BACKGROUND:This study was undertaken to examine whether there is an association between parity and age at first birth and risk of kidney cancer.METHODS:The study cohort consisted of 1 292 462 women who had a first and singleton childbirth between 1 January 1978 and 31 December 1987. We tracked each woman from the time of her first childbirth to 31 December 2009, and their vital status was ascertained by linking records with the computerized mortality database. Cox proportional hazard regression models were used to estimate the hazard ratios (HRs) of death from kidney cancer associated with parity and age at first birth.RESULTS:There were 95 kidney cancer deaths during 34,980,246 person-years of follow-up. The mortality rate of kidney cancer was 0.27 cases per 100,000 person-years. The adjusted HR was 1.88 [95% confidence interval (CI) 1.10-3.19] for women who gave birth between 24 and 26 years of age and 2.52 (95% CI 1.44-4.40) for women who gave birth after 26 years of age, when compared with women who gave birth when <23 years of age. A trend of increasing risk of kidney cancer was seen with increasing age at first birth. The adjusted HR was 0.88 (95% CI 0.49-1.59) for women who had two children and 0.89 (95% CI 0.47-1.67) for women with three or more births, when compared with women who had given birth to only one child.CONCLUSION:This study is the first to suggest that early age at first birth may confer a protective effect on the risk of kidney cancer.

Background: There are no prior studies that have estimated the risk of upper gastrointestinal bleeding (UGIB) among the dialysis population relative to the general population. The aim of this study was to examine the risk of UGIB among end-stage renal disease (ESRD) patients during a 6-year period following their initiation of hemodialysis (HD) therapy in Taiwan- a country with the highest incidence of ESRD in the world, using general population as an external comparison group.Methods: Data were obtained from the Taiwan National health Insurance Research Database. In total, 796 patients who were beginning HD between 1999 and 2003 were recruited as the study cohort and 3,184 patients matched for age and sex were included as comparison cohort. Multivariate Cox proportional hazard regression models were used to adjust for confounding and to compare the 6-year UGIB-free survival rate between these two cohorts.Results: The incidence rate of UGIB (42.01 per 1000 person-year) was significantly higher in the HD cohort than in the control cohort (27.39 per 1000 person-years). After adjusting for potential confounders, the adjusted hazard ratios for UGIB during the 6-year follow-up periods for HD patients was 1.27 (95% CI=1.03-1.57) compared to patients in the comparison cohort.Conclusions: We conclude that HD patients were at an increased risk for UGIB compared with the general population.

This study aimed to identify the risk association between pioglitazone exposure and bladder cancer. A nested case-control study was performed using a representative database randomly sampled from National Health Insurance enrollees. The source cohort consisted of newly diagnosed diabetic patients from 1997 to 2009. Cases were identified as those with a diagnosis of bladder cancer from 2002 to 2009. For each case, four matched control individuals were randomly selected. A multiple logistic regression model was used to estimate the relative magnitude of risk in relation to the use of pioglitazone. In total, 259 cases and 1036 controls were identified. The prevalent use of pioglitazone is similar in cases and controls (adjusted odds ratio, 1.20; 95% confidence interval, 0.58-2.49). Compared to nonusers, these values were 1.08 (0.41-2.88) for those with cumulative pioglitazone use ≤ 8268 mg and 1.35 (0.48-3.79) for those with cumulative pioglitazone use > 8268 mg. This study does not provide support for the risk association between pioglitazone exposure and bladder cancer. Further confirmation is needed due to the limitation of small case number with relatively shorter exposure duration and lower cumulative dose.

Aims: Data regarding the occurrence of stroke in dialysis patients are limited and epidemiologic studies to date are controversial with respect to the stroke subtype among dialysis patients. The aim of this study was to perform a population-based study with a retrospective cohort design to investigate the risk of stroke after the initiation of haemodialysis (HD) among end-stage renal disease (ESRD) patients in Taiwan a country with the highest incidence of ESRD in the world.Methods: Data were retrospectively obtained from the Taiwan National Health Insurance Research Database. In total, 644 patients who were beginning HD between 1999 and 2003 were recruited as the study cohort and 3220 patients matched for age and sex were included as the comparison cohort. Multivariate Cox proportional hazard regression models were used to adjust for confounding and to compare the 5 year stroke-free survival rate between these two cohorts.Results: The incidence rate of stroke (41.76 per 1000 person-years) was significantly higher in the HD cohort than in the control cohort (24.29 per 1000 person-years). After adjusting for potential confounders, the adjusted hazard ratios of ischaemic stroke and haemorrhagic stroke were 2.16 (95% confidence interval = 1.57-2.97) and 3.78 (95% confidence interval = 1.907.55), respectively.Conclusion: We conclude that HD patients were at an increased risk for both ischaemic and haemorrhagic stroke compared with the general population.

