Log-transformed Variables Research Articles

The hind limb of Octodontidae (Rodentia, Mammalia): Functional implications for substrate preferences

Octodontids are South American caviomorph rodents endemic to mesic and arid biomes displaying a wide range of substrate preferences, from terrestrial to subterranean habits. However, the hind limb morphology of these rodents remain relatively poorly understudied, particularly from an ecomorphological perspective. To investigate the association between hind limb morphology and substrate preference—epigean, semifossorial, fossorial, and subterranean— this study analyzed six skeletal measurements of femur and tibia, along with five morphological indices. We employed phylogenetic mapping, allometry, and multivariate analyses (Phylogentic Flexible Discriminant and Principal Component analyses) on log-transformed variables and indices. The results suggest that the epigeans and subterraneans possess hind limb skeletal features that enhance their mechanical capabilities, which are advantageous for their respective lifestyles. However, in the absence of clear behavioral adaptations or associations, the functional habits of Octodontidae do not requires significant structural modifications of the proximal bones of the hind limbs. These results indicate that understanding the form-function relationship in octodontids requires direct field or laboratory observations of behavior and environmental interactions, highlighting the limitations of current research without such data.

Neurofilament heavy chain and chitinase 3-like 1 as markers for monitoring therapeutic response in multiple sclerosis

AimsThe aim of this study was to evaluate the association of serum neurofilament heavy chain (sNfH) and chitinase 3-like 1 (sCHI3L1) with treatment response and disease activity in multiple sclerosis (MS). MethodsThis single-center, prospective, observational cohort study was conducted at the MS Centre, University Hospital Ostrava, Czech Republic, from May 2020 to August 2023. sNfH and sCHI3L1 were determined using ELISA. A mixed-effects linear model with a log-transformed outcome variable was applied. ResultsWe analyzed 459 samples from 57 people with MS. Patients were sampled an average of 8.05 times during 21.9 months of follow-up. Those experiencing a relapse at sampling had a sNfH concentration 50 % higher than those in remission (exp(β) 1.5, 95 % CI 1.15–1.96). A longer duration of treatment was associated with lower sNfH (exp(β) 0.95, 95 % CI 0.94–0.96). Patients switched from low- to high-efficacy disease-modifying therapies (DMTs) had higher sNfH than patients treated with low-efficacy DMTs only (exp(β) 1.95, 95 % CI 1.35–2.81). Higher sCHI3L1 was associated with older age (exp(β) 1.01, 95 % CI 1.00–1.02) and longer DMT use (exp(β) 1.01, 95 % CI 1.00–1.02). sCHI3L1 values were not associated with relapse at the time of sampling, renal function, sex, or type of DMT. ConclusionIn contrast to sCHI3L1, sNfH may be a potential biomarker for monitoring treatment response and confirming clinical relapse in MS. Further research is needed to determine the long-term dynamics of sNfH and develop related treatment strategies.

Increased Ventilatory Efficiency in Supramaximal Compared to Graded Exercise in Athletes

