Validation of the National Health Insurance Research Database with ischemic stroke cases in Taiwan

Sudden sensorineural hearing loss associated with chronic periodontitis: a population-based study

OBJECTIVE

Although plenty of researchers have reported systemic effects originating from chronic periodontitis (CP) on potentially distal inflammatory processes, such as those leading to coronary heart disease, cerebrovascular disease, and cancer, no study has reported the association between CP and sudden sensorineural hearing loss (SSNHL). The present study explored the association between CP and SSNHL using a large, population-based dataset in Taiwan.

STUDY DESIGN

A case-control study.

SETTING

Taiwan.

PATIENTS

We used administrative claims data from the Taiwan National Health Insurance program to identify 2,436 subjects with SSNHL and to randomly select 7,308 controls.

MAIN OUTCOME MEASURES

A conditional logistic regression analysis was conducted to calculate the odds ratio (OR) for having been previously diagnosed with CP between cases and controls.

RESULTS

In total, 1,663 (17.1%) of the 9,744 sampled subjects had received a CP diagnosis before the index date; 520 (21.4%) were cases and 1143 (15.6%) were controls. The χ2 test suggested that there was a significant difference in the prevalence of previous SSNHL between cases and controls (p < 0.001). The conditional logistic regression revealed after adjusting for hypertension, diabetes, hyperlipidemia, renal disease, coronary heart disease, obesity, and stroke, the OR of having previously received a CP diagnosis among cases was 1.44 (95% CI = 1.29∼1.63) that of controls.

CONCLUSION

This study found that SSNHL was significantly associated with a previous diagnosis of CP. Further prospective studies are warranted to confirm our findings and clarify the underlying pathomechanism.

Parkinson's disease is related to an increased risk of ischemic stroke-a population-based propensity score-matched follow-up study

Objective

The risk of stroke in patients with Parkinson’s disease (PD) remains controversial. The purpose of this population-based propensity score-matched longitudinal follow-up study was to determine whether there is an increased risk of ischemic stroke after PD.

Methods

We used a logistic regression model that includes age, sex, pre-existing comorbidities and socioeconomic status as covariates to compute the propensity score. A total of 2204 patients with at least two ambulatory visits with the principal diagnosis of PD in 2001 was enrolled in the PD group. The non- PD group consisted of 2204, propensity score-matched subjects without PD. The ischemic stroke-free survival rates of the two groups were estimated using the Kaplan-Meier method. Stratified Cox proportional hazard regression with patients matched on propensity score was used to estimate the effect of PD on the occurrence of ischemic stroke.

Results

During the three-year follow-up period, 328 subjects in the PD group and 156 subjects in the non-PD group developed ischemic stroke. The ischemic stroke-free survival rate of the PD group was significantly lower than that of the non-PD group (P<0.0001). The hazard ratio (HR) of stroke for the PD group was 2.37 (95% confidence interval [CI], 1.92 to 2.93, P<0.0001) compared to the non- PD group.

Conclusions

This study shows a significantly increased risk of ischemic stroke in PD patients. Further studies are required to investigate the underlying mechanism.

Bladder pain syndrome/interstitial cystitis is associated with anxiety disorder

AIM

Recent research demonstrated that bladder pain syndrome/interstitial cystitis (BPS/IC) is associated with many coexisting physical and psychiatric conditions. In this study, we explored the potential association between anxiety disorder (AD) and BPS/IC using a case-controlled population-based approach in Taiwan.

METHODS

Data on the sampled subjects analyzed in this study were retrieved from the Longitudinal Health Insurance Database 2000. Our study included 396 female cases with BPS/IC and 1,980 randomly selected female controls. We excluded subjects who had a history of major psychosis (except AD) or a substance-related disorder. A conditional logistic regression was performed to calculate the odds ratio (OR) for the association between a previous diagnosis of AD and IC/BPS.

RESULTS

Of the 2,376 sampled subjects, 136 (5.72%) had received an AD diagnosis. AD was found in 64 (16.16%) cases and in 72 (3.64%) controls (P < 0.001). The conditional logistic regression analysis (conditioned on age group and the index year) suggested that compared to controls, the OR for prior AD among cases was 4.59 (95% confidence interval (CI) = 2.32-9.08, P < 0.001). After adjusting for chronic pelvic pain, irritable bowel syndrome, fibromyalgia, migraines, sicca syndrome, allergies, asthma, and an overactive bladder, the OR for prior AD among cases was 4.37 (95% CI = 2.16-8.85, P < 0.001) compared to the controls.

CONCLUSIONS

There was an association between AD and BPS/IC, even after taking demographic characteristics, medical co-morbidities, and substance-related disorders into consideration. Results of this study should alert clinicians to evaluate and monitor the presence of BPS/IC in patients with AD.

Bladder pain syndrome/interstitial cystitis is associated with hyperthyroidism

BACKGROUND

Although the etiology of bladder pain syndrome/interstitial cystitis (BPS/IC) is still unclear, a common theme with BPS/IC patients is comorbid disorders which are related to the autonomic nervous system that connects the nervous system to end-organs. Nevertheless, no study to date has reported the association between hyperthyroidism and BPS/IC. In this study, we examined the association of IC/BPS with having previously been diagnosed with hyperthyroidism in Taiwan.

DESIGN

Data in this study were retrieved from the Longitudinal Health Insurance Database. Our study consisted of 736 female cases with BPS/IC and 2208 randomly selected female controls. We performed a conditional logistic regression to calculate the odds ratio (OR) for having previously been diagnosed with hyperthyroidism between cases and controls.

RESULTS

Of the 2944 sampled subjects, there was a significant difference in the prevalence of prior hyperthyroidism between cases and controls (3.3% vs. 1.5%, p<0.001). The conditional logistic regression analysis revealed that compared to controls, the OR for prior hyperthyroidism among cases was 2.16 (95% confidence interval (CI): 1.27∼3.66). Furthermore, the OR for prior hyperthyroidism among cases was 2.01 (95% CI: 1.15∼3.53) compared to controls after adjusting for diabetes, coronary heart disease, obesity, hyperlipidemia, chronic pelvic pain, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, depression, panic disorder, migraines, sicca syndrome, allergies, endometriosis, and asthma.

CONCLUSIONS

Our study results indicated an association between hyperthyroidism and BPS/IC. We suggest that clinicians treating female subjects with hyperthyroidism be alert to urinary complaints in this population.

Routine endoscopy for esophageal cancer is suggestive for patients with oral, oropharyngeal and hypopharyngeal cancer

Background

This study attempted to reveal the incidence and risk of synchronous and metachronous esophageal cancer in subjects with oral, oropharyngeal and hypopharyngeal cancer based on a population-wide database in Taiwan.

Methods

We retrieved data for this cross-sectional study from the Taiwanese Longitudinal Health Insurance Database 2000. The study group included 2,965 subjects who had received their first-time diagnosis of oral/oropharyngeal/hypopharyngeal cancer in 2002∼2009. We assigned the date of their first diagnosis of oral/oropharyngeal/hypopharyngeal cancer as the index date. We also randomly retrieved 29,650 comparison subjects matched with the study subjects in terms of gender and age group. We assigned their first medical utilization that occurred in the index year as the index date for the comparison group. We further performed a conditional logistic regression to investigate the association between esophageal cancer and oral cancer.

Results

Results showed that prevalences of esophageal cancer within 3 months before and after the index date were respectively 2.19% and 0.04% for the study and comparison groups. A conditional logistic regression revealed that the odds ratio (OR) of esophageal cancer for subjects with oral/oropharyngeal/hypopharyngeal cancer was 55.33 (95% confidence interval (CI): 29.86∼102.52) compared to comparison subjects. Furthermore, compared to comparison subjects, ORs for esophageal cancer were respectively 18.41 (95% CI: 8.50–39.85), 40.49 (95% CI: 15.11∼108.64), and 240.96 (95% CI: 125.49–462.69) for study subjects with a malignancy of the oral cavity, oropharynx, and hypopharynx.

