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ABSTRACT: 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.
PLoS ONE 01/2013; 8(1):e55253. · 4.09 Impact Factor
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ABSTRACT: OBJECTIVES: Although diabetes mellitus (DM) has been suggested as a risk factor of adhesive capsulitis of the shoulder (ACS), data on the temporal association between these two conditions are sparse. The purpose of this population-based, age- and sex- matched cohort study was to investigate the risk of developing ACS in patients with newly diagnosed DM. METHODS: A total of 78827 subjects with at least two ambulatory visits with the principal diagnosis of DM in 2001 were recruited in the DM group. The non-DM group comprised 236481, age- and sex-matched randomly sampled subjects without DM. The three-year cumulative risk of ACS was calculated using the Kaplan-Meier method. A Cox proportional hazards regression model was used to estimate the crude and adjusted hazard ratio (HR) of ACS. RESULTS: During the three-year follow-up, 946 (1.20%) subjects in the DM group and 2254 (0.95%) subjects in the non-DM group developed ACS. The crude HR of developing ACS for the DM group compared to the non-DM group was 1.333 (95% 1.236 - 1.439; p value < 0.0001), whereas the adjusted HR was 1.321 (95% 1.224 - 1.425; p value < 0.0001) after adjustment for age, sex, and dyslipidemia. CONCLUSIONS: This longitudinal population-based follow-up study shows a significantly increased risk of developing ACS after DM. © 2012 by the American College of Rheumatology.
Arthritis care & research. 12/2012;
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ABSTRACT: BACKGROUND: Although female pattern hair loss (FPHL) has been considered simply the female counterpart of male pattern hair loss in men, the risk factors may differ. OBJECTIVE: We sought to evaluate factors associated with FPHL and to estimate its prevalence in women. METHOD: In total, 26,226 subjects aged 30 years and older participated in a cross-sectional survey. Ludwig and Norwood classifications were used to assess the degree of hair loss. Information on possible risk factors for FPHL was collected using a questionnaire interview. RESULTS: The prevalence of FPHL (Ludwig grade >I) for all ages was 11.8% (95% CI 11.5%-12.2%), increasing with advancing age. After controlling for age and family history, statistically significant associations were noted between FPHL and high fasting glucose (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.04-1.28), fewer childbirths (OR 1.24, 95% CI 1.12-1.38), breast-feeding (OR 0.88, 95% CI 0.78-0.98), oral contraceptive use (OR 1.21, 95% CI 1.01-1.45), and ultraviolet exposure more than 16 hours per week (OR 1.12, 95% CI 1.02-1.22). LIMITATIONS: The validity and reliability of FPHL classification may be not perfect in this survey and may need to be verified. Information on family history may be still subject to recall bias. CONCLUSIONS: Risk factors for FPHL and male androgenic alopecia may differ.
Journal of the American Academy of Dermatology 11/2012; · 3.99 Impact Factor
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ABSTRACT: This study aimed to analyze the efficacy and prognostic significance of adjuvant tamoxifen in breast cancer patients with various hormone receptor statuses.
Typically, 1,260 female breast cancer patients were recruited in this study. The correlation between estrogen receptor (ER)/progesterone receptor (PR) phenotypes and clinical characteristics was investigated, and the survival rate was assessed after 5-year follow-up.
The 5-year overall survival (85%) was better in women under the age of 50 years. Patients with ER+/PR+ tumors had a better 5-year survival rate (94%); those with ER-/PR- tumors experienced the worst outcome (74% survival rate); whereas single-positive cases were in between. In 97 out of 128 patients with ER-/PR+ tumors, tamoxifen was given as adjuvant hormonal therapy, and it increased the survival benefit in the lower grade group in terms of overall survival and disease-free survival (p=0.01 and p=0.03, respectively).
For high-grade tumors with ER-/PR+, adjuvant tamoxifen therapy may have no survival benefit, whereas for the patients with low-grade ER-/PR+ tumors, adjuvant tamoxifen therapy is highly suggestive.
Journal of breast cancer. 09/2012; 15(3):288-95.
