Major Metropolitan Areas Research Articles

Changes in the economic value of ecosystem services in rapidly growing urban areas: the case of Dhaka, Bangladesh.

Assessing the effects of land use patterns on ecosystem services can provide a conceptual foundation and point of reference for spatial planning strategies. The benefits ecosystems bring to individuals' lives and general well-being are referred to as ecosystem services. Land use/land cover (LULC) could influence various ecosystems and have implications for natural habitats and the quality of life. LULC has changed dramatically in Bangladesh during the past few decades, notably in the Dhaka Metropolitan Area. However, no attempt has been made to examine the co-evolution of LULC variations and values of ecosystem services (ESV) in the Dhaka Metropolitan Area. The study's objective is to evaluate the impact of LULC changes and different socio-demographic factors on ESV. LULC data sets were extracted from Landsat OLI and TIRS images using maximum likelihood classification. Analyses were conducted on both ESV estimations and driving forces, and the influence of LULC dynamics on the ESV was assessed. Data from 1991, 2001, 2011, and 2021 were used to estimate ESVs. LULC in the major metropolitan area of Dhaka has seen considerable changes between 1991 and 2021, with the most important change being the declination of water bodies, vegetation, and agricultural land. Vegetation and agricultural land proportions dropped from 22.50% and 19.29%, respectively, to 6.45% and 10.60%. Overall, there was a US$25.11M drop in ESV during 1991-2021. The study emphasizes the value of integrated land use planning for tightly regulating and controlling the growth of built-up regions. This will be essential for maintaining ecological sustainability and contributing to ecosystem resilience.

Racial, Ethnic, and Socioeconomic Inequities in Access to Left Atrial Appendage Occlusion.

Background Inequitable access to high-technology therapeutics may perpetuate inequities in care. We examined the characteristics of US hospitals that did and did not establish left atrial appendage occlusion (LAAO) programs, the patient populations those hospitals served, and the associations between zip code-level racial, ethnic, and socioeconomic composition and rates of LAAO among Medicare beneficiaries living within large metropolitan areas with LAAO programs. Methods and Results We conducted cross-sectional analyses of Medicare fee-for-service claims for beneficiaries aged 66 years or older between 2016 and 2019. We identified hospitals establishing LAAO programs during the study period. We used generalized linear mixed models to measure the association between zip code-level racial, ethnic, and socioeconomic composition and age-adjusted rates of LAAO in the most populous 25 metropolitan areas with LAAO sites. During the study period, 507 candidate hospitals started LAAO programs, and 745 candidate hospitals did not. Most new LAAO programs opened in metropolitan areas (97.4%). Compared with non-LAAO centers, LAAO centers treated patients with higher median household incomes (difference of $913 [95% CI, $197-$1629], P=0.01). Zip code-level rates of LAAO procedures per 100 000 Medicare beneficiaries in large metropolitan areas were 0.34% (95% CI, 0.33%-0.35%) lower for each $1000 zip code-level decrease in median household income. After adjustment for socioeconomic markers, age, and clinical comorbidities, LAAO rates were lower in zip codes with higher proportions of Black or Hispanic patients. Conclusions Growth in LAAO programs in the United States had been concentrated in metropolitan areas. LAAO centers treated wealthier patient populations in hospitals without LAAO programs. Within major metropolitan areas with LAAO programs, zip codes with higher proportions of Black and Hispanic patients and more patients experiencing socioeconomic disadvantage had lower age-adjusted rates of LAAO. Thus, geographic proximity alone may not ensure equitable access to LAAO. Unequal access to LAAO may reflect disparities in referral patterns, rates of diagnosis, and preferences for using novel therapies experienced by racial and ethnic minority groups and patients experiencing socioeconomic disadvantage.

Does Deep Learning Enhance the Estimation for Spatially Explicit Built Environment Stocks through Nighttime Light Data Set? Evidence from Japanese Metropolitans.