Conclusion

We concluded that there were relatively high chances for synchronous and metachronous esophageal cancers being detected through panendoscopy in patients with oral, oropharyngeal, and hypopharyngeal cancers. The routine use of panendoscopy in such patients should be encouraged with a higher priority.

Rheumatoid arthritis and risk of acute myocardial infarction--a nationwide retrospective cohort study

OBJECTIVES

Rheumatoid arthritis (RA) imposes substantial social costs, including an increased risk of work-related disability and accelerated cardiovascular diseases. The aim of the study is to determine the risk of acute myocardial infarction (AMI) associated with RA in a nationwide retrospective cohort study.

METHODS

Using the catastrophic illness registry of the Taiwan National Health Insurance Research Database (NHIRD), we identified patients with RA from 1998 to 2010. We also randomly selected non-RA controls frequency-matched by age, sex, and index year from the general population free of RA. The risk of AMI was analyzed using Cox proportional hazards regression models including sex, age, and comorbidities.

RESULTS

From a total of 23.74 million people in the cohort, 29,260 RA patients and 117,040 controls were followed for 193,987 and 792,254 person-years, respectively. The incidence density rate increased in all groups of RA patients than those of the controls. RA patients had a 1.33-fold higher overall incidence of AMI than controls, with an adjusted hazard ration of 1.38. Although the overall adjusted hazard ratio of AMI increased with age, the age-specific RA patients to controls incidence rate ratio was higher for younger RA patients. Subjects with comorbidities of hypertension, diabetes hyperlipidemia, CVA, COPD, or ESRD had increased risk of AMI. Subjects with ESRD had the highest hazard of AMI.

CONCLUSION

This nationwide retrospective cohort study indicates that AMI risk increased by 38% in RA patients compared to the general population. Comorbidities increase the AMI risk independently.

Interferon-based therapy reduces risk of stroke in chronic hepatitis C patients: a population-based cohort study in Taiwan

BACKGROUND

Hepatitis C virus (HCV) infection has been linked to an increased risk of insulin resistance and carotid atherosclerosis.

AIM

To investigate the association between HCV infection and stroke, and the effect of interferon-based therapy (IBT) on stroke risk in chronic hepatitis C (CHC) patients.

METHODS

We conducted a retrospective cohort study that followed up 3113 subjects with a newly detected HCV infection and 12 452 age- and gender-matched subjects without HCV infection selected from a random sample of 10(6) beneficiaries from the Taiwan National Health Insurance Program up to 5 years. Use of IBT was defined as treatment with interferon alpha, pegylated interferon alpha-2a or pegylated interferon alpha-2b for at least 3 months. The hazard ratio (HR) for newly detected stroke was calculated for subjects with HCV compared to those without HCV, and for IBT-treated HCV patients compared to non-IBT-treated HCV patients while adjusting for possible confounding factors.

RESULTS

The overall person-years of follow-up were 8624.11 in patients with HCV, 54,533.69 in patients without HCV, 666.65 in IBT-treated patients, and 7886.49 in nontreated patients. The multivariable-adjusted hazard ratio (HR) for newly detected stroke was 1.23 for subjects with HCV compared to the age- and sex-matched subjects without HCV (adjusted HR = 1.23, 95% CI = 1.06-1.42, P = 0.008). Moreover, use of IBT significantly reduced the risk of stroke in HCV patients (adjusted HR = 0.39, 95% CI = 0.16-0.95, P = 0.039) after adjusting for known prognostic factors.

CONCLUSIONS

Interferon-based therapy may reduce the long-term risk of stroke in patients with chronic HCV infection.

Migraine and risk of dementia: a nationwide retrospective cohort study

OBJECTIVE

Migraines are one of the most common neurological disorders. Dementia is a neurodegenerative disease characterized by slow progressive memory loss and cognitive dysfunction. This retrospective cohort study investigates the association between migraines and dementia using a nationwide population-based database in Taiwan.

METHODS

We retrieved the data analyzed in this study from the National Health Insurance Research database (NHIRD) in Taiwan. We used multivariate Cox proportion-hazards regression models to assess the effects of migraines on the risk of dementia after adjusting for sociodemographic characteristics and comorbidities.

RESULTS

The migraine cohort had a higher prevalence of diabetes, hypertension, coronary artery disease, head injury and depression at baseline (p < 0.0001). After adjusting the covariates, migraine patients had a 1.33-fold higher risk of developing dementia [hazard ratio (HR) 1.33, 95% confidence interval (CI) 1.22-1.46]. The sex-specific incidence rate of dementia was higher in men than in women in both cohorts, with an HR of 1.09 (95% CI 1.00-1.18) for men compared to women. Kaplan-Meier analysis shows that the cumulative incidence of dementia was 1.48% greater in the migraine cohort than in the nonmigraine cohort (log-rank test, p < 0.0001).

CONCLUSIONS

This study shows that migraines are associated with a future higher risk of dementia after adjusting for comorbidities. Specifically, the association between migraine and dementia is greater in young adults than in older adults.

The effect of tropical cyclones (typhoons) on emergency department visits

BACKGROUND

Case reports have indicated that a tropical cyclone may increase Emergency Department (ED) visits significantly.

STUDY OBJECTIVES

To examine emergency health care demands across a series of tropical cyclones, and to build a predictive model to analyze a cyclone's potential effect.

METHODS

This was an observational non-concurrent prospective study performed in Taiwan. Twenty hospitals were included. The number of daily ED visits in each hospital was our primary end point, and data were retrieved from the database provided by the National Health Insurance Research Database. Our study examined the period from 2000 to 2008. A total of 22 tropical cyclones (typhoons) that had passed over eastern Taiwan and covered the area under study were included. Multiple linear regression time-series models were employed to estimate the effects of "days since typhoon landfall" and various characteristics of the typhoons on the end point of daily ED visits to each hospital.

RESULTS

The final multiple linear regression time-series model showed that the number of daily ED visits increased in areas where a strong typhoon had landed directly, with the increase being evident during the first 2 days since landfall. Our model also indicated that the three most important variables to predict a change in the pattern of daily ED visits were intensity of typhoon, simultaneous heavy rain, and direct landfall.

CONCLUSIONS

During tropical cyclones, emergency services were under increased demand in selected time periods and areas. Health care authorities should collect information to build local models to optimize their resources allocation in preparation.

Epidemiology of cervical spondylotic myelopathy and its risk of causing spinal cord injury: a national cohort study

Object

This study aimed to determine the age- and sex-specific incidence of cervical spondylotic myelopathy (CSM) and its associated risk of causing subsequent spinal cord injury (SCI).

Methods

Using the National Health Insurance Research Database (NHIRD), a 12-year nationwide database in Taiwan, this retrospective cohort study analyzed the incidence of hospitalization caused by CSM. All patients diagnosed with and admitted for CSM were identified during the study period. The CSM patients were divided into 2 groups, a control group and an operated group. An incidence density method was used to estimate age- and sex-specific incidence rates of CSM. The Kaplan-Meier method and Cox regression analyses were performed to compare the risk of SCI between the 2 groups.

Results

From 1998 to 2009, covering 349.5 million person-years, 14,140 patients were hospitalized for CSM. The overall incidence of CSM-related hospitalization was 4.04 per 100,000 person-years. Specifically, males and older persons had a higher incidence rate of CSM. During the follow-up of these patients for 13,461 person-years, a total of 166 patients were diagnosed with SCI. The incidence of SCI was higher in the control group than the operated group (13.9 vs 9.4 per 1000 person-years, respectively). During the follow-up, SCI was more likely to occur in CSM patients who were treated conservatively (crude HR 1.48, p = 0.023; adjusted HR 1.57, p = 0.011) than in those who underwent surgery for CSM.

