Yung-Sung Huang

Increased risk of dementia in patients with mild traumatic brain injury: a nationwide cohort study.

BACKGROUND It is known that the risk of dementia in patients with moderate to severe traumatic brain injury (TBI) is higher. However, the relationship between mild traumatic brain injury (mTBI) and dementia has never been established. OBJECTIVES We investigated the incidences of dementia among patients with mTBI in Taiwan to evaluate if there is higher risk compared with general population. METHODS We utilized a sampled National Health Insurance (NHI) claims data containing one million beneficiaries. We followed all adult beneficiaries from January 1, 2005 till December 31, 2009 to see if they had been diagnosed with dementia. We further identify patients with mTBI and compared their risk of dementia with the general population. RESULTS We identified 28551 patients with mTBI and 692382 without. After controlled for age, gender, urbanization level, socioeconomic status, diabetes, hypertension, coronary artery disease, hyperlipidemia, history of alcohol intoxication, history of ischemic stroke, history of intracranial hemorrhage and Charlson Comorbidity Index Score, the adjusted hazard ratio is 3.26 (95% Confidence interval, 2.69-3.94). CONCLUSIONS TBI is an independent significant risk factor of developing dementia even in the mild type.

Risk of Stroke in Patients Hospitalized for Isolated Vertigo A Four-Year Follow-Up Study

Background and Purpose— Vertigo is a common presenting symptom in ambulatory care settings, and stroke is its leading and most challenging concern. This study aimed to determine the risk of stroke in vertigo patients in a 4-year follow-up after hospitalization for acute isolated vertigo. Methods— The study cohorts consisted of all patients hospitalized with a principal diagnosis of vertigo (n=3021), whereas patients hospitalized for an appendectomy in 2004 (n=3021) comprised the control group and surrogate for the general population. Cox proportional hazard model was performed as a means of comparing the 4-year stroke-free survival rate between the 2 cohorts after adjusting for possible confounding and risk factors. Among vertigo patients, there was further stratification for risk factors to identify the group at high risk for stroke. Results— Of the 243 stroke patients, 185 (6.1%) were from the study cohort and 58 (1.9%) were from the control group. Comparing the 2 groups, patients with vertigo symptoms had a 3.01-times (95% CI, 2.20–4.11; P<0.001) higher risk for stroke after adjusting for patient characteristics, comorbidities, geographic region, urbanization level of residence, and socioeconomic status. Vertigo patients with ≥3 risk factors had a 5.51-fold higher risk for stroke (95% CI, 3.10–9.79; P<0.001) than those without risk factors. Conclusions— Vertigo patients are at higher risk for stroke than the general population. They should have a comprehensive neurological examination, vascular risk factors survey, and regular follow-up for several years after hospital discharge after treatment of isolated vertigo.

Increased risk of stroke in young head and neck cancer patients treated with radiotherapy or chemotherapy

BACKGROUND Chemo-radiotherapy-induced carotid stenosis and cerebrovascular events in head and neck cancer patients can cause severe disability and death. We aimed to estimate the risk of stroke in such patients over a six-year follow-up period. PATIENTS AND METHODS The study cohort consisted of head and neck cancer patients (n=10,172). Cox proportional hazard model was used to compare the stroke-free survival rate between the patients treated with radiotherapy or chemotherapy, surgery alone, and surgery with adjuvant therapy after adjusting for possible confounding factors. RESULTS At the end of follow-up, 384 patients had strokes: 126 (4.3%) from the surgery alone group, 167 (3.8%) from the radiotherapy or chemotherapy group, and 91 (3.2%) from the surgery with adjuvant therapy (P=0.222). Head and neck cancer patients aged less than 55 years treated with radiotherapy or chemotherapy conferred a 1.8-fold higher risk for stroke (95% CI, 1.22-2.56; P=0.003) after adjusting for patient characteristics, co-morbidities, geographic region, urbanization level, and socio-economic status. There was no statistical difference in stroke risk between different treatment modalities in head and neck cancer patients aged 55 years and more. CONCLUSIONS Young head and neck cancer patients treated with radiotherapy or chemotherapy have higher risks for stroke. Different treatment strategies should be considered in such patients.

Chronic Kidney Disease Itself Is a Causal Risk Factor for Stroke beyond Traditional Cardiovascular Risk Factors: A Nationwide Cohort Study in Taiwan