BACKGROUND:This study was undertaken to examine whether there is an association between parity and age at first birth and risk of death from chronic renal failure (CRF).STUDY DESIGN:Prospective cohort study.SETTING AND PARTICIPANTS:The study cohort consisted of 1 292 462 women who had a first and singleton childbirth between January 1, 1978 and December 31, 1987. We tracked each woman from the time of their first childbirth to December 31, 2009, and their vital status was ascertained by linking records with the computerized mortality database.PREDICTORS:Parity and age at first birth.OUTCOME:Death of chronic renal failure (CRF).RESULTS:There were 225 CRF deaths during 34 980 246 person-years of follow-up. The mortality rate of CRF was 0.64 cases per 100 000 person-years. Adjusted hazard ratios (HRs) were 1.75 (95% CI= 1.30-2.36) for women who gave birth between 26 and 30 years, 2.52 (95% CI=1.57-4.04) for women who gave birth after 30 years, respectively, when compared with women who gave birth younger than 25 years. Adjusted HRs were 0.47 (95% CI= 0.33-0.66) for women who had two children, and 0.40 (95% CI=0.28-0.58) for women with three or more births, respectively, when compared with women who had given birth to only one child. There was a significant decreasing trend in the HRs of CRF death with increasing parity.CONCLUSIONS:This study provides evidence that reproductive factors (parity and early age at first birth) may confer a protective effect on the risk of CRF death.

OBJECTIVE:To investigate whether the use of statins was associated with kidney cancer risk. METHODS:We conducted a population-based case-control study in Taiwan. Cases consisted of all patients who were aged 50 years and older, and had a first-time diagnosis of kidney cancer for the period between 2005 and 2009. The controls were matched to cases by age, sex, and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using multiple logistic regression. RESULTS:We examined 177 kidney cancer cases and 708 controls. The adjusted OR for any statin prescription was 1.08 (95% CI = 0.70 - 1.67). Compared with no use of statins, the adjusted ORs were 0.91 (95% CI = 0.50 - 1.63) for the group having been prescribed statins with cumulative defined daily dose (DDDs) below 105 and 1.28 (95% CI = 0.73 - 2.23) for the group with cumulative statin use of 105 DDDs or more. CONCLUSIONS:The present data do not provide evidence to support either beneficial or harmful associations between statin use and kidney cancer risk. However, there is a trend of increased kidney cancer risk with higher cumulative DDDs, and consequently that it is prudent to continue monitoring cancer incidence among long-standing statin users.

OBJECTIVE:The aim of this study was to investigate whether the use of statins was associated with a decreased risk of gallstone disease.METHODS:We conducted a population-based case-control study in Taiwan. Cases consisted of all patients who were aged 50 years and older and had a first-time diagnosis of gallstone disease or cholecystectomy for the period between 2005 and 2009. The controls were matched to cases by age, sex and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using multiple logistic regression.RESULTS:We examined 1014 gallstone disease cases and 1014 controls. The unadjusted ORs for any statin prescription was 1.06 (95% CI 0.86 to 1.29), and the adjusted OR was 1.14 (95% CI 0.90 to 1.43). Compared with no use of statins, the adjusted ORs were 1.05 (95% CI 0.72 to 1.54) for the group having been prescribed statins with cumulative defined daily doses (DDDs) below 41.53, 1.12 (95% CI 0.84 to 1.50) for the group with cumulative dose between 41.54 and 334.81 DDD, and 1.30 (95% CI 0.86 to 1.95) for the group with cumulative statin use of 334.81 DDDs or more.CONCLUSIONS:This study does not provide support for a beneficial association between usage of statin and gallstone disease.

The objectives of this study were to (1) examine the relationship between total trihalomethanes (TTHM) levels in public water supplies and death attributed to colon cancer and (2) determine whether magnesium (Mg) levels in drinking water modify the effects of TTHM on risk of colon cancer development. A matched case-control study was used to investigate the relationship between the risk of death attributed to colon cancer and exposure to total trihalomethanes (TTHM) in drinking water in 53 municipalities in Taiwan. All colon cancer deaths of the 53 municipalities from 1998 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels in drinking water were collected from Taiwan Environmental Protection Administration. Information on the levels of Mg in drinking water was obtained from the Taiwan Water Supply Corporation. The municipality of residence for cancer cases and controls was presumed to be the source of the subject's TTHM and Mg exposure via drinking water. Relative to individuals whose TTHM exposure levels were <4.9 ppb, the adjusted odds ration (OR) (with 95% confidence interval [CI]) for colon cancer was 1.14 (1.01-1.28) for individuals who had resided in municipalities served by drinking water with a TTHM exposure≥4.9 ppb. Evidence of an interaction between drinking-water TTHM and Mg intake via drinking water was noted. This is the first study to report an effect modification by Mg intake from drinking water in association between TTHM exposure and risk of colon cancer occurrence. Better knowledge of this modifying factor will help in public policymaking and setting health standards.

