ABSTRACT
The outbreak of the COVID-19 pandemic led demand for online grocery orders for both click & collect (C&C) and attended home delivery (AHD) to outstrip delivery capacity by a wide margin. In the United Kingdom, the booking systems of some e-retailers could not handle the flood of incoming requests, forcing the retailers to proactively reach out to certain priority customer segments with the aim of serving as many high-priority customers as possible. To determine when to contact each customer segment in this extraordinary demand environment, we investigate the new demand management concept of proactively contacting customers. We first develop a decision policy for the C&C fulfillment method to address the problem of when to contact customers. We then extend this approach to the AHD setting. To cope with increased problem complexity, we propose a three-step procedure to solve this problem. First, we subdivide the delivery area into smaller subareas;second, we select the most promising subareas;and third, we determine which customers to contact within the chosen subareas. To gain managerial insights and to show the practical benefits of our approaches, we apply both approaches to realistic data from the London area. Our results show that proactive customer contacting allows for a tailored allocation of scarce capacity in e-groceries. We conclude with a discussion on how these contacting techniques can be valuable in postcrisis times. Copyright: © 2022 INFORMS.
ABSTRACT
Pandemic-induced challenges to health and economic well-being for older adults likely increased the need for help from adult children, disrupted the help children provided for needs unrelated to COVID-19, and changed interactions among time help, financial help, and shared housing. This paper uses data from the Health and Retirement Study Core and COVID-19 Module to assess whether adult children's transfers of time, money, and coresidence with parents responded to the pandemic-related challenges older adults faced. Because of unequal health and economic impacts of the pandemic, non-White and less-educated older adults, and those living in areas hard-hit by the pandemic may have been less likely to receive help from family members, their children may have been less able to substitute financial support for time or in-kind help, and older adults may have experienced greater disruptions in existing help arrangements so we examine differences by socioeconomic status, race-ethnicity, and local pandemic severity.
ABSTRACT
The following text is a play co-written as a response to, and a remembrance of, the experiences during the height of the COVID-19 pandemic. It is based on writing during lockdown that was meant to make sense of our own experiences as academic labourers and those gained from informal conversations with colleagues. Following the conventions and the sensibilities of theatre, the text demands and offers a (re-)embodiment of voices and affectivities that connected those bodies in a situation in which bodies were absent, yet highly present in their vulnerability. We thus invite the readers to treat the text primarily as a stageable drama rather than an academic paper given unusual form. An introduction that belongs to a more classical academic genre expresses our inspirations and relevant points of reference. A short prose coda hints towards some of the insights we have gained by crafting the play.
ABSTRACT
Purpose: Liver transplant (LT) recipients have a decreased response to 2 doses of SARS-CoV-2 vaccine compared to the general population, so we aimed to understand response to a third dose to inform vaccination strategies. Method(s): LT recipients in our observational cohort who received 3 homologous mRNA vaccines and available antibody levels pre- and post-dose 3 (D3) were identified. Those who reported a prior COVID-19 diagnosis or used belatacept were excluded. The peak anti-spike antibody level collected between the second (D2) and third dose (D3), was compared to the antibody level at 1 month post-D3. Samples were tested with Roche Elecsys Anti-Sars-CoV-2 enzyme immunoassay (EIA) (positive >=0.8 U/mL) or EUROIMMUN EIA (positive >=1.1 AU). Result(s): 146 participants completed 3 homologous doses of BNT162b2 (53%) or mRNA-1273 (47%) vaccines between 5/15/2021 - 11/8/2021. The median (IQR) time of peak pre-D3 antibody collection was 89 (31, 104) days post-D2. The median time of 1-month post-D3 antibody collection was 30 (23, 33) days. The median time between D2 and D3 was 168 (149-188) days. Overall, 125/146 (86%) were seropositive pre-D3, and 139/146 (95%) were seropositive post-D3 (Figure 1). There were no seroreversions post D3, and among the 21 seronegative recipients pre-D3, 14 (67%) seroconverted post-D3. Risk factors significantly associated with persistent seronegativity post-D3 were less time since LT (1.3 vs 6 years, p=0.042), mycophenolate use (100% vs 37%, p=0.001), BNT162b2 series (100% vs 50%, p=0.01), and pre-D3 seronegative status (86% vs 10%, p<0.001). Conclusion(s): Most LT recipients have excellent responses to a third homologous mRNA vaccine dose, greater than that seen in other transplant recipients. Persons seronegative after D2, however, show weaker response and may remain at high risk for SARS-CoV-2 infection despite D3.