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ABSTRACT: BACKGROUND: This study estimated the excess incidence (overdiagnosis) of breast cancer associated with starting mammographic screening at an earlier age, by using data from the Dalarna County component of the Swedish Two-County Trial of breast cancer screening. METHODS: In Dalarna County, Sweden, 38,589 women aged 40 to 74 years were randomized to invitation to regular mammographic screening (active study population [ASP]) and 18,582 women to usual care (passive study population [PSP]). After 3 screening rounds (6-8 years after randomization), the PSP was invited to screening. The cumulative incidence of breast cancer was calculated in the ASP and PSP from randomization to 29 years later. In addition, cumulative incidence was calculated for invasive cancers, advanced invasive cancers (≥2 cm in maximum diameter or node-positive), and nonadvanced cancers (<2 cm and node negative). RESULTS: There was no excess of cancers in the ASP at 29 year follow-up (relative risk, 1.00; 95% confidence interval, 0.92-1.08). Cumulative incidence in the 2 arms approximately equalized at the conclusion of the first round of screening of the PSP. There was an excess of nonadvanced cancers and a deficit of advanced cancers in the ASP, both of which persisted to 29 years. CONCLUSIONS: There was no additional breast cancer incidence associated with 100,000 additional screens in the ASP. Results suggest that overdiagnosis is small and largely confined to the prevalence screen. Cancer 2012. © 2012 American Cancer Society.
Cancer 05/2012; · 4.77 Impact Factor
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ABSTRACT: This study aimed to investigate whether triple-negative breast cancer has a worse prognosis; here, we present the 10-year follow-up results of triple-negative breast cancer patients in Taiwan.
We identified 2858 breast cancer patients in Taiwan, of whom 416 (14.6%) had triple-negative breast cancer. Data used for analysis were derived from those breast cancer patients who were diagnosed between January 1996 and December 2006.
In the Kaplan-Meier analysis, tumor subgroup (triple-negative breast cancer vs. non-triple-negative breast cancer) was a prognostic factor related to 10-year breast cancer death-specific survival and disease-free survival. The results of univariate analysis showed that tumor subgroup was a significant factor related to 10-year disease-free survival and breast cancer death-specific survival, as well as menopausal status, tumor size, lymph node, metastasis, grade, stage, estrogen receptor status, progesterone receptor status and her2/neu gene expression status. Similarly, the multivariate analysis also revealed that tumor subgroup was a significant factor related to 10-year breast cancer death-specific survival and disease-free survival, in addition to tumor size, lymph node, metastasis and grade.
It was suggested that triple-negative breast cancer patients in Taiwan have worse 10-year survival. Notably, in node-positive patients, triple-negative breast cancer played a prognostic role in 10-year breast cancer death-specific survival.
Japanese Journal of Clinical Oncology 03/2012; 42(3):161-7. · 1.78 Impact Factor
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ABSTRACT: Few reports have identified and quantified significant risk factors responsible for multistate natural course of progression to hypertension and also regression of prehypertension to normal, which provides baseline risks to estimate the size of expected benefit derived from population-based life-style modification.
Data used for estimating clinical parameters governing temporal natural course of hypertension are derived from 42,027 participants attending screening annually between 1999 and 2002. Information on transition history between normal, prehypertension, stage 1 and stage 2 hypertension between screens was therefore collected to compute multistep composite risk scores without intervention program. The expected benefits of risk reduction in prehypertension and hypertension under different intervention programs by modifying the related risk factors from abnormal to normal ranges were estimated.
The majority of risk factors play a more remarkable role in prehypertension and stage 1 hypertension but less in stage 2 hypertension. The greater the number of risk factors included in the intervention programs becomes, the lower the mean risk score is expected to achieve. The 5-year predicted cumulative risk for stage 2 hypertension decreased from 23.6% in the absence of intervention program to 14% with the provision of "six-component intervention" in men. The results were similar for women.
Multiple risk factors responsible for multistep transitions between prehypertension and hypertension were identified by using population-based screening data to derive multistep composite risk scores, which are useful for the expected benefit of reducing risk of hypertension by providing population-based life-style modification.
American Journal of Hypertension 02/2012; 25(2):171-9. · 3.18 Impact Factor
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JAMIA. 01/2012; 19:102-110.