ABSTRACT Background: Supramaximal constant work rate tests (CWR) elicit intense hyperventilation, thus potentially up-shifting ventilation (⩒E)-to-carbon dioxide (CO2) responses when compared to graded exercise tests (GXT) in athletes. We predicted higher ventilatory efficiency on supramaximal CWR using a new method, challenging the classic orthodox interpretation of an increased ⩒ E -⩒CO2 as ventilatory inefficiency. This misinterpretation could make difficult to differentiate between physiological hyperventilation from heart disease conditions in athletes. Methods: On different days, a GXT and a CWR at 110% of the maximal velocity achieved in the GXT were performed. Twenty-seven athletes completed the two tests and were compared for usual (linear regression) and log-transformed new variables for ventilatory efficiency through paired t-Student statistics. Results: The ⩒ E -⩒CO2 slope (31.4 ± 4.9 vs. 26.2 ± 3.4, p < .001), ⩒ E -⩒CO2 intercept (7.2 ± 7.5 vs. 2.8 ± 4.2, p < .007), ⩒ E /⩒CO2 nadir (33.0 ± 3.6 vs. 25.4 ± 2.2, p < .001), ⩒CO2-log⩒ E slope (10.8 ± 2.9 vs. 6.9 ± 2.2 L*logL−1, p < .001), and η⩒ E (36.0 ± 12 vs. 22.8 ± 8.1%, p < .001) values were all significantly higher in the CWR compared to the GXT. We registered a bi-modal nadir response for ⩒E/⩒CO2 on CWR for 22 out of 27 subjects for the first time. A weak association was observed between ⩒ E /⩒CO2 nadir (coefficient of determination ~ 27%) and time to exhaustion. Conclusions: The new method allows us to improve the quantification and interpretation of ventilatory efficiency in athletes, avoiding misinterpretation due to the up-shifting elicited by the usual ⩒ E -⩒CO2 slope and ⩒ E /⩒CO2 nadir indices, which may be confounded with ventilatory inefficiency. This study suggests that ventilatory changes underpin better ventilatory efficiency during CWR.

Voxel-based dosimetry with integrated Y-90 PET/MRI and prediction of response of primary and metastatic liver tumors to radioembolization with Y-90 glass microspheres.

In this study, we aimed to evaluate the response of the primary and metastatic liver tumors to radioembolization with 90Y glass microspheres and investigate its correlations with dosimetric variables calculated with 90Y PET/MRI. In this ambispective study, 44 patients treated with 90Y glass microspheres and imaged with 90Y PET/MRI were included for analysis. Dosimetric analysis was performed for every perfused lesion using dose-volume histograms. Response was assessed by comparing pre-treatment and follow-up total lesion glycolysis (TLG) values derived from 18F-FDG PET imaging. The relationship between ΔTLG and log-transformed dosimetric variables was analyzed with linear mixed effects regression models. ROC analyses were performed to compare discriminatory power of the variables in predicting response and complete response. Regression and ROC analyses demonstrated that mean tumor dose and almost all D values were statistically significant predictors of treatment response and complete treatment response. Specifically, D60, D70 and D80 values exhibited significantly higher discriminatory power for predicting treatment response compared to the mean dose (Dmean) delivered to tumor. High specificity cut-off values to predict response were determined as 160.75 Gy for Dmean, 95.50 Gy for D60, 89 Gy for D70, and 59.50 Gy for D80. Similarly, high-specificity cut-off values to predict complete response were 262.75 Gy for Dmean, 173 Gy for D70, 140.5 Gy for D80, and 100 Gy for D90. In this study, we demonstrated that voxel-based dosimetry with post-treatment 90Y PET/MRI can predict response to treatment. D60, D70 and D80 variables also did have greater discriminatory power compared to Dmean in prediction of response. In addition, we present high-specificity cut-offs to predict response (CR + PR) and complete response (CR) for both Dmean and several D variables derived from dose-volume histograms.

Association of early dexmedetomidine exposure with brain injury biomarker levels following moderate - severe traumatic brain injury: A TRACK-TBI study