Background Cardiovascular disease (CVD) is a leading cause of mortality and morbidity in patients with chronic kidney disease (CKD). In Taiwan, CVD is dominated by strokes but there is no robust evidence for a causal relationship between CKD and stroke. This study aimed to explore such causal association. Methods We conducted a nationwide retrospective cohort study based on the Taiwan National Health Insurance Research Database from 2004 to 2007. Each patient identified was individually tracked for a full three years from the index admission to identify those in whom any type of stroke developed. The study cohort consisted of patients hospitalized with a principal diagnosis of CKD and no traditional cardiovascular risk factors at baseline (n = 1393) and an age-matched control cohort of patients hospitalized for appendectomies (n = 1393, a surrogate for the general population). Cox proportional hazard regression and propensity score model were used to compare the three-year stroke-free survival rate of the two cohorts after adjustment for possible confounding factors. Results There were 256 stroke patients, 156 (11.2%) in the study cohort and 100 (7.2%) in the control cohort. After adjusting for covariates, patients with primary CKD had a 1.94-fold greater risk for stroke (95% CI, 1.45–2.60; p<0.001) based on Cox regression and a 1.68-fold greater risk for stroke (95% CI, 1.25–2.25; p = 0.001) based on propensity score. This was still the case for two cohorts younger than 75 years old and without traditional cardiovascular risk factors. Conclusions This study of Taiwanese patients indicates that CKD itself is a causal risk factor for stroke beyond the traditional cardiovascular risk factors. Primary CKD patients have higher risk for stroke than the general population and all CKD patients, irrespective of the presence or severity of traditional cardiovascular risk factors, should be made aware of the stroke risk and monitored for stroke prevention.

Increased risk of vascular events in emergency room patients discharged home with diagnosis of dizziness or vertigo: a 3-year follow-up study.

Background Dizziness and vertigo symptoms are commonly seen in emergency room (ER). However, these patients are often discharged without a definite diagnosis. Conflicting data regarding the vascular event risk among the dizziness or vertigo patients have been reported. This study aims to determine the risk of developing stroke or cardiovascular events in ER patients discharged home with a diagnosis of dizziness or vertigo. Methodology A total of 25,757 subjects with at least one ER visit in 2004 were identified. Of those, 1,118 patients were discharged home with a diagnosis of vertigo or dizziness. A Cox proportional hazard model was performed to compare the three-year vascular event-free survival rates between the dizziness/vertigo patients and those without dizziness/vertigo after adjusting for confounding and risk factors. Results We identified 52 (4.7%) vascular events in patients with dizziness/vertigo and 454 (1.8%) vascular events in patients without dizziness/vertigo. ER patients discharged home with a diagnosis of vertigo or dizziness had 2-fold (95% confidence interval [CI], 1.35–2.96; p<0.001) higher risk of stroke or cardiovascular events after adjusting for patient characteristics, co-morbidities, urbanization level of residence, individual socio-economic status, and initially taking medications after the onset of dizziness or vertigo during the first year. Conclusions ER patients discharged home with a diagnosis of dizziness or vertigo were at a increased risk of developing subsequent vascular events than those without dizziness/vertigo after the onset of dizziness or vertigo. Further studies are warranted for developing better diagnostic and follow-up strategies in increased risk patients.

Increased Risk of Ischemic Stroke in Young Nasopharyngeal Carcinoma Patients

PURPOSE Radiation/chemoradiotherapy-induced carotid stenosis and cerebrovascular events in patients with nasopharyngeal carcinoma (NPC) can cause severe disability and even death. This study aimed to estimate the risk of ischemic stroke in this patient population over more than 10 years of follow-up. METHODS AND MATERIALS The study cohorts consisted of all patients hospitalized with a principal diagnosis of NPC (n=1094), whereas patients hospitalized for an appendectomy during 1997 and 1998 (n=4376) acted as the control group and surrogate for the general population. Cox proportional hazard model was performed as a means of comparing the stroke-free survival rate between the two cohorts after adjusting for possible confounding and risk factors. RESULTS Of the 292 patients with ischemic strokes, 62 (5.7%) were from the NPC cohort and 230 (5.3%) were from the control group. NPC patients ages 35-54 had a 1.66 times (95% CI, 1.16-2.86; p=0.009) higher risk of ischemic stroke after adjusting for patient characteristics, comorbidities, geographic region, urbanization level of residence, and socioeconomic status. There was no statistical difference in ischemic stroke risk between the NPC patients and appendectomy patients ages 55-64 years (hazard ratio=0.87; 95% CI, 0.56-1.33; p=0.524) after adjusting for other factors. CONCLUSIONS Young NPC patients carry a higher risk for ischemic stroke than the general population. Besides regular examinations of carotid duplex, different irradiation strategies or using new technique of radiotherapy, such as intensity modulated radiation therapy or volumetric modulated arc therapy, should be considered in young NPC patients.

The association between zolpidem and infection in patients with sleep disturbance

OBJECTIVE Recent case reports suggest that zolpidem usage may be associated with infection events. The aim of this study was to determine the risk of infection events in patients with sleep disturbance taking zolpidem in a full 3-year follow-up study. METHODS A total of 17474 subjects with a diagnosis of sleep disturbance in 2002 and 2003 were identified, of whom 5882 had used zolpidem after recruitment. A Cox proportional hazard model was used to estimate the 3-year infection event-free rates for the patients using zolpidem and those not using zolpidem after adjusting for confounding factors. To maximize case ascertainment, only patients hospitalized for infection events were included. RESULTS A total of 646 patients had had infection events, 331 (5.63%) of whom had been taking zolpidem and 315 (2.71%) had not. Zolpidem usage increased the risk of infection events. After adjustments for gender, age, co-morbidities, and other medications, patients using zolpidem with cDDD 1-28, 29-84, and >84 had hazard ratios of 1.67 (95% CI, 1.32-2.11), 1.91 (95% CI, 1.47-2.49) and 1.62 (95% CI, 1.32-1.98) respectively, compared with patients who did not use zolpidem. CONCLUSIONS Zolpidem increased the risk of infection events in sleep disturbance patients. This increased risk of infection should be explained to sleep disturbance patients, and prescriptions of zolpidem to chronic insomnia patients should be restricted.

