External Validation and Recalibration of a Mortality Prediction Model for Patients with Ischaemic Stroke.

BACKGROUND: Stroke is a highly prevalent disease that can provoke severe disability. We evaluate a predictive model based on the Minimum Basic Data Set (MBDS) compiled by the Spain Health Ministry, obtained for the period 2008-2012 for patients with ischaemic stroke in Spain, to establish the model's validity and to optimise its calibration. The MBDS is the main clinical-administrative database for hospitalisations recorded in Spain, and to our knowledge, no predictive models for stroke mortality have previously been developed using this resource. The main study aim is to perform an external validation and recalibration of the coefficients of this predictive model with respect to a chronologically later cohort. MATERIAL AND METHODS: External validation (testing the model on a different cohort to assess its performance) and recalibration (validation with optimisation of model coefficients) were performed using the MBDS for patients admitted for ischaemic stroke in the period 2016-2018. A cohort study was designed, in which a recalibrated model was obtained by applying the variables of the original model without their coefficients. The variables from the original model were then applied to the subsequent cohort, together with the coefficients from the initial model. The areas under the curve (AUC) of the recalibration and the external validation procedure were compared. RESULTS: The recalibrated model produced an AUC of 0.743 and was composed of the following variables: age (odds ratio, OR:1.073), female sex (OR:1.143), ischaemic heart disease (OR:1.192), hypertension (OR:0.719), atrial fibrillation (OR:1.414), hyperlipidaemia (OR:0.652), heart failure (OR:2.133) and posterior circulation stroke (OR: 0.755). External validation produced an AUC of 0.726. CONCLUSIONS: The recalibrated clinical model thus obtained presented moderate-high discriminant ability and was generalisable to predict death for patients with ischaemic stroke. Rigorous external validation slightly decreased the AUC but confirmed the validity of the baseline model for the chronologically later cohort.

Predictive Model and Mortality Risk Score during Admission for Ischaemic Stroke with Conservative Treatment.

BACKGROUND: Stroke is the second cause of mortality worldwide and the first in women. The aim of this study is to develop a predictive model to estimate the risk of mortality in the admission of patients who have not received reperfusion treatment. METHODS: A retrospective cohort study was conducted of a clinical-administrative database, reflecting all cases of non-reperfused ischaemic stroke admitted to Spanish hospitals during the period 2008-2012. A predictive model based on logistic regression was developed on a training cohort and later validated by the "hold-out" method. Complementary machine learning techniques were also explored. RESULTS: The resulting model had the following nine variables, all readily obtainable during initial care. Age (OR 1.069), female sex (OR 1.202), readmission (OR 2.008), hypertension (OR 0.726), diabetes (OR 1.105), atrial fibrillation (OR 1.537), dyslipidaemia (0.638), heart failure (OR 1.518) and neurological symptoms suggestive of posterior fossa involvement (OR 2.639). The predictability was moderate (AUC 0.742, 95% CI: 0.737-0.747), with good visual calibration; Pearson's chi-square test revealed non-significant calibration. An easily consulted risk score was prepared. CONCLUSIONS: It is possible to create a predictive model of mortality for patients with ischaemic stroke from which important advances can be made towards optimising the quality and efficiency of care. The model results are available within a few minutes of admission and would provide a valuable complementary resource for the neurologist.

Eslicarbazepine acetate and carotid intima-media thickness in epileptic patients.

OBJECTIVE: Evaluate if eslicarbazepine acetate (ESL) in combination with other non-inducer antiepileptic drugs (AEDs) in the treatment of epilepsy may represent a positive impact in the cardiovascular risk profile. METHODS: multicentre, retrospective, observational, non-interventional, real-life study comparing patients treated with cytochrome P450 (CYP) inducer vs. ESL plus non-inducer AEDs. Primary endpoint: Carotid intima-media thickness (CIMT) measured following the Manheim Consensus criteria. RESULTS: Patients included: 163. The main demographic, clinical and vascular risk parameters were comparable between the two groups except for duration of the disease, prevalence of dyslipidemia and use of lipid-lowering drugs (significantly higher in the inducers group) and number of previous antiepileptic drugs (significantly higher in the non-inducers group). Bivariate analysis of the main endpoint showed almost significant differences (p=0.05) in CIMT measures favourable to non-inducers (average 0.617mm+SD=0.148) vs. inducers (average 0.663mm+SD=0.147). Other variables reaching statistical significance were: age >50 years (p<0.001), high blood pressure (p<0.01) and dyslipidemia (p<0.05). A multivariate analysis including these variables and biochemical vascular risk factors showed a predictor model including two variables: inducers group (p=0.031; Coefficient ß=0.234) and age >50 years (p=0.001; Coefficient ß=0.387). Regarding gender, the mean CIMT in males was significantly higher in the inducers (0.693mm; SD=0.139) than in the non- inducers groups (0.628mm; SD=0.151; p<0.05). In females the differences were not significant. SIGNIFICANCE: The use of CYP inducer AEDs is associated with a significant increase in CIMT as compared with ESL and other non-inducer AEDs. The study shows a decrease in the vascular risk measured by ultrasound criteria in male patients treated with ESL compared with patients treated with inducer AEDs.

