Local Polynomial Regression Model Research Articles

PDE5is-naïve versus non-naïve patients at first investigation for erectile dysfunction-findings from a long-term, real-life cross-sectional study.

Phosphodiesterase 5 inhibitors (PDE5is) represent a first-line pharmacological therapy for erectile dysfunction (ED). Men could obtain PDE5is for recreational purposes without any proper medical prescription. We aimed to analyze clinical characteristics of patients who already used any PDE5i for ED without previous formal medical prescription. Data from 2012 heterosexual, sexually active men seeking first medical help for ED at our outpatient clinic between 2005 and 2022 were analyzed. All patients were assessed with a comprehensive sexual and medical history and completed the International Index of Erectile Function (IIEF) at baseline. Comorbidities were scored with the Charlson comorbidity index (CCI). Thereof, according to exposure to any PDE5i before their first visit, patients were subdivided into: PDE5i-naïve and non-PDE5i-naïve patients. Descriptive statistics tested the sociodemographic and clinical characteristics of both groups. A logistic regression model predicted the likelihood of being PDE5i-naïve at the baseline. Linear regression analysis (LRA) estimated the likelihood of being PDE5i-naïve versus non-PDE5i-naïve over the analyzed timeframe. Lastly, local polynomial regression models graphically explored the likelihood of being PDE5i-naïve at the first clinical assessment over the analyzed timeframe, and the sensitivity analyses tested the probability of being PDE5i-naïve at baseline. Overall, 1,491 (70.9%) patients were PDE5i-naïve and 611 (29.1%) were non-PDE5i-naïve at the first assessment. PDE5is-naïve patients were younger, with a lower prevalence of CCI ≥ 1 and of normal erectile function (EF) than non-PDE5i-naïve men (all p<0.05). Multivariable logistic regression found that patients with lower BMI (OR: 0.99), higher IIEF-EF scores (OR: 1.02), lower rates of severe ED (OR: 0.94), and who had been assessed earlier throughout the study timeframe (OR: 1.27) were less likely to be PDE5i-naïve at baseline. Univariate LRA revealed that younger patients (Coeff: -0.02), with lower CCI (Coeff: -0.29) and higher alcohol intake per week (Coeff: 0.52) were more likely to be PDE5i-naïve over the analyzed timeframe. Moreover, for the same IIEF-EF score, patients with higher CCI had lower probability of being PDE5i-naïve. Self-prescription of PDE5is is an attitude presents in the general population, despite this phenomenon has decreased overtime. Current data outline the importance to keep promoting educational campaigns to promote PDE5is as effective and safe medicinal products, while avoiding their improper use.

COMPARISON OF LOCAL POLYNOMIAL REGRESSION AND ARIMA IN PREDICTING THE NUMBER OF FOREIGN TOURIST VISITS TO INDONESIA

Indonesia is a country that has a variety of exotic tourist destinations and can attract tourists to visit. Currently, tourism is one of the sectors that plays a major role in driving the Indonesian economy. Various tourists, both domestic and foreign, are expected to continue to increase in number every year. Therefore, appropriate policies are needed from the government to develop the tourism sector so that it can be even better over time. This research aims to predict the number of foreign tourist visits to Indonesia using the Autoregressive Integrated Moving Average (ARIMA) model and local polynomial regression. The data used in this research is the number of foreign tourist visits per month from January 2017 to December 2022 obtained from the the Kemenparekraf website. This data is fluctuating so that the method a local polynomial approach is appropriate for this study. The data analysis method used are local polynomial regression and ARIMA model. In the ARIMA model there are assumptions that must be met. In this study, the ARIMA model obtained has met the assumption of residual normality but does not meet the assumption of homoscedasticity so that ARIMA modeling cannot be continued and analysis is only carried out with local polynomial regression. The result of this study is a prediction of future tourist visits. The MAPE value of the local polynomial regression approach is 1.43% which is categorized as a prediction with high accuracy because the value is less than 10%. Thus, the local polynomial regression approach is very well used to predict the number of foreign tourist visits to Indonesia.