Conclusions

In a national cohort of eastern Asia, the incidence of CSM-caused hospitalization was 4.04 per 100,000 person-years, with higher incidences observed in older and male patients. Subsequent SCI was more likely to develop in patients who received nonoperative management than in those who underwent surgery. Therefore, patients with CSM managed without surgery should be cautioned about SCI. However, further investigations are still required to clarify the risks and complications associated with surgery for CSM.

Zolpidem Use and the Risk of Injury: A Population-Based Follow-Up Study

Background

While an association between zolpidem use and fracture and road accident was previously proposed, this study aimed to further explore the frequency and risk of a wide spectrum of injuries in subjects prescribed with zolpidem in Taiwan.

Methods

We identified 77,036 subjects who received Zolpidem treatment between 2005 and 2007. We randomly selected 77,036 comparison subjects who were frequency-matched based-on their demographic profiles. We individually tracked each subject for a 90-day period to identify those who subsequently suffered an injury. Cox proportional hazards regressions were performed to calculate the hazard ratio of injury between the two groups.

Results

The incidence rate of injury during the 90-day follow-up period for the total subjects was 18.11 (95% CI = 17.69–18.54) per 100 person-years; this was 24.35 (95% CI = 23.66–25.05) and 11.86 (95% CI = 11.39–12.36) for the study and comparison cohort, respectively. After adjusting for demographic variables, the hazard ratio (HR) of injury during the 90-day follow-up period for study subjects was 1.83 (95% CI = 1.73–1.94) that of comparison subjects. Additionally, compared to comparison subjects, the adjusted HR of injury during the 90-day follow-up period for study subjects who were prescribed Zolpidem for >30 days was as high as 2.17 (95% CI = 2.05–2.32). The adjusted HR of injury to blood vessels for study subjects was particularly high when compared to comparison subjects (HR = 6.34; 95% CI = 1.37–29.38).

Conclusions

We found that patients prescribed with Zolpidem were at a higher risk for a wide range of injuries.

Bladder pain syndrome/interstitial cystitis increase the risk of coronary heart disease

AIM

Vascular factor was proposed as being involved in the etiology of bladder pain syndrome/interstitial cystitis (BPS/IC). However, few studies have attempted to investigate the relationship between BPS/IC and cardiovascular disease. This study aimed to investigate the risk of coronary heart disease (CHD) among BPS/IC subjects during a 3-year follow-up period.

METHODS

Data for this retrospective matched-cohort study were retrieved from the Taiwan "Longitudinal Health Insurance Database 2000." There were 752 BPS/IC female subjects in the study cohort and 3,760 randomly selected female subjects in the comparison cohort. We individually tracked each subject for 3 years and identified each subject that received a subsequent diagnosis of CHD during that follow-up period.

RESULTS

Results showed that incidence rates of CHD during the 3-year follow-up period were 19.50 (95% confidence interval (CI): 14.35-25.95) and 8.87 (95% CI: 7.25-10.74) per 1,000 person-years for the study and comparison cohorts, respectively. The Cox proportional hazards regression suggested that the hazard ratio for CHD in subjects with BPS/IC was 1.65 (95% CI: 1.09-2.48) within the 3-year follow-up period following the index date compared to the comparison subjects after adjusting for monthly income, geographic region, hypertension, diabetes, hyperlipidemia, chronic kidney disease, bladder outlet obstruction, urinary tract infection, chronic pelvic pain, overactive bladder, and number of physician visits during the 3-year follow up period.

CONCLUSIONS

Our study demonstrated an association between BPS/IC and a subsequent CHD diagnosis. We advise clinicians to screen subjects with BPS/IC for modifiable risk factors for CHD.

Association between osteoporosis and psoriasis: results from the Longitudinal Health Insurance Database in Taiwan

This population-based analysis explored the association between osteoporosis and a previous diagnosis of psoriasis. We found that the adjusted odds ratio (OR) of having been previously diagnosed with psoriasis for subjects with osteoporosis was 1.65 (95 % confidence interval [CI], 1.42-1.94) when compared to controls.

INTRODUCTION

Although previous studies have investigated this association between psoriasis and osteoporosis, significant controversy remains regarding its presence. Therefore, this study set out to explore the association between osteoporosis and a previous diagnosis of psoriasis through a population-based case-control study in Taiwan.

METHODS

We identified 17,507 cases with a diagnosis of osteoporosis and randomly extracted 52,521 controls without a history of osteoporosis. We used conditional logistic regression analyses to calculate the OR for having been previously diagnosed with psoriasis.

RESULTS

Subjects with osteoporosis had a significantly higher prevalence of previously diagnosed psoriasis (1.50 % vs. 0.87 %, p < 0.001) compared to controls. Conditional logistic regression analysis revealed that the OR of having been previously diagnosed with psoriasis for subjects with osteoporosis was 1.65 (95 % CI, 1.42-1.94) when compared to controls after adjusting for monthly income, hypertension, diabetes, coronary heart disease, hyperlipidemia, rheumatoid arthritis, stroke, renal disease, Parkinson's disease, hyperthyroidism, chronic hepatopathy, Cushing's syndrome, malabsorption, tobacco use disorder, obesity, alcohol abuse/alcohol dependence syndrome, the use of SSRIs, and the use of systemic glucocorticoids. Furthermore, osteoporosis was significantly associated with a previous diagnosis of psoriasis in both sexes; the adjusted OR of prior psoriasis for cases when compared to controls was 1.52 (95 % CI, 1.16-1.99) and 1.73 (95 % CI, 1.44-2.13) for males and females, respectively. We also found that the adjusted OR of prior severe psoriasis for cases was 1.96 (95 % CI, 1.37-2.81) that of controls.

CONCLUSIONS

This investigation succeeded in detecting an association between osteoporosis and prior psoriasis among both men and women.

Claims-based definition of death in Japanese claims database: validity and implications

Background

For the pending National Claims Database in Japan, researchers will not have access to death information in the enrollment files. We developed and evaluated a claims-based definition of death.

Methodology/Principal Findings

We used healthcare claims and enrollment data between January 2005 and August 2009 for 195,193 beneficiaries aged 20 to 74 in 3 private health insurance unions. We developed claims-based definitions of death using discharge or disease status and Charlson comorbidity index (CCI). We calculated sensitivity, specificity and positive predictive values (PPVs) using the enrollment data as a gold standard in the overall population and subgroups divided by demographic and other factors. We also assessed bias and precision in two example studies where an outcome was death. The definition based on the combination of discharge/disease status and CCI provided moderate sensitivity (around 60%) and high specificity (99.99%) and high PPVs (94.8%). In most subgroups, sensitivity of the preferred definition was also around 60% but varied from 28 to 91%. In an example study comparing death rates between two anticancer drug classes, the claims-based definition provided valid and precise hazard ratios (HRs). In another example study comparing two classes of anti-depressants, the HR with the claims-based definition was biased and had lower precision than that with the gold standard definition.

Conclusions/Significance

The claims-based definitions of death developed in this study had high specificity and PPVs while sensitivity was around 60%. The definitions will be useful in future studies when used with attention to the possible fluctuation of sensitivity in some subpopulations.

Epidemiology and disease burden of ischemic stroke in Taiwan

BACKGROUND

The incidence and prevalence of ischemic stroke (IS) are increasing in Asian countries. We conducted this retrospective database research to investigate epidemiology and disease burden of IS in Taiwan.

METHODS

We identified cases from the National Health Insurance Research Database during period from 2000 to 2005 to calculate prevalence and mortality. We analyzed the relationship between disease burden and gender in Taiwan during the period from 2000 to 2005 using Dismod II.

RESULTS

From study period, stroke mortality increased from 50 to 2300 per 100 000 among individuals aged 50-90 years, with a higher prevalence among females than males. The highest prevalence was observed among men aged 80-84 years, but prevalence among women was highest in patients aged >85 years. The burden of stroke during the period per 1000 population was estimated as follows: the sum of the years of life lost as a result of premature mortality of 55-80 years, years lost as a result of disability of 11-19 years, and disability-adjusted life years (DALYs) of 70-80 years. Most of the DALYs of stroke occurred among those aged 65-69 years. The DALY value was higher among women than among men before 2005; there was no clear trend in 2005.