Built environment stocks have attracted much attention in recent decades because of their role in material and energy flows and environmental impacts. Spatially refined estimation of built environment stocks benefits city management, for example, in urban mining and resource circularity strategy making. Nighttime light (NTL) data sets are widely used and are regarded as high-resolution products in large-scale building stock research. However, some of their limitations, especially blooming/saturation effects, have hampered performance in estimating building stocks. In this study, we experimentally proposed and trained a convolution neural network (CNN)-based building stock estimation (CBuiSE) model and applied it to major Japanese metropolitan areas to estimate building stocks using NTL data. The results show that the CBuiSE model is capable of estimating building stocks at a relatively high resolution (approximately 830 m) and reflecting spatial distribution patterns, although the accuracy needs to be further improved to enhance the model performance. In addition, the CBuiSE model can effectively mitigate the overestimation of building stocks arising from the blooming effect of NTL. This study highlights the potential of NTL to provide a new research direction and serve as a cornerstone for future anthropogenic stock studies in the fields of sustainability and industrial ecology.

Uprooting urban garden contamination

Contamination in urban community gardens is widespread. Yet few studies have used transdisciplinary methods to investigate the physical sources of contamination in gardens as well as the sociopolitical factors that result in persistent contamination. Furthermore, contaminant concentrations in community gardens are not regulated, and gardeners are often unaware of the harms that soils and vegetables in their gardens might pose to human health and the broader ecosystem. In this study we aimed to document widespread contamination issues in soil, compost mixtures, and vegetables in a major metropolitan area, and situate the issue of contamination in the broader context of the lack of testing and regulation within community gardens in the U.S. We used a mixed methods approach (e.g., soil and vegetable sampling, interviews and surveys, laboratory analysis, and community science) to determine the extent of, and sociopolitical causes of, contamination in urban community gardens in the Seattle metropolitan region, but also in the U.S. We found that soils and vegetables in all of the community gardens of this study exceeded health standards for a variety of contaminants. We also documented how physical practices and perceptions influenced contaminant concentrations in community gardens. The analysis pointed to larger systemic issues related to environmental injustices, and a need for intervention on local and regulatory levels that centers community feedback. Finally, legacies of environmental racism have resulted in limited choices for underserved gardeners who seek access to healthy food, and better strategies for mitigating contamination that empower communities is needed.

Automated Street Light Adjustment System on Campus with AI-Assisted Data Analytics.

The smart city concept has been popularized in the urbanization of major metropolitan areas through the implementation of intelligent systems and technology to serve the increasing human population. This work developed an automatic light adjustment system at Thammasat University, Rangsit Campus, Thailand, with a primary objective of optimizing energy efficiency, while providing sufficient illumination for the campus. The development consists of two sections: the device control and the prediction model. The device control functionalities were developed with the user interface to enable control of the smart street light devices and the application programming interface (API) to send the light-adjusting command. The prediction model was created using an AI-assisted data analytic platform to obtain the predicted illuminance values so as to, subsequently, suggest light-dimming values according to the current environment. Four machine-learning models were performed on a nine-month environmental dataset to acquire predictions. The result demonstrated that the three-day window size setting with the XGBoost model yielded the best performance, attaining the correlation coefficient value of 0.922, showing a linear relationship between actual and predicted illuminance values using the test dataset. The prediction retrieval API was established and connected to the device control API, which later created an automated system that operated at a 20-min interval. This allowed real-time feedback to automatically adjust the smart street lighting devices through the purpose-designed data analytics features.

Exploring the rationalization, functional integration and socio-spatial implications of Zimbabwe’s New Capital City (NCC)

ABSTRACT The development of new master-planned cities is a popular approach to decongest major metropolitan areas in different African countries, including Zimbabwe. This paper is an exploratory analysis of Zimbabwe’s New Capital City (NCC), being created roughly 20 kilometers outside Harare. Specifically, the paper analyzes the design of the NCC, the principles underpinning its production, the different rationalities used by policymakers for its legitimation, as well as the socioeconomic and spatial implications. Based on review of secondary literature, plans, and interviews with city planners and other professionals, the paper finds that the creation of Zimbabwe’s NCC represents urban boosterism, an active promotion of a city through development of large-scale urban development schemes and creating a new image for the city. The production of the new city is also underpinned by neoliberal motivations and imported ideas of urban planning which disregard the local planning urban context, where poverty and informality are prevalent. The creation of new master-planned cities must therefore strive to address these contemporary urban challenges rather than exacerbating them. The paper contributes to scholarly debate on the production of new master-planned cities in Africa and the Global South more broadly.

