Hui Wen Lin

Risk of ovarian cancer in women with pelvic inflammatory disease: a population-based study

BACKGROUND Ovarian cancer is commonly fatal and incidence has persistently risen in Taiwan over the past 20 years. Prevention strategies, however, are limited. Pelvic inflammatory disease (PID) has been suggested to increase the risk of developing ovarian cancer, but the results of studies have been inconsistent. Therefore, we investigated whether PID increases the risk of developing ovarian cancer in a large, nationwide cohort. METHODS From the Longitudinal Health Insurance Database 2005 (LHID2005) in Taiwan, we obtained data for women aged 13-65 years for whom a diagnosis of PID, confirmed by multiple episodes, had been recorded between Jan 1, 2004, and Dec 31, 2005. We also obtained data for two controls per patient, matched for age and the year of first entry into the LHID2005. All patients were followed up from the date of entry in the LHID2005 until they developed ovarian cancer or to the end of 2006, whichever was earlier. We used Coxs regression models to assess the risk of developing ovarian cancer, with adjustment for age, comorbid disorders, and socioeconomic characteristics. FINDINGS We identified 67,936 women with PID and 135,872 controls. Among these 90 had developed ovarian cancer during the 3-year follow-up period (42 patients with PID and 48 controls, incidence 2·78 and 1·44 per 10,000 person-years, respectively). The adjusted hazard ratio for ovarian cancer in patients with PID was 1·92 (95% CI 1·27-2·92) compared with controls, which rose to 2·46 (1·48-4·09) in women who had had at least five episodes of PID. The adjusted hazard ratio was slightly higher for women aged 35 years or younger with PID than in older women with PID (2·23, 1·02-4·79 vs 1·82, 1·10-3·04). INTERPRETATION We found an association between PID and ovarian cancer. PID might, therefore, be a useful marker for ovarian cancer, and early treatment could help to improve prognosis. Whether pelvic inflammation itself accelerates the growth of ovarian cancers or affects cancer-cell differentiation in ways that adversely alter prognosis needs to be investigated. FUNDING None.

Risk of Herpes Zoster in CKD: A Matched-Cohort Study Based on Administrative Data

BACKGROUND Immune system dysregulation is associated with end-stage renal disease. Although decreased cellular immunity increases susceptibility to herpes zoster, the risk of herpes zoster in patients with earlier stages of chronic kidney disease (CKD) is unclear. STUDY DESIGN A matched-cohort study. SETTING & PARTICIPANTS Data from the Taiwan Longitudinal Health Insurance Database (LHID) for 2004-2006 were analyzed. The study cohort included patients 18 years or older given a diagnosis of CKD (excluding patients treated by dialysis or transplant) in 2004-2005 (n = 13,321). The comparison cohort (n = 66,605) included 5 randomly selected age- and sex-matched controls for each patient in the study cohort. PREDICTOR CKD. Incident cases of CKD were identified using the Taiwan LHID. CKD was ascertained from International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. OUTCOMES Herpes zoster, ascertained from ICD-9-CM codes. All participants were followed up from the date of cohort entry until they developed herpes zoster or the end of 2006. Cox proportional hazard regressions were performed to compare the hazard rates of herpes zoster in the CKD cohort and the age- and sex-matched comparison cohort. RESULTS We identified 13,321 patients with a diagnosis of CKD who matched the inclusion criteria. 1,602 patients developed herpes zoster during the study period, of whom 353 were from the CKD cohort and 1,249 were from the comparison cohort. After adjusting for potential confounding factors, CKD was associated independently with greater risk of herpes zoster (HR, 1.60; 95% CI, 1.41-1.81). LIMITATIONS Some patients with CKD or herpes zoster may have chosen not to seek medical care. Misclassification of CKD due to use of diagnostic codes also is a limitation. CONCLUSIONS This population-based cohort study indicated that patients with CKD are at increased risk of herpes zoster compared with the general population.

