Identification and medical utilization of newly diagnosed panic disorder: A Nationwide case-control study.

OBJECTIVE: Ascertaining comorbid illnesses and patterns of medical utilization early in the course of psychiatric illness can help identify patients with panic disorder. We investigated how such cases were diagnosed and the comorbidities associated with newly diagnosed panic disorder in a nationwide database. METHODS: We enrolled a large representative cohort of the general population in Taiwan (N = 1000,000) and selected 9759 cases of panic disorder from January 1, 2000 to December 31, 2013. The distribution of the departments in which the cases were identified and the medical utilization 12 months before diagnosis were analyzed. Based on a nested case-control study, four controls were randomly selected for each case and matched for sex, age, and incidence year. Conditional logistic regression was used to explore the factors associated with newly-diagnosed panic disorder such as demographic factors, concomitant medications, and physical and psychiatric comorbidities. RESULTS: Most (58.5%) cases of panic disorder were diagnosed in the psychiatry department, whereas only 3.7% were identified in the emergency department. Before diagnosis, the patients frequently visited the departments of internal medicine, family practice, and Chinese herbal medicine. A multivariate analysis revealed a higher number of physical and psychiatric comorbidities before diagnosis in the cases compared with the controls, especially depressive disorder and other anxiety disorders. CONCLUSIONS: Individuals with certain comorbidities and patterns of medical utilization are more likely to be diagnosed with panic disorder. We suggest providing more training to general practitioners and emergency physicians for the early diagnosis of panic disorder.

Excess incidence and risk factors for recurrent pneumonia in bipolar disorder.

AIM: Patients with bipolar disorder (BD) tend to have poorer outcomes after pneumonia and could have a higher risk for recurrence of pneumonia. We aimed to investigate the incidence and risk factors of recurrent pneumonia in patients with BD. METHODS: In a nationwide cohort of BD patients (derived from the National Health Insurance Research Database in Taiwan) who were hospitalized for pneumonia between 1996 and 2012, we identified 188 patients who developed recurrent pneumonia after a baseline pneumonia episode. Applying risk-set sampling at a 1:2 ratio, 353 matched controls were selected from the study cohort. We used multivariate conditional logistic regression analysis to explore the association between recurrent pneumonia and physical illness, concomitant medications, and psychotropic drugs. RESULTS: The findings showed that the incidence of recurrent pneumonia in BD was 6.60 cases per 100 person-years, which was higher than that in the general population. About 10% (9.24%) of cases with recurrent pneumonia died within 30 days of hospitalization. Patients had increased risk of recurrent pneumonia if they had hypertension, diabetes mellitus, cancer, or asthma. Conversely, psychotropic drugs, both first- and second-generation antipsychotics, which are known to increase susceptibility to baseline pneumonia, were not associated with risk of pneumonia recurrence. CONCLUSION: We found an excess incidence of recurring pneumonia in patients with BD, and this risk was associated with pre-existing medical conditions but not psychotropic agents. Physicians should carefully consider the comorbid medical conditions of patients with BD that could lead to recurrent pneumonia.

Antipsychotic medications and stroke in schizophrenia: A case-crossover study.

BACKGROUND: The association between antipsychotic use and the risk of stroke in schizophrenic patients is controversial. We sought to study the association in a nationwide cohort with schizophrenia. METHODS: Using a retrospective cohort of patients with schizophrenia (N = 31,976) derived from the Taiwan National Health Insurance Research Database, 802 new-onset cases of stroke were identified within 10 years of follow-up (from 2000 through 2010). We designed a case-crossover study using 14-day windows to explore the risk factors of stroke and the association between antipsychotic drugs and the risk of stroke. We analyzed the risks of individual antipsychotics on various subgroups of stroke including ischemic, hemorrhagic, and other strokes, and the risks based on the antipsychotic receptor-binding profile of each drug. RESULTS: Use of any second-generation antipsychotic was associated with an increased risk of stroke (adjusted risk ratio = 1.45, P = .009) within 14 days while the use of any first-generation antipsychotic was not. Intriguingly, the use of any second-generation antipsychotic was associated with ischemic stroke but not hemorrhagic stroke. The antipsychotic receptor-binding profile analysis showed that the antihistamine 1 receptor was significantly associated with ischemic stroke (adjusted risk ratio = 1.72, P = .037), and the sensitivity analysis based on the 7-day window of exposure validated the association (adjusted risk ratio = 1.87, P = .015). CONCLUSIONS: Use of second-generation antipsychotic drugs appeared to be associated with an increased risk of ischemic stroke in the patients studied, possibly mediated by high affinity for histamine-1 receptor blockade. Further research regarding the underlying biological mechanism and drug safety is suggested.