Platelet Modeling in DHF Patients Using Local Polynomial Semiparametric Regression on Longitudinal Data

Regression analysis is one of the statistical methods used to model the relationship between response variables and predictor variables. Semiparametric regression is a combination of parametric and nonparametric regression. The estimator used in estimating the semiparametric regression model in this research is the Local Polynomial. Longitudinal data can be found in the health sector, including dengue hemorrhagic fever (DHF) data. The laboratory criteria for indication of DHF is thrombocytopenia. This research aims to obtain platelets model for DHF patients that can be used for forecasting so that it is hoped that it can provide information to the medical team in treating DHF patients. The estimated model used is Local Polynomial semiparametric regression on longitudinal data. The response variables in this research were platelets of DHF patients, which were influenced by hemoglobin as parametric predictor variable and examination time while hospitalized as nonparametric predictor variable. In the local polynomial regression model, it is necessary to select the optimal bandwidth and polynomial order method, GCV. The optimum bandwidth selection based on the GCV method obtained is 1.5 and polynomial order of 2, then applied to DHF patient platelet data, producing an estimated local polynomial semiparametric regression model that follows the actual data pattern. Modeling the platelets of DHF patients obtained using a local polynomial estimator resulted in an R2 value of 84.25% and MAPE of 4.5%, indicating highly accurate forecasting, so it can be concluded that the resulting model is better at predicting.

A new time-varying coefficient regression approach for analyzing infectious disease data

Since the beginning of the global pandemic of Coronavirus (SARS-COV-2), there has been many studies devoted to predicting the COVID-19 related deaths/hospitalizations. The aim of our work is to (1) explore the lagged dependence between the time series of case counts and the time series of death counts; and (2) utilize such a relationship for prediction. The proposed approach can also be applied to other infectious diseases or wherever dynamics in lagged dependence are of primary interest. Different from the previous studies, we focus on time-varying coefficient models to account for the evolution of the coronavirus. Using two different types of time-varying coefficient models, local polynomial regression models and piecewise linear regression models, we analyze the province-level data in Canada as well as country-level data using cumulative counts. We use out-of-sample prediction to evaluate the model performance. Based on our data analyses, both time-varying coefficient modeling strategies work well. Local polynomial regression models generally work better than piecewise linear regression models, especially when the pattern of the relationship between the two time series of counts gets more complicated (e.g., more segments are needed to portray the pattern). Our proposed methods can be easily and quickly implemented via existing R packages.

(378) Still One Out of Five Men Presenting for Erectile Dysfunction are Young than 40 years of Age: Findings of a Real-life Cross-sectional Study over Last Decade

Abstract Introduction Erectile dysfunction (ED) has been demonstrated to be reasonably prevalent among young men (≤40 yr). Objective We aimed to i) assess changes in patterns of reported ED in men ≤ 40 yr, and ii) compare the sociodemographic and clinical characteristics of ED men ≤ 40 yr vs. &amp;gt; 40 yr of age over a 8-yr period at a single academic centre. Methods Comprehensive data of 1179 patients seeking first medical help for ED and assessed by a single Sexual Medicine expert between 2013 and 2021 were analysed. Health-significant comorbidities were scored using the Charlson comorbidity index. All patients completed the International Index of Erectile Function (IIEF) at baseline. Descriptive statistics tested the sociodemographic and clinical characteristics of ED men ≤ 40 yr vs. &amp;gt; 40 yr of age. Within the two groups, multivariable linear regression models tested the association between advancing age and IIEF scores. Local polynomial regression models were applied to explore and graphically display ≤ 40 yr patients’ likelihood to report ED over the analysed time frame and to display changes of the IIEF-EF scores over increasing age between the two groups (≤ 40 yr vs. &amp;gt; 40 yr). Results Overall, median (IQR) age was 52 (41-62) yr. Median (IQR) IIEF-EF was 18 (15-22) at baseline. Of all, 268 (22.7%) were ≤ 40 yr whereas 911 (77.3%) were &amp;gt; 40 yr at baseline. Rates of severe ED according to IIEF-EF did not differ between men ≤ 40 yr and &amp;gt;40yr (60 (22.4%) vs. 155 (17%)). No significant differences were found for the IIEF domains (-IS, -OS, -SD) but IIEF-OF domains, which scored higher in younger men (9 () vs. 8 (), p=0.002). At baseline, younger patients reported less comorbidities, less active smoking, lower BMI, higher total testosterone (tT) levels than older patients (all p 40 yr, increasing age was linearly correlated with decreasing IIE-EF (all p 40 yr). Conclusions We observed that one out of five men seeking first medical help for ED at a single academic centre were younger than 40 yr. This trend has remained stable over the last 8-years, but slightly lower than the previous decade. Increasing age among younger patients is not associated with worse erectile function as oppositely occurs among patients &amp;gt; 40 yr. Disclosure No

(330) Trends of Reporting Premature Ejaculation Among Men with Erectile Dysfunction – Findings From a Real-life Cross-sectional Study