BACKGROUND AND AIM:The incidence of infantile hypertrophic pyloric stenosis (IHPS) varies among different countries and is supposed to be lower in Asian countries than in Western countries. However, the incidence of IHPS in Taiwan has not been well investigated. METHODS:The National Health Insurance (NHI) program was implemented in Taiwan in 1995 and covers most of the population (>99%). We used the NHI database to investigate the epidemiological features of IHPS in Taiwan and to compare the data with that of other countries. RESULTS:We identified 962 new IHPS cases during the period from 1996 to 2004. The overall incidence of IHPS was 0.39 (0.34-0.50) cases per 1000 live births. The estimation was 0.39-0.59 per 1000 live births after adjustment for the misdiagnosis rate. The peak incidence (0.58 per 1000 live births) occurred in winter in 1999. Rates were consistently higher in male subjects. The 1-year survival rate was not significantly different in the patients receiving pyloromyotomy in medical centers, regional hospitals, and district hospitals (P=0.389). CONCLUSIONS:Taiwan had the second lowest incidence of IHPS reported in the medical literature. IHPS patients can be successfully treated in district and general hospitals with good prognosis.

PURPOSE:The chronic effect of various analgesics on the progression of chronic kidney disease (CKD) is inconclusive. There is also lack of information on the renal safety of selective cyclooxygenase-2 (COX-2) inhibitors. This study aimed to clarify the renal risk of analgesic use in CKD patients. METHODS:A cohort study using a nationally representative database randomly sampled from National Health Insurance (NHI) enrollees was performed. The study population included a total of 19,163 newly diagnosed CKD patients. Clinical conditions were defined by diagnostic codes and exposure information on analgesics was derived from service claims. Cox proportional hazard model was used to assess the association between analgesic use and the risk of progression to end stage renal disease (ESRD). RESULTS:CKD patients using acetaminophen, aspirin, and non-selective non-steroidal anti-inflammatory drugs (NSAIDs) had an increased risk for ESRD with multivariable-adjusted HRs (95%CIs) of 2.92 (2.47-3.45), 1.96 (1.62-2.36), and 1.56 (1.32-1.85), respectively. The trends toward higher risk with increasing exposure dose were significant for all classes of analgesics (all P for trend < 0.001). Among COX-2 inhibitors, only rofecoxib, but not celecoxib, shows a significant risk association with ESRD (HR = 1.98; 95%CI, 1.15-3.40). CONCLUSIONS:Our data indicated exacerbating effects of acetaminophen, aspirin, and non-selective NSAIDs on CKD in a dose-dependent manner. For COX-2 inhibitors, only rofecoxib showed an increased risk for ESRD. Although the possibility of residual confounding cannot be completely ruled out, given the common use of analgesics, the possible relation suggested by this study warrants further investigation.

The objectives of this study were (1) to examine the relationship between total trihalomethanes (TTHM) levels in public water supplies and risk of rectal cancer development and (2) to determine whether calcium (Ca) and magnesium (Mg) levels in drinking water might modify the effects of TTHM on risk of developing rectal cancer. A matched cancer case-control study was used to investigate the relationship between the risk of death attributed to rectal cancer and exposure to TTHM in drinking water in 53 municipalities in Taiwan. All rectal cancer deaths in the 53 municipalities from 1998 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels in drinking water were collected from the Taiwan Environmental Protection Administration. Information on the levels of Ca and Mg in drinking water was obtained from the Taiwan Water Supply Corporation. The municipality of residence for cancer cases and controls was presumed to be the source of the subject's TTHM, Ca, and Mg exposure via drinking water. Relative to individuals whose TTHM exposure level was 4.9 ppb, the adjusted OR (95% CI) for rectal cancer occurrence was 1.04 (0.88-1.22) for individuals who resided in municipalities served by drinking water with a TTHM exposure epsilon 4.9 ppb. There was no evidence of an interaction of drinking-water TTHM levels with low Ca intake via drinking water. However, evidence of an interaction was noted between drinking-water TTHM concentrations and Mg intake via drinking water. Our findings showed that the correlation between TTHM exposure and risk of rectal cancer is influenced by Mg in drinking water. Increased knowledge of the interaction between Mg and TTHM in reducing rectal cancer risk will aid in public policymaking and standard setting.