Risk of stroke in patients with rheumatism: A nationwide longitudinal population-based study

The aim of this study was to investigate rheumatoid arthritis (RA), and systemic lupus erythematous (SLE) as risk factors for stroke. The study was analyzed by Using the Taiwan Longitudinal Health Insurance Database 2005 (LHID2005), this cohort study investigated patients with a recorded diagnosis of RA (N = 6114), and SLE (N = 621) between January 1, 2004, and December 31, 2007, with age-matched controls (1:4) (for RA, N = 24456; SLE, N = 2484). We used Cox proportional-hazard regressions to evaluate the hazard ratios (HRs) after adjusting confounding factors. Our study found 383 of 6114 RA patients, experienced stroke during the 20267 person-year follow-up period. The adjusted HR of stroke for RA patients was 1.24 (95% CI, 1.11 to 1.39), and for SLE patients was 1.88 (95% CI, 1.08 to 3.27). When steroid was added as additional confounding factor, the adjusted HR of ischemic stroke for RA patients was 1.32 (95% CI, 1.15 to 1.50), and for SLE patients was 1.31 (95% CI, 0.51 to 3.34). In conclusion, the rheumatic diseases of RA, and SLE are all risk factors for stroke. After controlled the effect of steroid prescription, RA is risk factor for ischemic stroke.

Simple Association Analysis Combining Data From Trios/Sibships and Unrelated Controls

We consider genetic association analysis that combines data from case‐parent trios/sibships and unrelated controls. A general and simple methodology is proposed, using a weighted least‐squares approach to combine separate information from the case‐parent/case‐sibling analysis and the case‐unrelated control analysis. The new proposal improves over the existing methods in that it requires no assumptions and estimation on the mating‐type distribution. Simulation results show that the new method competes well with the likelihood‐based method when the latter is applicable, and achieves substantial power gains over separate analyses in general. Therefore, the proposed combined association analysis can enjoy wide applications, including the multiallele/locus, haplotype, and genome‐wide association studies. Genet. Epidemiol. 2008.

Risk of stroke among patients with rhinosinusitis: a population-based study in Taiwan.

BACKGROUND Research has found evidence that chronic inflammation may promote atherosclerotic disease. The purpose of this study was to test the hypothesis that rhinosinusitis is a risk factor for stroke. METHODS This prospective cohort study comprised patients recorded on the Taiwan Longitudinal Health Insurance Database 2005 (LHID2005) who had received a diagnosis of rhinosinusitis (n = 53,653) between January 1, 2004 and December 31, 2005. A control group (1:4) drawn from the same database was matched for age and gender (n = 214,624). Each patient was followed up using data entered until the end of 2006. Cox proportional hazard regressions were performed to evaluate the hazard ratios (HRs) after adjusting for potential confounding factors. RESULTS We found that patients with rhinosinusitis were more likely to suffer strokes than the control population, after adjusting for potential confounders (adjusted HR, 1.39; 95% confidence interval [CI], 1.28~1.50). The HR of stroke was 1.39 (95% CI, 1.28~1.51) for acute sinusitis patients, and 1.34 (95% CI, 1.04~1.74) for chronic sinusitis patients. CONCLUSION Both acute and chronic sinusitis are risk factors or markers for stroke that is independent of traditional stroke risk factors. Further research in this important area of epidemiology is warranted.

Chronic Obstructive Pulmonary Disease Increases the Risk of Hip Fracture: A Nationwide Population-Based Cohort Study.

Hip fractures can lead to functional disability and high mortality rates among elderly patients. The aim of this study was to investigate whether chronic obstructive pulmonary disease (COPD) is a risk factor for hip fracture. A retrospective population-based 4-year cohort study was conducted using case–control matched analysis of data from the Taiwan Longitudinal Health Insurance Database 2005 (LHID2005). Patients with a diagnosis of COPD between January 1, 2004 and December 31, 2007 were enrolled. A 2-stage approach and data from the National Health Interview Survey 2005 were applied to adjust for missing confounders in the LHID2005 cohort. Hazard ratios (HRs) and adjusted HRs were estimated hip fracture risk for the COPD. We enrolled 16,239 patients in the COPD cohort and 48,747 (1:3) patients in non-COPD cohort. The hip fracture incidences were 649 per 100,000 person-years in the study cohort and 369 per 100,000 person-years in non-COPD cohort. The hip fracture HR during the follow-up period was 1.78 (P < 0.001) and the adjusted hip fracture HR was 1.57 (P < 0.001) after adjustment for covariates by using the 2-stage approach method. Patients with COPD were at hip fracture risk and fracture-prevention strategies are essential for better quality of care.