Abstract Introduction Patients with erectile dysfunction (ED) may have an increased risk to report concomitant premature ejaculation (PE) Objective We aimed to explore the trend of reporting PE across three different age groups of a homogenous cohort of men seeking first medical help for ED (&amp;lt; 40 yr, 40-60 yr, &amp;gt; 70yr) over a 16-year period at a single tertiary academic centre. Methods Complete data of 1258 men consecutively assessed for ED as primary complaint by a single Sexual Medicine expert between 2005 and 2021 were analysed. Patients were divided into three age categories: i) &amp;lt;40 years, ii) 40-69 years, and iii) ≥ 70 years. All patients were assessed with a comprehensive medical and sexual history. Comorbidities were scored with the Charlson Comorbidity Index (CCI). All patients completed the International Index of Erectile Function (IIEF) at baseline. Between the three groups i) descriptive statistics tested the sociodemographic and clinical differences; ii) regression models tested the probability of reporting concomitant PE over time; and, iii) local polynomial regression models graphically explored the probability of reporting PE (primary/secondary) together with ED over the analysed time frame. Results Overall, median (IQR) age was 51 (40-61) years. Of all, 326 (25.9%) reported either life-long or acquired PE at time of first clinical assessment. Among the three age groups (70) there were no significant differences in terms of baseline IIEF domains. Younger patients reported higher rates of PE in respect to older ones (0.5% vs. 0.4% vs. 0.3%, p=0.001). Logistic regression analysis showed a statistically significant trend of reporting PE over the years among the &amp;lt; 40yr (OR: 1.4; 95%CI: 1.3-1.5) and 40-69yr (OR: 1.3; 95%CI: 1.2-1.4) groups respectively (all p&amp;lt;0.0001). A not significant trend was found in the ≥ 70yr group. Figure 1 graphically displays the probability of reporting PE in the whole cohort and among the three age-matched groups between 2005 and 2021. Conclusions Almost one out of four patients seeking first medical help for ED also reports to suffer from PE. The probability of reporting PE (either primary or secondary) has been exceptionally increasing over the last 15 years among young (&amp;lt;40) and middle-age (40-69) men with ED. This finding is of major clinical relevance in order to a better tailored therapeutic work-up in the real life setting. Disclosure No

PD11-04 EFFECT OF HEALTH AND AGE ON TOTAL TESTOSTERONE: HEALTHY MEN HAVE HIGHER TESTOSTERONE REGARDLESS OF AGE

You have accessJournal of UrologyCME1 Apr 2023PD11-04 EFFECT OF HEALTH AND AGE ON TOTAL TESTOSTERONE: HEALTHY MEN HAVE HIGHER TESTOSTERONE REGARDLESS OF AGE William Shyr, Jonathan Davilla, Darius Paduch, and Great Neck William ShyrWilliam Shyr More articles by this author , Jonathan DavillaJonathan Davilla More articles by this author , Darius PaduchDarius Paduch More articles by this author , and Great NeckGreat Neck More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003251.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The arbitrary cut-off total testosterone (TT) level of 300 ng/dL is used to diagnose hypogonadism in men of all ages, although intuitively, younger men should have higher TT levels. There is growing evidence that TT level is a proxy of men’s overall health. This study aimed to analyze the effects of age, common comorbidities, and body mass index (BMI) on TT. METHODS: Data from the 2013-2016 NHANES survey were analyzed. TT was measured using liquid chromatography-mass spectrometry certified by the CDC. Only men 18-79 years old were evaluated in the study. Men taking testosterone and aromatase inhibitors were excluded. We conducted a multivariate analysis of the following risk factors for low TT: age, BMI, diabetes mellitus (DM), hypertension (HTN), hypercholesterolemia, and coronary artery disease (CAD). DM was defined as HgA1c ≥ 6.5% or diagnosis by a physician, and hypercholesterolemia as cholesterol above 240 mg/dL or diagnosis by a physician. Healthy men were defined as men with BMI <24.9 without any of the above risk factors. Linear and local polynomial regression models were used for fitting TT. The t-test was used to compare mean TT between groups. Statistical significance (SS) was set at p<0.05. RESULTS: The study consisted of 4,615 men with a median age of 46 years. Multivariate analysis showed that hypercholesterolemia (p<0.001), DM (p=0.03), and elevated BMI (p<0.001) were predictors of low TT. Neither age nor HTN was SS for TT in the multivariate analysis. With age, TT level slightly decreased, especially from 18 to 34. There were twice as many hypogonadal (TT < 300 ng/dL) men at the age of 34 than at the age of 18 (25% v 12.5%; p<0.001). The overall mean TT level for healthy men was higher at 522 ng/dL (95%CI: 506-538) than unhealthy men at 390 ng/dL (95%CI: 382-398) (p<0.001) (Figure 1). Mean values of TT in both healthy men and men with comorbidities are higher than the cutoff value of 300 ng/dL. CONCLUSIONS: Obesity, even being overweight, and poor cardiovascular health, but not age, are strongly associated with lower TT. Healthy men, regardless of age, typically have TT levels above 500 ng/dL. Our study suggests that weight loss, controlling DM and cardiovascular risk factors likely increase TT, and such interventions should be discussed with patients in addition to testosterone therapy. Source of Funding: Fracchia Research Scholarship © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e333 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information William Shyr More articles by this author Jonathan Davilla More articles by this author Darius Paduch More articles by this author Great Neck More articles by this author Expand All Advertisement PDF downloadLoading ...

