Automatic Detection and Segmentation of Breast Cancer on MRI Using Mask R-CNN Trained on Non-Fat-Sat Images and Tested on Fat-Sat Images.

RATIONALE AND OBJECTIVES: Computer-aided methods have been widely applied to diagnose lesions on breast magnetic resonance imaging (MRI). The first step was to identify abnormal areas. A deep learning Mask Regional Convolutional Neural Network (R-CNN) was implemented to search the entire set of images and detect suspicious lesions. MATERIALS AND METHODS: Two DCE-MRI datasets were used, 241 patients acquired using non-fat-sat sequence for training, and 98 patients acquired using fat-sat sequence for testing. All patients have confirmed unilateral mass cancers. The tumor was segmented using fuzzy c-means clustering algorithm to serve as the ground truth. Mask R-CNN was implemented with ResNet-101 as the backbone. The neural network output the bounding boxes and the segmented tumor for evaluation using the Dice Similarity Coefficient (DSC). The detection performance, and the trade-off between sensitivity and specificity, was analyzed using free response receiver operating characteristic. RESULTS: When the precontrast and subtraction image of both breasts were used as input, the false positive from the heart and normal parenchymal enhancements could be minimized. The training set had 1469 positive slices (containing lesion) and 9135 negative slices. In 10-fold cross-validation, the mean accuracy = 0.86 and DSC = 0.82. The testing dataset had 1568 positive and 7264 negative slices, with accuracy = 0.75 and DSC = 0.79. When the obtained per-slice results were combined, 240 of 241 (99.5%) lesions in the training and 98 of 98 (100%) lesions in the testing datasets were identified. CONCLUSION: Deep learning using Mask R-CNN provided a feasible method to search breast MRI, localize, and segment lesions. This may be integrated with other artificial intelligence algorithms to develop a fully automatic breast MRI diagnostic system.

Quantitative Measurement of Breast Tumors Using Intravoxel Incoherent Motion (IVIM) MR Images.

Breast magnetic resonance imaging (MRI) is currently a widely used clinical examination tool. Recently, MR diffusion-related technologies, such as intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI), have been extensively studied by breast cancer researchers and gradually adopted in clinical practice. In this study, we explored automatic tumor detection by IVIM-DWI. We considered the acquired IVIM-DWI data as a hyperspectral image cube and used a well-known hyperspectral subpixel target detection technique: constrained energy minimization (CEM). Two extended CEM methods-kernel CEM (K-CEM) and iterative CEM (I-CEM)-were employed to detect breast tumors. The K-means and fuzzy C-means clustering algorithms were also evaluated. The quantitative measurement results were compared to dynamic contrast-enhanced T1-MR imaging as ground truth. All four methods were successful in detecting tumors for all the patients studied. The clustering methods were found to be faster, but the CEM methods demonstrated better performance according to both the Dice and Jaccard metrics. These unsupervised tumor detection methods have the advantage of potentially eliminating operator variability. The quantitative results can be measured by using ADC, signal attenuation slope, D*, D, and PF parameters to classify tumors of mass, non-mass, cyst, and fibroadenoma types.

Development of U-Net Breast Density Segmentation Method for Fat-Sat MR Images Using Transfer Learning Based on Non-Fat-Sat Model.