CONCLUSIONS

Stroke is a significant health concern in Taiwan. The associated disease burden was found to increase each year, especially among individuals aged 65-69 years. Overall, the DALY value increased from 2000 to 2005, which suggests that the associated disease burden will continue to increase over time.

Association between chronic prostatitis/chronic pelvic pain syndrome and anxiety disorder: a population-based study

BACKGROUND

This case-control study utilized a population-based dataset to examine the association of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) with prior anxiety disorder (AD) by comparing the risk of prior AD between subjects with CP/CPPS and matched controls in Taiwan.

METHODS

We study used data sourced from the Taiwan Longitudinal Health Insurance Database. The cases comprised 8,088 subjects with CP/CPPS and 24,264 randomly matched subjects as controls. We used a conditional logistic regression to calculate the odds ratio (OR) for having been previously diagnosed with AD between subjects with and without CP/CPPS.

RESULTS

Of the 24,264 sampled subjects, 2309 (7.1%) had received an AD diagnosis before the index date; AD was found in 930 (11.5%) cases and 1379 (5.7%) controls (p<0.001). The conditional logistic regression analysis revealed that compared to controls, the OR for prior AD among cases was 2.10 (95% CI = 1.92∼2.29, p<0.001) after adjusting for diabetes, hypertension, hyperlipidemia, and sexually transmitted diseases. Our results show that CP/CPPS was consistently and significantly associated with prior AD in all age groups (18∼39, 40∼59, and >59 years). In particular, subjects aged 40∼59 years had the highest adjusted OR (of 2.53) for prior AD among cases compared to controls.

CONCLUSIONS

We concluded that CP/CPPS is associated with previously diagnosed AD. Urologists should be alert for the association between CP/CPPS and AD in subjects suffering from AD.

Obstructive sleep apnea and the subsequent risk of depressive disorder: a population-based follow-up study

STUDY OBJECTIVES

Empirical findings on the prospective link between obstructive sleep apnea (OSA) and subsequent depression are mixed. This nationwide, population-based study thus aimed at assessing the risk of depressive disorder within the first year following a diagnosis with OSA. Gender effects were further examined.

DESIGN

Cohort study.

SETTING

Taiwan.

PATIENTS

This study used data from the Longitudinal Health Insurance Database 2000. A total of 2,818 patients diagnosed with OSA between 2002 and 2008 were evaluated, and 14,090 matched non-OSA enrollees used as a comparison cohort.

MEASUREMENTS AND RESULTS

Each patient was followed for one year to identify subsequent depressive disorder. We found that during the one-year follow-up, the incidence of depressive disorder per thousand person-years was about twice as high among patients with OSA (18.10, 95% CI = 13.62-23.61) as those without OSA (8.23, 95% CI = 6.83-9.84). The Cox proportional hazards model revealed that patients with OSA were independently associated with a 2.18 times (95% CI = 1.55-3.08) increased risk of subsequent depressive disorder within a year, compared to those without OSA. As epidemiological studies have consistently documented an increased risk for depression in women, we hypothesized and confirmed higher risks of depressive disorder among female patients with OSA (2.72, 95% CI = 1.68-4.40) than their male counterparts (1.81, 95% CI = 1.09-3.01).

CONCLUSION

A prospective link between OSA and subsequent depressive disorder within one year was confirmed by the current study. The risk was particularly evident among women. Regular psychiatric screening among patients with OSA is suggested to prompt the timely detection of depression.

COMMENTARY

A commentary on this article appears in this issue on page 425.

Increased risk of ischemic heart disease in young patients with newly diagnosed ankylosing spondylitis--a population-based longitudinal follow-up study

BACKGROUND

Prospective data is sparse on the association between ischemic heart disease (IHD) and ankylosing spondylitis (AS) in the young. The purpose of this population-based, age- and sex-matched follow-up study was to investigate the risk of IHD in young patients with newly diagnosed AS.

METHODS

A total of 4794 persons aged 18 to 45 years with at least two ambulatory visits in 2001 with the principal diagnosis of AS were enrolled in the AS group. The non-AS group consisted of 23970 age- and sex-matched, randomly sampled subjects without AS. The three-year IHD-free survival rate and cumulative incidence of IHD were calculated using the Kaplan-Meier method. The Cox proportional hazards regression model was used to estimate the hazard ratio of IHD after controlling for demographic and cardiovascular co-morbidities.

RESULTS

During follow-up, 70 patients in the AS group and 253 subjects in the non-AS group developed IHD. The cumulative incidence rate of IHD over time was higher in the AS group than the non-AS group. The crude hazard ratio of IHD for the AS group was 1.47 (95% CI, 1.13 to 1.92; p = 0.0043) and the adjusted hazard ratio after controlling for demographic characteristics and comorbid medical disorders was 1.47 (95% CI, 1.13 to 1.92; p = 0.0045).

CONCLUSIONS

This study showed an increased risk of developing IHD in young patients with newly diagnosed AS.

Obstructive sleep apnea and increased risk of glaucoma: a population-based matched-cohort study

PURPOSE

Previous studies had reported an increased prevalence of glaucoma in patients with obstructive sleep apnea (OSA). However, the risk of open-angle glaucoma (OAG) among patients with OSA remains unclear. Using a nationwide, population-based dataset in Taiwan, this study aimed to examine the prevalence and risk of OAG among patients with OSA during a 5-year follow-up period after a diagnosis of OSA.

DESIGN

A retrospective, matched-cohort study.

PARTICIPANTS AND CONTROLS

This study used data sourced from the Longitudinal Health Insurance Database 2000. We included 1012 subjects with OSA in the study cohort and randomly selected 6072 subjects in the comparison group.

METHODS

Each subject in this study was individually traced for a 5-year period to identify those subjects who subsequently received a diagnosis of OAG. Cox proportional hazards regression was performed to calculate the 5-year risk of OAG between the study and comparison cohorts.

MAIN OUTCOME MEASURES

The incidence and risk of OAG between the study and comparison groups.

RESULTS

During the 5-year follow-up period, the incidence rate per 1000 person-years was 11.26 (95% confidence interval [CI], 8.61-14.49) and 6.76 (95% CI, 5.80-7.83) for subjects with and without OSA, respectively. After adjusting for monthly income, geographic region, diabetes, hypertension, coronary heart disease, obesity, hyperlipidemia, renal disease, hypothyroidism, and the number of outpatient visits for ophthalmologic care during the follow-up period, stratified Cox proportional hazards regression revealed that the hazard ratio for OAG within the 5-year period for subjects with OSA was 1.67 (95% CI, 1.30-2.17; P<0.001) that of comparison subjects.

CONCLUSIONS

Our results suggest that OSA is associated with an increased risk of subsequent OAG diagnosis during a 5-year follow-up period.

FINANCIAL DISCLOSURES(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Assessment of statin-associated muscle toxicity in Japan: a cohort study conducted using claims database and laboratory information

OBJECTIVE

To estimate the incidence of muscle toxicity in patients receiving statin therapy by examining study populations, drug exposure status and outcome definitions.

DESIGN

A retrospective cohort study.

SETTING

16 medical facilities in Japan providing information on laboratory tests performed in and claims received by their facilities between 1 April 2004 and 31 December 2010.

PARTICIPANTS

A database representing a cohort of 35 903 adult statin (atorvastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin) users was studied. Use of interacting drugs (fibrates, triazoles, macrolides, amiodarone and ciclosporin) by these patients was determined.