The objectives of this study were (1) to examine the relationship between total trihalomethanes (TTHM) levels in public water supplies and mortality attributed to colon cancer and (2) to determine whether calcium levels (Ca) in drinking water modify the effects of TTHM on risk to develop colon cancer. A matched cancer case-control study was used to investigate the relationship between the risk of death attributed to colon cancer and exposure to TTHM in drinking water in 53 municipalities in Taiwan. All colon cancer deaths in the 53 municipalities from 1998 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels in drinking water were collected from the Taiwan Environmental Protection Administration. Information on the levels of Ca in drinking water was obtained from the Taiwan Water Supply Corporation. The municipality of residence for cancer cases and controls was presumed to be the source of the subject's TTHM and Ca exposure via drinking water. Relative to individuals whose TTHM exposure level was 4.9 ppb, the adjusted OR (95% CI) for colon cancer was 1.14 (1.01-1.28) for individuals who resided in municipalities served by drinking water with a TTHM exposure epsilon 4.9 ppb. Data demonstrated evidence of an interaction between drinking-water TTHM concentrations and Ca intake via drinking water. Our findings showed that the correlation between TTHM exposure and risk of colon cancer development is influenced by Ca in drinking water. Increased knowledge of the interaction between Ca and TTHM in reducing colon cancer risk will aid in public policymaking and standard setting.

The objective of this study was to evaluate whether exposure to disinfection by-products (DBP) is associated with colon cancer. A matched case-control study was used to investigate the relationship between the risk of death attributed to colon cancer and exposure to total trihalomethanes (TTHM) in drinking water in 65 municipalities in Taiwan. All colon cancer deaths of the 65 municipalities from 1997 through 2006 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels in drinking water in study municipalities were collected from the Taiwan Environmental Protection Administration. The municipality of residence for cancer cases and controls was assumed to be the source of the subject's TTHM exposure via drinking water. The adjusted odds ratios (OR) for colon cancer death for those with high TTHM levels in their drinking water were 1.02 (0.87-1.2) and 1.04 (0.89-1.21) compared to the lowest group. The results of the present study show that there was no statistically significant association between TTHM in drinking water at levels in this study and risk of death from colon cancer.

BACKGROUND End-stage renal disease is epidemic in Taiwan. Although early intervention in chronic kidney disease (CKD) has proven to be effective in modifying its clinical course, little is known about the quality and trend of CKD care in Taiwan. METHODS From a nationally representative database of 200,000 individuals, CKD patients were identified by diagnostic codes, and their medical interventions were extracted from service claims. The predictors for care delivery were analyzed in a logistic regression model. RESULTS Of the 7,740 patients with CKD, only 54.8% had follow-up of renal function. Tests for anemia, calcium/ phosphorus and lipid profile were performed in 34.5%, 5.2% and 40.9% of patients, respectively. Most hypertensive CKD patients have used antihypertensive agents, but only 58.1% of them received angiotensinconverting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). Of CKD patients with diabetes, less than half had glycosylated hemoglobin measured, and only 49.7% received ACEIs/ARBs. We observed an encouraging trend in the use of ACEIs/ ARBs and in most aspects of laboratory monitoring. CONCLUSIONS Management of CKD patients is suboptimal, and lack of awareness is common. Further work is needed to evaluate the impact of educational initiatives and multidisciplinary teams on outcomes in CKD patients.

In spring, windblown dust storms originating in the deserts of Mongolia and China make their way to Taipei city. These occurrences are known as Asian dust storm (ADS) events. These ADS events lead to enhanced PM(10) levels over that contributed by the usual local sources. The objective of this study was to assess the possible associations of PM(10) with hospital admissions for chronic obstructive pulmonary disease (COPD) in Taipei, Taiwan, during the period 1996-2001. We identified 54 dust storm episodes that were classified as index days. Daily COPD admissions on the index days were compared with admissions on the comparison days. We selected 2 comparison days for each index day, 7 days before the index days and 7 days after the index days. The effects of dust storms on hospital admissions for COPD were prominent 3 days after the event (relative risk = 1.057; 95% confidence interval = 0.982-1.138). However, the association was not statistically significant. There may not have been enough power to detect associations resulting from the inadequate sample size of COPD admissions on ADS events days. However, It seems worthwhile to pay more attention to the ADS events and health in the future.

