Changzhen Wang

Dr. Changzhen Wang

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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THTao Hu
Tao Hu
HYHan Yue
Han Yue
CWChangzhen Wang
Changzhen Wang
BSBing She
Bing She
Xinyue YeXinyue Ye
Xinyue Ye
SBShuming Bao
Shuming Bao
The U.S. has merely 4% of the world population, but contains 25% of the world’s COVID-19 cases. Since the COVID-19 outbreak in the U.S., Massachusetts has been leading other states in the total number of COVID-19 cases. Racial residential segregation is a fundamental cause of racial disparities in health. Moreover, disparities of access to health care have a large impact on COVID-19 cases. Thus, this study estimates racial segregation and disparities in testing site access and employs economic, demographic, and transportation variables at the city/town level in Massachusetts. Spatial regression models are applied to evaluate the relationships between COVID-19 incidence rate and related variables. This is the first study to apply spatial analysis methods across neighborhoods in the U.S. to examine the COVID-19 incidence rate. The findings are: (1) Residential segregations of Hispanic and Non-Hispanic Black/African Americans have a significantly positive association with COVID-19 incidence rate, indicating the higher susceptibility of COVID-19 infections among minority groups. (2) Non-Hispanic Black/African Americans have the shortest drive time to testing sites, followed by Hispanic, Non-Hispanic Asians, and Non-Hispanic Whites. The drive time to testing sites is significantly negatively associated with the COVID-19 incidence rate, implying the importance of the accessibility of testing sites by all populations. (3) Poverty rate and road density are significant explanatory variables. Importantly, overcrowding represented by more than one person per room is a significant variable found to be positively associated with COVID-19 incidence rate, suggesting the effectiveness of social distancing for reducing infection. (4) Different from the findings of previous studies, the elderly population rate is not statistically significantly correlated with the incidence rate because the elderly population in Massachusetts is less distributed in the hotspot regions of COVID-19 infections. The findings in this study provide useful insights for policymakers to propose new strategies to contain the COVID-19 transmissions in Massachusetts.

1 January 2018 in Brain Research
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Journal Article
Closed access
WZWei-Jia Zhi
Wei-Jia Zhi
RPRuiyun Peng
Ruiyun Peng
HLHaijuan Li
Haijuan Li
YZYong Zou
Yong Zou
BYBin-Wei Yao
Bin-Wei Yao
XHXiang-Jun Hu
Xiang-Jun Hu

1 June 2024 in JCO Oncology Practice
Verified
Journal Article
Closed access
BSBruno T. Scodari
Bruno T. Scodari
ASAndrew P. Schaefer
Andrew P. Schaefer
NKNirav S. Kapadia
Nirav S. Kapadia
AOA. James O'MAlley
A. James O'MAlley
GBGabriel A. Brooks
Gabriel A. Brooks
EMErika L. Moen
Erika L. Moen
PURPOSE: Oncology outreach is a common strategy for extending cancer care to rural patients. However, a nationwide characterization of the traveling workforce that enables this outreach is lacking, and the extent to which outreach reduces travel burden for rural patients is unknown. METHODS: This cross-sectional study analyzed a rural (nonurban) subset of a 100% fee-for-service sample of 355,139 Medicare beneficiaries with incident breast, colorectal, and lung cancers. Surgical, medical, and radiation oncologists were linked to patients using Part B claims, and traveling oncologists were identified by observing hospital service area (HSA) transition patterns. We defined oncology outreach as the provision of cancer care by a traveling oncologist outside of their primary HSA. We used hierarchical gamma regression models to examine the separate associations between patient receipt of oncology outreach and one-way patient travel times to chemotherapy, radiotherapy, and surgery. RESULTS: On average, 9,935 of 39,960 oncologists conducted annual outreach, where 57.8% traveled with low frequency (0-1 outreach visits/mo), 21.1% with medium frequency (1-3 outreach visits/mo), and 21.1% with high frequency (>3 outreach visits/mo). Oncologists provided surgery, radiotherapy, and chemotherapy to 51,715, 27,120, and 5,874 rural beneficiaries, respectively, of whom 2.5%, 6.9%, and 3.6% received oncology outreach. Rural patients who received oncology outreach traveled 16% (95% CI, 11 to 21) and 11% (95% CI, 9 to 13) less minutes to chemotherapy and radiotherapy than those who did not receive oncology outreach, corresponding to expected one-way savings of 15.9 (95% CI, 15.5 to 16.4) and 11.9 (95% CI, 11.7 to 12.2) minutes, respectively. CONCLUSION: Our study introduces a novel claims-based approach for tracking the nationwide traveling oncology workforce and supports oncology outreach as an effective means for improving rural access to cancer care.