To develop a U-net deep learning method for breast tissue segmentation on fat-sat T1-weighted (T1W) MRI using transfer learning (TL) from a model developed for non-fat-sat images. The training dataset (N = 126) was imaged on a 1.5 T MR scanner, and the independent testing dataset (N = 40) was imaged on a 3 T scanner, both using fat-sat T1W pulse sequence. Pre-contrast images acquired in the dynamic-contrast-enhanced (DCE) MRI sequence were used for analysis. All patients had unilateral cancer, and the segmentation was performed using the contralateral normal breast. The ground truth of breast and fibroglandular tissue (FGT) segmentation was generated using a template-based segmentation method with a clustering algorithm. The deep learning segmentation was performed using U-net models trained with and without TL, by using initial values of trainable parameters taken from the previous model for non-fat-sat images. The ground truth of each case was used to evaluate the segmentation performance of the U-net models by calculating the dice similarity coefficient (DSC) and the overall accuracy based on all pixels. Pearson's correlation was used to evaluate the correlation of breast volume and FGT volume between the U-net prediction output and the ground truth. In the training dataset, the evaluation was performed using tenfold cross-validation, and the mean DSC with and without TL was 0.97 vs. 0.95 for breast and 0.86 vs. 0.80 for FGT. When the final model developed with and without TL from the training dataset was applied to the testing dataset, the mean DSC was 0.89 vs. 0.83 for breast and 0.81 vs. 0.81 for FGT, respectively. Application of TL not only improved the DSC, but also decreased the required training case number. Lastly, there was a high correlation (R2 > 0.90) for both the training and testing datasets between the U-net prediction output and ground truth for breast volume and FGT volume. U-net can be applied to perform breast tissue segmentation on fat-sat images, and TL is an efficient strategy to develop a specific model for each different dataset.

A functional recovery profile for patients with stroke following post-acute rehabilitation care in Taiwan.

BACKGROUND: Functional impairment is frequently seen in patients with stroke. Although the progression of functional recovery after stroke has been proposed, the recovery profile after acute stroke is not well described. The objective of this study is to investigate functional recovery in stroke patients entering post-acute rehabilitation care. METHODS: A retrospective cohort study collected the data of patients who entered the stroke Post-acute Care (PAC) programs. Ninety-five patients after stroke with a modified Ranking Scale (mRS) score of 3-4 who were referred to a post-acute care unit for intensive rehabilitation were recruited. The patients underwent functional, quality of life, and neuropsychological evaluation tests at admission and before discharge. The test scores before discharge were used as outcome variables and were compared with the test scores at admission to show functional recovery. RESULTS: The average length of stay was 58.15 days. After an intensive rehabilitation intervention, significant improvements were observed in all test scores. Additionally, a significant removal rate for nasogastric tubes (p = 0.000) and Foley catheters (p = 0.003) was found at discharge. CONCLUSION: This study showed that the PAC rehabilitation unit was beneficial for patients with acute stroke who had functional impairments. The study results may call for further investigation to identify and develop better models for the delivery of rehabilitation in the stroke PAC unit.

Reconstruction of Diabetic Foot Defects With the Proximal Lateral Leg Perforator Flap.

BACKGROUND: In patients with diabetic foot ulcers requiring flap reconstruction, the choice of local flaps is limited by the lack of adequate tissue available. Free flaps are often bulky, presenting footwear difficulty due to poor contouring. Here, we present our experience of using the proximal lateral leg perforator flap in the reconstruction of thin diabetic foot ulcers. METHODS: This is a retrospective study of 17 patients with diabetic foot ulcers reconstructed with the proximal lateral leg perforator flap during January 2013 and December 2015. RESULTS: Nine patients had varying degrees of peripheral arterial disease. The perforator was located 7 to 14 cm (mean, 9.7 cm) from the fibula head. The pedicle length ranged from 5 to 9 cm (mean, 6.9 cm). The arterial diameter of the pedicle measured 0.8 to 1.9 mm (mean, 1.4 mm). There was 1 total flap failure. One other flap complicated by venous thrombosis was successfully salvaged. All donor sites were closed primarily without morbidities. All the wounds were stable without recurrent ulceration during a mean follow-up time of 12 months. CONCLUSION: The thin, pliable proximal lateral leg perforator flap is an option for the reconstruction of small to moderate diabetic foot defects especially when it is located over the dorsal foot or the ankle. The flap is simple and quick to harvest without sacrificing a major artery. Although it is limited by the short length and the small diameter of the pedicle, for experienced microsurgeons, the success rate is high.

A comparison study between endoscope-assisted and the standard approach in the harvesting of the free rectus femoris muscle flap.