The relationship between nitrate levels in drinking water and rectal cancer development has been inconclusive. A matched case-control and nitrate ecology study was used to investigate the association between mortality attributed to rectal cancer and drinking-water nitrate exposure in Taiwan. All deaths due to rectal cancer of Taiwan residents from 1999 through 2003 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair matched to the cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. Data on nitrate-nitrogen (NO3- N) levels in drinking water throughout Taiwan were collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was assumed to be the source of the subject's nitrate exposure via drinking water. The adjusted odds ratios for rectal cancer death for those with high nitrate levels in their drinking water, as compared to the lowest tertile, were 1.22 (0.98-1.52) and 1.36 (1.08-1.70), respectively. The findings of this study warrant further investigation of the role of nitrates in drinking water in the etiology of rectal cancer in Taiwan.

Background and Aim: The incidence of biliary atresia (BA) varies among different countries. It is supposed to be higher in Asian countries than in Western countries; however, the incidence of BA in Taiwan has not been well investigated. The aim of this study was to analyze the epidemiological characteristics and the incidence of BA in Taiwan.Methods: National Health Insurance (NHI) was implemented in Taiwan in 1995, and covers most of the population (> 99%). We use the NHI database to investigate the epidemiological features of BA and compare Taiwan's annual BA incidence with that of other countries.Results: We identified 327 new BA cases during the period from 1996 to 2003. The overall incidence of BA was 1.46 cases per 10 000 live births (0.89-1.90 per 10 000). The estimation was 1.32-1.65 per 10 000 after adjustment for the misdiagnosis rate. The peak incidence occurred in 2002 (1.90 per 10 000), accompanying Taiwan's dengue fever epidemic in 2002. The 5-year overall survival rate during 1999-2003 was higher than that during 1996-1998 (74.8% vs 61.1%, P = 0.014).Conclusion: Taiwan has the second-highest incidence of BA reported in world literature. Viral infection outbreaks remain a potential candidate as a cause of BA. The management of BA has been improving, with a better 5-year overall survival rate.

This study was undertaken to determine whether there is an association between exposure to air pollutants levels and number of hospital admissions for asthma in Taipei, Taiwan. Hospital admissions for asthma and ambient air pollution data for Taipei were obtained for the period from 1996 through 2003. The relative risk of hospital admission for asthma was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. In the single-air-pollutant model, on warm days (≥25°C) statistically significant positive associations were found for SO2, NO2, and CO levels with an increase in asthmatic admissions. On cool days (<25°C), all air pollutants were significantly associated with elevated asthma admissions except SO2. For the two-air-pollutant model, CO significantly increases hospital admissions for asthma in combination with each of the other four pollutants on warm days. On cool days, NO2 and O3 significantly elevated asthma rates in all the two-air-pollutant models. This study provides evidence that higher levels of ambient air pollutant concentrations increase the risk of hospital admissions for asthma.

BACKGROUND:The incidence of end-stage renal disease (ESRD) in Taiwan is the highest in the world. However, epidemiological features of earlier chronic kidney disease (CKD) have not been investigated.METHODS:Since implementation of the National Health Insurance Program in 1995, more than 96% of the population in Taiwan has been enrolled. A nationally representative cohort of 200,000 individuals randomly sampled from the National Health Insurance enrollees was followed up from 1996 to 2003. Clinical conditions were defined by using diagnostic codes. The prevalence and incidence of clinically recognized CKD were assessed. We also identified risk factors associated with the development of CKD.RESULTS:The prevalence of clinically recognized CKD increased from 1.99% in 1996 to 9.83% in 2003. The overall incidence rate during 1997 to 2003 was 1.35/100 person-years. The multivariate model indicates that age is a key predictor of CKD, with an odds ratio of 13.95 for the group aged 75-plus years compared with the group younger than 20 years. Other factors associated with increased risk for the development of CKD include diabetes, hypertension, hyperlipidemia, and female sex.CONCLUSION:The prevalence and incidence of CKD in Taiwan are relatively high compared with other countries. Our finding provides a reasonable explanation for the subsequent epidemic of ESRD in Taiwan. Further study is needed to identify the entire burden of CKD and the effectiveness of risk-factor modification.

The authors examined the relationship in women between age at first birth, parity, and subarachnoid hemorrhage mortality. They followed each woman from the time of her first birth and linked vital status with a mortality database. The risk was increased by 8% for each additional year of mother's age at first birth. The relative risk was 0.63 for women who had borne two children and 0.62 for women with three or more births.