Verified
Journal Article
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CWChangzhen Wang
Changzhen Wang
MLMichael Leitner
Michael Leitner
GPGernot Paulus
Gernot Paulus
Health care accessibility studies are well established in the US but lacking in Austria, even though both experience high costs and have hospital care as the largest contributor to health care spending. This study aims to examine multiscale spatial accessibility to acute hospitals in Carinthia, Austria. Using the most recent data at census block and 250 meter grid levels, we refine proximity and generalized two-step floating catchment area (G2SFCA) methods while accounting for the modifiable areal unit problem (MAUP) and edge effects. For census blocks and 250 meter grids, the mean travel times to the nearest acute hospitals are 16 and 21 min, respectively, covering 58.8% and 76.2% of the population, which, however, increases to 25 and 31 min to the three nearest hospitals with similar populations. People bypassing the nearest hospital to seek hospitals at a longer distance, termed “bypass behavior”, is more influential, as 20% more of the population living in mountainous or rural areas need to travel 30 min longer. The G2SFCA method with a more pronounced distance decay results in a more decentralized polycentric structure of accessibility and identifies poorer access areas. While urban advantage is most evident in Klagenfurt and Villach, not all areas near hospitals enjoy the highest accessibility. A combination of the proximity and G2SFCA methods identifies less accessible areas. The MAUP overestimates accessibility at a coarse level and in less populous areas. Edge effects occur at the border when using proximity only, but they are more sensitive when considering bypass behavior or a weak distance decay effect. This study contributes to our understanding of acute hospitals’ accessibility in Carinthia and highlights the need to improve low-accessible areas in addition to universal health coverage. Cautions need to be exercised when using different geographic units or considering edge effects for health care planning and management.

24 May 2022 in Cancer Research Communications
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Journal Article
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CWChangzhen Wang
Changzhen Wang
FWFahui Wang
Fahui Wang
TOTracy Onega
Tracy Onega
Defining a reliable geographic unit pertaining to cancer care is essential in its assessment, planning, and management. This study aims to delineate and characterize the cancer service areas (CSA) accounting for the presence of major cancer centers in the United States. We used the Medicare enrollment and claims from January 1, 2014 to September 30, 2015 to build a spatial network from patients with cancer to cancer care facilities that provided inpatient and outpatient care of cancer-directed surgery, chemotherapy, and radiation. After excluding those without clinical care or outside of the United States, we identified 94 NCI-designated and other academic cancer centers from the members of the Association of American Cancer Institutes. By explicitly incorporating existing specialized cancer referral centers, we refined the spatially constrained Leiden method that accounted for spatial adjacency and other constraints to delineate coherent CSAs within which the service volumes were maximal but minimal between them. The derived 110 CSAs had a high mean localization index (LI; 0.83) with a narrow variability (SD = 0.10). The variation of LI across the CSAs was positively associated with population, median household income, and area size, and negatively with travel time. Averagely, patients traveled less and were more likely to receive cancer care within the CSAs anchored by cancer centers than their counterparts without cancer centers. We concluded that CSAs are effective in capturing the local cancer care markets in the United States. They can be used as reliable units for studying cancer care and informing more evidence-based policy.Significance: Using the most refined network community detection method, we can delineate CSAs in a more robust, systematic, and empirical manner that incorporates existing specialized cancer referral centers. The CSAs can be used as a reliable unit for studying cancer care and informing more evidence-based policy in the United States. The cross-walk tabulation of ZIP code areas, CSAs, and related programs for CSAs delineation are disseminated for public access.

3 September 2025 in Cancer Epidemiology, Biomarkers & Prevention
Verified
Journal Article
Closed access
NDNataki Duncan
Nataki Duncan
CAChimaraije Amu-Nnadi
Chimaraije Amu-Nnadi
KMKelsey B. Montgomery
Kelsey B. Montgomery
NRNicole Rademacher
Nicole Rademacher
CWChangzhen Wang
Changzhen Wang
KBKristy K. Broman
Kristy K. Broman
Background: Treatment at a cancer center improves outcomes for individual patients, but the impact of cancer centers on the regions they serve is unknown. This study examines the association between cancer center presence and cancer mortality within health service areas (HSA), which define US regional care markets. Methods: Cancer centers and cancer mortality were mapped to HSAs using geospatial analysis. The association between cancer center presence and cancer mortality was analyzed using a multivariable spatial lag model, adjusting for the percent of incident cases presenting at late stage, social vulnerability, environmental burden, and rurality. Results are reported as deaths per 100,000 people with 95% confidence interval (CI). Results: Of 940 HSAs, 43% (n = 407) contained at least one cancer center. HSAs with a cancer center had lower cancer mortality than those without a cancer center [158 (95% CI, 155.9–159.5) versus 165 (95% CI, 162.5–166.6) deaths per 100,000 people]. In adjusted analyses, metropolitan HSAs with cancer centers had 4.4 fewer deaths (−8.4 to −0.4) than those without cancer centers whereas there was no observed effect of cancer center presence in nonmetropolitan HSAs (1.4; 95% CI, −1.4 to 4.3). Factors associated with higher cancer mortality were late stage at presentation and greater environmental burden. Conclusions: Cancer center presence within metropolitan healthcare markets was associated with modestly lower cancer mortality. Impact: There is a need to evaluate underlying mechanisms whereby cancer center presence may affect population-level cancer mortality in metropolitan, but not nonmetropolitan HSAs, including direct patient care and indirect effects such as community health promotion.