MAIN OUTCOME MEASURE

Statin-associated muscle toxicity (the 'event') was identified based on a diagnosis of muscle-related disorders (myopathy or rhabdomyolysis) and/or abnormal elevation of creatine kinase (CK) concentrations. Events were excluded if the patients had CK elevation-related conditions other than muscle toxicity. Incidence rates for muscle toxicity were determined per 1000 person-years, with 95% CI determined by Poisson regression.

RESULTS

A total of 18 036 patients accounted for 42 193 person-years of statin therapy, and 43 events were identified. The incidence of muscle toxicity in the patients treated with statins was 1.02 (95% CI 0.76 to 1.37)/1000 person-years. The estimates varied when outcome definitions were modified from 0.09/1000 person-years, which met both diagnosis and CK 10× greater than the upper limit of normal range (ULN) criteria, to 2.06/1000 person-years, which met diagnosis or CK 5× ULN criterion. The incidence of muscle toxicity was also influenced by the statin therapies selected, but no significant differences were observed. Among 2430 patients (13.5%) received interacting drugs with statins, only three muscle toxicity cases were observed (incidence: 1.69/1000 person-years).

CONCLUSIONS

This database study suggested that statin use is generally well tolerated and safe; however, the risk of muscle toxicity related to the use of interacting drugs requires further exploration.

Psychiatric disorders after epilepsy diagnosis: a population-based retrospective cohort study

BACKGROUND

Psychiatric manifestations after occurrence of epilepsy have often been noted. However, the association between newly diagnosed epilepsy and psychiatric disorders afterward is not completely understood. We conducted two longitudinal cohorts for patients with and without epilepsy to investigate the risk factors and hazard ratios of developing psychiatric disorders after patients were newly diagnosed with epilepsy.

METHODS

We identified 938 patients with a new diagnosis of epilepsy and 518,748 participants without epilepsy from the National Health Insurance Research Database in 2000-2002 and tracked them until 2008. We compared the incidence of developing psychiatric disorders between the two cohorts, evaluated risk factors and measured the associated hazard ratios (HRs) and 95% confidence intervals (CIs) of developing psychiatric disorders.

FINDINGS

The incidences of psychiatric disorders for people with and without epilepsy were 94.1 and 22.6 per 1000 person-years, respectively. After adjusting the covariates, the epilepsy cohort showed the highest risks in mental retardation (HR 31.5, 95% CI 18.9 to 52.4), bipolar disorder (HR 23.5, 95% CI 11.4 to 48.3) and alcohol or drug psychosis (HR 18.8, 95% CI 11.1 to 31.8) among psychiatric complications developed after newly diagnosed epilepsy. The risk increased with epileptic general seizure and frequency of outpatient visits for epilepsy, as well as with emergency room visits and hospitalizations for epilepsy, and with older age. Chronologically, the highest risk occurred in the first year after epilepsy diagnosis (HR 11.4, 95% CI 9.88 to 13.2).

CONCLUSION

Various psychiatric disorders were demonstrated after newly diagnosed epilepsy and closely related to general seizure and use of medical services for epilepsy. This shows a need for integrated psychiatric care for patients newly diagnosed with epilepsy, especially in the first year.

Tourette syndrome and risk of depression: a population-based cohort study in Taiwan

OBJECTIVE

The temporal relationship between Tourette syndrome (TS) and depression is unclear. This cohort study evaluates the relationship between TS and depression in Taiwan.

METHODS

Claims data from the Taiwan National Health Insurance database were used to conduct retrospective cohort analyses. The study cohort contained 1337 TS patients who were frequency matched by sex, age, urbanization of residence area, parental occupation, and baseline year with 10 individuals without TS. Cox's proportional hazard regression analysis was conducted to estimate the effects of TS on depression risk.

RESULTS

In patients with TS, the risk of developing depression was significantly higher than in patients without TS (p value for log-rank test < .0001). After adjusting for potential confounding, the TS cohort was 4.85 times more likely to develop depression than the control cohort (HR = 4.85, 95% CI = 3.46-6.79).

CONCLUSIONS

In Taiwan, patients with TS have a higher risk of developing depression. The findings of this study are compatible with studies from other countries. This study could provide an evidence to inform the prognosis for a child with TS. The mechanism between TS and increased depression risk requires further investigation.

Obstructive sleep apnea increases the risk of bladder pain syndrome/interstitial cystitis: a population-based matched-cohort study

AIMS

Previous studies indicated a possible association between bladder pain syndrome/interstitial cystitis (BPS/IC) and sleep disorders including sleep abnormalities with delayed onset of sleep, waking up before needed, and snoring. Nevertheless, no previous study has reported the association between obstructive sleep apnea (OSA) and BPS/IC. In this retrospective cohort study, we examined the risk of BPS/IC among subjects with OSA during a 3-year follow-up in Taiwan using a population-based dataset.

METHODS

This study comprised 2,940 study subjects with OSA, and 29,400 randomly selected comparison subjects. We individually followed-up each sampled subject (n = 32,340) for a 3-year period to identify those subjects who subsequently received a diagnosis of BPS/IC. A Cox proportional hazards regression model was constructed to estimate the risk of subsequent BPS/IC following a diagnosis of OSA.

RESULTS

Incidences of BPS/IC during the 3-year follow-up period were 13.61 (95% confidence interval [CI] = 7.37-23.13) and 3.60 (95% CI = 2.06-4.39) for subjects with and those without OSA, respectively. After adjusting for diabetes, hypertension, coronary heart disease, obesity, hyperlipidemia, chronic pelvic pain, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, depression, panic disorder, migraines, sicca syndrome, allergies, endometriosis, asthma, tobacco use disorder, and alcohol abuse, the stratified Cox proportional hazards regressions revealed that the hazard ratio for BPS/IC among subjects with OSA was 3.71 (95% CI = 1.81-7.62, P < 0.001) that of comparison subjects.

CONCLUSIONS

This study provides epidemiological evidence of a link between OSA and a subsequent BPS/IC diagnosis. We suggest that clinical practitioners treating subjects with OSA be alert to urinary complaints in this population.

Increased risk of pemphigoid following scabies: a population-based matched-cohort study

BACKGROUND

No prior study has investigated the possibility that scabies patients may be at an increased risk for developing pemphigoid.

OBJECTIVE

To evaluate the risk of pemphigoid following scabies during a 3-year follow-up period using a Taiwanese population-based claims database and taking clinical and demographic characteristics into consideration.

METHODS

This investigation consisted of a study group of 6793 subjects with a diagnosis of scabies and 33 965 randomly selected subjects used as a comparison group. Each patient was tracked for 3 years following their index dates to identify those who received a subsequent diagnosis of pemphigoid. Stratified Cox proportional hazards regressions were used to compute the hazard ratio (HR) of pemphigoid during the 3-year follow-up period.

RESULTS

Of the 40 758 subjects, 52 (0.13%) had received a diagnosis of pemphigoid during the 3-year follow-up period; 33 (0.49% of the study group) were from the study group and 19 (0.06% of the comparison group) were from the comparison group. Compared to subjects without scabies, the HR for pemphigoid for subjects with scabies was 5.93 within the 3-year follow-up period following the index date after adjusting for monthly income, hypertension, diabetes, obesity, psoriasis, stroke, dementia, Parkinson's disease, coronary heart disease, schizophrenia or bipolar disorder, and after censoring those that died during the follow-up period.

CONCLUSIONS

This study detected an increased risk for pemphigoid among patients suffering from scabies. Physicians treating elderly patients with a history of scabies should be alert to the development of pemphigoid.

Are non-cardiac surgeries safe for dialysis patients? - A population-based retrospective cohort study

BACKGROUND

End-stage renal disease represents a risk complex that complicates surgical results. The surgical outcomes of dialysis patients have been studied in specific fields, but the global features of postoperative adverse outcomes in dialysis patients receiving non-cardiac surgeries have not been examined.