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ABSTRACT: BACKGROUND: Angiogenesis is a fundamental component of oncogenesis. In this study we provided morphologic evidence of vascularization by using power Doppler ultrasound to correlate the clinicopathologic features of tumorigenesis, ER/c-erbB-2 expression, and tumor grade in invasive breast carcinoma. METHODS: Three indices (VI, vascularization index; FI, flow index; VFI, vascularization flow index) were used to analyze 3D power Doppler ultrasound images from 168 patients with malignant breast carcinoma and to correlate their clinicopathologic features. RESULTS: VI (the mean tumor vascularity) was correlated with ER negativity (p < 0.0029) and VFI (the overall perfusion) was correlated with ER positivity (p < 0.0029). HER2 positivity was statistically significantly correlated with tumor vasculature (VI, VFI) and tumor size/volume. FI (the mean blood flow volume) was significantly correlated with tumor size/volume, but VI was not. The univariate or multivariate logistic regression analysis also showed the reverse correlations between ER expression and tumor vascularity, and positive correlations between HER2 expression and tumor vascularity as well as tumor volume. CONCLUSIONS: This morphologic evidence of vascularization is correlated with tumor angiogenesis and ER/c-erbB-2 co-expression, which could clarify the biology of breast cancer.
Breast Cancer 11/2011; · 1.36 Impact Factor
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ABSTRACT: We studied geographic variation in age- and gender-specific prevalence and incidence of epilepsy in four different areas of Taiwan.
By using large-scale, National Health Insurance (NHI)-based data from 2000-2003 in Taiwan, we identified 131,287 patients diagnosed with epilepsy (ICD code 345) receiving at least of one of 11 antiepileptic drugs (AEDs). Information on age, gender, and location were also collected. The multivariable Poisson regression analysis was used to assess the heterogeneity of the morbidity of epilepsy in different regions. External data validation was also performed to assess the accuracy of capturing epilepsy cases through our NHI data set.
The age-adjusted prevalence and incidence of epilepsy were 5.85 (per 1,000) between 2000 and 2003 and 97 (per 100,000 person-years) during the follow-up time from 2001 to 2003 in Taiwan. The sensitivity and specificity of ICD-9 coding for epilepsy in the NHI data set were 83.91% and 99.83%, respectively, resulting in a slight overestimation. Male patients had a higher probability of having epilepsy than did females. East Taiwan had significantly higher prevalence and incidence than did other areas. The age-specific incidence pattern in east Taiwan was atypical in that it revealed clustering in young and middle-aged groups.
Our study demonstrated geographic variation in epidemiologic patterns of epilepsy within Taiwan. The findings are informative and provide insight into the clinical management of epilepsy based on consideration of different target groups in different areas.
Epilepsia 11/2011; 53(2):283-90. · 3.96 Impact Factor
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ABSTRACT: This study aimed to reveal the relationships between histologic grade and other clinicopathologic parameters including intrinsic subtype in Taiwanese women with breast cancer.
There were 1302 women diagnosed with breast cancer recruited for this study. Histologic grade was scored according to the Nottingham-modified Bloom-Richardson grading system.
Higher tumor grade was associated with larger tumor size (P = 0.021), a larger number of lymph node metastases (P = 0.001), advanced clinical stage (P = 0.010), higher human epithelial growth receptor-2 positivity (P < 0.001), negative estrogen receptor and progesterone receptor (P < 0.0001) status. Triple negative breast cancer (56.6%) and human epithelial growth receptor-2 (44.3%) subtypes were associated with more Grade III breast cancer in contrast to luminal A (22.3%) and B (29.9%) breast cancer. In multivariate Cox regression analysis for cancer-specific survival, histologic grade (hazard ratio = 1.78) was a significant prognostic factor.
This study demonstrated that histologic grade is highly correlated with some valuable biomarkers and confirmed the significance of histologic grade in Taiwanese female breast cancers.
Japanese Journal of Clinical Oncology 11/2011; 41(12):1327-35. · 1.78 Impact Factor
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ABSTRACT: Small hepatocellular carcinoma (HCC) affects millions of individuals worldwide. Surveillance of high-risk patients increases the early detection of small HCC.
To identify prognostic factors affecting the overall survival (OS) and recurrence-free survival (RFS) of patients with small HCC.