BACKGROUND: Endoscopic harvesting of muscle flaps is well described for gracilis, latissimus dorsi, gastrocnemius, and pectoralis major amongst others. So far there has been no description of endoscopic harvesting of the rectus femoris muscle as a free flap. The purpose of this study was to compare the perioperative outcomes of harvesting the free rectus femoris muscle flap endoscopically as compared to the standard approach. METHODS: Fifty patients with lower limb defects reconstructed with free rectus femoris muscle flap between January 2014 and December 2016 were included in this study. Their ages ranged from 37 years old to 92 years old. The flaps were harvested with both the standard and endoscopical method. Comparative data between the two methods collected included: age, gender, comorbid illnesses, flap size, defect size, reconstruction time, and flap survival rate RESULTS: Twenty patients underwent flap harvesting endoscopically and 30 were harvested with the standard technique. Their mean ages were 67 ± 9.4 and 65 ± 14 years old respectively (P = .47). The defect size was 96 ± 60 cm2 versus 81 ± 74 cm2 (P = .45). The flap size was 72 ± 34 cm2 in the endoscopic group and 60 ± 42 cm2 in the standard group (P = .52). The mean total reconstruction time in the endoscopic group was 228 ± 48 minutes and 216 ± 64 minutes in the standard group (P = .50). There was no significant difference between flap survival (P = N/A), complication rates (P = .33), and length of admission (P = .84) in the two groups. CONCLUSION: Endoscope-assisted harvesting of a free rectus femoris muscle flap is a feasible option and permits a small scar at the donor site.

Appendectomy correlates with increased risk of pyogenic liver abscess: A population-based cohort study in Taiwan.

Little is known on the association between appendectomy and pyogenic liver abscess. The objective of this study was to investigate the association between appendectomy and the risk of pyogenic liver abscess in Taiwan.This population-based retrospective cohort study was conducted using the hospitalization dataset of the Taiwan National Health Insurance Program. There were 212,530 subjects age 20 to 84 years with newly diagnosed appendectomy as the appendectomy group since 1998 to 2010, and 850,099 randomly selected subjects without appendectomy as the nonappendectomy group. Both appendectomy and nonappendectomy groups were matched with sex, age, comorbidities, and index year of diagnosing appendectomy. The incidence of pyogenic liver abscess at the end of 2011 was estimated in both groups. The multivariable Cox proportional hazards regression model was applied to investigate the hazard ratio (HR) and 95% confidence interval (CI) for risk of pyogenic liver abscess associated with appendectomy and other comorbidities including alcoholism, biliary stone, chronic kidney disease, chronic liver diseases, and diabetes mellitus.The overall incidence of pyogenic liver abscess was 1.73-fold greater in the appendectomy group than that in the nonappendectomy group (3.85 vs 2.22 per 10,000 person-years, 95% CI 1.71, 1.76). The multivariable regression analysis disclosed that the adjusted HR of pyogenic liver abscess was 1.77 for the appendectomy group (95% CI 1.59, 1.97), when compared with the nonappendectomy group.Appendectomy is associated with increased hazard of pyogenic liver abscess. Further studies remain necessary to confirm our findings.

A comparison between combined open bypass revascularization and free tissue transfer versus endovascular revascularization and free tissue transfer for lower limb preservation.

BACKGROUND: Extensive defects of the lower limb as a result of diabetes and peripheral vascular disease require multidisciplinary treatment. Numerous studies with regards combining vascular bypass surgery and free tissue reconstruction of the lower limb had been published. However the trend has evolved toward a combination of endovascular revascularization and free flap reconstruction. The aim of this study was to compare the safety and efficacy of this combination of treatment to the traditional combination of bypass surgery and free tissue reconstruction. METHODS: All patients who had undergone vascular bypass surgery and free tissue reconstruction of the lower limb as well as those who had undergone endovascular angioplasty with free tissue transfer for lower limb preservation, over a 10-year period was included in this study. RESULTS: A total of 46 patients that underwent limb preservation were included in this study, 22 patients underwent open bypass revascularization and free flap transfer and 24 patients underwent endovascular revascularization and free tissue transfer. There were no differences between the two methods with regards to age, sex, defect size, TransAtlantic InterSociety Consensus level, Wagner classification, length of hospitalization, limb preservation rate, total flap necrosis rate, and partial flap necrosis rate. More importantly, there was no significant difference in the limb preservation rate (P = 0.14). CONCLUSION: In this study we found that the safety and the success rate of lower limb preservation using a combination of endovascular revascularization and free tissue reconstruction is comparable to using a combination of bypass surgery and free tissue transfer.

