) pilot data to investigate the association between serum 25-hydroxyvitamin D (25(OH)D) and % body fat (BF) composition as well as BMI.Material and methodsData from a total of 399 Emirati men and women aged ≥ 18 years were analyzed. Serum 25(OH)D and standard measures of weight and height were included in the analyses. Vitamin D deficiency was defined as serum 25(OH)D concentration<20 ng/ml. Multivariate quantile regression models were performed to explore the relationship between serum 25(OH)D levels and % BF composition and BMI correspondingly.ResultsThere were 281 (70.4%) males and 118 (29.6%) females included in this study. More than half of the study participants had vitamin D insufficiency (52.4%), and nearly a third had vitamin D deficiency (30.3%); while only 17.3% had optimal levels. A statistically significant negative association between serum 25(OH) D levels and % BF composition was observed at intermediate percentiles while a statistically significant negative association between serum 25(OH)D and BMI was only observed at the median (50th percentile).ConclusionThe study findings support the association between low serum 25(OH) D levels (low vitamin D status) and high % BF composition and high BMI among adult Emiratis. Further longitudinal data from the prospective UAEHFS could better elucidate the relationship between serum 25(OH) D levels, % BF composition, and BMI in the context of various health outcomes among this population.

Which patients bring the most costs for hospital? A study on the cost determinants among COVID-19 patients in Iran

BackgroundAccurate information on the cost determinants in the COVID-19 patients could provide policymakers a valuable planning tool for dealing with the future COVID-19 crises especially in the health systems with limited resources.ObjectivesThis study aimed to determine the factors affecting direct medical cost of COVID-19 patients in Hamadan, the west of Iran.MethodsThis study considered 909 confirmed COVID-19 patients with positive real-time reverse-transcriptase polymerase-chain-reaction test which were hospitalized from 1 March to 31 January 2021 in Farshchian (Sina) hospital in Hamadan, Iran. A checklist was utilized to assess the relationship of demographic characteristics, clinical presentation, medical laboratory findings and the length of hospitalization to the direct hospitalization costs in two groups of patients (patients with hospitalization ≤ 9 days and > 9 days). Statistical analysis was performed using chi-square, median test and multivariable quantile regression model at 0.05 significance levels with Stata 14 software program.ResultsThe median cost of hospitalization in patients was totally 134.48 dollars (Range: 19.19–2397.54) and respectively 95.87 (Range: 19.19–856.63) and 507.30 dollars (Range: 68.94–2397.54) in patients with hospitalization ≤ 9 days and > 9 days. The adjusted estimates presented that in patients with 9 or less hospitalization days history of cardiovascular disease, wheezing pulmonary lung, SPO2 lower than 90%, positive CRP, LDH higher than 942 U/L, NA lower than 136 mEq/L, lymphosite lower than 20% and patients with ICU experience had significantly positive relationship to the median of cost. Moreover, in patients with more than 9 hospitalization days, history of cardiovascular disease and ICU experience was statistically positive association and age older than 60 years and WBC lower than 4.5 mg/dL had statistically negative relationship to the median of hospitalization cost.ConclusionAs the length of hospital stay, which can be associated with the severity of the disease, increases, health systems become more vulnerable in terms of resource utilization, which in turn can challenge their responsiveness and readiness to meet the specialized treatment needs of individuals.

The Ultra-Processed Food Content of School Meals and Packed Lunches in the United Kingdom.