The present prospective study enrolled 140 Taiwanese patients with stage I or stage II small HCC. Clinical parameters of interest included operation type, tumour size, tumour histology, Child- Pugh class, presence of hepatitis B surface antigen and liver cirrhosis, hepatitis C status, alpha-fetoprotein, total bilirubin and serum albumin levels, and administration of antiviral and salvage therapies.
Tumour size correlated significantly with poorer OS in patients with stage I small HCC (P=0.014); however, patients with stage II small HCC experienced a significantly poorer RFS (P=0.033). OS rates did not differ significantly between patients with stage I and stage II small HCC. Tumour margins, tumour histology and cirrhosis did not significantly affect OS or RFS (P>0.05).
Increasing tumour size has generally been associated with poorer prognoses in cases of HCC. The present study verified the relationship between small HCC tumour size and OS; however, a reduction in OS with increasing tumour size was demonstrated for patients with stage I - but not for stage II - small HCC.
Patients with stage II small HCC may benefit from aggressive surveillance for tumour recurrence and appropriate salvage treatment. Further studies are needed for additional stratification of stage I patients to identify those at increased risk of death.
Canadian journal of gastroenterology = Journal canadien de gastroenterologie 09/2011; 25(9):485-91. · 1.21 Impact Factor
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ABSTRACT: To develop a population-based proband-oriented pedigree information system that can be easily applied to various diseases in genetic epidemiological studies, making allowance for the capture of theoretical family relationships. DESIGNS AND MEASUREMENTS: A population-based proband-oriented pedigree information system with ties of consanguinity based on both population-based household registry data and Keelung Community Integrated Screening data was proposed to build a comprehensive extended family pedigree structure to accommodate a series of genetic studies on different diseases. We also developed an algorithm to efficiently assess how well theoretical family relationships affecting the occurrence of diseases across three generations with respect to the relative relationship score, a quantitative indicator of genetic influence, were captured.
We applied this population-based proband-oriented pedigree information system to estimate the rate of hypertension with various relative relationships given the selection of probands. The degree of capturing complete familial relationships was assessed for three generations. The risk for early onset of hypertension was proportional to the proband-oriented relative relationship score with 2% increased risk and 1% correction for incomplete capture.
The population-based proband-oriented pedigree information system is powerful and can support various genetic descriptive and analytic epidemiological studies.
Journal of the American Medical Informatics Association 07/2011; 19(1):102-10. · 3.61 Impact Factor
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ABSTRACT: There are no reports on the risk of stroke after trigeminal neuralgia (TN). The aim of this population-based follow-up study was to investigate whether the occurrence of TN is associated with a higher risk of developing stroke.
A total of 1453 people with at least three ambulatory visits in 2001 with the principal diagnosis of TN were enrolled in the TN cohort. The non-TN cohort consisted of 5812 age- and sex-matched, randomly sampled subjects without TN. The 2-year stroke-free survival rate between the two groups was compared using the Kaplan-Meier method. The Cox proportional hazards regression model was used to estimate the hazard ratio of stroke after adjustment for demographic and clinical covariates.
In the TN cohort, 73 patients developed stroke during follow-up, while in the non-TN cohort, 157 subjects suffered a stroke. The crude hazard ratio of stroke for the subjects with TN was 1.86 (95% CI, 1.41-2.45; p<0.0001). The adjusted hazard ratio was 1.76 (95% CI, 1.33-2.33; p<0.0001) after adjusting for demographic characteristics and comorbid medical disorders.
This study showed a significantly increased risk of developing stroke after TN. Further studies are needed to investigate the underlying mechanism of this association.
Cephalalgia 06/2011; 31(8):937-42. · 3.43 Impact Factor
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ABSTRACT: Despite widespread use of the immunochemical faecal occult blood test (iFOBT), little is known about the subsequent risk of developing colorectal neoplasia for participants with negative iFOBT results. We investigated whether the concentration of faecal haemoglobin at the first screen is predictive of the subsequent incidence of colorectal neoplasia in those with a negative screening result.