METHODS

Taiwan's National Health Insurance Research Database was used to study 8,937 patients under regular dialysis with 8,937 propensity-score matched-pair controls receiving non-cardiac surgery between 2004 and 2007. We investigated the influence of hemodialysis and peritoneal dialysis, effects of hypertension and diabetes, and impact of additional comorbidities on postoperative adverse outcomes.

RESULTS

Postoperative mortality in dialysis patients was higher than in controls (odds ratio [OR] 3.33, 95% confidence interval [CI] 2.56 to 4.33) when receiving non-cardiac surgeries. Complications such as acute myocardial infarction, pneumonia, bleeding, and septicemia were significantly increased. Postoperative mortality was significantly increased among peritoneal dialysis patients (OR 2.71, 95% CI 1.70 to 4.31) and hemodialysis patients (OR 3.42, 95% CI 2.62 to 4.47) than in controls. Dialysis patients with both hypertension and diabetes had the highest risk of postoperative complications; these risks increased with number of preoperative medical conditions. Patients under dialysis also showed significantly increased length of hospitalization, more ICU stays and higher medical expenditures.

CONCLUSION

Surgical patients under dialysis encountered significantly higher postoperative complications and mortality than controls when receiving non-cardiac surgeries. Different dialysis techniques, pre-existing hypertension/diabetes, and various comorbidities had complication-specific impacts on surgical adverse outcomes. These findings can help surgical teams provide better risk assessment and postoperative care for dialysis patients.

Hospitalized osteoporotic vertebral fracture increases the risk of stroke: a population-based cohort study

The association between osteoporosis and cardiovascular diseases has been demonstrated. Higher cardiovascular risk has also been correlated with vertebral fractures. However, the association between osteoporotic vertebral fracture and the possibly higher risk of stroke remains uncertain. This study aimed to evaluate the incidence, risk, and type of stroke in patients with osteoporotic vertebral fracture. Patients with osteoporotic vertebral fracture were identified (n = 380) and 10 age- and sex-matched controls per case (comparison group, n = 3795) were chosen from a nationwide representative cohort of 999,997 people from 1998 to 2005. Both groups were followed-up for stroke events for 3 years, matched by propensity scores with adjustments for covariates such as comorbidities (ie, hypertension, diabetes, arrhythmia, or coronary heart diseases) and exposure to medications (ie, aspirin, lipid lowering drug, or nitrates), and assessed by Kaplan-Meier and Cox regression analyses. The incidence rate of stroke in the osteoporotic vertebral fracture group (37.5 per 1000 person-years; 95% confidence interval [CI], 27.5-51.2) was significantly higher than in the comparison group (14.0 per 1000 person-years; 95% CI, 12.0-16.4, p < 0.001). Stroke was more likely to occur in the osteoporotic vertebral fracture patients than in the normal controls (crude hazard ratio [HR] 2.68, 95% CI 1.89-3.79, p < 0.001; adjusted HR 2.71, 95% CI 1.90-3.86, p < 0.001). In conclusion, patients with osteoporotic vertebral fracture have a higher risk of stroke (ie, both ischemic and hemorrhagic) and require stroke prevention strategies.

Association of stroke with the receptor-binding profiles of antipsychotics-a case-crossover study

BACKGROUND

Previous research suggests a link between antipsychotic use and stroke, but the relationships between receptor-binding profiles of antipsychotics and the risk of cerebrovascular events are unclear.

METHODS

A total of 14,584 patients with incident stroke were enrolled in the National Health Insurance Research Database in Taiwan from 1998 to 2007. We conducted a case-crossover study to compare the rates of antipsychotic use. The effects of receptor-binding profiles of antipsychotics on stroke risk were estimated, while the moderating effects of age, sex, presence of dementia, and duration of antipsychotic treatment were evaluated by stratified analyses.

RESULTS

The adjusted odds ratio of stroke risk with antipsychotics exposure was 1.60 (95% confidence interval, 1.51-1.69) using a 14-day time window. The use of antipsychotics with a high binding affinity of M1 muscarinic and α2 adrenergic receptors was associated with a greater risk of stroke than the use of other types of antipsychotics. An increased risk of stroke with antipsychotic use was noted in the patients who were older and/or who suffered from dementia. Moreover, our results showed that stroke risk with antipsychotic use was in a dose-related relationship.

CONCLUSIONS

Our findings suggest an association between stroke risk and high M1 muscarinic and α2 adrenergic affinity. The clinical implication is to start antipsychotics treatment at low dosages and to closely monitor the side effects in the initial treatment, particularly for individuals with older age and the presence of dementia.

Association between prostate cancer and urinary calculi: a population-based study

BACKGROUND

Understanding the reasons underlying the emerging trend and the changing demographics of Asian prostate cancer (PC) has become an important field of study. This study set out to explore the possibility that urinary calculi (UC) and PC may share an association by conducting a case-control study on a population-based database in Taiwan.

METHODS

The cases of this study included 2,900 subjects ≥ 40 years-old who had received their first-time diagnosis of PC and 14,500 randomly selected controls without PC. Conditional logistic regressions were employed to explore the association between PC and having been previously diagnosed with UC.

RESULTS

We found that prior UC was found among 608 (21.0%) cases and 2,037 (14.1%) controls (p<0.001). Conditional logistic regression analysis revealed that compared to controls, the odds ratio (OR) of prior UC for cases was 1.63 (95% CI = 1.47-1.80). Furthermore, we found that cases were more likely to have been previously diagnosed with kidney calculus (OR = 1.71; 95% CI = 1.42-2.05), bladder calculus (OR = 2.06; 95% CI = 1.32-3.23), unspecified calculus (OR = 1.66; 95% CI = 1.37-2.00), and ≥2 locations of UC (OR = 1.73; 1.47-2.02) than controls. However, there was no significant relationship between PC and prior ureter calculus. We also found that of the patients with UC, there was no significant difference between PC and treatment method.

CONCLUSIONS

This investigation detected an association between PC and prior UC. These results highlight a potential target population for PC screening.

Association between multiple sclerosis and chronic periodontitis: a population-based pilot study

BACKGROUND AND PURPOSE

The pathogenesis of multiple sclerosis (MS) is still not fully understood, but multiple infections are known to be crucial in the development of the disease. Periodontitis caused by periodontopathic polymicrobial infections is among the most common chronic infectious disorders. This case-control study aimed to investigate the association between chronic periodontitis (CP) and MS using a population-based dataset in Taiwan.

METHODS

This study included 316 cases who had a diagnosis of MS and 1580 randomly selected controls. We performed conditional logistic regressions to investigate the association between MS and having been previously diagnosed with CP.

RESULTS

The results reveal that the prevalence of earlier CP was 25.6% and 15.4% for cases and controls, respectively (P < 0.001). Conditional logistic regression analysis revealed that cases were 1.86 [95% confidence interval (CI) = 1.39-2.48] times as likely as controls to have been previously diagnosed with CP, after adjusting for sociodemographic characteristics as well as hyperlipidemia, hypertension, coronary heart disease, alcohol abuse/alcohol-dependence syndrome, tobacco use disorder and chronic obstructive pulmonary disease. After analyzing by gender, it was realized that while female cases had a higher chance than female controls of having earlier CP (adjusted odds ratio = 2.08; 95% CI = 1.49-2.95), there was no statistical association detected between these two conditions in men.

CONCLUSIONS

This study provides evidence for an association between CP and MS in female, but not male, subjects. Further epidemiological studies are needed to confirm the association and gender-specific differences found in the present study.

Scabies increased the risk of chronic kidney disease: a 5-year follow-up study

BACKGROUND

The most documented complication of scabies has been reported to be infection by group A streptococci, which has in turn been suggested to contribute to the development of glomerulonephritis.

OBJECTIVE

This study aimed to investigate the risk of chronic kidney disease (CKD) subsequent to scabies utilizing a population-based dataset in Taiwan.