Estimation of Critical Collapse Solutions to Black Holes with Nonlinear Statistical Models

The self-similar gravitational collapse solutions to the Einstein-axion–dilaton system have already been discovered. Those solutions become invariants after combining the spacetime dilation with the transformations of internal SL(2, R). We apply nonlinear statistical models to estimate the functions that appear in the physics of Black Holes of the axion–dilaton system in four dimensions. These statistical models include parametric polynomial regression, nonparametric kernel regression and semi-parametric local polynomial regression models. Through various numerical studies, we reached accurate numerical and closed-form continuously differentiable estimates for the functions appearing in the metric and equations of motion.

Premature ejaculation among men with erectile dysfunction-findings from a real-life cross-sectional study.

Concomitant sexual disorders have progressively shown increased prevalence in men at first outpatient presentation. We sought to i) estimate the prevalence of unreported premature ejaculation (PE) in a homogenous cohort of 1258 men seeking first medical help for erectile dysfunction (ED) as their primary compliant; ii) compare the baseline sociodemographic and clinical characteristics of men with only ED(ED-only) compared to those with ED and PE(ED + PE); and, iii) investigate the likelihood of detecting PE among men self-reporting only ED over a 16-year period at a single tertiary-referral centre. Descriptive statistics compared sociodemographic and clinical characteristics between ED-only patients and those with unreported concomitant primary/secondary PE(ED + PE). Logistic regression models predicted the risk of having ED + PE at baseline. Local polynomial regression models graphically explored the probability of reporting PE among ED men with ≤40 vs. 41-60 vs. >60 years over the analysed timeframe. Of all, 932 (74.1%) were ED-only and 326 (25.9%) ED + PE patients, respectively. ED + PE patients were younger, presented with fewer comorbidities, and lower rates of severe ED (all p ≤ 0.04). At multivariable logistic regression analysis, younger age (OR:0.98) and low sexual desire/interest (OR:1.54) were independently associated with ED + PE at first clinical assessment (all p = 0.03). The likelihood of detecting unreported concomitant primary/secondary PE among patients complaining of only ED at first presentation worrisomely increased among younger and middle-aged men over the last 16 years.

MP21-12 STILL ONE OUT OF FIVE MEN PRESENTING FOR ERECTILE DYSFUNCTION ARE YOUNG THAN 40 YEARS OF AGE: FINDINGS OF A REAL-LIFE CROSS-SECTIONAL STUDY OVER LAST DECADE