BackgroundTraumatic brain injury (TBI) triggers autonomic dysfunction and inflammatory response that can result in secondary brain injuries. Dexmedetomidine is an alpha-2 agonist that may modulate autonomic function and inflammation and has been increasingly used as a sedative agent for critically ill TBI patients. We aimed to investigate the association between early dexmedetomidine exposure and blood-based biomarker levels in moderate-to-severe TBI (msTBI). MethodsWe conducted a retrospective cohort study using data from the Transforming Clinical Research and Knowledge in Traumatic Brain Injury Study (TRACK-TBI), which enrolled acute TBI patients prospectively across 18 United States Level 1 trauma centers between 2014–2018. Our study population focused on adults with msTBI defined by Glasgow Coma Scale score 3–12 after resuscitation, who required mechanical ventilation and sedation within the first 48 h of ICU admission. The study’s exposure was early dexmedetomidine utilization (within the first 48 h of admission). Primary outcome included brain injury biomarker levels measured from circulating blood on day 3 following injury, including glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCH-L1), neuron-specific enolase (NSE), S100 calcium-binding protein B (S100B) and the inflammatory biomarker C-reactive protein (CRP). Secondary outcomes assessed biomarker levels on days 5 and 14. Linear mixed-effects regression modelling of the log-transformed response variable was used to analyze the association of early dexmedetomidine exposure with brain injury biomarker levels. ResultsAmong the 352 TRACK-TBI subjects that met inclusion criteria, 50 (14.2 %) were exposed to early dexmedetomidine, predominantly male (78 %), white (81 %), and non-Hispanic (81 %), with mean age of 39.8 years. Motor vehicle collisions (27 %) and falls (22 %) were common causes of injury. No significant associations were found between early dexmedetomidine exposure with day 3 brain injury biomarker levels (GFAP, ratio = 1.46, 95 % confidence interval [0.90, 2.34], P = 0.12; UCH-L1; ratio = 1.17 [0.89, 1.53], P = 0.26; NSE, ratio = 1.19 [0.92, 1.53], P = 0.19; S100B, ratio = 1.01 [0.95, 1.06], P = 0.82; hs-CRP, ratio = 1.29 [0.91, 1.83], P = 0.15). The hs-CRP level at day 14 in the dexmedetomidine group was higher than that of the non-exposure group (ratio = 1.62 [1.12, 2.35], P = 0.012). ConclusionsThere were no significant associations between early dexmedetomidine exposure and day 3 brain injury biomarkers in msTBI. Our findings suggest that early dexmedetomidine use is not correlated with either decrease or increase in brain injury biomarkers following msTBI. Further research is necessary to confirm these findings.

Association of aortic valve calcium with dementia and stroke: The Multi-Ethnic Study of Atherosclerosis

Background and aimsCalcific aortic valve disease is associated with increased thrombin formation, platelet activation, decreased fibrinolysis, and subclinical brain infarcts. We examined the long-term association of aortic valve calcification (AVC) with newly diagnosed dementia and incident stroke in the Multi-Ethnic Study of Atherosclerosis (MESA). MethodsAVC was measured using non-contrast cardiac CT at Visit 1. We examined AVC as a continuous (log-transformed) and categorical variable (0, 1–99, 100–299, ≥300). Newly diagnosed dementia was adjudicated using International Classification of Disease codes. Stroke was adjudicated from medical records. We calculated absolute event rates (per 1000 person-years) and multivariable adjusted Cox proportional hazards ratios (HR). ResultsOverall, 6812 participants had AVC quantified with a mean age of 62.1 years old, 52.9 % were women, and the median 10-year estimated atherosclerotic cardiovascular disease (ASCVD) risk was 13.5 %. Participants with AVC >0 were older and less likely to be women compared to those with AVC=0. Over a median 16-year follow-up, there were 535 cases of dementia and 376 cases of stroke. The absolute risk of newly diagnosed dementia increased in a stepwise pattern with higher AVC scores, and stroke increased in a logarithmic pattern. In multivariable analyses, AVC was significantly associated with newly diagnosed dementia as a log-transformed continuous variable (HR 1.09; 95 % CI 1.04–1.14) and persons with AVC ≥300 had nearly a two-fold higher risk (HR 1.77; 95 % CI 1.14–2.76) compared to those with AVC=0. AVC was associated with an increased risk of stroke after adjustment for age, sex, and race/ethnicity, but not after adjustment for ASCVD risk factors. ConclusionsAfter multivariable adjustment, AVC >0 was significantly associated with an increased risk of newly diagnosed dementia, but not incident stroke. This suggests that AVC may be an important risk factor for the long-term risk of dementia beyond traditional ASCVD risk factors.