Between 2001 and 2007, we did a prospective cohort study within the Keelung community-based iFOBT screening programme for residents aged 40-69 years, using a cutoff faecal haemoglobin concentration of 100 ng/mL to classify attendees as negative and positive groups for further clinical investigations. 44,324 participants with negative findings and 1668 with a positive result at the first screen (854 non-referrals who refused colonoscopy and 814 with a false-positive result as assessed by colonoscopy) were followed up to ascertain cases of colorectal neoplasia. We investigated the association between baseline faecal haemoglobin concentration and risk of incident colorectal neoplasia, after adjusting for possible confounders.
Median follow-up was 4·39 years (IQR 2·53-6·12) for all 45 992 participants, during which the incidence of colorectal neoplasia increased from 1·74 per 1000 person-years for those with baseline faecal haemoglobin concentration 1-19 ng/mL, to 7·08 per 1000 person-years for those with a baseline concentration of 80-99 ng/mL. The adjusted hazard ratios (HRs) increased from 1·43 (95% CI 1·08-1·88) for baseline faecal haemoglobin concentration of 20-39 ng/mL, to 3·41 (2·02-5·75) for a baseline concentration of 80-99 ng/mL (trend test p<0·0001), relative to 1-19 ng/mL. These results did not change when we included repeated iFOBT measurements. Non-referrals had the highest risk of incident colorectal neoplasia (adjusted HR 8·46 [6·08-11·76]).
Quantitative faecal haemoglobin concentration at first screening predicts subsequent risk of incident colorectal neoplasia. During follow-up, risk stratification based on faecal haemoglobin could help clinicians, with particular attention being paid to those with higher initial faecal haemoglobin concentrations, especially those just under the threshold taken to indicate presence of colorectal neoplasia.
None.
The lancet oncology 06/2011; 12(6):551-8. · 14.47 Impact Factor
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Journal of neurology, neurosurgery, and psychiatry 05/2011; 83(3):341-3. · 4.87 Impact Factor
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ABSTRACT: To incorporate clinical complications in the susceptible-infectious-recovered model to estimate parameters needed in dynamic changes of infectious diseases and to further evaluate the impact of disease-controlling methods.
We developed a new extended epidemic model that incorporates of disease-related complications. This model was applied to empirical data on influenza during the epidemic season of 2001-2002 in Taipei County, Taiwan, to estimate the transmission parameters that were converted to the basic reproductive rate (R(0)). The proposed model, in conjunction with estimated parameters, was applied in quantifying the efficacy of different preventive strategies.
During the study period there were 5 outbreaks of influenza. The estimated transmission probability for outbreak 1 was 0.135, with corresponding estimate of R(0), 2.7; for outbreak 2, 0.165, with estimated R(0), 3.3; for outbreak 3, 0.15, with R(0), 4.5; for outbreak 4, 0.165, with R(0), 5; and for outbreak 5, 0.165, with R(0), 5. The efficacy of antiviral prophylaxis to reduce the total episodes was 18% (95% CI, 15%-21%) under the coverage rate of 30%, 31% (95% CI, 26%-36%) under the coverage rate of 50%, and 73% (95% CI, 59%-90%) under the coverage rate of 80%. The corresponding figures for the efficacy of vaccination were 17% (95% CI, 15%-20%), 41% (95% CI, 35%-48%), and 76% (95% CI, 61%-95%). Combination of both methods would yield efficacy of 32% (95% CI, 28%-38%), 59% (95% CI, 49%-71%), and 88% (95% CI, 66%-118%), respectively.
We demonstrate how to apply a novel extended model to empirical surveillance data of an influenza study for estimating parameters pertaining to dynamic changes in the infection process. These parameters were further used to evaluate the impact of antiviral prophylaxis alone, vaccination alone, or the use of both methods.