‘A foreigner is not a person in this country’: xenophobia and the informal sector in South Africa’s secondary cities

South Africa’s major cities are periodically wracked by large-scale xenophobic violence directed at migrants and refugees from other countries. Informal sector businesses and their migrant owners and employees are particularly vulnerable targets during these attacks. Migrant-owned businesses are also targeted on a regular basis in smaller-scale looting and destruction of property. There is now a large literature on the characteristics and causes of xenophobic violence and attitudes in South Africa, most of it based on quantitative and qualitative research in the country’s major metropolitan areas. One of the consequences of big-city xenophobia has been a search for alternative markets and safer spaces by migrants, including relocating to the country’s many smaller urban centres. The question addressed in this paper is whether they are welcomed in these cities and towns or subject to the same kinds of victimization as in large cities. This paper is the first to systematically examine this question by focusing on a group of towns in Limpopo Province and the experiences of migrants in the informal sector there. Through survey evidence and in-depth interviews and focus groups with migrant and South African vendors, the paper demonstrates that xenophobia is also pervasive in these smaller centres, in ways that both echo and differ from that in the large cities. The findings in this paper have broader significance for other countries attempting to deal with the rise of xenophobia.

THE ALEXANDRA TOWNSHIP DE DENSIFICATION PROJECT DURING THE COVID 19 CRISIS: CHALLENGES AND POTENTIAL LESSONS

In response to the Covid-19 (hereafter referred to as ‘virus’) pandemic, the South Africa government established different measures to try to slow down the spread of the virus. One of the strategies was to focus on population density, specifically in informal settlements. The argument was that high population density in informal settlements could increase the risk of transmission of the virus. The Bloomberg CityLab reported in 2020 that urban density does play a role in the transmission of the virus.1 South Africa is no exception, as its major metropolitan areas have borne the brunt of Covid-19 infections, with Cape Town and Johannesburg classified as epicentres. However, there is debate amongst scholars and policy-makers as to whether de-densification is a good strategy, given the various ways in which urban life benefits from higher population densities, and whether density does or does not increase the spread of the virus.

Heterogenous Canopy in a Lagrangian-Stochastic Dispersion Model for Particulate Matter from Multiple Sources over the Haifa Bay Area

The Haifa Bay area (HBA) is a major metropolitan area in Israel, which consists of high volume transportation routes, major industrial complexes, and the largest international seaport in Israel. These, which lie relatively near densely populated residential areas, result in a multitude of air pollution sources, many of whose emissions are in the form of particulate matter (PM). Previous studies have associated exposure to such PM with adverse health effects. This potential consequence serves as the motivation for this study whose aim is to provide a realistic and detailed three-dimensional concentration field of PM, originating simultaneously from multiple sources. The IIBR in-house Lagrangian stochastic pollutant dispersion model (LSM) is suitable for this endeavor, as it describes the dispersion of a scalar by solving the velocity fluctuations in high Reynolds number flows. Moreover, the LSM was validated in urban field experiments, including in the HBA. However, due to the fact that the multiple urban sources reside within the canopy layer, it was necessary to integrate into the LSM a realistic canopy layer model that depicts the actual effect of the roughness elements’ drag on the flow and turbulent exchange of the urban morphology. This was achieved by an approach which treats the canopy as patches of porous media. The LSM was used to calculate the three-dimensional fields of PM10 and PM2.5 concentrations during the typical conditions of the two workday rush-hour periods. These were compared to three air quality monitoring stations located downstream of the PM sources in the HBA. The LSM predictions for PM2.5 satisfy all acceptance criteria. Regarding the PM10 predictions, the LSM results comply with three out of four acceptance criteria. The analysis of the calculated concentration fields has shown that the PM concentrations up to 105 m AGL exhibit a spatial pattern similar to the ground level. However, it decreases by a factor of two at 45 m AGL, while, at 105 m, the concentration values are close to the background concentrations.