Re-expressing coefficients from regression models for inclusion in a meta-analysis

Meta-analysis poses a challenge when original study results have been expressed in a non-uniform manner, such as when regression results from some original studies were based on a log-transformed key independent variable while in others no transformation was used. Methods of re-expressing regression coefficients to generate comparable results across studies regardless of data transformation have recently been developed. We examined the relative bias of three re-expression methods using simulations and 15 real data examples where the independent variable had a skewed distribution. Regression coefficients from models with log-transformed independent variables were re-expressed as though they were based on an untransformed variable. We compared the re-expressed coefficients to those from a model fit to the untransformed variable. In the simulated and real data, all three re-expression methods usually gave biased results, and the skewness of the independent variable predicted the amount of bias. How best to synthesize the results of the log-transformed and absolute exposure evidence streams remains an open question and may depend on the scientific discipline, scale of the outcome, and other considerations.

How to improve the substantive interpretation of regression results when the dependent variable is logged

Abstract Regression models with log-transformed dependent variables are widely used by social scientists to investigate nonlinear relationships between variables. Unfortunately, this transformation complicates the substantive interpretation of estimation results and often leads to incomplete and sometimes even misleading interpretations. We focus on one valuable but underused method, the presentation of quantities of interest such as expected values or first differences on the original scale of the dependent variable. The procedure to derive these quantities differs in seemingly minor but critical aspects from the well-known procedure based on standard linear models. To improve empirical practice, we explain the underlying problem and develop guidelines that help researchers to derive meaningful interpretations from regression results of models with log-transformed dependent variables.

Levels of Arsenic, Cadmium, and Mercury in Urine of Indigenous People Living Close to Oil Extraction Areas in the Peruvian Amazon.

Levels of Arsenic, Cadmium, and Mercury in Urine of Indigenous People Living Close to Oil Extraction Areas in the Peruvian Amazon.

Prenatal bisphenol A and S exposure and atopic disease phenotypes at age 6

BackgroundAtopic disease may be influenced by prenatal and early life exposure to endocrine disrupting chemicals, including bisphenols, but results from epidemiological studies have been mixed. This study aimed to extend the epidemiological literature, hypothesizing that children with higher prenatal bisphenol exposure are more likely to have childhood atopic disease. MethodsUrinary bisphenol A (BPA) and S (BPS) concentrations were measured in each trimester from 501 pregnant women in a multi-center, prospective pregnancy cohort. Ever asthma, current asthma, wheeze, and food allergy) were assessed at age six via standardized ISAAC questionnaire. We constructed generalized estimating equations to examine BPA and BPS exposure jointly at each trimester for each atopy phenotype. BPA was modeled as a log-transformed continuous variable, whereas BPS was modeled as detected versus not detected. We also modeled pregnancy-averaged BPA values and a categorical indicator for number of detectable BPS values over pregnancy (0–3) in logistic regression models. ResultsFirst trimester BPA was associated with inverse odds of food allergy among the entire study sample (OR = 0.78, 95% CI = 0.64–0.95, p = 0.01) and females only (OR = 0.69, 95% CI = 0.52–0.90, p = 0.006). The inverse relationship persisted in pregnancy-averaged models of BPA among females (OR = 0.56, 95% CI = 0.35–0.90, p = 0.006). Second trimester BPA was associated with greater odds of food allergy in the entire sample (OR = 1.27, 95% CI = 1.02–1.58, p = 0.03) and among males only (OR = 1.48, 95% CI = 1.02–2.14, p = 0.04). Odds of current asthma increased among males in the pregnancy-averaged BPS models (OR = 1.65, 95% CI = 1.01–2.69, p = 0.045). ConclusionWe saw opposite effects of BPA on food allergy that were trimester- and sex-specific. These divergent associations warrant further investigation. There is some evidence to suggest that prenatal BPS is associated with asthma among males, but further research is required in cohorts with a greater proportion of prenatal urine samples with detectable BPS to validate these results.