You have accessJournal of UrologyCME1 May 2022MP21-12 STILL ONE OUT OF FIVE MEN PRESENTING FOR ERECTILE DYSFUNCTION ARE YOUNG THAN 40 YEARS OF AGE: FINDINGS OF A REAL-LIFE CROSS-SECTIONAL STUDY OVER LAST DECADE Edoardo Pozzi, Paolo Capogrosso, Giuseppe Fallara, Luca Boeri, Christian Corsini, Daniele Cignoli, Massimiliano Raffo, Luigi Candela, Nicolò Schifano, Alessia d'Arma, Rayan Matloob, Federico Dehò, Vincenzo Mirone, Francesco Montorsi, and Andrea Salonia Edoardo PozziEdoardo Pozzi More articles by this author , Paolo CapogrossoPaolo Capogrosso More articles by this author , Giuseppe FallaraGiuseppe Fallara More articles by this author , Luca BoeriLuca Boeri More articles by this author , Christian CorsiniChristian Corsini More articles by this author , Daniele CignoliDaniele Cignoli More articles by this author , Massimiliano RaffoMassimiliano Raffo More articles by this author , Luigi CandelaLuigi Candela More articles by this author , Nicolò SchifanoNicolò Schifano More articles by this author , Alessia d'Arma Alessia d'Arma More articles by this author , Rayan MatloobRayan Matloob More articles by this author , Federico DehòFederico Dehò More articles by this author , Vincenzo MironeVincenzo Mirone More articles by this author , Francesco MontorsiFrancesco Montorsi More articles by this author , and Andrea SaloniaAndrea Salonia More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002554.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Erectile dysfunction (ED) has been demonstrated to be reasonably prevalent among young men (≤40 yr). We aimed to i) assess changes in patterns of reported ED in men ≤40 yr, and ii) compare the sociodemographic and clinical characteristics of ED men ≤40 yr vs. >40 yr of age over a 8-yr period at a single academic centre. METHODS: Data of 1179 patients seeking first medical help for ED and assessed by a single Sexual Medicine expert between 2013 and 2021 were analysed. All patients completed the IIEF at baseline. Descriptive statistics tested the sociodemographic and clinical characteristics of ED men ≤ 40 yr vs. > 40 yr of age. Within the two groups, multivariable linear regression models tested the association between advancing age and IIEF scores. Local polynomial regression models were applied to explore and graphically display ≤ 40 yr patients’ likelihood to report ED over the analysed time frame and to display changes of the IIEF-EF scores over increasing age between the two groups. RESULTS: Overall, median (IQR) age was 52 (41-62) yr. Median (IQR) IIEF-EF was 18 (15-22) at baseline. Of all, 268 (22.7%) were ≤40 yr whereas 911 (77.3%) were >40 yr at baseline. Rates of severe ED according to IIEF-EF did not differ between men ≤40 yr and >40yr (60 (22.4%) vs. 155 (17%)). No significant differences were found for the IIEF domains (-IS, -OS, -SD) but IIEF-OF domains, which scored higher in younger men (9 () vs. 8 (), p=0.002). At baseline, younger patients reported less comorbidities, less active smoking, lower BMI, higher total testosterone (tT) levels than older patients (all p<0.005). At linear regression models, within the ≤ 40 yr group, increasing age was not associated with changes across all IIEF domains. In contrast, in men > 40 yr, increasing age was linearly correlated with decreasing IIE-EF (all p<0.001), after adjusting for tT, BMI, CCI, smoking and arterial hypertension. Figure 1 graphically displays a stable 8-yr temporal trend of ≤40 yr ED patients. CONCLUSIONS: One out of five men seeking first medical help for ED at a single academic centre were younger than 40 yr. This trend has remained stable over the last 8-years. Increasing age among younger patients is not associated with worse erectile function as oppositely occurs among patients > 40 yr. Source of Funding: N/A © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e331 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Edoardo Pozzi More articles by this author Paolo Capogrosso More articles by this author Giuseppe Fallara More articles by this author Luca Boeri More articles by this author Christian Corsini More articles by this author Daniele Cignoli More articles by this author Massimiliano Raffo More articles by this author Luigi Candela More articles by this author Nicolò Schifano More articles by this author Alessia d'Arma More articles by this author Rayan Matloob More articles by this author Federico Dehò More articles by this author Vincenzo Mirone More articles by this author Francesco Montorsi More articles by this author Andrea Salonia More articles by this author Expand All Advertisement PDF DownloadLoading ...

Estimation of Critical Collapse Solutions to Black Holes with Nonlinear Statistical Models

The self-similar gravitational collapse solutions to the Einstein-axion-dilaton system have already been found out. Those solutions become invariants after combining the spacetime dilation with the transformations of internal SL(2, R). We apply nonlinear statistical models to estimate the functions that appear in the physics of Black Holes of the axion-dilaton system in four dimensions. These statistical models include polynomial regression, nonparametric kernel regression and local polynomial regression models. Through various numerical studies, we reached accurate numerical and closed-form continuously differentiable estimates for the functions appearing in the metric and equations of motion.

Propagation Map Reconstruction via Interpolation Assisted Matrix Completion

Constructing a propagation map from a set of scattered measurements finds important applications in many areas, such as localization, spectrum monitoring and management. Classical interpolation-type methods have poor performance in regions with very sparse measurements. Recent advance in matrix completion has the potential to reconstruct a propagation map from sparse measurements, but the spatial resolution is limited. This paper proposes to integrate interpolation with matrix completion to exploit both the spatial correlation and the potential low rank structure of the propagation map. The proposed method first enriches matrix observations using interpolation, and develops the statistics of the interpolation error based on a local polynomial regression model. Then, two uncertainty-aware matrix completion algorithms are developed to exploit the interpolation error statistics. It is numerically demonstrated that the proposed method outperforms Kriging and other state-of-the-art schemes, and reduces the mean squared error (MSE) of propagation map reconstruction by 10%-50% for a medium to large number of measurements.

COMPARATIVE ANALYSIS FOR FUZZY NONPARAMETRIC REGRESSION MODELS

Statistical modeling is essential in revealing the relationships between variables. These models can be classified as parametric and nonparametric methods in studies using crisp values. However, most of the data collected are inherently fuzzy. In this framework, it has been a subject that has been studied from past to present that the methods derived for exact values are expressed as methods with fuzzy valued input and output variables. The study aims to describe nonparametric local polynomial regression models in fuzzy structure to examine the results for cases where an input variable is a crisp number, and the output variable is a symmetrical triangular and trapezoidal fuzzy number. According to the results, the bandwidth parameter was smaller in models where the degree of the polynomial was taken as one and larger in the case of three. In addition, the bandwidth parameter was found to be larger in models using the Epanechnikov kernel.