METHODS

This retrospective matched-cohort study included 5071 subjects with scabies and 25 355 randomly selected comparison subjects. We individually tracked each subject for a 5-year period to identify those who subsequently received a diagnosis of CKD during the follow-up period. Stratified Cox proportional hazards regressions were performed to compute the hazard ratio (HR) of CKD during the 5-year follow-up period.

RESULTS

The incidence rate of CKD during the 5-year follow-up period was 9.66 (8.51-10.93) per 1,000 person-years and 6.24 (5.82-6.69) per 1000 person-years for subjects with and without scabies respectively. The HR for CKD during the 5-year follow-up period for subjects with scabies was 1.34 (95% CI = 1.15-1.56) that of comparison subjects after adjusting for monthly income, hypertension, diabetes, obesity, stroke, coronary heart disease, chronic obstructive pulmonary disease, tobacco use disorder, hyperlipidemia and alcohol abuse during the 5-year follow-up period. Male subjects with scabies were 1.40 (95% CI = 1.14-1.71) times more likely than comparison subjects to suffer from subsequent CKD, and female study subjects were 1.27 (95% CI = 1.05-1.61) times more likely.

CONCLUSIONS

We concluded that there was an increased risk for CKD among patients suffering from scabies.

Risk of hepato-biliary cancer after cholecystectomy: a nationwide cohort study

BACKGROUND

Epidemiologic studies have identified cholecystectomy as a possible risk factor for cancers in Western countries. The aim of this study was to estimate the risk of hepato-biliary cancer after cholecystectomy in Taiwan.

METHODS

Based on the Taiwan National Health Insurance Research Database, 2,590 cholecystectomized patients without prior cancers in the period 1996-2008 were identified from a cohort dataset of 1,000,000 randomly sampled individuals. The standard incidence ratio (SIR) of each cancer was calculated.

RESULTS

After a median follow-up of 4.82 years, 67 liver cancer and 17 biliary tract cancer patients were diagnosed. Patients who received cholecystectomy had higher risks of liver cancer (SIR, 3.29) and biliary tract cancer (SIR, 8.50). Cholecystectomized patients aged ≤60 years had higher risks of liver cancer (SIR, 11.14) and biliary tract cancer (SIR, 55.86) compared to those aged >60 years (SIR, 2.31 and 5.67). Female cholecystectomized patients had higher risks of liver cancer (SIR, 4.18) and biliary tract cancer (SIR, 10.56) than males (SIR, 2.96 and 7.26). Cholecystectomized patients with cirrhosis had higher SIR of liver cancer than patients without cirrhosis (SIR, 33.84 vs. 1.41).

CONCLUSIONS

Cholecystectomy may be associated with an increased risk of hepato-biliary cancer. Further and regular surveillance should be performed on such patients.

Chronic rhinosinusitis increased the risk of stroke: a 5-year follow-up study

OBJECTIVES/HYPOTHESIS

It has been recognized that chronic rhinosinusitis (CRS) involves intracranial vessels and may be associated with stroke occurrence. However, the detailed epidemiological profile of stroke risk among patients with CRS is still not well understood. Therefore, this study aimed to explore the frequency and risk for stroke among patients with CRS by conducting a large scale population-based cohort study in Taiwan.

METHODS

All study cohorts were retrieved from the Taiwan Longitudinal Health Insurance Database. This study included 15,846 CRS subjects in the study cohort and 47,538 randomly selected subjects in the comparison cohort. We individually tracked each subject in this study for a 5 year period following their index dates to identify each subject that received a subsequent diagnosis of stroke. Stratified Cox proportional hazards regressions were analyzed to compare the 5 year risk of subsequent stroke following a diagnosis of CRS.

RESULTS

The incidence rate of stroke during the 5-year follow-up period was 10.65 (95% CI: 9.93-11.41) per 100 person years and 7.53 (95% CI: 7.18-7.89) per 100 person years for the study and comparison cohort, respectively. The covariate-adjusted hazard ratio (HR) for stroke revealed that that subjects with CRS were more likely than comparison subjects to have a diagnosis of ischemic stroke during the 5-year follow-up period (HR = 1.34, 95% CI = 1.18-1.53). However, there was no significant difference in the risk of subarachnoid hemorrhage (HR = 1.52, 95% CI = 0.94-2.47) or intracerebral hemorrhage (HR = 0.96, 95% CI = 0.71-1.31).

CONCLUSIONS

Patients with CRS were at higher risk for stroke occurrence during the 5 year follow-up.

Topiramate use and the risk of glaucoma development: a population-based follow-up study

PURPOSE

To investigate the risk of glaucoma development after being prescribed topiramate.

DESIGN

A retrospective, population-based cohort study using an administrative database.

METHODS

The study group comprised 1956 patients who received their first prescription of topiramate between 2001 and 2007. The comparison cohort consisted of 15 648 randomly matched patients who never took topiramate. Each sampled patient was traced for a 1-year period from his or her index date to identify patients who subsequently received a diagnosis of glaucoma.

RESULTS

Glaucoma was diagnosed in 0.36%, 0.05%, and 0.66% of the study cohort during the first month, second to third month, and fourth to twelfth month following the index date, respectively. For the comparison cohort, glaucoma was diagnosed in 0.04%, 0.11%, and 0.46% of subjects during the first month, second to third month, and fourth to twelfth month following the index date, respectively. After adjusting for potential confounding factors, patients prescribed topiramate were found to have a 7.41-fold (95% confidence interval [CI] = 2.45-22.46) greater risk of subsequently being diagnosed with glaucoma than the comparison cohort during the first month after the index date. However, this association became statistically nonsignificant during the second-to-third-month and fourth-to-twelfth-month periods following the index date between the 2 cohorts (adjusted hazard ratio, 0.56, 95% CI = 0.07-4.29; and 1.35, 95% CI = 0.74-2.47, respectively).

CONCLUSIONS

Topiramate use in Taiwan was associated with a significantly increased risk of being diagnosed with glaucoma within the first month after receiving a prescription for the drug.

Psoriasis is associated with an increased risk of parkinsonism: a population-based 5-year follow-up study

BACKGROUND

Few studies have examined the association between autoimmune diseases and parkinsonism.

OBJECTIVE

We sought to investigate the risk for parkinsonism during a 5-year follow-up period after a diagnosis of psoriasis using a population-based data set in Taiwan.

METHODS

We identified 4885 patients with psoriasis for the study cohort and randomly selected 24,425 patients as a control cohort. Each subject was individually followed up for a 5-year period to identify those who subsequently developed parkinsonism.

RESULTS

Stratified Cox proportional hazards regression showed that the adjusted hazard ratio for parkinsonism during the 5-year follow-up period for patients with psoriasis was 1.74 (95% confidence interval 1.35-2.20) that of control patients. Furthermore, the adjusted hazard ratios for parkinsonism within the 5-year follow-up period after the index date for subjects with psoriasis were similar between both sexes (1.78 and 1.66 for men and women, respectively).

LIMITATION

Our data set did not provide detailed information on the severity of psoriasis, or individual factors such as cigarette smoking, alcohol consumption, body mass index, and dietary patterns.

CONCLUSION

Patients with psoriasis were found to be at a significant risk of parkinsonism during a 5-year follow-up.

Increased risk of hemorrhagic stroke in patients with migraine: a population-based cohort study

Objective

Previous studies on the association between migraine and the risk of developing hemorrhagic stroke (HS) have generated inconsistent results. The aim of the present population-based, age- and sex- matched follow-up study was to investigate whether migraine is associated with an increased risk of HS.

Method

A total of 20925 persons with at least two ambulatory visits in 2001 with the principal diagnosis of migraine were enrolled in the migraine group. The non-migraine group consisted of 104625, age- and sex- matched, randomly sampled subjects without migraine. The two-year HS-free survival rates for these 2 groups were estimated using the Kaplan-Meier method. Cox proportional hazards regression was used to estimate the effect of migraine on the occurrence of HS.

