Ping-Hsun Wu

Predicting Mortality of Incident Dialysis Patients in Taiwan - A Longitudinal Population-Based Study

Background Comorbid conditions are highly prevalent among patients with end-stage renal disease (ESRD) and index score is a predictor of mortality in dialysis patients. The aim of this study is to perform a population-based cohort study to investigate the survival rate by age and Charlson comorbidity index (CCI) in incident dialysis patients. Methods Using the catastrophic illness registration of the Taiwan National Health Insurance Research Database for all patients from 1 January 1998 to 31 December 2008, individuals newly diagnosed with ESRD and receiving dialysis for more than 90 days were eligible for our study. Individuals younger than 18 years or renal transplantation patients either before or after dialysis were excluded. We calculated the CCI, age-weighted CCI by Deyo-Charlson method according to ICD-9 code and categorized CCI into six groups as index scores <3, 4–6, 7–9, 10–12, 13–15, >15. Cox regression models were used to analyze the association between age, CCI and survival, and the risk markers of survival. Results There were 79,645 incident dialysis patients, whose mean age (± SD) was 60.96 (±13.92) years; 51.43% of patients were women and 51.2% were diabetic. In cox proportional hazard models and stratifying by age, older patients had significantly higher mortality than younger patients. The mortality risk was higher in persons with higher CCI as compared with low CCI. Mortality increased steadily with higher age or comorbidity both for unadjusted and for adjusted models. For all age groups, mortality rates increased in different CCI groups with the highest rates occurring in the oldest age groups. Conclusions Age and CCI are both strong predictors of survival in Taiwan. The older age or higher comorbidity index in incident dialysis patient is associated with lower long-term survival rates. These population-based estimates may assist clinicians who make decisions when patients need long-term dialysis.

High cost and low survival rate in high comorbidity incident elderly hemodialysis patients.

Background The comorbidity index is a predictor of mortality in dialysis patients but there are few reports for predicting elderly dialysis mortality and national population-based cost studies on elderly dialysis. The aim of this study was to evaluate the long-term mortality of incident elderly dialysis patients using the Deyo - Charlson comorbidity index (CCI) and to assess the inpatient and outpatient visits along with non-dialysis costs. Methods Data were obtained from catastrophic illness registration of the Taiwan National Health Insurance Research Database. Incident elderly dialysis patients (age >75 years) receiving hemodialysis for more than 90 days between Jan 1, 1998, and dec 31, 2007, were included. Baseline comorbidities were determined one year prior to the first dialysis day according to ICD-9 CM codes. Survival time, mortality rate, hospitalization time, outpatient visit frequency, and costs were calculated for different age and CCI groups. Results In 10,759 incident elderly hemodialysis patients, hazard ratios for all-cause mortality were significantly increased in the different age groups (p < 0.001) and CCI patients (p < 0.001). Death rates increased with both increasing age and CCI score. High comorbidity incident hemodialysis and elderly patients were found to have increased length of hospital stay and total hospitalization costs. Conclusions This population-based cohort study indicated that both age and higher CCI values were predictors of survival in incident elderly hemodialysis. Increased costs and mortality rates were evident in the oldest patients and in those with high CCI scores. Conservative treatment might be considered in high comorbidity and low-survival rate end stage renal disease (ESRD) patients.

Cirrhosis as a Risk Factor for Tuberculosis Infection—A Nationwide Longitudinal Study in Taiwan

Tuberculosis (TB) and cirrhosis of the liver are both endemic in many regions of the world. However, the risk of TB in cirrhotic patients has rarely been investigated. A nationwide cohort study was conducted to elucidate and characterize the association between cirrhosis and TB in Taiwan. The study included 41,076 cirrhotic patients and 204,244 noncirrhotic controls from 1998 through 2007. Cirrhotic and noncirrhotic subjects were matched 1:5 on age and sex. A total of 957 of 41,076 (2.32%) cirrhotic patients developed TB, yielding a rate that was significantly higher than that of the 955 of 204,244 (0.46%) noncirrhotic patients (P < 0.001). In a Cox regression model adjusted for age, sex, and underlying medical disorders, a significantly higher active TB rate was maintained for cirrhotic patients compared with their noncirrhotic counterparts (adjusted hazard ratio = 3.55, 95% confidence interval (CI): 3.08, 4.09; P < 0.001). Alcoholism and hepatitis C infection were associated with significantly higher TB risk with adjust hazard ratios of 2.18 (95% CI: 1.86, 4.09; P < 0.001) and 1.18 (95% CI: 1.02, 1.30; P < 0.001), respectively. Cirrhotic patients have a greater risk of TB than noncirrhotic patients, particularly those with alcoholism and hepatitis C infection.