Infection Control and Hospital Epidemiology 05/2011; 32(5):456-64. · 3.67 Impact Factor
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ABSTRACT: BACKGROUND AND AIM: The widespread use of screening programs has resulted in an increase in detection of small hepatocellular carcinoma (HCC). Surgical resection generally leads to favorable outcomes in this group of patients; however, the prognostic significance of tumor size and the optimal cutoff point in resected specimens of small HCC have not been well defined. The aim of current study is to evaluate the prognostic significance of tumor size in small resected HCC. Methods: Patients who underwent surgical resection for small HCC at the Changhua Christian Hospital during January 2001 to June 2007 were enrolled. Small HCC was defined as a single HCC nodule with maximum diameter ≤ 5 cm. Cox regression hazard ratios for cancer-specific death were calculated to survey the prognostic significance of tumor size. We then determined the optimal cut-point for tumor size that could be used to stratify patients into 5-year disease-free survival (DFS) and cancer-specific survival (CSS) groups. Results: A total of 140 patients who underwent resection of small HCC were enrolled. The mean tumor size was 2.9 cm (range 0.9-5.0) and the mean follow-up period was 43.4 months. The 5-year DFS and CSS rates were 46.6% and 81.6%, respectively. Cox regression analysis revealed that tumor size (hazard ratio = 2.973, 95% confidence interval: 1.073-8.239, P = 0.036) was an independent prognostic factor. Our analysis showed that a tumor size of 3 cm was the cut-point that could dichotomize patients into statistically different 5-year DFS and CSS risk groups. Conclusions: Tumor size is an independent prognostic factor in resected small HCC and the prognostic significance of tumor size may vary according to different cut-off points.
Journal of Gastroenterology and Hepatology 12/2010; 26(5):851-7. · 2.87 Impact Factor
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ABSTRACT: This study is to identify an optimal cut-off for two-stage breast cancer screening making allowance for variation of the baseline incidence rate and utility values between sensitivity and specificity.
We used data from a two-stage breast cancer screening of Taiwanese women aged 50-69 years for whom risk stratification was based on a composite risk score (conventional risk factors); subjects with a risk score greater than the cut-off score were screened using mammography. The Bayesian posterior risk for breast cancer was computed by incorporation of the baseline incidence rate and the risk score. Bayes' maximum utility decision rule was then developed to determine the optimal screening cut-off.
With a risk score of -9 applied to the current two-stage breast cancer screening programme, we could detect one breast cancer case for every 1406 women. Given different predetermined risks, the selected cut-offs were -9 for 1:1200, -8 for 1:800, -4 for 1:600, -1 for 1:400 and 3 for 1:200 for women aged 50-59 years. When the regret utility ratio of positive predictive value to negative predictive value was set at 1:10, the specificity and sensitivity were 58.5% and 70.4%, respectively, and the optimal cut-off was -5.5. When the ratio was set at 10:1, the sensitivity and specificity were 75.5% and 57.1%, respectively, and the optimal cut-off value was -7.5.
This study demonstrates that Bayes' maximum utility decision rule can be used to determine optimal cut-off values for two-stage breast cancer screening in countries or areas with lower or intermediate incidence of breast cancer.
Journal of Evaluation in Clinical Practice 12/2010; 16(6):1345-52. · 1.23 Impact Factor
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ABSTRACT: Population-based routine service screening has gained popularity following an era of randomized controlled trials. The evaluation of these service screening programs is subject to study design, data availability, and the precise data analysis for adjusting bias. We developed a computer-aided system that allows the evaluation of population-based service screening to unify these aspects and facilitate and guide the program assessor to efficiently perform an evaluation.
This system underpins two experimental designs: the posttest-only non-equivalent design and the one-group pretest-posttest design and demonstrates the type of data required at both the population and individual levels. Three major analyses were developed that included a cumulative mortality analysis, survival analysis with lead-time adjustment, and self-selection bias adjustment. We used SAS AF software to develop a graphic interface system with a pull-down menu style.
We demonstrate the application of this system with data obtained from a Swedish population-based service screen and a population-based randomized controlled trial for the screening of breast, colorectal, and prostate cancer, and one service screening program for cervical cancer with Pap smears. The system provided automated descriptive results based on the various sources of available data and cumulative mortality curves corresponding to the study designs. The comparison of cumulative survival between clinically and screen-detected cases without a lead-time adjustment are also demonstrated. The intention-to-treat and noncompliance analysis with self-selection bias adjustments are also shown to assess the effectiveness of the population-based service screening program. Model validation was composed of a comparison between our adjusted self-selection bias estimates and the empirical results on effectiveness reported in the literature.
We demonstrate a computer-aided system allowing the evaluation of population-based service screening programs with an adjustment for self-selection and lead-time bias. This is achieved by providing a tutorial guide from the study design to the data analysis, with bias adjustment.
Annals of epidemiology 10/2010; 20(10):786-96. · 2.95 Impact Factor