Shifting Treatment Patterns and Clinical Outcomes in Veterans Diagnosed with Waldenstrom Macroglobulinemia from 2006 to 2018

Background Waldenström's Macroglobulinemia (WM) is a rare indolent lymphoma with an estimated 1,500 new cases diagnosed each year in the United States (US). Over the last decade, several treatments have been introduced into the WM therapeutics landscape including, bendamustine, bortezomib, and most recently oral Bruton's kinase inhibitor (ibrutinib). There is limited information in the adoption of these WM treatments in real-world clinical settings in the US. We describe the practice patterns and clinical outcomes of first-line (1L) treatment of WM in a nationwide cohort of Veterans. Methods Using Veteran Affairs electronic health records (EHR) data, we identified Veterans who were diagnosed and received 1L treatment for WM between January 2006 and December 2018 in the Veterans Health Administration (VHA). Human annotation of EHR clinical records confirmed the diagnosis and 1L treatment regimens. Patients with another cancer diagnosis or patients with documentation that 1L treatment was received outside the VHA were excluded. Eligible patients were followed until loss to follow-up, death, or the end of the study period (June 30, 2019). Patient demographics, disease characteristics, and treatment patterns were identified. Local polynomial regression model curves were generated to demonstrate treatment changes over time. Unadjusted progression-free survival (PFS) and the unadjusted overall survival (OS) are also provided. Results We identified 505 patients diagnosed with WM in VHA between January 2006 thru December 2018. Of these, 318 patients received 1L treatment, with a median time from diagnosis to 1L treatment of 1.2 months (95% confidence interval [CI]: 0.5-5 months). The median age of WM patients was 69.9 years (standard deviation [SD]: 9.4 years), with approximately 73% of WM patients ≥65 years old. Prior to 1L treatment, the median hemoglobin and platelets observed were similar across all treatment groups, regardless of first 1L treatment. However, the median immunoglobulin M (IgM) was substantially lower in patient's treated with ibrutinib (2,570 mg/dL [range: 422-9,001 mg/dL]) and single-agent rituximab (R), 2,855 mg/dL (range: 84-7,880 mg/dL) when compared to those treated with chlorambucil +/- rituximab (4,416 mg/dL [range: (9-8,130 mg/dL]) and bortezomib/dexamethasone +/- rituximab (BDR), 4,086 mg/dL (range: 16-9,944 mg/dL). MYD88 testing occurred in 40 (13%) of patients, with testing most frequently occurring in patients treated with bendamustine +/- rituximab (BR), ibrutinib, and BDR- likely reflecting increased adoption in later periods. Hepatitis C testing occurred in 61 (19%) of patients, with testing most frequently occurring in patients treated with dexamethasone, rituximab, and cyclophosphamide (DRC), BDR, and BR. Over the study observation period, 1L practice patterns shift significantly with increased adoption of BR, BDR and ibrutinib and de-adoption of chemotherapy (Figure 1). The median follow-up time for all patients was 44 months (range: 1-147 months), although a shorter median follow-up time was observed in patients treated with therapeutics in recent years, such as ibrutinib (18 months [range: 2-53 months]) and BR (23 months [range: 4-86 months]). The median unadjusted PFS for all WM patients was 44 months (95% CI: 37-58 months) and the median unadjusted overall survival (OS) was 94 months (95% CI: 82-117 months). Conclusions The introduction of numerous therapeutic options throughout the past decade has profoundly altered the treatment landscape for WM, suggesting a shift in 1L practices from chlorambucil to BDR, BR, and most recently ibrutinib which has been increasingly adopted, since its approval in 2015, especially in older patients, suggesting that it may provide an effective therapeutic option for patients who may not be able to tolerate more aggressive treatment regimens. Limitations of this study include the differences observed in follow-up time as well as the limited number of patients in some 1L treatment groups. Further research is required to establish the long-term benefits and potential treatment-related toxicities of WM treatments in real-world clinical settings. Disclosures Sauer: Roche: Research Funding; Genentech, Inc.: Research Funding; Pharmacyclics: Research Funding; AbbVie: Research Funding. Halwani:AbbVie: Research Funding; Takeda: Research Funding; Roche: Research Funding; Genentech, Inc.: Research Funding; Miragen: Research Funding; Immunedesign: Research Funding; Kyowa Hakko Kirin: Research Funding; Seattle Genetics: Research Funding; Amgen: Research Funding; Pharmacyclics: Research Funding; Bristol Myers Squibb: Research Funding.

