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Featured researches published by Yifei Ma.


Hpb | 2012

Failure to comply with NCCN guidelines for the management of pancreatic cancer compromises outcomes

Brendan C. Visser; Yifei Ma; Yulia Zak; George A. Poultsides; Jeffrey A. Norton; Kim F. Rhoads

INTRODUCTION There are little data available regarding compliance with the National Comprehensive Cancer Network (NCCN) guidelines. We investigated variation in the management of pancreatic cancer (PC) among large hospitals in California, USA, specifically to evaluate whether compliance with NCCN guidelines correlates with patient outcomes. METHODS The California Cancer Registry was used to identify patients treated for PC from 2001 to 2006. Only hospitals with ≥ 400 beds were included to limit evaluation to centres possessing resources to provide multimodality care (n= 50). Risk-adjusted multivariable models evaluated predictors of adherence to stage-specific NCCN guidelines for PC and mortality. RESULTS In all, 3706 patients were treated for PC in large hospitals during the study period. Compliance with NCCN guidelines was only 34.5%. Patients were less likely to get recommended therapy with advanced age and low socioeconomic status (SES). Using multilevel analysis, controlling for patient factors (including demographics and comorbidities), hospital factors (e.g. size, academic affiliation and case volume), compliance with NCCN guidelines was associated with a reduced risk of mortality [odds ratio (OR) for death 0.64 (0.53-0.77, P < 0.0001)]. CONCLUSIONS There is relatively poor overall compliance with the NCCN PC guidelines in Californias large hospitals. Higher compliance rates are correlated with improved survival. Compliance is an important potential measure of the quality of care.


Journal of Clinical Oncology | 2015

How Do Integrated Health Care Systems Address Racial and Ethnic Disparities in Colon Cancer

Kim F. Rhoads; Manali I. Patel; Yifei Ma; Laura A. Schmidt

PURPOSE Colorectal cancer (CRC) disparities have persisted over the last two decades. CRC is a complex disease requiring multidisciplinary care from specialists who may be geographically separated. Few studies have assessed the association between integrated health care system (IHS) CRC care quality, survival, and disparities. The purpose of this study was to determine if exposure to an IHS positively affects quality of care, risk of mortality, and disparities. PATIENTS AND METHODS This retrospective secondary-data analysis study, using the California Cancer Registry linked to state discharge abstracts of patients treated for colon cancer (2001 to 2006), compared the rates of National Comprehensive Cancer Network (NCCN) guideline-based care, the hazard of mortality, and racial/ethnic disparities in an IHS versus other settings. RESULTS More than 30,000 patient records were evaluated. The IHS had overall higher rates of adherence to NCCN guidelines. Propensity score-matched Cox models showed an independent and protective association between care in the IHS and survival (hazard ratio [HR], 0.87; 95% CI, 0.85 to 0.90). This advantage persisted across stage groups. Black race was associated with increased hazard of mortality in all other settings (HR, 1.15; 95% CI, 1.04 to 1.27); however, there was no disparity within the IHS for any minority group (P > .11 for all groups) when compared with white race. CONCLUSION The IHS delivered higher rates of evidence-based care and was associated with lower 5-year mortality. Racial/ethnic disparities in survival were absent in the IHS. Integrated systems may serve as the cornerstone for developing accountable care organizations poised to improve cancer outcomes and eliminate disparities under health care reform.


Cancer | 2014

What factors influence minority use of National Cancer Institute-designated cancer centers?

Lyen C. Huang; Yifei Ma; Justine V. Ngo; Kim F. Rhoads

National Cancer Institute (NCI) cancer centers provide high‐quality care and are associated with better outcomes. However, racial and ethnic minority populations tend not to use these settings. The current study sought to understand what factors influence minority use of NCI cancer centers.


American Journal of Clinical Oncology | 2015

Age and genetics: how do prognostic factors at diagnosis explain disparities in acute myeloid leukemia?

