Discriminant analysis – simplified

Background: Discriminant function analysis is the statistical analysis used to analyze data when the dependent variable or outcome is categorical and independent variable or predictor variable is parametric. Discriminant function analysis is used to find out the accuracy of a given classification system or predictor variable in predicting the sample into a particular group. Discriminant function analysis includes the development of discriminant functions for each sample and deriving a cutoff score. The cutoff score is used for classifying the samples into different groups. Aim: The aim of this review article is to simplify and explain the discriminant function analysis so that it can be used by medical and dental researchers whenever it is applicable. Conclusion: Discriminant function analysis is a statistical analysis used to find out the accuracy of a given classification system or predictor variables. This paper explains the basics of discriminant analysis and how to interpret the results along with one simple example of mandibular canine index for gender identification. Clinical significance: Whenever a new classification system is introduced or any predictor variable is identified, discriminant function analysis can be used to find out the accuracy with which the classification system or predictor variable can differentiate a sample into different groups. Thus, it is a very useful tool in dental and medical research

Effect of intravenous midazolam on intracranial pressure during endotracheal suctioning in patients with severe head injury

Background: Patients with severe traumatic brain injury (TBI) require elective ventilation and sedation to decrease intracranial pressure (ICP) and any increase in ICP may be detrimental for the outcome in these patients. Methods: This prospective study was done in a neurotrauma intensive care unit (ICU )of a level 1 trauma centre in India over a one month period. All adult male patients with severe TBI on mechanical ventilation and monitored for ICP were included in this study. Baseline ICP was measured before starting endotracheal (ET) suctioning and serial readings were taken during and after ET suctioning. Patients were divided into two groups (control and intervention) with intervention group receiving intravenous bolus dose of 2 mg of midazolam before ET suction. Results: A total of 20 patients were enrolled during the study period. Both groups were well matched with regards to age and admission Glasgow coma scale (GCS). There were 10 patients in the midazolam group and 10 patients in the control group. The mean rise of ICP following ET suctioning in control group was found to be 24.1mm Hg ±11.1 as compared to 18.25 mm Hg ±-9.29 in the midazolam group (P < 0.05). Conclusions: Significant rise in ICP from baseline occurs following ET suctioning in ventilated, severe TBI patients. Our study suggests that additional intravenous bolus of midazolam prior to suctioning may significantly reduce the rise in ICP and should be practiced by ICU nurses