ABSTRACT
Purpose: nti-spike antibody response to SARS-CoV-2 vaccination is diminished in LT recipients compared to the general population so understanding durability for those that do respond is critical to mitigating risks of infection. We measured serial antibody titers in LT recipients for 6 months after two-dose mRNA vaccine series to describe kinetics and sero-reversion rates. Method(s): LT recipients without known prior COVID-19 had anti-spike antibody testing at 1, 3, and 6 months after the second dose of mRNA vaccine (D2) using two commercial assays (Roche Elecsys anti-receptor binding domain immunoassay (EIA) [positive >=0.8 U/mL] or EUROIMMUN anti-S1 EIA [positive >=1.1 AU]). We compared titer distributions over time and identified factors associated with sero-reversion. Result(s): 180 LT recipients received BNT162b2 (48%) or mRNA-1273 (52%) 2-dose series between 1/7/2021-5/7/2021. At 1 month post-D2 (n=173), 146 (84%) had positive antibody levels at a median (IQR) of 30 (28, 32) days post-D2. At 3 months post-D2 (n=164), 149 (91%) had positive levels at a median of 92 (90, 96) days post-D2. At 6 months post-D2 (n=73), 62 (85%) had positive levels at a median of 180 (176, 185) days post-D2. Among the 66 seropositive at 1 or 3 months post-D2, 58 (88%) remained seropositive by 6 months post-D2. Neither age, years since transplant, vaccine type, nor mycophenolate (MMF) use were associated with sero-reversion, though there was a trend toward more triple immunosuppressive use (25% vs 3%, p=0.07). Of those Roche-tested, the median anti-RBD levels were >=250 U/mL (14, >=250;n=120) at 1 month post-D2, >=250 U/mL (58, >=250;n=113) at 3 months, and >=250 U/mL (30, >=250;n=49) at 6 months . Of those EUROIMMUN-tested, the median anti-S1 levels were 7.25 AU (4.31, 8.71;n=53) at 1 month, 5.71 AU (1.27, 7.90;n=51) at 3 months, and 1.73 AU (0.76, 6.01;n=25) at 6 months. Conclusion(s): Overall, most LT recipients demonstrated 6 month durability of anti-spike antibody following vaccination, but a subset did sero-revert, potentially associated with heavier immunosuppression. Further investigation into clinical consequences of waning antibody levels is key to guide timing of additional vaccine doses.
ABSTRACT
The outbreak of the COVID-19 pandemic led demand for online grocery orders for both click & collect (C&C) and attended home delivery (AHD) to outstrip delivery capacity by a wide margin. In the United Kingdom, the booking systems of some e-retailers could not handle the flood of incoming requests, forcing the retailers to proactively reach out to certain priority customer segments with the aim of serving as many high-priority customers as possible. To determine when to contact each customer segment in this extraordinary demand environment, we investigate the new demand management concept of proactively contacting customers. We first develop a decision policy for the C&C fulfillment method to address the problem of when to contact customers. We then extend this approach to the AHD setting. To cope with increased problem complexity, we propose a three-step procedure to solve this problem. First, we subdivide the delivery area into smaller subareas;second, we select the most promising subareas;and third, we determine which customers to contact within the chosen subareas. To gain managerial insights and to show the practical benefits of our approaches, we apply both approaches to realistic data from the London area. Our results show that proactive customer contacting allows for a tailored allocation of scarce capacity in e-groceries. We conclude with a discussion on how these contacting techniques can be valuable in postcrisis times.