Risk of Ear-Associated Diseases After Zygomaticomaxillary Complex Fracture.

PURPOSE: Investigate the risk of ear-associated diseases after zygomaticomaxillary complex (ZMC) fracture in a population-based retrospective cohort study. MATERIALS AND METHODS: This is a retrospective cohort study using Taiwan's National Health Insurance Research Database of reimbursement claims. A total of 1,330 ZMC fracture patients and 5,320 non-ZMC fracture participants were included and newly developed ear-associated disease data were collected. A Poisson regression and multivariate Cox proportion hazard regression were used for data analysis. RESULTS: The ZMC fracture cohort had a higher incidence of tinnitus than non-ZMC fracture cohort (IRR 1.64, 95 % CI 1.37-1.96), particularly in younger patients (≤34 years of age; IRR 4.05, 95 % CI 3.18-5.15) and male patients (IRR 2.08, 95 % CI 1.12-3.73). ZMC fracture patients also showed a significantly increased risk of having trigeminal neuralgia [IRR 4.06, 95 % CI 3.34-4.94, adjusted HR 4.07 (1.02-16.3)]. For sudden hearing loss and peripheral vertigo, the incidence densities were higher in the ZMC fracture cohort, but these relationships were not significant in the multivariate Cox proportional hazard regression analyses (HR 2.69, 95 % CI 0.76-9.53 for risk of sudden hearing loss; HR 1.36, 95 % CI 0.77-2.40 for risk of peripheral vertigo). CONCLUSIONS: The findings of the study suggest an increased risk of ear-associated diseases among individuals with ZMC fractures, particularly within 2-years follow-ups after injury. We suggest performing detailed examinations for ear-associated diseases in patients with ZMC fractures for early diagnosis and adequate treatment.

Strengthening health promotion in hospitals with capacity building: a Taiwanese case study.

Organizational capacity building for health promotion (HP) is beneficial to the effective implementation of HP in organizational settings. The World Health Organization (WHO) Health Promoting Hospitals' (HPHs) initiative encourages hospitals to promote the health of their stakeholders by developing organizational capacity. This study analyzes an application case of one hospital of the HPH initiative in Taiwan, characterizes actions aiming at building organizational support to strengthen health gains and identifies facilitators of and barriers to the implementation of the HP in this hospital. Case study methodology was used with a triangulation of various sources; thematic analysis was used to analyze qualitative information. This study found a positive impact of the HPH initiative on the case hospital, such as more support from leadership, a fine-tuned HP mission and strategy, cultivated pro-HP habits of physical activities, a supportive intramural structure, an HP-inclusive system, improved management practices and enhanced staff participation. Transformational and transactional enablers are of equal importance in implementing HPH. However, it was also found that the case hospital encountered more transactional barriers than transformational ones. This hospital was hindered by insufficient support from external environments, leadership with limited autonomy and authority, a preference for ideals over professionalism, insufficient participation by physicians, a lack of manpower and time, a merit system with limited stimulating effect, ineffective management practices in weak central project management, a lack of integration, insufficient communication and an inability to inculcate the staff on the importance of HP, and inadequate staff participation. Several implications for other hospitals are suggested.

The proximal lateral lower leg perforator flap revisited: anatomical study and clinical applications.