Spatial Analysis of Local Competitiveness: Relationship of Economic Dynamism of Cities and Municipalities in Major Regional Metropolitan Areas in the Philippines

The measurement of cities and municipalities competitiveness in the Philippines has been put in place by the Department of Trade and Industry since 2013. However, its use as a spatial planning parameter is lacking in the literature. This paper reviewed the factors that drive competitiveness. The research revealed that “economic dynamism” appeared at the top of the factors that contribute to competitiveness and influence regional development. Given urban and regional planning theories, metropolitan areas were chosen as the most appropriate case study sites that exhibit economic dynamism. The study revealed that the “Economic Dynamism Index”, or EDi, of cities and municipalities are spatially correlated, indicative of their clustering pattern in the economic space. The clustering pattern was determined by treating the EDi as a spatial attribute in the major metropolitan case study areas. Using Moran’s I global spatial autocorrelation analysis, the clustering pattern of cities and municipalities observed through the GIS map was validated by the 99% significance in the spatial statistics of the EDi dataset. This suggests that “complementation” among cities and municipalities exists rather than competition. Thus, sustainable regional spatial/economic development strategies can be reformulated, given the spatial interactions of areas with higher EDi with the less endowed cities/municipalities at the periphery.

Navigating the Urban-Rural Divide: A Case Study of a Small-City Newspaper in the United States, 1920 - 1929

ABSTRACT Through a case study and historical textual analysis, this article explores how small-city newspapers offer a window into urbanism and identity formation in the early twentieth century. These newspapers pursued a content and circulation strategy that combined publishing characteristics associated with the mass circulation dailies and industrial journalism of major metropolitan areas with more community-oriented elements, such as booster content and hyperlocal news items. These newspapers operated as an important part of the early twentieth century American media system and represented a distinct type of publication that embraced the aspirational urbanism of local business interests and civic boosters. Despite flourishing literature on newspapers in twentieth century American society, large, urban areas tend to dominate scholarly analysis, while leaving out the sorts of communities that had a self-conscious experience of industrial modernity. By focusing analysis on the 1920s, this article explores how the Superior (Wisconsin) Telegram embraced this aspirational urbanism. It shows how the Telegram operated as a platform for its readers to navigate the tensions of the decade, articulate the city’s urban ambitions, and serve as a symbol of the city’s modern and progressive ideals.

A case study on the impacts of COVID-19 on bus ridership, bikesharing, and equity in a small U.S. county

Several studies highlight how the coronavirus (COVID-19) lockdowns have permanently changed the way people travel, but there has been less focus on impacts outside major metropolitan areas, where alternative transportation modes are more limited or scarce. This case study focuses on the long-term effects of the COVID-19 lockdowns on public transit and bikesharing using micro-level data in Lane County, Oregon. Lane County reflects the nearly 3,000 small U.S. counties that are a mixture of rural and urban landscape. Findings show that both transportation modes have begun to recover after large reductions in usage, though bikesharing seems to be less resilient relative to public transit 18-months post-lockdown. Additionally, findings show changes in bus ridership and bikeshare trips differed based on sociodemographic characteristics, though bikeshare trips were more sensitive to change. For example, there were statistically significant differences in bikeshare trips among tracts with a higher proportion of Black, Hispanic, or low-income residents, but no such differences for bus ridership. Given that small U.S. counties are typically less diverse, if not addressed, inequitable access could worsen in the long-run. Results from this case study could help inform other small U.S. counties, especially those that do not have the resources to collect micro-level data and are based around a university or where public transit is free for a large portion of the population, on future local policies regarding urban mobility and equity.