Manali I. Patel; Yifei Ma; Beverly S. Mitchell; Kim F. Rhoads

Objectives:Survival disparities in acute myeloid leukemia (AML) among blacks and Hispanics have been described but not studied extensively in adults. Although younger age and cytogenetic profiles of t(8;21) and acute promyelocytic leukemia (APL) subtypes of AML are associated with improved survival, these factors have not been investigated by race. The purpose is to evaluate whether the observed survival differences for blacks and Hispanics with AML are attributable to older age at diagnosis or lower rates of favorable cytogenetic profiles at diagnosis. The hypothesis is that survival disparities for blacks and Hispanics with AML will be explained by older age at diagnosis and lower rates of favorable cytogenetics. Methods:Patients with AML were identified in the Surveillance Epidemiology and End Results database (1999 to 2008). Kaplan-Meier (KM) survival curves predicted survival by race/ethnicity, stratified by age. Cox proportional hazard models estimated mortality by race with adjustment for age, sex, year of diagnosis, t(8;21), and APL subtypes. Results:A total of 25,692 patients were included. Blacks and Hispanics were diagnosed at younger ages (younger than 61 y), and had higher rates of t(8;21) and APL compared with non-Hispanic whites (NHWs). The overall KM curve shows that NHWs had a worse survival compared with other races/ethnicities. However, when KM curves were stratified by age, blacks and Hispanics had worse survival in younger age categories (younger than 61 y). In multivariable models, black race was associated with an increased risk of death compared with NHWs (HR, 1.10; 95% CI, 1.04-1.16). Adjustment for t(8;21) and APL subtypes did not attenuate the disparity. Conclusions:Despite younger age and higher prevalence of favorable cytogenetics at diagnosis, blacks and Hispanics have an increased mortality from AML compared with other racial/ethnic groups. Future studies should investigate other factors that may influence outcomes among minority populations.


Cancer Epidemiology, Biomarkers & Prevention | 2015

How Do Differences in Treatment Impact Racial and Ethnic Disparities in Acute Myeloid Leukemia

Manali I. Patel; Yifei Ma; Beverly S. Mitchell; Kim F. Rhoads

Background: We previously demonstrated disparate acute myelogenous leukemia (AML) survival for black and Hispanic patients; these differences persisted despite younger ages and higher prevalence of favorable cytogenetics in these groups. This study determined: (i) whether there are differences in treatment delivered to minorities, and (ii) how these differences affect outcomes in AML. We hypothesize that differences in treatment explain some proportion of survival disparities. Methods: We used California Cancer Registry data linked to hospital discharge abstracts for patients with AML (1998–2008). Logistic regression models estimated odds of treatment (chemotherapy and/or hematopoietic stem cell transplant) by race/ethnicity. Cox proportional hazard models estimated mortality by race after adjustment for treatment. Results: We analyzed 11,084 records. Black race was associated with lower odds of chemotherapy [OR, 0.74; 95% confidence interval (CI), 0.61–0.91]. Black and Hispanic patients had decreased odds of transplant [(OR, 0.64; 95% CI, 0.46–0.87); (OR, 0.74; 95% CI, 0.62–0.89), respectively]. Black patients had increased hazard of mortality (HR, 1.14; 95% CI, 1.04–1.25) compared with whites. Adjustment for receipt of any treatment resulted in decreased mortality (HR, 1.09; 95% CI, 1.00–1.20) for black patients. Conclusions: AML treatment differences for black patients explain some proportion of the disparity. Future AML disparities studies should investigate socioeconomic and other characteristics. Impact: Study findings may better elucidate drivers of disparities in AML. Cancer Epidemiol Biomarkers Prev; 24(2); 344–9. ©2015 AACR.


Diseases of The Colon & Rectum | 2015

Factors that influence minority use of high-volume hospitals for colorectal cancer care.