A two-year follow-up of oral antioxidant supplementation in primary open-angle glaucoma: an open-label, randomized, controlled trial.

PURPOSE: To evaluate the effect of oral antioxidant supplementation (OAS) on primary open-angle glaucoma (POAG) over a 2-year follow-up period. PATIENTS AND METHODS: In this open-label, randomized controlled trial, 117 eyes of 117 patients with mild or moderate POAG and intraocular pressure under control with topical antiglaucoma medications were recruited and randomly divided into three groups according to supplementation: (1) OAS with (ICAPS R(®) - Alcon Laboratories, n = 26); (2) OAS without ω-3 fatty acids (OFTAN MACULA(®) - Laboratorios Esteve, n = 28); and (3) a control group without OAS (n = 63). They all underwent visual field (VF) tests (Humphrey 24-2) and scans using a Fourier-domain optical coherence tomography (FD-OCT) device (RTVue-100) at the beginning of the study and 2 years later. Mean deviation (MD), standard pattern deviation (PSD), peripapillary retinal nerve fibre layer (RNFL) and macular ganglion cell complex (GCC) parameters were considered for the analysis. Patients were also classified according to MD deterioration (fast deterioration vs. slow deterioration). RESULTS: Visual field global indices, peripapillary RNFL thickness and macular GCC thickness showed no differences among the groups at the beginning and end of the follow-up. Besides all the comparisons among groups for differences before and after the follow-up of the MD, PSD, RNFL and GCC parameters were also non-significant. The proportions of patients according to MD deterioration were similar among the groups and subgroups (p > 0.05 for all the comparisons). CONCLUSION: Oral antioxidant supplementation with or without ω-3 fatty acids does not appear useful as an adjuvant treatment of mild/moderate POAG in the short term.

Central corneal thickness, intraocular pressure, and degree of myopia in an adult myopic population aged 20 to 40 years in southeast Spain: determination and relationships.

OBJECTIVE: To determine the values of, and study the relationships among, central corneal thickness (CCT), intraocular pressure (IOP), and degree of myopia (DM) in an adult myopic population aged 20 to 40 years in Almeria (southeast Spain). To our knowledge this is first study of this kind in this region. METHODS: An observational, descriptive, cross-sectional study was done in which a sample of 310 myopic patients (620 eyes) aged 20 to 40 years was selected by gender- and age-stratified sampling, which was proportionally fixed to the size of the population strata for which a 20% prevalence of myopia, 5% epsilon, and a 95% confidence interval were hypothesized. We studied IOP, CCT, and DM and their relationships by calculating the mean, standard deviation, 95% confidence interval for the mean, median, Fisher's asymmetry coefficient, range (maximum, minimum), and the Brown-Forsythe's robust test for each variable (IOP, CCT, and DM). RESULTS: In the adult myopic population of Almeria aged 20 to 40 years (mean of 29.8), the mean overall CCT was 550.12 µm. The corneas of men were thicker than those of women (P = 0.014). CCT was stable as no significant differences were seen in the 20- to 40-year-old subjects' CCT values. The mean overall IOP was 13.60 mmHg. Men had a higher IOP than women (P = 0.002). Subjects over 30 years (13.83) had a higher IOP than those under 30 (13.38) (P = 0.04). The mean overall DM was -4.18 diopters. Men had less myopia than women (P < 0.001). Myopia was stable in the 20- to 40-year-old study population (P = 0.089). A linear relationship was found between CCT and IOP (R(2) = 0.152, P ≤ 0.001). CCT influenced the IOP value by 15.2%. However no linear relationship between DM and IOP, or between CCT and DM, was found. CONCLUSIONS: CCT was found to be similar to that reported in other studies in different populations. IOP tends to increase after the age of 30 and is not accounted for by alterations in CCT values.