Indoxyl sulfate, not p-cresyl sulfate, is associated with cognitive impairment in early-stage chronic kidney disease

BACKGROUNDS Patients with chronic kidney disease (CKD) more commonly experience cognitive impairment, but the etiologies are not clear. Uremic toxins such as p-cresyl sulfate (PCS) and indoxyl sulfate (IS) have been shown to increase the risks of cardiovascular diseases and mortality; however, no study has investigated the associations of PCS and IS with cognitive function in patients with CKD. METHODS Patients with CKD aged ≥50 years and age- and sex-matched non-CKD comparison subjects were recruited. CKD stage was defined according to the National Kidney Foundation guidelines. Cognitive function was evaluated using comprehensive neuropsychological tests. The associations between uremic toxins and cognitive function domains were examined using multiple linear regression analysis. The interaction between uremic toxins and CKD stages on cognitive functions were also examined. RESULTS In total, 199 patients with CKD and 84 comparison subjects completed the study. The patients with CKD had poorer cognitive function and higher serum PCS and IS levels. A higher serum IS level was associated with poor executive function (β=-0.31, P=0.003) only in stage 3 CKD patients after adjustment for age, sex and educational level. Serum PCS level was not associated with cognitive function in patients with CKD. CONCLUSIONS Our study showed that a higher serum IS level was associated with poor executive function in the early stage of CKD. It would be worthwhile to investigate the effect of IS removal in early-stage CKD on the prevention of cognitive impairment in future studies.

Comparison of dementia risk between end stage renal disease patients with hemodialysis and peritoneal dialysis - a population based study

A higher risk of dementia was reported in patients undergoing maintenance hemodialysis (HD) compared to those undergoing peritoneal dialysis (PD). Selection bias and competing risk of death were not considered in previous studies. The aim of this study was to investigate dementia risk in patients undergoing HD and PD by using the Taiwan Longitudinal Health Insurance Database. We enrolled 52,332 incident HD patients and 3292 incident PD patients who were older than 40 years between January 1, 1998 and December 31, 2007. During the study period, 3775 patients were diagnosed with dementia in the HD group (177.5 per 10,000 person-years incidence rate) and 181 patients in the PD group (145.9 per 10,000 person-years incidence rate). The results revealed that the higher hazard ratio of HD compared with PD for dementia disappeared after controlling for demographic characteristics, propensity score, and competing death risk (subdistribution hazard ratio was 1.086; 95% confidence interval, 0.940–1.255). In conclusion, HD did not increase the risk of dementia in dialysis-dependent patients compared to PD.

Association between acetylcholinesterase inhibitors and risk of stroke in patients with dementia.

Patients with dementia are at increased risk of stroke. Acetylcholinesterase inhibitors (AChEIs) have endothelial function protection effects and anti-inflammatory properties. We investigated the ischemic stroke risk in AChEIs use in dementia patients without stroke history. Using Taiwan National Health Insurance Database from 1999 to 2008, 37,352 dementia patients over 50 years old without stroke history were eligible. The results were analyzed by propensity score–matched Cox proportional hazard models with competing risk adjustment. AChEIs users had lower incidence of ischemic stroke (160.3/10,000 person-years), compared to the propensity score–matched reference (240.8/10,000 person-years). The adjusted hazard ratio for ischemic stroke based on propensity score–matched Cox proportional hazard model was 0.508 (95% confidence interval, 0.434–0.594; P < 0.001). There was no significant difference in all-cause mortality between AChEIs users and nonusers. In conclusion, among dementia patients without previous ischemic stroke history, AChEIs treatment was associated with a decreased risk of ischemic stroke but not greater survival.

Impact of acetylcholinesterase inhibitors on the occurrence of acute coronary syndrome in patients with dementia.