Evaluation of Historical CMIP5 GCM Simulation Results Based on Detected Atmospheric Teleconnections

Atmospheric teleconnections are characteristic to the climate system and exert major impacts on the global and regional climate. Accurate representation of teleconnections by general circulation models (GCMs) is indispensable given their fundamental role in the large scale circulation patterns. In this study a statistical method is introduced to evaluate historical GCM outputs of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) with respect to teleconnection patterns. The introduced method is based on the calculation of correlations between gridded time series of the 500 hPa geopotential height fields in the Northern Hemisphere. GCMs are quantified by a simple diversity index. Additionally, potential action centers of the teleconnection patterns are identified on which the local polynomial regression model is fitted. Diversity fields and regression curves obtained from the GCMs are compared against the NCEP/NCAR Reanalysis 1 and the ERA-20C reanalysis datasets. The introduced method is objective, reproducible, and reduces the number of arbitrary decisions during the analysis. We conclude that major teleconnection patterns are positioned in the GCMs and in the reanalysis datasets similarly, however, spatial differences in their intensities can be severe in some cases that could hamper the applicability of the GCM results for some regions. Based on the evaluation method, best-performing GCMs can be clearly distinguished. Evaluation of the GCMs based on the introduced method might help the modeling community to choose GCMs that are the most applicable for impact studies and for regional downscaling exercises.

Trends in reported male sexual dysfunction over the past decade: an evolving landscape.

We investigated changes in patterns of reported male SDs at a single academic centre over a 10-year time frame. Comprehensive data of 2013 patients consecutively assessed for the first time by a single Sexual Medicine expert between 2006 and 2019 has been analysed. All patients were assessed with a thorough sexual and medical history. Primary reason for seeking medical help at first assessment was recorded for all patients and categorized as: erectile dysfunction (ED), premature ejaculation (PE), low/reduced sexual desire/interest (LSD/I), Peyronie's disease (PD), and other SDs. Linear and logistic regression models tested the association between different reasons for seeking medical help and the time at first evaluation. Local polynomial regression model explored the probability of reporting different SDs over the analysed time frame. Median (IQR) age at first clinical assessment was 50 (38-61) years. Overall, most patients were assessed for ED (824; 41%), followed by PD (369; 18%), PE (322; 16%), LSD/I (204; 10%) and other SDs (294; 15%). Significant changes in terms of reported SD over the analysed time frame were observed. The likelihood of assessing patients for ED significantly increased up to 2013, with a decrease in the past 5 years (p < 0.001). PE assessment at presentation linearly decreased over time (OR: 0.94; 95% CI: 0.91-0.96; p < 0.001). Patients assessed during the past few years were more likely to report PD (OR: 1.20; 95% CI: 1.15-1.25; p < 0.001) and LSD/I (OR: 1.21; 95% CI: 1.16-1.26; p < 0.001), with a linear increase over the evaluated time frame. Likewise, patients were also more likely to report other SDs (Coeff: 1.06; 95% CI: 1.02-1.10; p = 0.004), with a linear increase over time. These results may reflect real changes in SD incidence, increased public awareness towards different SDs and the possible impact of novel treatments available on the market throughout the same time frame.

Dynamic property of consumer-based brand competitiveness (CBBC) in human interaction behavior