Lyen C. Huang; Thuy B. Tran; Yifei Ma; Justine V. Ngo; Kim F. Rhoads

BACKGROUND: Previous studies suggest that minorities cluster in low-quality hospitals despite living close to better performing hospitals. This may contribute to persistent disparities in cancer outcomes. OBJECTIVE: The purpose of this work was to examine how travel distance, insurance status, and neighborhood socioeconomic factors influenced minority underuse of high-volume hospitals for colorectal cancer. DESIGN: The study was a retrospective, cross-sectional, population-based study. SETTINGS: All hospitals in California from 1996 to 2006 were included. PATIENTS: Patients with colorectal cancer diagnosed and treated in California between 1996 and 2006 were identified using California Cancer Registry data. MAIN OUTCOME MEASURES: Multivariable logistic regression models predicting high-volume hospital use were adjusted for age, sex, race, stage, comorbidities, insurance status, and neighborhood socioeconomic factors. RESULTS: A total of 79,231 patients treated in 417 hospitals were included in the study. High-volume hospitals were independently associated with an 8% decrease in the hazard of death compared with other settings. A lower proportion of minorities used high-volume hospitals despite a higher proportion living nearby. Although insurance status and socioeconomic factors were independently associated with high-volume hospital use, only socioeconomic factors attenuated differences in high-volume hospital use of black and Hispanic patients compared with white patients. LIMITATIONS: The use of cross-sectional data and racial and ethnic misclassifications were limitations in this study. CONCLUSIONS: Minority patients do not use high-volume hospitals despite improved outcomes and geographic access. Low socioeconomic status predicts low use of high-volume settings in select minority groups. Our results provide a roadmap for developing interventions to increase the use of and access to higher quality care and outcomes. Increasing minority use of high-volume hospitals may require community outreach programs and changes in physician referral practices.


Journal of The American College of Surgeons | 2014

Reassessment of the Current American Joint Committee on Cancer Staging System for Pancreatic Neuroendocrine Tumors

Motaz Qadan; Yifei Ma; Brendan C. Visser; Pamela L. Kunz; George A. Fisher; Jeffrey A. Norton; George A. Poultsides

BACKGROUND Adopting a unified staging system for pancreatic neuroendocrine tumors (PNETs) has been challenging. Currently, the American Joint Committee on Cancer (AJCC) recommends use of the pancreatic adenocarcinoma staging system for PNETs. We sought to explore the prognostic usefulness of the pancreatic adenocarcinoma staging system for PNETs. STUDY DESIGN The Surveillance, Epidemiology, and End Results program data were used to identify patients with PNETs who underwent curative-intent surgical resection from 1983 to 2008. The discriminatory ability of the AJCC system was examined and a new TNM system was devised using extent of disease variables. RESULTS In 1,202 patients identified, lymph node metastasis was associated with worse 10-year overall survival after resection (51% vs 63%; p < 0.0001), as was the presence of distant metastatic disease (35% vs 62%; p < 0.0001). The current AJCC system (recorded by the Surveillance, Epidemiology, and End Results program in 412 patients since 2004) distinguished 5-year overall survival only between stages I and II (p = 0.01), but not between stages II and III (p = 0.97), or stages III and IV (p = 0.36). By modifying the T stage to be based on size alone (0.1 to 1.0 cm, 1.1 to 2.0 cm, 2.1 to 4.0 cm, and >4.0 cm) and revising the TNM subgroups, we propose a novel TNM system with improved discriminatory ability between disease stages (stages I vs II; p = 0.16; II vs III; p < 0.0001; and III vs IV; p = 0.008). CONCLUSIONS In this study evaluating the current AJCC staging system for PNETs, there were no significant differences detected between stages II and III or stages III and IV. We propose a novel TNM system that might better discriminate between outcomes after surgical resection of PNETs.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2016

Regional variation in head and neck cancer mortality: Role of patient and hospital characteristics

Vasu Divi; Yifei Ma; Kim F. Rhoads

The purpose of this study was to determine whether outcomes in head and neck cancer would vary based on geographic location of patients.


