RESUMEN
El diseño ideal para estimar los efectos de intervenciones es un ensayo clínico con asignación aleatoria (AA), en los que esta AA a la intervención, equilibra características observadas y no observadas de los sujetos que componen los grupos en estudio. Si no se puede realizar AA, existe una alternativa para controlar sesgos, conocida como puntajes de propensión (PP). Los PP son útiles para estimar el efecto de una intervención o exposición sobre un resultado en estudios observacionales, especialmente cuando se estima la posibilidad que existan sesgos de confusión y selección debido a una asignación de tratamiento no aleatoria. Son una técnica de emparejamiento avanzada de variables de confusión como edad, sexo, etc., permitiendo que se puedan comparar pacientes de edad similar en grupos de intervención y de comparación. Esto, se puede complejizar si se decide agregar muchas variables al proceso de emparejamiento (edad, sexo, etnia, nivel educacional), puesto que será difícil encontrar coincidencias exactas para los sujetos. Entonces, los PP resuelven este problema de dimensionalidad comprimiendo factores relevantes en un solo puntaje, así, los pacientes con PP similares se comparan entre los grupos de intervención y comparación. El objetivo de este manuscrito fue generar un documento de estudio referente al uso de los PP y su rol en investigación quirúrgica.
The ideal design to estimate the effects of interventions, is a randomized clinical trial (RCT), in which the random allocation (RA) to the intervention allows balancing the observed and unobserved characteristics of the subjects that make up the study groups. In situations where RA cannot be performed, there is an alternative to bias control, which is known as propensity score (PS). This tool is useful for estimating the effect of an intervention or exposure on an outcome in observational studies, especially when it is estimated that confounding and selection biases may exist due to an unintended intervention RA. Is an advanced matching technique for confounding variables such as age, sex, etc., which allows patients of similar age to be compared in the intervention and comparison groups. This can become more complex if it is decided to add many variables to the matching process (age, sex, ethnicity, educational level), since it will be difficult to find exact matches for the subjects under study. PS then solves this dimensionality problem by compressing the relevant factors into a single score, such that patients with similar PS are compared between the intervention and comparison groups. The aim of this manuscript was to generate a study document referring to some issues of the use of PS in surgical research.
RESUMEN
AIM: To explore the effect of intestinal flora disturbance on postoperative cognitive dysfunction in patients with inhalation anesthesia by using propensity score matching method. METHODS: Patients received inhalation anesthesia of patients between January 2018 and December 2021 in our hospital were included in the study. 91 cases of postoperative cognitive dysfunction patients as cognitive impairment group, 85 cases of postoperative cognitive dysfunction patients as control group. Propensity score matching method was used to compare the clinical data and bacterial DNA, which was extracted from the stool samples of the two groups before surgery. And 16S rRNA sequencing was performed to analyze the differences of intestinal flora between the two groups. RESULTS: A total of 20 pairs of patients were successfully matched between the two groups. There was no significant difference in age, gender and other general information between the two groups (P>0.05). PCoA analysis showed that although there was some overlap in the PCoA plot of stool samples from the two groups, the PCoA scatter plot showed significant differences between the two groups. LEfse multistage species difference discriminant analysis showed that at the genus level, the abundance of 6 bacteria genera was higher in the cognitive impairment group. The intestinal bacillus genus, MAO spirillum, thick wall bacteria door, clostridium, neisseria bacterium, neisseria bacteria genera abundance increased in the cognitive impairment group, majorly the klebsiella bacillus clostridium, platts bacteria and enterobacteriaceae, mesh, wool spirillum, addicted to bile bacteria genera, door deformation, clostridium, enterobacteriaceae bacteria enriched, etc. CONCLUSION: Cognitive dysfunction in patients with inhalation anesthesia is related to intestinal flora disorder, which is mainly manifested by the enrichment of Bacteria such as Leiborella and Prevotella.