BACKGROUND: The proximal lateral lower leg flap is a flap suited for the reconstruction of small and thin defects. The purpose of this study was to map the position and consistency of the perforator vessels and to review its reliability and technical considerations clinically. METHODS: The location, number, and size of perforator vessels in the proximal third of the lateral lower leg were investigated in 20 fresh frozen cadaveric lower limbs. This was analyzed together with 22 clinical cases. RESULTS: Cadaveric dissection showed that there were 1-2 perforators in the proximal third of the lateral lower leg and these perforator vessels were found to be 63% septocutaneous and 37% musculocutaneous. The source vessel of the perforators was variable. Clinically the recipient site consisted of the head and neck in 8 cases, the foot and ankle region in 13 cases, and 1 case in the hand. The mean thickness of this flap was 5.8 ± 0.8 mm. Vascular pedicle length ranged from 5 to 8.5 cm. The mean diameter of flap artery was 1.3 ± 0.3 mm. One flap failure was seen due to arterial thrombosis. The overall flap survival rate was 95%. CONCLUSIONS: The proximal lateral lower leg flap has the advantages of being thin and pliable, quick to harvest with no major arteries sacrificed. There is minimal donor site morbidity and primary closure of the donor site is possible in the majority of cases.

Application of a smartphone nurse call system for nursing care.

BACKGROUND: Traditionally, a patient presses the nurse call button and alerts the central nursing station. This system cannot reach the primary care nurse directly. The aim of this study was to apply a new smartphone system through the cloud system and information technology that linked a smartphone and a mobile nursing station for nursing care service. MATERIALS AND METHODS: A smartphone and mobile nursing station were integrated into a smartphone nurse call system through the cloud and information technology for better nursing care. RESULTS: Waiting time for a patient to contact the most responsible nurse was reduced from 3.8 min to 6 s. The average time for pharmacists to locate the nurse for medication problem was reduced from 4.2 min to 1.8 min by the new system. CONCLUSIONS: After implementation of the smartphone nurse call system, patients received a more rapid response. This improved patients' satisfaction and reduced the number of complaints about longer waiting time due to the shortage of nurses.

Application of proximal lateral leg perforator flaps for head and neck reconstructions.

OBJECTIVE: Analyze the reliability, complications, and donor site morbidity of the proximal lateral leg flap when applied to head and neck reconstruction. STUDY DESIGN: Case series and chart review. SETTING: Tertiary care teaching hospital. SUBJECTS AND METHODS: Nineteen patients who underwent reconstruction of various head and neck defects with this flap were analyzed. The patient demographics, flap characteristics, method of donor site closure, scars of the donor area, complication rates, as well as functional results at the recipient site were assessed. RESULTS: The flap size ranged from 4 × 4 cm to 11 × 8 cm. Vascular pedicle length ranged from 5 to 9 cm. The mean distance of the perforator from the fibula head was 9.2 cm. The mean thickness of this flap was 5.5 mm. All the donor wounds were closed primarily. The flap survival rate was 100%. CONCLUSION: This flap has the advantages of thinness, short harvesting time, minimal donor site morbidity, and primary closure at the donor site when the flap width is less than 6 cm. This flap may be useful for reconstruction in selected patients with small and thin heads and neck defects.

Endovascular revascularization and free tissue transfer for lower limb salvage.

Combined bypass surgery with free flap reconstruction is an established method for lower limb salvage. But the success of the combination of endovascular revascularization together with free tissue transfer has so far not been well established. A retrospective review of all patients who had undergone endovascular revascularization and reconstructed with free tissue transfer for lower limb salvage at Tzu Chi Dalin General Hospital between 2008 and 2012 was performed. A total of 26 legs underwent limb salvage in 24 patients. There were 10 male and 14 female patients. Their average age was 71.4 years. The average time interval between endovascular intervention and free tissue transfer was 8 days. There was 100% flap survival but partial flap necrosis was seen in three patients. A high rate of wound infection was seen in eight patients, all requiring further debridement. The total limb salvage rate at 1-year follow-up was 96% and 92% at the 2-year follow-up. In conclusion, the success rate of lower limb salvage using a combination of endovascular revascularization and free tissue reconstruction is comparable to using a combination of bypass surgery and free tissue transfer. It is associated with a high flap success rate and a high limb salvage rate. It provides physicians with a further treatment option in the management of ischemic lower limbs with extended tissue loss.

A comparison between proximal lateral leg flap and radial forearm flap for intraoral reconstruction.