POvaStim: An online tool for directing individualized FSH doses in ovarian stimulation

POvaStim: An online tool for directing individualized FSH doses in ovarian stimulation

Linear Combination of Leukocyte Count and D-Dimer Levels in the Diagnosis of Patients with Non-traumatic Acute Abdomen

Aim: Rapid intervention is required in patients with non-traumatic acute abdominal pain. It is very important to distinguish between surgical and non-surgical pathologies during this intervention. This study aimed to increase the diagnostic accuracy by combining the leukocyte count and D-dimer levels used in this evaluation with linear combination methods. Materials and Methods: Logistic regression, scoring, min-max, minimax, Su &amp;amp; Liu, Pepe &amp;amp; Thompson, Pepe, Cai &amp;amp; Langton, and Todor &amp;amp; Saplacan methods were used as linear combination methods. The data set was divided into 70% training set and 30% test set. Parameter optimization was performed on the training data by 5 fold cross-validation method using 10 repeats. The area under the ROC curve, sensitivity, selectivity, accuracy, positive and negative predictive value, and positive and negative likelihood ratio statistics were used in the performance evaluation.Results: The area under the ROC curve statistic for D-dimer level and log-transformed leukocyte count variable were obtained as 0.71 and 0.70, respectively. The accuracy rate was 0.69 for the D-dimer level and 0.73 for log-transformed leukocyte count. For the linear combination methods, the area under the ROC curve was between 0.77 and 0.81, and the accuracy statistics were between 0.72 and 0.79. The best performance was obtained with the min-max method.Conclusion: In patients with non-traumatic acute abdominal pain, leukocyte count and D-dimer levels can be evaluated together by using linear combination methods in differentiating surgical and non-surgical pathologies. The obtained results showed that the diagnostic performance of the combined results with the min-max procedure was higher than the leukocyte count and D-dimer levels.

Serum Long Noncoding RNA H19 and CKD Progression in IgA Nephropathy.

IgA nephropathy (IgAN) is one of the most common primary glomerular diseases worldwide, especially in young Asian adults. Long RNA H19 is associated with renal pathologies, such as renal cell injury; however, a connection between serum H19 expression and kidney disease progression has not been demonstrated. Our cohort consisted of 204 patients with IgAN. Serum H19 levels were determined with reverse-transcription quantitative polymerase between 1 May, 2014 and 1 May, 2015. H19 levels were log-transformed and categorical variables were categorized according to cutoff points of a ROC curve. Restricted cubic spline and generalized estimating equation analyses were performed to determine the association between serum H19 and kidney disease progression. H19 expression was significantly downregulated in patients with IgAN compared to healthy controls. Restricted cubic spline analyses showed that the relationship was negatively and linearly correlated (P for nonlinearly = 0.256). After adjusting for other potential clinical, pathologic, and treatment factors, H19 was found to be a protective factor for prognosis in IgAN (HR, 0.52; 95% CI 0.32-0.84; P = 0.008). ROC curve analysis showed that the clinical value of lncRNA H19 with CKD and area under the ROC curve was 0.746 (95% CI 0.663-0.829; P < 0.001) of the clinical prognostic value of H19. Serum restricted cubic spline analyses showed that the relationship was negatively and linearly correlated (P for non-linearly = 0.256). H19 > 0.097 in patients in IgAN was associated with a reductionofthe risk of kidney progression by approximately 70% within 5yearscompared to H19≤0.097 (HR, 0.30;95% CI 0.12-0.74; P = 0.009). H19 is an independent protective factor, and a high level of H19 often indicates better renal outcome within 5years.

