arXiv subjects

Susana Mondschein

Publications and source records attributed to Susana Mondschein.

4 recordsLinked to original sources

arXiv2022

Inequities in Breast Cancer Outcomes in Chile: An Analysis of Case Fatality and Survival Rates (2007-2018)

Introduction: The goal of this paper is to study inequities in breast cancer (BC) health care outcomes for Chilean women, including case fatality (FR) and survival rates (SR), stratified by type of health care provider and geographical area. A secondary goal is to estimate BC incidence (IR) and mortality (MR) rates by health care providers and region. Methods: We used two public anonymized databases provided by the Ministry of Health: the national death and hospital discharges datasets. For survival analysis, we used the Kaplan Meier product-limit estimator (KM) with a 95% ci and the Cox proportional hazards model (CM) with null-hypothesis significance testing of p>0.001. Results: We considered a cohort of 58,254 and 16,615 BC hospital discharges and deaths for the period 2007-2018. New cases and deaths due to BC increased by 43.6% and 33.6% respectively. Avg age-adjusted IR and MR were 44.0 and 10.5, respectively. Women affiliated to a private provider (ISAPRE) have an avg age adjusted IR of 60.6 compared to 38.8 for women affiliated with the public provider (FONASA). The national FR has remained constant over time, with a mean of 26.8. Women affiliated with ISAPRE had a considerably lower FR during the period under study, with an avg of 15.7 compared to 27.5 for women in FONASA. The avg 5-year SR were 0.81 and 0.90 for FONASA and ISAPRE. Women from the Metropolitan area have higher SRs than women from other regions. SRs obtained using the CM have a similar behavior to those obtained by the KM. Discussion: Despite the inclusion of BC in the GES plan in 2005 to provide greater, there are still significant differences in FR and SR for patients affiliated to ISAPRE compared to those in FONASA, a choice that is directly associated with socioeconomic level, and for patients in the Metropolitan and other regions. Further studies are required to determine the causes of these disparities.

stat.AP↗

arXiv2022

Replacing quarantine of COVID-19 contacts with periodic testing is also effective in mitigating the risk of transmission

The quarantine of identified close contacts has been vital to reducing transmission rates and averting secondary infection risk before symptom onset and by asymptomatic cases. The effectiveness of this contact tracing strategy to mitigate transmission is sensitive to the adherence to quarantines, which may be lower for longer quarantine periods or in vaccinated populations (where perceptions of risk are reduced). This study develops a simulation model to evaluate contact tracing strategies based on the sequential testing of identified contacts after exposure as an alternative to quarantines, in which contacts are isolated only after confirmation by a positive test. The analysis considers different number and types of tests (PCR and lateral flow antigen tests (LFA)) to identify the cost-effective testing policies that minimize the expected infecting days post-exposure considering different levels of testing capacity. This analysis suggests that even a limited number of tests can be effective at reducing secondary infection risk: two LFA tests (with optimal timing) avert infectiousness at a level that is comparable to 14-day quarantine with 80-90% adherence, or equivalently, 7-9 day quarantine with full adherence (depending on the sensitivity of the LFA test). Adding a third test (PCR or LFA) reaches the efficiency of a 14-day quarantine with 90-100% adherence. These results are robust to the exposure dates of the contact, test sensitivity of LFA and alternative models of viral load evolution, which suggests that simple testing rules can be effective for improving contact tracing in settings where strict quarantine adherence is difficult to implement.

q-bio.PE↗

arXiv2022

Colorectal cancer trends in Chile: a Latin-American country with marked socioeconomic inequities

Colorectal cancer (CRC) is the third most frequent malignant disease in the world. In some countries with established screening programs, its incidence and mortality have decreased, and survival has improved. AIMS: To obtain reliable data about the epidemiology of CRC in Chile, we analyzed the trends in the last ten years and the influence of observable factors on survival, including explicit guarantees in CRC treatment access (GES program). Publicly available data published by the Health Ministry and National Institute of Statistics were used. Data were obtained from registries of mortality and hospital discharges, making follow-up of the individuals possible. Crude and age-standardized incidence and mortality rates were calculated, and individual survival was studied by constructing Kaplan-Meier curves. Finally, a Cox statistical model was established to estimate the impact of the observable factors.

stat.ME↗

arXiv2020

Safer working spaces at coronavirus time: A novel use of antibody tests

The SARS-CoV-2 pandemic has transformed the way that the world functions. Health issues and population safety have driven countries' economies to a critical state; therefore, sustaining economic activity while keeping workers safe has become a worldwide goal. In this paper, we present a novel safety protocol based on rapid antibody testing (ABT). Using discrete event simulation, we evaluated its performance on the cumulative number of infected workers, effective reproductive number ($R_e$), and active work force within a company. Using a synthetic experiment, we showed that ABT twice a week (ABT 3) performed the best, detecting 5.7% of infected workers, compared to 16.9% when no ABT was applied. $R_e$ was reduced from 1.75 to 0.84, with a slight decrease in the active workers within the firm. A sensitivity analysis on the duration of the shedding period and sensitivity of ABT was performed and led to the same qualitative conclusions. We applied this protocol in a Chilean winery: the estimation of the initial $R_e$ of 1.3 was reduced to 0.7 when the ABT 3 protocol was implemented, with a 27% decrease in the number of infected workers. Although ABT is not approved for COVID-19 diagnosis, our study shows that upgraded safety standards can already be implemented in workspaces.

physics.soc-ph↗