British children have the highest levels of ultra-processed food (UPF) consumption in Europe. Schools are posited as a positive setting for impacting dietary intake, but the level of UPFs consumed in schools is currently unknown. This study determined the UPF content of school food in the UK. We conducted a pooled cross-sectional analysis of primary (4–11 years, n = 1895) and secondary schoolchildren (11–18 years, n = 1408) from the UK’s National Diet and Nutrition Survey (2008–2017). Multivariable quantile regression models determined the association between meal-type (school meal or packed lunch) and lunchtime UPF intake (NOVA food classification system). We showed that on average, UPF intake was high in both primary (72.6% total lunch Kcal) and secondary schoolchildren (77.8% total lunch Kcal). Higher UPF intakes were observed in packed lunch consumers, secondary schoolchildren, and those in lower income households. This study highlights the need for a renewed focus on school food. Better guidance and policies that consider levels of industrial processing in food served in schools are needed to ensure the dual benefit of encouraging school meal uptake and equitably improving children’s diets.

The Impact of Venous Thromboembolism on Mortality and Morbidity During Nephrectomy for Renal Mass

To determine the morbidity, mortality, and costs associated with having concurrent venous thromboembolism (VTE) at the time of surgical resection of a renal mass. We identified 108,430 patients undergoing elective partial or radical nephrectomy for a renal mass from 2013 to 2017 using the Premier Healthcare database. The association of VTE with 90-day complication rates, mortality, ICU admission, readmission, and direct hospital costs (2019 US dollars) was determined with multivariable logistic regression and quantile regression models, respectively. Of the 108,430 patients who underwent elective partial or radical nephrectomy, 1.2% (n=1301) of patients were diagnosed with a preoperative VTE. Patients with preoperative VTE have higher rates of minor (odds ratio [OR] 1.47, 95% confidence inteval [CI] 1.34-1.62, P < .0001) and major complications (OR 2.53, 95% CI 2.23-2.86, P < .0001), mortality (OR 2.03, 95% CI 1.6-2.57, P < .0001), and readmissions (OR 1.73, 95% CI 1.57-1.90, P < .0001) compared to patients without preoperative VTE at the time of nephrectomy. Notably, the predicted probability for a major complication was significantly higher among patients with preoperative VTE who underwent either partial or radical nephrectomy, irrespective of the surgical approach utilized. Furthermore, rates of all types of complications except endocrine and soft tissue were significantly increased in patients undergoing nephrectomy with preoperative VTE compared to those without VTE. VTE at the time of nephrectomy is associated with significantly higher rates of major complications, increased mortality, and higher overall costs. Taken together, these findings have important implications for the counseling and management of renal masses in presence of VTE.

Fragmentation of care in the last year of life: Does dementia status matter?

BackgroundCare at the end of life is commonly fragmented; however, little is known about commonly used measures of fragmentation of care in the last year of life (LYOL). We sought to understand differences in fragmentation of care by dementia status among seriously ill older adults in the LYOL.MethodsWe analyzed data from adults ≥65 years in the National Health and Aging Trends Study who died and had linked 2011–2017 Medicare fee‐for‐service claims for ≥12 months before death. We categorized older adults as having serious illness due to dementia (hereafter dementia), non‐dementia serious illness or no serious illness. For outpatient fragmentation, we calculated the Bice–Boxerman continuity of care index (COC), which measures care concentration, and the known provider of care index (KPC), which measures the proportion of clinicians who were previously seen. For acute care fragmentation, we divided the number of hospitals and emergency departments visited by the total number of visits. We built separate multivariable quantile regression models for each measure of fragmentation.ResultsOf 1793 older adults, 42% had dementia, 53% non‐dementia serious illness and 5% neither. Older adults with dementia had fewer hospitalizations than older adults with non‐dementia serious illness but more than older adults without serious illness (mean 1.9 vs 2.3 vs 1, p = 0.002). In adjusted models, compared to older adults with non‐dementia serious illness, those with dementia had significantly less fragmented care across all quantiles of COC (range 0.016–0.110) but a lower predicted 90th percentile of KPC, meaning more older adults with dementia had extremely fragmented care on the KPC measure. There was no significant difference in acute care fragmentation.ConclusionsIn the LYOL, older adults with dementia have fewer healthcare encounters and less fragmentation of care by the COC index than older adults with non‐dementia serious illness.