367. Procalcitonin as a Potential Biomarker in the Study of Human Babesiosis

Abstract Background Procalcitonin (Pct) has been gaining momentum as a potential biomarker during parasitic infections as studies have demonstrated that Pct levels are significantly elevated during certain forms of protozoal sepsis. Given this, the goal of this pilot study is to determine the relationship between Pct levels and parasitemia (Par) during infection with Babesia microti and to elucidate the potential for Pct to be used as a biomarker in the study of babesiosis. Methods Babesia cases were collected from Stony Brook University Hospital (SBUH) and South Hampton Hospital (SHH) from 2012 to 2019. Median values of maximum Par and Pct throughout hospitalization were recorded and cases were referenced for admission to the intensive care unit (ICU). Correlation between maximum Par and Pct values were examined with the nonparametric Spearman rank correlation and fractional polynomials were used to assess the functional form of the correlation. Receiver-operator characteristic (ROC) curve analyses were used to identify cutoff points for Pct and maximum Par as markers for prediction of ICU admission. Results A total of 33 patients met the inclusion criteria for acute babesiosis. In fractional polynomial analysis, log-transformed Pct levels had a linear correlation with log-transformed maximum Par, r=0.556 (P=0.001, Fig 1A). In ROC curve analysis, a cut off level of ≥ 1.2 ng/mL for Pct had optimal prediction characteristics for ICU admission (sensitivity 62.5%, specificity 88%; correct classification 82%) with a relevant AUC of 0.77 (95% CI: 0.58–0.89; P=0.005, Fig 1B). A cut off level of ≥ 3.6% for maximum Par had optimal prediction characteristics for ICU admission (sensitivity 75%, specificity 92%, correct classification 88%) with a relevant AUC of 0.75 (95% CI 0.58—0.89; P= 0.005, Fig 1B). Comparison of AUC for Pct and Par yielded no significant difference (P=0.8). Figure 1A. Linear correlation between log10-parasitemia and log10- procalcitonin levels. The linear correlation of the log-transformed variables was r=0.556 (P=0.001), similar to the nonparametric (Spearman) correlation coefficient (ρ=0.567). The red dots represent patients who were admitted to the intensive care unit. Figure 1B. Receiver-operator characteristic curve of parasitemia for prediction of intensive care unit admission (0.75; 95%CI: 0.58—0.89; P=0.005); optimal cut-off is 3.6%. Receiver-operator characteristic curve of procalcitonin for prediction of intensive care unit admission (C=0.77; 95%CI: 0.58–0.89; P=0.005); optimal cut-off is 1.2 ng/mL. Conclusion Our analysis demonstrated a positive linear correlation between Pct and maximum Par, which is the current standard marker for severe disease. Also, our ROC analyses estimate that Pct values ≥ 1.2 ng/mL and Par ≥ 3.6% suggests severe disease and need for ICU admission (Fig 1A, 1B). Given this, our findings suggest that Pct may have potential for predicting severe disease during babesiosis. Disclosures All Authors: No reported disclosures.

High adherence to the Mediterranean diet and Alternative Healthy Eating Index are associated with reduced odds of metabolic syndrome and its components in participants of the ORISCAV-LUX2 study.

Metabolic syndrome (MetS) is a major risk factor for cardiometabolic complications. Certain dietary patterns play a pivotal role in improving MetS components. The aim of this investigation was to study associations between the Mediterranean Diet Score (MDS) and the Alternative Healthy Eating Index (AHEI) and the odds of MetS and its components in adults living in Luxembourg. Data from 1,404 adults participating in the cross-sectional ORISCAV-LUX2 study were analyzed by a self-reported questionnaire, anthropometric measures, a food frequency questionnaire (174 items), and blood/urine samples. A significant association of dietary indices and MetS was not found except when expressing MetS as a score (continuous variable, log-transformed), based on the weighting of compounds using exploratory factor analysis with the MDS (β = -0.118, 95% CI: -0.346, -0.120) and AHEI (β = -0.133, 95% CI: -0.059, -0.019). Fully adjusted linear regression models further showed significant inverse associations between components of MetS and MDS (all as log-transformed variables), including body mass index (BMI) (β = -0.0067, 95% CI: -0.0099, -0.0036), waist-circumference (WC) (β = -0.0048, 95% CI: -0.0072, -0.0024), systolic blood pressure (SBP) (β = -0.0038, 95% CI: -0.0061, -0.0016), and diastolic blood pressure (DBP) (β = -0.0035, 95% CI: -0.0060, -0.0009). Similarly, significant inverse associations between AHEI and components of MetS (log-transformed) included BMI (β = -0.0001, 95% CI: -0.0016, -0.0002), WC (β = -0.0007, 95% CI: -0.0011, -0.0002), SBP (β = -0.0006, 95% CI: -0.0010, -0.0002), and DBP (β = -0.0006, 95% CI: -0.0011, -0.0001). Higher adherence to a Mediterranean diet and following healthy eating guidelines were associated with reduced odds of MetS and several of its components in Luxembourgish residents, highlighting that balanced and healthy eating patterns are a crucial cornerstone in the fight against MetS.