Results

During the 2 year follow-up, 113 subjects in the migraine group (0.54%) and 255 in the non-migraine group (0.24%) developed HS. The crude hazard ratio (HR) for developing HS in the migraine group was 2.22 compared to the non-migraine group (95% confidence interval [CI]: 1.78–2.77, p<0.0001) and the adjusted HR was 2.13 (95% CI: 1.71–2.67, p<0.0001) after controlling for demographic characteristics and comorbid medical disorders.

Conclusions

This population-based age- and sex- matched cohort study shows that migraine was linked to an increased risk of HS.

Adverse postoperative outcomes in surgical patients with immune thrombocytopenia

Background

Patients with immune thrombocytopenia (ITP) are likely to have various medical co-morbidities, yet their global features regarding adverse postoperative outcomes and use of medical resources when undergoing major surgery are unknown. The objective of this study was to validate whether ITP is an independent risk factor for adverse postoperative outcomes, and to explore the potential clinical predictors of outcomes after major surgery among patients with ITP.

Methods

A retrospective population-based cohort study was conducted using Taiwan's National Health Insurance Research Database, controlling for preoperative co-morbidities by means of multiple logistic regression. Major postoperative complication and mortality rates, and in-hospital medical costs were analysed.

Results

The study included 11 085 surgical patients with ITP and 44 340 controls without ITP matched for sex, age, and type of surgery and anaesthesia. Surgical patients with ITP had a higher risk of postoperative death (odds ratio (OR) 1·89, 95 per cent confidence interval 1·57 to 2·27), and overall postoperative complications (OR 1·47, 1·39 to 1·56), and increased hospital stay (OR 1·90, 1·80 to 2·01), admission to the intensive care unit (OR 1·73, 1·63 to 1·83) and medical costs (OR 1·89, 1·79 to 1·99). Amount of preoperative platelet and/or red blood cell transfusion, emergency visits and admission to hospital for ITP care were identified as risk factors for adverse postoperative outcomes.

Conclusion

Patients with ITP undergoing surgery are at increased risk of adverse perioperative events, particularly if blood or blood product transfusion are required preoperatively, or the procedure is done as an emergency.

Association between hypertensive disorders during pregnancy and end-stage renal disease: a population-based study

BACKGROUND

Studies into the association between hypertensive disorders during pregnancy and end-stage renal disease are limited. We investigated the risk of end-stage renal disease after delivery among women with hypertensive disorders during pregnancy.

METHODS

We used insurance claims data from 1998 to 2009 to identify 26,651 women aged 19-40 years old who experienced hypertensive disorders during pregnancy; these women had no history of hypertension, diabetes, kidney disease or lupus. We also randomly selected 213,397 women without hypertensive disorders during pregnancy as a comparison cohort; the frequency was matched by age and index year of pregnancy. We compared the incidence of end-stage renal disease in the 2 cohorts. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) after controlling for demographic and clinical factors.

RESULTS

Women with hypertensive disorders during pregnancy had a greater risk of chronic kidney disease and end-stage renal disease, with adjusted HRs of 9.38 (95% CI 7.09-12.4) and 12.4 (95% CI 8.54-18.0), respectively, after controlling for urban status, coronary artery disease, congestive heart failure, hyperlipidemia and abruption. The HR for end-stage renal disease was 2.72 (95% CI 1.76-4.22) after we also controlled for hypertension and diabetes. Women with preeclampsia or eclampsia had a higher risk of end-stage renal disease (adjusted HR 14.0, 95% CI 9.43-20.7) than women who had gestational hypertension only (adjusted HR 9.03, 95% CI 5.20-15.7).

INTERPRETATION

Women with hypertensive disorders during pregnancy were at a high risk of end-stage renal disease. The risk was much greater for women who had preeclampsia or eclampsia than those who had gestational hypertension only.

Postoperative adverse outcomes in surgical patients with dementia: a retrospective cohort study

BACKGROUND

Dementia patients often present with coexisting medical conditions and potentially face higher risk of complications during hospitalization. Because the general features of postoperative adverse outcomes among surgical patients with dementia are unknown, we conducted a nationwide, retrospective cohort study to characterize surgical complications among dementia patients compared with sex- and age-matched nondementia controls.

METHODS

Reimbursement claims from the Taiwan National Health Insurance Research Database were studied. A total of 18,923 surgical patients were enrolled with preoperative diagnosis of dementia for 207,693 persons aged 60 years or older who received inpatient major surgeries between 2004 and 2007. Their preoperative comorbidities were adjusted and risks for major surgical complications were analyzed.

RESULTS

Dementia patients who underwent surgery had a significantly higher overall postoperative complication rate, adjusted odds ratio (OR) 1.79 (95 % confidence interval [CI] 1.72-1.86), with higher medical resources use, and in-hospital expenditures. Compared with controls, dementia patients had a higher incidence of certain postoperative complications that are less likely to be identified in their initial stage, such as: acute renal failure, OR = 1.32 (1.19-1.47); pneumonia, OR = 2.18 (2.06-2.31); septicemia, OR = 1.8 (1.69-1.92); stroke, OR = 1.51 (1.43-1.6); and urinary tract infection, OR = 1.62 (1.5-1.74).

CONCLUSIONS

These findings have specific implications for postoperative care of dementia patients regarding complications that are difficult to diagnose in their initial stages. Acute renal failure, pneumonia, septicemia, stroke, and urinary tract infection are the top priorities for prevention, early recognition, and intervention of postoperative complications among surgical patients with dementia. Further efforts are needed to determine specific protocols for health care teams serving this population.

An investigation of the use of traditional chinese medicine in stroke patients in taiwan

Background. The use of complementary and alternative medicine in critical illness is increasing worldwide. This study investigates how traditional Chinese medicine (TCM) is used in stroke patients. Methods. Using Taiwan National Health Insurance reimbursement claims, we compared the annual use of TCM between stroke patients and general population, identifying 15,330 patients with a new onset of stroke in 2000-2009. The sociodemographic status and medical comorbidities between stroke patients receiving TCM services and those without using the service were compared. Results. The use of TCM was higher in stroke patients than in the general population, 27.9% versus 25.4% in 2000 and 32.7% versus 27.8% in 2009, respectively, and grew consistently from 2000 to 2009. Among stroke patients, women, younger patients, white-collar employees, higher-income residents, and those living in areas with more TCM physicians were more likely to use TCM. Stroke patients using rehabilitation services were more likely to have more TCM visits (OR = 2.28, 95% CI = 1.96-2.66) and higher expenditure on TCM (OR = 2.67, 95% CI = 2.29-3.12) compared with stroke patients without rehabilitation. Conclusion. TCM is popular and well accepted in Taiwan. Patients with stroke have a higher TCM utilization rate than people without stroke.

Cluster headache is associated with an increased risk of depression: A nationwide population-based cohort study

Objective

To investigate whether cluster headache (CH) was a risk factor for depression in a nationwide population-based follow-up study.

Background

There are few studies about the relationship between CH and depression, and prior research has been limited by cross-sectional studies or small sample sizes.

Methods

We identified 673 CH patients from the Taiwan National Health Insurance database between 2005 and 2009. The two comparison cohorts included age-, sex- and Charlson’s score-matched migraine patients ( n = 2692) and controls (patients free from migraine or CH, n = 2692). The cumulative incidence of depression was compared among these three cohorts until the end of 2009. We also calculated predictors of depression in the CH cohort.

Results

After the median 2.5-year follow-up duration, the CH cohort had a greater risk for developing depression compared to the control cohort (adjusted hazard ratio; aHR = 5.6, 95% CI 3.0–10.6, p < 0.001) but not the migraine cohort (aHR = 1.1, 95% CI 0.7–1.7, p = 0.77). Of the CH patients, the number of cluster bout periods per year was a risk factor for depression (aHR = 3.8, 95% CI 2.6–5.4, p < 0.001).

Conclusion

Our results showed that CH is associated with an increased risk for depression. The strength of this association is similar to that of migraine.