Structural Equation Model (SEM) of Stroke Mortality in Spanish Inpatient Hospital Settings: The Role of Individual and Contextual Factors

Introduction: Traditionally, predictive models of in-hospital mortality in ischemic stroke have focused on individual patient variables, to the neglect of in-hospital contextual variables. In addition, frequently used scores are betters predictors of risk of sequelae than mortality, and, to date, the use of structural equations in elaborating such measures has only been anecdotal. Aims: The aim of this paper was to analyze the joint predictive weight of the following: (1) individual factors (age, gender, obesity, and epilepsy) on the mediating factors (arrhythmias, dyslipidemia, hypertension), and ultimately death (exitus); (2) contextual in-hospital factors (year and existence of a stroke unit) on the mediating factors (number of diagnoses, procedures and length of stay, and re-admission), as determinants of death; and (3) certain factors in predicting others. Material and Methods: Retrospective cohort study through observational analysis of all hospital stays of Diagnosis Related Group (DRG) 14, non-lysed ischemic stroke, during the time period 2008-2012. The sample consisted of a total of 186,245 hospital stays, taken from the Minimum Basic Data Set (MBDS) upon discharge from Spanish hospitals. MANOVAs were carried out to establish the linear effect of certain variables on others. These formed the basis for building the Structural Equation Model (SEM), with the corresponding parameters and restrictive indicators. Results: A consistent model of causal predictive relationships between the postulated variables was obtained. One of the most interesting effects was the predictive value of contextual variables on individual variables, especially the indirect effect of the existence of stroke units on reducing number of procedures, readmission and in-hospital mortality. Conclusion: Contextual variables, and specifically the availability of stroke units, made a positive impact on individual variables that affect prognosis and mortality in ischemic stroke. Moreover, it is feasible to determine this impact through the use of structural equation methodology. We analyze the methodological and clinical implications of this type of study for hospital policies.

[The stroke care system in Terres de l'Ebre, Spain, after the implementation of the Stroke Code model: Ebrictus Study]

BACKGROUND AND OBJECTIVE

We aimed to know the characteristics of the urgent stroke assistance system, the Stroke Code (SC) model, 2 years after its implementation through testing the specific impact on several result indicators on individuals with a first stroke.

PATIENTS AND METHOD

Prospective study of a cohort who suffered a first stroke episode, 15 to 89-year-old. Several clinical indicators were selected to evaluate results according to the SC and an analysis survival for Kaplan-Meier's curves was made as well as a bivariate analysis between dead and surviving patients. Data were collected by a community based registry.

RESULTS

A total of 380 patients ≤80-year-aged were enrolled and the SC was activated in 54.3% (CI95%: 49,0-59.3), 77% at the hospital. An 80% of the therapeutic window was wasted before arrival to hospital. In 13.9% (CI95%: 9,2-19,8) thrombolysis was used. The immediate mortality was 9.9% (CI95%: 7.5-12.5).

CONCLUSIONS

The implantation of the SC is a system that improved the welfare chain of stroke in the whole territory, but its activation in the area of primary care was low.