The study aimed to investigate the association of acetylcholinesterase inhibitors (AChEIs) use with the risk of acute coronary syndrome (ACS). We conducted a population-based retrospective cohort study of dementia patients during 1 January 1999 to 31 December 2008 using the National Health Insurance Database in Taiwan. New AChEI users during the study period were matched with AChEI nonusers in age-matched and gender-matched cohorts. The risk of ACS associated with use of AChEIs was analyzed using modified Kaplan-Meier analysis and Cox proportional hazard models after adjustment for competing death risk. Use of AChEIs was associated with a lower incidence of ACS (212.8/10,000 person-years) compared to the matched reference cohort (268.7/10,000 person-years). The adjusted hazard ratio for ACS in patients with dementia treated with AChEIs was 0.836 (95% confidence interval, 0.750–0.933; P < 0.001). Further sensitivity analysis of different study populations demonstrated consistent results. A statistical dose–response relationship for AChEI use and ACS risk was significant for the patients with dementia. In patients with dementia, AChEI treatment was associated with decreased risk of ACS.

The increased risk of active tuberculosis disease in patients with dermatomyositis – a nationwide retrospective cohort study

The risk of active tuberculosis (TB) in patients with dermatomyositis (DM) is poorly understood. The cohort study aimed to investigate the association between DM and the risk of active TB disease. We conducted a population based study on 4,958 patients with newly diagnosed DM and 19,832 matched controls according to age, sex, and index date between 1998 and 2008. The hazard ratios (HRs) and cumulative incidences of active TB disease between DM patients and controls were analyzed. During the study period, a total of 85 (1.7%) DM patients developed active TB disease, which was significantly higher than that of non-DM patients (0.64%). The incidence rate of active TB disease was higher among DM patients than controls (incidence rate ratio 2.95; 95% confidence interval [CI], 2.24 to 3.88). The Cox regression model demonstrated significantly higher active TB disease rate among DM patients compared with controls (adjusted HR, 2.64; 95% CI, 1.97 to 3.54; p < 0.001) after adjusting for age, sex, and underlying medical disorders. The most significant risk factors for developing active TB included male sex, diabetes mellitus comorbidity, and use of corticosteroids and azathioprine in DM patients. In conclusion, DM patients are at a greater risk for active TB disease.

A complication of double lumen hemocatheter guide wire entrapment in a hemodialysis patient.

Double lumen hemocatheter is commonly used for temporary hemodialysis patient and various complications have been documented but few reports of guide wire‐related complications. We report a complication of double lumen hemocatheter guide wire entrapment in a 43‐year‐old female of type 1 diabetes mellitus and hemodialysis patient. She was admitted for left arteriovenous shunt dysfunction and right internal jugular vein hemocatheter chamber clotting was found while on hemodialysis, so a new hemocatheter was changed over guide wire. Guide wire was introduced without any resistance and the clotting hemocatheter was removed. During the procedure, the J‐tipped guide wire could not be withdrawn and portable chest radiography revealed the J‐tip of the guide wire was in the right ventricle near the region of tricuspid valve. Fluoroscopy was arranged and it also confirmed the J‐tip was lying in the ventricle near the tricuspid valve where it was stuck. Snare catheter kit was inserted through the 10 Fr sheath and the cardiologist untied the knot by endovascular snare and removed the guide wire smoothly. This report emphasizes the importance of awareness on guide wire entrapment while inserting double lumen hemocatheter. When a guide wire became hard to withdraw, extracting an entrapped guide wire with fluoroscopy guide and snare catheter is a preferable and minimal invasive approach.

Multiple Hypovascular Tumors in Kidney: A Rare Case Report and Differential Diagnosis

The most common malignant renal tumor is renal cell carcinoma and surgery is the standard treatment. The proportion of lymphoma with renal involvement is 2~15% and lymphoma could be cured by chemotherapy without nephrectomy. Sonography, computed tomography (CT), and magnetic resonance imaging (MRI) can detect and characterize a renal mass. We present a case of right renal hypovascular tumors and differential diagnosis of hypovascular tumors by image study. CT scan showed hypovascular tumors and MRI image revealed multifocal hypovascular solid tumors with significantly increased apparent diffusion coefficient (ADC) of diffusion weighted imaging (DWI). Based on image finding, renal lymphoma was highly suspected. Renal lymphoma was confirmed by renal biopsy and this patient received chemotherapy without surgery. The noninvasive CT scan and MRI image can help clinicians to diagnose the characteristics of renal mass and to avoid unnecessary nephrectomy.