Hyperthyroidism is a Risk Factor for Developing Adhesive Capsulitis of the Shoulder: A Nationwide Longitudinal Population-Based Study

The purpose of this study was to investigate the prevalence and risk of adhesive capsulitis among hyperthyroidism patients. The data were obtained from the Longitudinal Health Insurance Database 2005 (LHID 2005) in Taiwan, using 1 million participants and a prospective population-based 7-year cohort study of survival analysis. The ambulatory-care claim records of patients diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes relating to hyperthyroidism between January 1, 2004 and December 31, 2007, were obtained. The prevalence and the adjusted hazard ratio (HR) of adhesive capsulitis among hyperthyroid patients and the control group were estimated. Of 4472 hyperthyroid patients, 162 (671/100 000 person-years) experienced adhesive capsulitis during the 24 122 person-year follow-up period. The crude HR of stroke was 1.26 (95% confidence interval [CI], 1.06 to 1.49), which was larger than that of the control group. The adjusted HR of developing adhesive capsulitis was 1.22 (95% CI, 1.03 to 1.45) for hyperthyroid patients during the 7-year follow-up period, which achieved statistical significance. The results of our large-scale longitudinal population-based study indicated that hyperthyroidism is an independent risk factor of developing adhesive capsulitis.

Obesity is the predominant predictor of impaired glucose tolerance and metabolic disturbance in polycystic ovary syndrome

Objective. To evaluate the contribution to glucose intolerance and metabolic syndrome of obesity combined with the diagnostic criteria of polycystic ovary syndrome (PCOS). Design. Prospective study. Setting. University teaching hospital from 31 August 2010 to 31 August 2011. Population. Two hundred and twenty women with PCOS and seventy normal control women. Methods. The clinical and biochemical characteristics of women with PCOS and control women were evaluated. Main outcome measures. The impact of obesity, hyperandrogenism, oligo‐anovulation and polycystic ovary morphology on impaired glucose tolerance and metabolic disturbances. Results. Obese women with PCOS had significantly higher insulin resistance than obese normal control women. Logistic regression analysis showed that obesity was the only factor that predicted impaired glucose tolerance and metabolic syndrome. Use of the area under the receiver operating characteristic curve (AUROC) for the body mass index to predict impaired glucose tolerance and metabolic syndrome was more accurate than AUROCs for serum total testosterone level and the average menstrual interval. Conclusions. Body weight status was the major factor determining the risk of impaired glucose tolerance and metabolic syndrome in women with PCOS. Obesity should be treated as the major factor determining long‐term health consequences associated with PCOS.

Two-stage analysis for gene-environment interaction utilizing both case-only and family-based analysis

The case‐only study and family‐based study are two popular study designs for detecting gene‐environment interactions. It is well known that the case‐only analysis is efficient, but its validity relies crucially on the assumption of gene‐environment independence in the study population. In contrast, the family‐based analysis is robust to the violation of such an assumption, but is less efficient. We propose a two‐stage study design for detecting gene‐environment interactions, where a case‐only study is performed at the first stage, and a case‐parent/case‐sibling study is performed at the second stage on a random subsample of the first‐stage case sample as well as their parents/unaffected siblings. Statistical inference procedures are developed for the proposed two‐stage study designs, which not only preserve the robustness property of the family‐based analysis, but also utilize information from the case‐only analysis to enhance estimation efficiency and testing power. Simulation results reveal both the robustness and efficiency of the proposed strategies. Genet. Epidemiol. 2008.

Increased Risk of Dementia in Patients With Systemic Lupus Erythematosus: A Nationwide Population-Based Cohort Study

Systemic lupus erythematosus (SLE) is a systemic autoimmune disorder characterized by varied clinical symptoms and can be comorbid with neuropsychiatric disorders. However, the association between SLE and dementia risk in patients with SLE remains unclear. In this study, we evaluated the incidence of dementia in patients with SLE.