Analyzing the relationship between product waste footprints and environmental damage – A life cycle analysis of 1,400+ products

A major problem for the circular economy is monitoring improvements in environmental sustainability. Measuring how much waste reduction efforts contribute to the decrease of environmental impact is difficult, because knowledge on whether life cycle waste amounts correlate with environmental damage is limited. In this article, product waste footprints are used to explore structural similarities and differences in associations with environmental damage. Using the waste flows linked to the production system of 1487 reference products from the Ecoinvent database, we found significant regression equations with R2 of 0.75–0.89 between product waste footprints and potential impact on ecosystem diversity, human health and resource availability using log-transformed variables. For each 1 % increase in solid waste, potential impact on the environment increased by 0.75–0.84 %. This strong association between pre-consumer waste and environmental damage is particularly important for advocating for circular economy efforts at the point of consumption, where life cycle waste is invisible to consumers.

SARIMA and ARDL models for predicting leptospirosis in Anuradhapura district Sri Lanka.

Leptospirosis is considered a neglected tropical disease despite its considerable mortality and morbidity. Lack of prediction remains a major reason for underestimating the disease. Although many models have been developed, most of them focused on the districts situated in the wet zone due to higher case numbers in that region. However, leptospirosis remains a major disease even in the dry zone of Sri Lanka. The objective of this study is to develop a time series model to predict leptospirosis in the Anuradhapura district situated in the dry zone of Sri Lanka. Time series data on monthly leptospirosis incidences from January 2008 to December 2018 and monthly rainfall, rainy days, temperature, and relative humidity were considered in model fitting. The first 72 months (55%) were used to fit the model, and the subsequent 60 months(45%) were used to validate the model. The log-transformed dependent variable was employed for fitting the Univariate seasonal ARIMA model. Based on the stationarity of the mean of the five variables, the ARDL model was selected as the multivariate time series technique. Residuals analysis was performed on normality, heteroskedasticity, and serial correlation to validate the model. The lowest AIC and MAPE were used to select the best model. Univariate models could not be fitted without adjusting the outliers. Adjusting seasonal outliers yielded better results than the models without adjustments. Best fitted Univariate model was ARIMA(1,0,0)(0,1,1)12,(AIC-1.08, MAPE-19.8). Best fitted ARDL model was ARDL(1, 3, 2, 1, 0),(AIC-2.04,MAPE-30.4). The number of patients reported in the previous month, rainfall, rainy days, and temperature showed a positive association, while relative humidity was negatively associated with leptospirosis. Multivariate models fitted better than univariate models for the original data. Best-fitted models indicate the necessity of including other explanatory variables such as patient, host, and epidemiological factors to yield better results.

Association between Official Development Assistance for Water and Sanitation and Countries' Needs from 2002 to 2019.

Although an enormous amount of aid has been invested in water and sanitation, few studies have analyzed the criteria used by the international community to select recipient countries and allocate official development assistance (ODA). We examined whether ODA has been allocated in proportion to water and sanitation needs and whether this has improved over the past 18 years. For water, 141 low- and middle-income countries (LMICs) and least-developed countries (LDCs) were selected, whereas 104 LMICs and LDCs were chosen for sanitation due to a lack of data. For aid disbursement, we used ODA data from the Organization for Economic Cooperation and Developments (OECD) Creditor Reporting System (CRS) from 2002 to 2019. OECD CRS data on water and sanitation are available from 2002 onward. For water and sanitation coverage, we collected data from the WHO/UNICEF Joint Monitoring Program from 2002 to 2019. We examined annual ODA trends and performed linear regression analysis adjusted for GNI per capita using log-transformed dependent variables. Neither total ODA nor ODA per capita was found to be associated with countries’ needs for water and sanitation. For instance, no significant association was detected between at least basic water and sanitation coverage and total ODA per capita in 2019 (log coefficient: 0.002, p = 0.52). The global community needs to determine the reasons for and means of addressing this discrepancy.