ABSTRACT
Background: Coronavirus disease 2019 (COVID-19) is an unprecedented global pandemic caused by the novel betacoronavirus SARS-CoV-2 Extrapulmonary clinical features such as abnormal liver enzymes are often present, and almost 50% of patients experienced different degrees of liver injury in studies from China However, the prevalence of elevated liver enzymes and the association with clinical outcomes in U S based cohorts have not been well studied Aims: 1 ) To assess the prevalence of elevated liver enzymes in patients with COVID-19 in a U S based cohort 2 ) To compare differences in clinical characteristics and outcomes in patients with and without elevated alanine aminotransferase (ALT) Methods: In this retrospective cohort study, we analyzed data from patients hospitalized at the Johns Hopkins Health System (JHHS) between February 1, 2020, and July 1, 2020, who tested positive for SARSCoV- 2. Identified COVID-19 patients were then stratified into two groups, those with elevated ALT (>35 U/L for men and > 25 U/L for women) at admission or subsequently and thosewith normal ALT Pearson's chi-squared test and analysis of variance and were used to compare variables between the two groups Clinical outcomes assessed included the need for mechanical ventilation or vasopressor support, hospital length of stay (LOS), and mortality Results: During the study period, 2293 patients with COVID-19 were hospitalized at JHHS The mean age was 60 (SD 17 7) years;52 5% were men 35 6% were black, 31 2% white, and 26 3% Hispanic 33 7% were obese;1479 (64 5%) had abnormal liver ALT values Compared to those with normal ALT, patients with elevated ALT were more likely to be non-white (72 3% vs 61 9%, p < 0 001), Hispanic (30 4% vs 18 5%, p < 0 001), obese (43 7% vs 34 2%, p < 0 001), and have underlying liver disease (7 1% vs 3 0%, p < 0 001) Those with elevated ALT more often required mechanical ventilation (23 7% vs 6 0%, p < 0 001) and vasopressor support (23 0% vs 7 2%, p < 0 001) The group with elevated ALT had a longer hospital LOS (11 0 vs 5 9 days, p < 0 001) However, there were no differences in mortality found between the two groups (13 8% vs 15 6%, p = 0 3) Conclusion: There was a high prevalence of elevated ALT among inpatients with COVID-19 (64 5%) The presence of elevated ALT was associated with adverse clinical outcomes, including the need for mechanical ventilation and vasopressor support and prolonged hospital LOS.
ABSTRACT
Background: Patients with coronavirus disease 2019 (COVID-19) often present with various degrees of liver injury Thus, patients with pre-existing chronic liver disease (LD) may be at increased risk of complications from COVID-19, but this has not yet been well characterized Aim: To examine the impact of pre-existing LD on outcomes in patients with COVID-19 Methods: In this retrospective cohort study, we analyzed data from COVID-19 patients hospitalized at the Johns Hopkins Health System between February 1, 2020, and July 1, 2020, who tested positive for COVID-19 Identified patients were then stratified into two groups based on the presence or absence of pre-existing LD The LD group consisted of patients with a diagnosis of pre-existing liver disease at the time of diagnosis of COVID-19 We studied outcomes, including the need for hemodialysis or vasopressor support, hospital length of stay (LOS), and in-hospital mortality We described categorical data as percentages, and continuous data as mean with standard error (SD) We used Pearson's chi-squared tests and analysis of variance to compare variables between the patients with and without LD Results: In a study of 2,293 patients with laboratoryconfirmed COVID-19, 129 (17.8%) patients had pre-existing LD Among them, 32 (24 8%) patients had cirrhosis;18 (14 0%) had non-alcoholic fatty liver disease;20 (15 5%) had chronic hepatitis C;5 (3 87%) had chronic hepatitis B, and 5 (3 87%) were liver transplant recipients Patients with LD were more often black (41 9%) compared to patients with no preexisting LD (35 1%, p = 0 029) LD patients had substantially higher prevalence of comorbidities, including hypertension (79 9% vs 61%, p < 0 001), diabetes (27 9% vs 15 6%, p < 0 001), chronic pulmonary disease (31 0% vs 18 4%, p < 0 0001), and anemia (43 4% vs 22%, p < 0 001) Those with LD required hemodialysis more often (10% vs 4 4%, p = 0 015) There was no difference in need for vasopressor support (20 0% vs 18 8%, p = 0 12) The hospital LOS was similar between the groups (9 5 vs 9 6 days) There was no difference in mortality between the two groups (10 0% vs 14 6%, p = 0 14) Conclusion: Patients with pre-existing LD and COVID-19 infection were more likely black, have underlying comorbidities and require hemodialysis However, they had similar hospital LOS and mortality as those without LD. These findings have important implications for patients with LD but require further validation.