Pneumococcal Pneumonia and the Risk of Stroke: A Population-Based Follow-Up Study

Background To investigate the risk of developing stroke in patients hospitalized following a diagnosis of pneumococcal pneumonia. Methods The study cohorts comprised of patients hospitalized with a principal diagnosis of pneumococcal pneumonia (n  = 745), with a random sampling of control individuals in 2004 (n  = 1490). The Cox proportional hazard model was used to compare the stroke-free survival rate between the cohorts after adjusting for possible confounding and risk factors for a two-year follow up. Instrumental variable analysis (IVA) was used to address potential biases associated with measured and unmeasured confounding variables. Results Of the 153 patients with stroke, 80 (10.7%) were from the pneumococcal pneumonia cohort, and 73 (4.9%) were from the control group. The risk of stroke was 3.65 times higher (95% confidence interval, 2.25–5.90; P<0.001) in patients with pneumococcal pneumonia after adjusting for patient characteristics, co-morbidities, geographic region, urbanization level of residence, and socioeconomic status during the first year. IVA showed an additional 14% risk of stroke for pneumococcal pneumonia patients (odds ratio = 1.14; 95% CI, 1.02–1.26, P = 0.032). Conclusions Patients with pneumococcal pneumonia carry an increased risk for stroke than the general population. Further studies are warranted for developing better diagnostic and follow-up strategies for patients with increased risk.

The Impact of Influenza Vaccinations on the Adverse Effects and Hospitalization Rate in the Elderly: A National Based Study in an Asian Country

Objectives To examine the risk of adverse effects of special interest in persons vaccinated against seasonal influenza compared with unvaccinated persons aged 65 and above. Methods We retrospectively observed 41,986 vaccinated elderly persons and 50,973 unvaccinated elderly persons in Taiwan from October 1, 2008, through September 30, 2009, using the National Health Insurance database. Neurological and autoimmune disorders and one-year hospitalization rates and in-hospital mortality rates were analyzed according to the vaccination status. Propensity score analysis was used to assess the relationship between adverse outcomes, hospitalization rates, and vaccination status. Results 45% of the elderly received influenza vaccination. Multiple logistic regression showed that the probability of being vaccinated was related to more patients visiting for URI symptoms (odds ratio (OR), 1.03; 95% CI, 1.02–1.03), men (OR, 1.15; 95% CI, 1.12–1.17), increased age (OR, 1.02; 95% CI, 1.02–1.03), and more comorbidities (OR, 1.2; 95% CI, 1.17–1.23). There were no statistical differences in neurological and autoimmune diseases between the vaccinated and unvaccinated individuals using propensity score analysis, but vaccinated persons had a reduced hospitalization rate of 19% (odds ratio [OR], 0.81; 95% CI, 0.77–0.84) for the first six-months and 13% for one-year of follow-up (OR, 0.87; 95% CI, 0.85–0.9). Conclusions Based on data from the one-year follow-ups among 93,049 elderly persons in Taiwan, reassuring results for selected neurological and autoimmune diseases were found among the vaccinated individuals after adjusting other factors. Influenza vaccination decreased the risk for hospitalization. Public health strategies must continue to improve the influenza vaccination rate among the elderly with information based upon tangible evidence.

Effect of different antipsychotic drugs on short-term mortality in stroke patients.

Abstract The safety, tolerability, and efficacy data for antipsychotic drugs used in the acute phase of stroke are limited. The primary aim of this study was to examine the effectiveness and safety of typical and atypical antipsychotics on acute ischemic stroke mortality. This observational study was conducted in a retrospective cohort of patients selected from the 2010–2011 National Health Research Institute database in Taiwan. Patients were tracked for 1 month from the time of their first hospitalization for acute ischemic stroke. A nested case–control analysis was used to estimate the odds ratio (OR) of 30-day mortality associated with antipsychotic drug, adjusted for age, gender, disease severity, and comorbidities. The study cohort included 47,225 subjects with ischemic stroke, including 9445 mortality cases and 37,780 matched controls. After adjustment for the covariates, antipsychotics users before ischemic stroke are associated with a 73% decrease in the rate of mortality (OR 0.27; 95% CI 0.23–0.31). After ischemic stroke, the use of antipsychotics is associated with 87% decrease in the rate of mortality (OR 0.13; 95% CI 0.1–0.16). The users of conventional antipsychotics are associated with a 78% decrease in the rate of mortality (OR 0.22; 95% CI 0.18–0.26). The users of atypical antipsychotics are also associated with a 86% decrease in the rate of mortality (OR 0.14; 95% CI 0.12–0.17). We found that 1-month mortality among acute stroke patients treated with antipsychotics is significantly lower. The benefit on lower mortality was found not only among ischemic stroke patients who had received antipsychotics previously but also among patients who start antipsychotics after their stroke.