Impact of telecommuting on Japanese Citizen's travel, activities, and residential locations: Experiences and future expectations under COVID-19 pandemic

In the past few years, telecommuting has diffused on a large scale across many developed countries; however, its popularity in Japan is low due to various factors and cultural differences. The outbreak of COVID-19 has made the adoption of telecommuting indispensable, reaching an unprecedented level in Japan, bringing dramatic changes in the lifestyles and behaviors of citizens. This study investigates how and to what extent this pandemic-induced telecommuting affected employees’ travel, activities, and residence locations and explores their expectations of post-pandemic life. The data were collected through the online questionnaire survey across three major metropolitan areas in Japan that incorporates a comprehensive set of questions regarding telecommuting implementation and feasibility, lifestyles before and during the pandemic, and expected way of life after the pandemic, and the total of 2045 respondents were collected. The analysis has been done based on revealed preference data considering two time periods i.e., before COVID-19, during COVID-19, and for the post-COVID 19 scenario where stated preferences are considered. In the first step, telecommuting behavior, telecommuting preferences and plans, and activity patterns are estimated based on aggregate sample data. Next, by using the stated preference survey conducted, ordered probit model and mixed logit model are applied to identify factors influencing post-pandemic telecommuting frequency and residential location preference, respectively. The analysis revealed two major findings: telecommuting brought significant changes in multiple aspects of people’s lifestyles and activities that might persist after the pandemic; although determinants that govern telecommuting frequency and residential location choice after COVID-19 may differ across metropolitan areas, commuting/telecommuting frequency is the prime factor influencing residential location decisions. The findings of this research can guide transportation and urban planners in establishing effective travel demand management tools and sustainable urban networks for the new-normal era.

Rapid response EEG with needle electrodes in an intensive care unit with limited resources

ObjectiveContinuous EEG (cEEG) is the gold standard for detecting seizures and rhythmic and periodic patterns (RPPs) in critically ill patients but is often not available in health systems with limited resources. The current study aims to determine the feasibility and utility of low-cost, practical, limited montage, sub-dermal needle electrode EEG in a setting where otherwise no EEG would be available. MethodsThe study included all adult patients admitted to the intensive care unit of a single center over a 24-month period. Members of the existing ICU care team, mostly nurses, were trained to place 8 sub-dermal needle EEG electrodes to achieve rapid, limited montage-EEG recording. Clinical outcomes were recorded, including any reported major complications; and the EEG findings documented, including background characterization, RPPs, and seizures. ResultsOne hundred twenty-three patients, mean age 68 years, underwent an average of 15.6 min of EEG recording. There were no complications of electrode placement. Overall, 13.0% had seizures (8.1% qualifying as status epilepticus [SE]), 18.7 % had generalized periodic discharges (GPDs), 4.9% had lateralized periodic discharges (LPDs), and 11.4 % sporadic epileptiform discharges (sEDs). Greater mortality was observed in patients with worse background EEGs, seizures, LPDs, or sEDs. ConclusionsRapid, limited montage EEG could be achieved safely and inexpensively in a broad population of critically ill patients following minimal training of existing care teams. SignificanceFor resource poor centers or centers outside of major metropolitan areas who otherwise have no access to EEG, this may prove a useful method for screening for non-convulsive seizures and status epilepticus.

Biofilters and bioretention systems: the role of biochar in the blue-green city concept for stormwater management

The main aim of the blue-green city concept is the reduction of the adverse impacts of stormwater by recreating the natural water cycle with the aid of green infrastructure in major metropolitan areas worldwide.

Research on the impact of financial agglomeration on the coordinated development of urban ecological green: based on the empirical comparison of four metropolitan areas in the Yangtze River Delta of China.