JAMA Surgery | 2015

Association Between Weekend Discharge and Hospital Readmission Rates Following Major Surgery

Jordan M. Cloyd; Joy Chen; Yifei Ma; Kim F. Rhoads

IMPORTANCE Although evidence suggests worse outcomes for patients admitted to the hospital on a weekend, to our knowledge, no previous studies have investigated the effects of weekend discharge. OBJECTIVE To determine whether weekend discharge would be associated with an increased rate of 30- and 90-day hospital readmission. DESIGN, SETTING, AND PARTICIPANTS Retrospective review of discharge abstracts from the California Office of State Health Planning and Development from 2012 identifying all patients who underwent abdominal aortic aneurysm (AAA) repair, colectomy, total hip arthroplasty, and pancreatectomy. This study was conducted from January to December 2012. MAIN OUTCOMES AND MEASURES Thirty- and 90-day readmission rates were compared between patients discharged on a weekend vs weekday. RESULTS Of 128 057 patients, 5225 patients (4.1%) underwent AAA repair; 29 388 (22.9%), colectomy; 91 168 (71.2%), hip replacement; and 2276 (1.8%), pancreatectomy. Overall, 29 883 (23.3%) were discharged on a weekend. Although there were no significant differences with respect to sex, age, race/ethnicity, insurance status, or type of admission, patients discharged on a weekend had shorter length of stays and were less often discharged to a skilled nursing facility. Overall, the 30-day readmission rate was 9.4% after AAA repair, 13.6% after colectomy, 7.5% after hip replacement, and 16.3% after pancreatectomy. Hospital readmission rates were similar for those discharged on a weekend vs weekday after AAA repair (8.8% vs 9.3%; P = .55) and pancreatectomy (17.5% vs 15.9%; P = .40). However, weekend discharge was associated with a lower 30-day readmission rate for patients undergoing colectomy (12.1% vs 14.1%; P < .001) and hip replacement (6.9% vs 7.7%; P < .001). On multivariable analysis, weekend discharge was inversely associated with readmission after colectomy (odds ratio [OR], 0.86; 95% CI, 0.79-0.93) but not AAA repair (OR, 0.93; 95% CI, 0.73-1.19), hip replacement (OR, 0.97; 95% CI, 0.91-1.03), or pancreatectomy (OR, 1.02; 95% CI, 0.76-1.36). Finally, a substantial percentage of 30-day readmissions occurred at a different hospital (AAA repair: 40.5%; colectomy: 25.8%; hip replacement: 32.5%; and pancreatectomy: 19.7%) compared with the index hospitalization. Similar results were seen for 90-day readmissions. CONCLUSIONS AND RELEVANCE Weekend discharge after major surgery is not associated with higher 30- or 90-day readmission rates.


Oral Oncology | 2017

Racial disparities in oropharyngeal cancer survival

Uchechukwu C. Megwalu; Yifei Ma

BACKGROUND Oropharyngeal cancer is an important cause of mortality and morbidity. Several studies have revealed racial disparities in head and neck cancer outcomes. The goal of our study was to evaluate the impact of race on survival in patients with oropharyngeal cancer, using a large population-based cancer database. MATERIALS AND METHODS This was a retrospective cohort study. Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) 18 Database of the National Cancer Institute. The study cohort included patients diagnosed with oropharyngeal squamous cell carcinoma between 2004 and 2012. The outcomes of interest were overall survival (OS) and disease-specific survival (DSS). RESULTS After adjusting for age, sex, marital status, tumor site, and year of diagnosis, black race was associated with worse OS (HR 1.67, p<0.0001) and DSS (HR 1.67, p<0.0001). CONCLUSION Black race is associated with worse survival in patients with oropharyngeal cancer. Further research is needed to elucidate the mechanism by which race impacts survival in oropharyngeal cancer. This may reveal potential areas of opportunity for public health interventions aimed at addressing disparities in cancer outcomes.

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