Purpose The purpose of this paper is to identify potential competitive relationships among brands by analyzing the dynamic clicking behavior of consumers. Design/methodology/approach Consumer sequential online click data, collected from JD.com, is used to analyze the dynamic competitive relationship between brands. It is found that the competition intensity across categories of products can differ considerably. Consumers exhibit big differences in purchasing time of durable-like goods, that is, the purchasing probability of such products changes considerably over time. The local polynomial regression model (LPRM) is used to analyze the relationship between brand competition of durable-like goods and the purchasing probability of a particular brand. Findings The statistical results of collective behaviors show that there is a 90/10 rule for the category durable-like goods, implying that ten percent of the brands account for 90 percent market share in terms of both clicking and purchasing behavior. The dynamic brand cognitive process of impulsive consumers displays an inverted V shape, while cautious consumers display a double V shaped cognitive process. The dynamic consumers’ cognition illustrates that when the brands capture a half of the click volume, the brands’ competitiveness reaches to its peak and makes no significant different from brands accounting for 100 percent of the click volume in terms of the purchasing probability. Research limitations/implications There are some limitations to the research, including the limitations imposed by the data set. One of the most serious problems in the data set is that the collected click-stream is desensitized severely, restricting the richness of the conclusions of this study. Second, the data set consists of many other consumer behavioral data, but only the consumer’s clicking behavior is analyzed in this study. Therefore, in future research, the parameters brand browsing by consumers and the time of browsing in each brand should be added as indicators of brand competitive intensity. Practical implications The authors study brand competitiveness by analyzing the relationship between the click rate and the purchase likelihood of individual brands for durable-like products. When the brand competitiveness is less than 50 percent, consumers tend to seek a variety of new brands, and their purchase likelihood is positively correlated with the brand competitiveness. Once consumers learn about a particular brand excessively among all other brands at a period of time, the purchase likelihood of its products decreases due to the thinner consumer’s short-term loyalty the brand. Till the brand competitiveness runs up to 100 percent, consumers are most likely to purchase a brand and its product. That indicates brand competitiveness maintain 50 percent of the whole market is most efficient to be profitable, and the performance of costing more to improve the brand competitiveness might make no difference. Originality/value There are many studies on brand competition, but most of these research works analyze the brand’s marketing strategy from the perspective of the company. The limitation of this research is that the data are historical and failure to reflect time-variant competition. Some researchers have studied brand competition through consumer behavior, but the shortcoming of these studies is that it does not consider sequentiality of consumer behavior as this study does. Therefore, this study contributes to the literature by using consumers’ sequential clicking behavior and expands the perspective of brand competition research from the angle of consumers. Simultaneously, this paper uses the LPRM to analyze the relationship between consumer clicking behavior and brand competition for the first time, and expands the methodology accordingly.

Short-Term Electricity Demand Forecasting Using Components Estimation Technique

Currently, in most countries, the electricity sector is liberalized, and electricity is traded in deregulated electricity markets. In these markets, electricity demand is determined the day before the physical delivery through (semi-)hourly concurrent auctions. Hence, accurate forecasts are essential for efficient and effective management of power systems. The electricity demand and prices, however, exhibit specific features, including non-constant mean and variance, calendar effects, multiple periodicities, high volatility, jumps, and so on, which complicate the forecasting problem. In this work, we compare different modeling techniques able to capture the specific dynamics of the demand time series. To this end, the electricity demand time series is divided into two major components: deterministic and stochastic. Both components are estimated using different regression and time series methods with parametric and nonparametric estimation techniques. Specifically, we use linear regression-based models (local polynomial regression models based on different types of kernel functions; tri-cubic, Gaussian, and Epanechnikov), spline function-based models (smoothing splines, regression splines), and traditional time series models (autoregressive moving average, nonparametric autoregressive, and vector autoregressive). Within the deterministic part, special attention is paid to the estimation of the yearly cycle as it was previously ignored by many authors. This work considers electricity demand data from the Nordic electricity market for the period covering 1 January 2013–31 December 2016. To assess the one-day-ahead out-of-sample forecasting accuracy, Mean Absolute Percentage Error (MAPE), Mean Absolute Error (MAE), and Root Mean Squared Error (RMSE) are calculated. The results suggest that the proposed component-wise estimation method is extremely effective at forecasting electricity demand. Further, vector autoregressive modeling combined with spline function-based regression gives superior performance compared with the rest.

Prediction of daily reservoir inflow using atmospheric predictors

Reservoir systems need the forecast of rainfall and inflow on daily time scale for planning of water allocation to different users. Prediction of daily rainfall or daily reservoir inflow is a challenging task in water resource management. This study aims at forecasting the daily reservoir inflow using the projections of atmospheric variables extracted from the global climatic models as input. Daily rainfall series for the future period is simulated using a calibrated weather generator based on generalized linear models. The simulated daily rainfall series are compared with the monthly predictions obtained from local polynomial regression model, and the best correlated daily rainfall simulation is transformed into stream flow using a calibrated and validated soil and water assessment tool to generate the daily inflow series. The modelling procedure was applied to a typical reservoir catchment in India. Diagnostic checks carried out to assess the performance of the rainfall simulations revealed that the simulated series are having the same statistical characteristics as that of the observed series. The simulated inflow was found to be acceptable with respect to the performance indicators evaluated in the study. The methodology adopted is data driven, flexible and easy to implement.

Investigating effects of bandwidth selection in local polynomial regression model with applications

Cross-validation (CV) and direct plug-in (DPI) are two commonly used bandwidth selection methods in nonparametric estimation. In this paper, we compare the performance of CV and DPI methods in local polynomial kernel regression through simulation study. We consider continuous response and binary re sponse cases, with local constant, local linear and local quadratic kernel estimators, respectively. Furthermore, we investigate the first derivatives of local quadratic kernel estimators. Our results show that CV and DPI methods excel in different cases, in terms of minimizing the Mean Integrated Squared Errors (MISE); the results are also verified in empirical studies.