As key carriers of new urbanization, metropolitan areas should pay more attention to the green and coordinated development of economy, society, and environment. Finance is an important tool to support China's high-quality development. Exploring the key dynamics and mechanisms of financial agglomeration for a green and coordinated development is important to obtain strategic support for the green development of the Yangtze River Delta metropolitan area. Using panel data of 25 prefecture-level cities in the four major metropolitan areas of the Yangtze River Delta region from 2003 to 2019, a Dubin model of three types of spatial weight matrices is constructed to explore the impact of financial agglomeration on coordinated ecological green development. Results show that, first, the positive local and neighborhood effects of financial agglomeration on the coordinated ecological green development are mainly reflected in the Hefei, Hangzhou, and Shanghai metropolitan areas and that the intensity of such effect decreases sequentially. Information transfer and technology correlation are important mechanisms to improve the local effect of financial agglomeration, and the neighborhood effect varies from one metropolitan area to another. Second, in addition to the adverse impact of the concentration of financial personnel on the ecological green integration, the agglomeration of securities, banking, and insurance industries can release "green driving potential energy," and the intensity of contribution gradually weakens. Third, the financial agglomeration of Shanghai exerts the strongest radiation effect, those of Nanjing and Hangzhourespectively demonstrate a "U"-shaped and inverted "U"-shapedimpact, and that of Hefei does not play a role.

Effect of Oral β-Glucan on Antibody Response to Ganglioside Vaccine in Patients With High-Risk Neuroblastoma

Among patients with high-risk relapsed metastatic neuroblastoma, oral β-glucan adjuvant during GD2/GD3 ganglioside vaccine boost has stimulated IgG antibody response, which was associated with improved survival; however, the effectiveness of oral β-glucan during the vaccine priming phase remains unproven. To isolate the adjuvant effect of oral β-glucan on antibody response to GD2/GD3 ganglioside vaccine in patients with high-risk neuroblastoma. In this phase 2 randomized clinical trial, enrolled patients with high-risk neuroblastoma were randomized to 2 groups to receive the GD2/GD3 vaccine at a large cancer center in a major metropolitan area from October 2018 to September 2020. Data were analyzed from October 7, 2021, to February 28, 2022. Eligible patients receiving GD2/GD3 vaccine were randomly assigned to group 1 (n = 54) to receive no β-glucan or group 2 (n = 53) to receive an oral β-glucan regimen during the first 5 weeks of vaccine priming. From week 6 onwards, all 107 patients received oral β-glucan during vaccine boost for 1 year or until disease progression. Primary end point was comparison of anti-GD2 IgG1 response before vaccine injection 6 (week 32) in group 1 vs group 2. Seroconversion rate and the association of antibody titer with β-glucan receptor dectin-1 single nucleotide polymorphism (SNP) rs3901533 were also assessed. In all, 107 patients with high-risk neuroblastoma were randomized to the 2 groups: 54 patients (median [range] age, 5.2 [1.0-17.3] years; 28 [52%] male and 26 [48%] female) in group 1; and 53 patients (median [range] age, 6.2 [1.9-18.4] years; 25 [47%] male and 28 [53%] female) in group 2; both groups were also comparable in their first remission status at study entry (70% vs 70%). Adding oral β-glucan during the first 5 weeks of vaccine priming elicited a higher anti-GD2 IgG1 antibody response in group 2 (1.80; 90% CI, 0.12-3.39; P = .08; planned type I error, 0.10). Anti-GD2 IgG1 titer of 230 ng/mL or greater by week 8 was associated with statistically favorable PFS. Antibody titer correlated significantly with dectin-1 SNP. The genotype frequency, seroconversion rates, and vaccine-related toxic effects were similar in the 2 groups. This phase 2 randomized clinical trial found that adding oral β-glucan during vaccine priming increased anti-GD2 IgG1 titer among genetic responders without added toxic effects. Because responder dectin-1 SNP was identical in the 2 randomized groups, no difference was detected in seroconversion rates. Alternative or additional adjuvants may be needed to enhance seroconversion. ClinicalTrials.gov Identifier: NCT00911560.