Free flaps have become a popular option for the reconstruction of intraoral defects. The radial forearm flap used to be the workhorse flap for small and thin defects, but was associated with numerous donor-site morbidities. The proximal lateral leg flap can provide a thin and pliable tissue similar to the radial forearm flap but without the related donor-site morbidities. We compared the differences between these 2 flaps. Thirty-four patients with intraoral defects from September 2005 to October 2011 were reconstructed, using the radial forearm flap in 23 cases, and the proximal lateral leg flap in 11 cases. The radial forearm flap group had a success rate of 95.6%. The flap survival rate was 100% in the proximal lateral leg flap group. However, the difference was statistically insignificant. Skin graft was required in 22 of the 23 cases for the donor site of the radial forearm flap. Partial loss of the skin graft occurred in 5/22 (23%) of the patients, with exposure of tendons in 3/22 (14%). Delay in healing of the donor sites occurred in 6/23 (26%) of the patients. The donor sites of the proximal lateral leg flap were all closed primarily. One case developed wound dehiscence and this healed by conservative treatment. Long-term follow-up showed functional impairment of the donor forearm (reduced extension or grip strength) in 17% of the patients. Thirty percent of the patients developed sensory disturbance and 48% complained of poor outcome of the donor forearms. In the proximal lateral leg flap group, no motor or sensory functional deficits were seen. No patients complained of poor outcome of the donor legs. Primary closure of the donor site of the proximal lateral leg flap could be performed if the flap width was less than 6 cm. This flap is useful for patients with small and thin intraoral defects and is associated with minimal donor-site morbidity when compared to the radial forearm flap.

Association of acute phase protein-haptoglobin, and epithelial-mesenchymal transition in buccal cancer: a preliminary report.

BACKGROUND: The aim of this study was to determine the influence of inflammation on acute phase protein and epithelial-mesenchymal transition (EMT) in buccal cancer. METHODS: Western blotting was carried out to investigate the expression of haptoglobin and epithelial-mesenchymal transition in oral cancer cell lines with or without IL-6 stimulation. We studied patients with buccal cancer patients without distant metastasis at diagnosis. Correlation between cellular haptoglobin, EMT, and clinical characteristics of buccal cancer was analyzed to assess the prognostic value of cellular haptoglobin level and EMT. The relationship of haptoglobin, and EMT expression with survival was assessed using Cox proportional hazard models. RESULTS: Western blotting analysis showed that increased haptoglobin protein was associated with overexpression of vimentin. Under IL-6 stimulation, overexpression of haptoglobin, EMT-associated motile phenotype was noted in OC2 cell lines. Overexpression of haptoglobin was also associated with an increased risk for locoregional recurrence [hazard ratio (HR) 1.04; p=0.011] after adjusting for age, gender, disease site, stage, and treatment modality. CONCLUSIONS: Increased cellular expression of haptoglobin is associated with EMT in oral cancer cell lines and this phenomenon could be exaggerated with IL-6. Cellular expression of haptoglobin is related to locoregional recurrence rate in buccal cancer patients.

Reconstruction of advance head and neck cancer patients after tumor ablation with simultaneous multiple free flaps: indications and prognosis.

Simultaneous multiple free flaps have become a useful option in head and neck reconstructions. We performed a 10-year retrospective study between 2001 and 2010. There were 58 men and 1 woman. The overall mortality rate was 51.7%. The longest surviving patient is 9 years and 4 months, whereas the shortest surviving patient was 72 days. The mean survival period was 47.1 (6.8) months. Age (P = 0.755) and tumor size (P = 0.115) did not play a major role, but surgical margin, lymph node, and tumor recurrence were significant in patient survival with a P value of 0.026, 0.01, and 0.026, respectively. If wide excision with a margin that can be free of tumor can be performed, lymph nodes are not involved, and this is a primary tumor, then time and effort should be spent in a successful simultaneous multiple free flap reconstruction.

Expanding the applications of the pedicled anterolateral thigh and vastus lateralis myocutaneous flaps.