Applicant Characteristics Associated with Retina Fellowship Match from 2010–2019

To describe trends in the surgical and medical retina fellowship match and applicant characteristics associated with matching in retina fellowship. Retrospective study. Ophthalmology fellowship applicants who applied through the San Francisco (SF) Match. Publicly available SF Match data were used to describe trends in the number of programs participating and positions offered, filled, and left vacant in the retina fellowship match from 2014 to 2019. Deidentified applicant data for match cycles from 2010 to 2017 were stratified by match status, and characteristics were compared across groups. Trends in matched applicant characteristics were evaluated using linear regression on log-transformed variables. Multivariable logistic regression was used to determine applicant characteristics that were associated with a successful match. Match status. From 2014 to 2019, the number of programs participating, positions filled, and positions left vacant in the retina fellowship match increased from 101 to 119 (P= 0.010), 118 to 123 (P= 0.078), and 18 to 37 (P= 0.045), respectively. Compared with unmatched applicants, matched applicants were more likely to have graduated from a top 10 residency program, US residency, or medical school; hold a United States (US) visa (J-1, H-1B, or O1); distribute more applications; complete more interviews; rank more programs; and score higher on the United States Medical Licensing Examination (USMLE) Step examinations 1-3. Matched applicants completed a median of 10 interviews. After controlling for potential covariates, graduating from a US residency (odds ratio [OR], 2.08; 95% confidence interval [CI], 1.48-2.92), a top 10 residency (OR, 1.74; 95% CI, 1.07-2.84), having an allopathic medical degree (MD; OR, 2.39; 95% CI, 1.08-5.33), completing more interviews (OR, 1.28; 95% CI, 1.23-1.33), and scoring higher on USMLE Step 3 (OR, 1.01; 95% CI, 1.01-1.03) were associated with matching into a retina fellowship. Although the number of programs participating and positions offered in the retina fellowship match are increasing, the number of positions filled remained relatively stagnant. Factors associated with matching in both medical and surgical retina included graduating from a US and top 10-ranked residency program, having an MD, completing more interviews, and scoring higher on USMLE Step3.

In the footsteps of Albert Calmette: an ecological study of TB, leprosy and potential exposure to wild-type Mycobacterium bovis.

One hundred years ago, Albert Calmette developed an avirulent strain of Mycobacterium bovis, but there is no evidence that his BCG strain was more immunogenic than wild-type M. bovis. Geographic variations in BCG efficacy remain ill-understood. We hypothesized that exposure to M. bovis through unpasteurized milk might protect against Mycobacterium tuberculosis and Mycobacterium leprae. After excluding high-income countries (with universal milk pasteurization) and microstates, an ecological study comprising 113 countries was conducted. National data were obtained from United Nations agencies and international organizations about milk production per capita (1980-1999) as a proxy for exposure to wild-type M. bovis, TB (2000-2019) and leprosy (2005-2019) incidence, HIV prevalence (2000-2019), human development index (2010), global hunger index (2010), neonatal BCG coverage (1980-1999), urbanization (2000) and temperature (1990-2020). Multiple linear regression analyses were performed using log-transformed variables. For TB, the association differed by region. An inverse association with milk production was seen in regions outside, but not within, sub-Saharan Africa, after adjustment for confounders. The incidence of leprosy was inversely associated with milk production when combining all countries, but the association was stronger in sub-Saharan Africa. Exposure to wild-type M. bovis through unpasteurized milk may provide cross-protection against M. tuberculosis and M. leprae and contribute to geographic disparities in BCG efficacy. This needs to be confirmed by individual-level studies.