Association of Caregiver Availability and Training With Patient Community Discharge After Stroke

To examine the association between committed caregivers and caregiver training with community discharge from inpatient rehabilitation after a stroke. Secondary analysis of data extracted from electronic health records linked with the Uniform Data System for Medical Rehabilitation. Three hospital-based inpatient rehabilitation facilities (IRF) in a major metropolitan area. 1397 adult patients (mean ± SD age: 69.4 [13.5]; 724 men) transferred from an acute care setting to inpatient rehabilitation after an ischemic or hemorrhagic stroke (N=1397). None. Community discharge from IRF. 82.4% of patients had caregivers, 63.4% of patient caregivers received training at the IRF, and 79.5% had community discharge. After adjusting for age, stroke severity, functional status, and other social risk factors, having a committed caregiver and caregiver training were significantly associated with community discharge (odds ratio [OR]=7.80, 95% confidence interval [CI]: 5.03-12.10 and OR=4.89, 95% CI: 3.16-7.57, respectively). Caregivers increase a patient's likelihood of discharge from IRF; the added benefit of caregiver training needs to be further assessed, with essential elements prioritized prior to patients' IRF discharge.

Contested Infrastructures: Water, Privatization, and Place-Based Protest in Greater Buenos Aires

Activists opposing urban water privatization often continue organizing even after water infrastructure returns to the public sector. Why? Analyzing water privatization and renationalization in Greater Buenos Aires, Argentina, I argue that as these policy changes unfolded, activists from neighborhoods lacking necessary infrastructure organized not only about privatization but also around place. Place-based mobilization emerged from a longstanding lack of services as well as environmental threats like flooding and pollution affecting residents’ daily lives. While privatization activated collective action, amplified by a broader economic crisis and protest cycle, it was organizing grounded in local environmental conditions and associational spaces that sustained it. The analysis, based on historical and interview data, reveals continuities and disjunctures between neoliberal and state-led modes of social provision, showing how place makes large-scale policy changes tangible and shapes patterns of collective action in a major South American metropolitan area.

2060. Evaluation of the real world incidence of integrase inhibitor resistance since adoption as guideline preferred therapy

Abstract Background There are limited data reporting real-world incidence of integrase inhibitor resistance (INSTI-R) since the approval and first-line treatment recommendation of INSTIs in the US. A recent analysis of the national surveillance data estimated INSTI-R to be 6.3%. The purpose of this study was to describe real-world incidence of INSTI-R in patients who used an INSTI-based single tablet regimen (STR) in a major metropolitan area and identify risk factors for resistance. Methods This was a retrospective study of adult patients living with human immunodeficiency virus (HIV) who were prescribed an INSTI-STR between September 2017 and September 2020 and followed for > 12 months at the University of Illinois Chicago Community Clinic Network (UCCN). The primary endpoint was the difference in INSTI-R in UCCN patients compared to the national prevalence of 6.3%. Other outcomes included development of virologic failure (VF), defined as 2 consecutive HIV-1 viral loads (VL) > 200 copies/mL after week 24, and documented INSTI-R mutations. Patient specific factors associated with medication nonadherence were also collected. All endpoints were analyzed using chi-square and Fisher’s exact tests. Results Of 948 patients screened, 248 patients were included. Baseline characteristics are summarized in Table 1. VF occurred in 17 subjects (6.8%). Two of the 17 (11.8%) received subsequent INSTI-R testing and nine eventually virally suppressed without regimen changes (52.9%). Patients without VF were assumed to have no INSTI-R. No subjects developed INSTI-R, which was significantly less than the national prevalence of 6.3% (p=0.0029). Patients with a high VL at baseline were more likely to experience VF (p=0.001). The most common factors associated with nonadherence in patients with VF are summarized in Table 2. Conclusion The true rate of INSTI-R in UCCN patients is still unknown and factors associated with developing INSTI-R were unable to be assessed. Among patients at UCCN on INSTI-based STRs, INSTI-R rates were lower than the national average. Future analyses should also include patients on INSTI-based non-STR regimens as increased pill burden is a known risk factor for nonadherence leading to VF and drug resistance. Disclosures All Authors: No reported disclosures.