We describe our experience in expanding the use of pedicled anterolateral thigh and vastus lateralis myocutaneous flaps. A total of 33 patients underwent 34 flaps between March 2003 and January 2012. The defects included 18 ischial, 3 trochanteric, 5 lower abdomen, 2 perineogenital, 1 groin, and 5 knee defects. There were 29 proximal pedicled (2 of which were preexpanded), 3 distal pedicled, and 2 propeller flaps. Complications included 1 total necrosis, 1 partial necrosis, 3 wound dehiscence in recipient site, 1 hematoma, and 1 donor-site dehiscence. The total flap survival rate was 94%. There were no donor-site morbidities except poor cosmesis in the skin-grafted sites. Pedicled anterolateral thigh flap is highly versatile with a wide arc of rotation. A proximal pedicled flap can be used for lower abdomen, perineogenital, ischial, and trochanteric defects and the distal pedicled or a propeller flap for knee and proximal lower leg defects.

The combined effect of individual and neighborhood socioeconomic status on cancer survival rates.

BACKGROUND: This population-based study investigated the relationship between individual and neighborhood socioeconomic status (SES) and mortality rates for major cancers in Taiwan. METHODS: A population-based follow-up study was conducted with 20,488 cancer patients diagnosed in 2002. Each patient was traced to death or for 5 years. The individual income-related insurance payment amount was used as a proxy measure of individual SES for patients. Neighborhood SES was defined by income, and neighborhoods were grouped as living in advantaged or disadvantaged areas. The Cox proportional hazards model was used to compare the death-free survival rates between the different SES groups after adjusting for possible confounding and risk factors. RESULTS: After adjusting for patient characteristics (age, gender, Charlson Comorbidity Index Score, urbanization, and area of residence), tumor extent, treatment modalities (operation and adjuvant therapy), and hospital characteristics (ownership and teaching level), colorectal cancer, and head and neck cancer patients under 65 years old with low individual SES in disadvantaged neighborhoods conferred a 1.5 to 2-fold higher risk of mortality, compared with patients with high individual SES in advantaged neighborhoods. A cross-level interaction effect was found in lung cancer and breast cancer. Lung cancer and breast cancer patients less than 65 years old with low SES in advantaged neighborhoods carried the highest risk of mortality. Prostate cancer patients aged 65 and above with low SES in disadvantaged neighborhoods incurred the highest risk of mortality. There was no association between SES and mortality for cervical cancer and pancreatic cancer. CONCLUSIONS: Our findings indicate that cancer patients with low individual SES have the highest risk of mortality even under a universal health-care system. Public health strategies and welfare policies must continue to focus on this vulnerable group.

Increased risk of vascular events in emergency room patients discharged home with diagnosis of dizziness or vertigo: a 3-year follow-up study.

BACKGROUND: Dizziness and vertigo symptoms are commonly seen in emergency room (ER). However, these patients are often discharged without a definite diagnosis. Conflicting data regarding the vascular event risk among the dizziness or vertigo patients have been reported. This study aims to determine the risk of developing stroke or cardiovascular events in ER patients discharged home with a diagnosis of dizziness or vertigo. METHODOLOGY: A total of 25,757 subjects with at least one ER visit in 2004 were identified. Of those, 1,118 patients were discharged home with a diagnosis of vertigo or dizziness. A Cox proportional hazard model was performed to compare the three-year vascular event-free survival rates between the dizziness/vertigo patients and those without dizziness/vertigo after adjusting for confounding and risk factors. RESULTS: We identified 52 (4.7%) vascular events in patients with dizziness/vertigo and 454 (1.8%) vascular events in patients without dizziness/vertigo. ER patients discharged home with a diagnosis of vertigo or dizziness had 2-fold (95% confidence interval [CI], 1.35-2.96; p<0.001) higher risk of stroke or cardiovascular events after adjusting for patient characteristics, co-morbidities, urbanization level of residence, individual socio-economic status, and initially taking medications after the onset of dizziness or vertigo during the first year. CONCLUSIONS: ER patients discharged home with a diagnosis of dizziness or vertigo were at a increased risk of developing subsequent vascular events than those without dizziness/vertigo after the onset of dizziness or vertigo. Further studies are warranted for developing better diagnostic and follow-up strategies in increased risk patients.