RESUMEN
Background: The alarming rise of mental disorders worldwide stimulates the need to study them from a statistical viewpoint. Schizophrenia is one of the most prevalent mental illness which is characterised by various symptoms, the presence of a cluster of which leads to its diagnosis. Regular treatment leads to a remission of the illness which might relapse on discontinuity of medicines. There have been numerous epidemiological studies and clinical trials on the illness. However, schizophrenia also poses a challenge to statisticians in theorising and statistically modeling its different aspects. Aim: This is an attempt to study, by developing suitable stochastic models, the behaviour of the symptoms of schizophrenia manifested in a patient in relation to the successive visits to the doctor. Methods: The concepts of probability theory, structure functions, binomial distribution, Markov chain, and transition probabilities are the statistical tools used to model the medical facts regarding schizophrenia. Results: By developing probabilistic and stochastic models, a relationship between the number of symptoms at the time of diagnosis and the number of revisits to the doctor has been developed and thereby an important result regarding the expected number of symptoms present at a particular visit to the doctor has been established. A Markovian model studying the pattern of the symptoms in the course to recovery has been presented and its application in the behaviour of the symptoms of schizophrenia has been verified. Conclusions: It is expected that the above results might help doctors in planning out the treatment schedule in advance. It can also lead to a further study on cost benefit analysis of the treatment process.
RESUMEN
PURPOSE: Revisit to the pediatric emergency department (ED) in the short-term period may be due to inadequate evaluation during the previous visit, which may indicate a problem with quality in emergency care. The aims of this study are to analyze the characteristics of patients who revisited the pediatric ED within 48 hours after discharge and to evaluate the relation between overcrowding and revisit rates. METHODS: Retrospectively, we reviewed the charts of patients who returned within 48 hours after visiting a PED during a one-year period between June 1st, 2011 and December 31st, 2011. We determined the rate of return visits and review the characteristics of patients, emergency severity index (ESI) level at visits, cause of revisit, diagnosis, and crowding degree of the pediatric ED at the patient's first visit. RESULTS: A total of 16,688 patients visited the pediatric ED and 13,716 patients were discharged from the PED during the period. Of these discharged patients, 534 patients revisited inevitably within 48 hours. The most common cause of revisit was relapse or worsened symptoms (70.0%). There was no significant difference in sex, severity of patient, and crowding degree of the pediatric ED at the first visit, however, patients who revisited were younger than those who did not (p=0.005). The ESI level at the return visit was significantly higher irrespective of admission after revisit (p<0.001). In diagnosis grouping, patients with gastrointestinal diseases, respiratory diseases, and neoplastic diseases showed a higher rate of revisit. CONCLUSION: Approximately 4% of our pediatric ED visits were for children returning within 48 hours. Patients who revisited were younger and patients with gastrointestinal diseases, neoplastic diseases, and respiratory diseases were more likely to revisit. Careful explanation of the possibility of worsened symptoms is necessary for these patients.