Social and Behavioral Sciences Commons^™

The Importance Of The First Generic Substitution: Evidence From Sweden, Aljoscha Janssen, David Granlund

Research Collection School Of Economics

We analyze changes in the willingness to substitute from prescribed pharmaceuticals to more affordable generic equivalents in response to the first experience with a substitution. Using Swedish individual-level data of prescribed and dispensed pharmaceuticals, we em-ploy a dynamic event study and an instrumental variable approach to show that an initial substitution reduces the probability of opposing subsequent substitutions by 39 percent-age points. We recommend that policy-makers target patients with a history of opposed substitution and offer additional discounts to promote substitution as long-term savings outweigh one-time costs.

Cities In A Pandemic: Evidence From China, Badi H. Baltagi, Ying Deng, Li Jing, Zhenlin Yang

Research Collection School Of Economics

This paper studies the impact of urban density, city government efficiency, and medical resources on COVID-19 infection and death outcomes in China. We adopt a simultaneous spatial dynamic panel data model to account for (i) the simultaneity of infection and death outcomes, (ii) the spatial pattern of the transmission, (iii) the intertemporal dynamics of the disease, and (iv) the unobserved city-specific and time-specific effects. We find that, while population density increases the level of infections, government efficiency significantly mitigates the negative impact of urban density. We also find that the availability of medical resources improves public health outcomes conditional on …

Retail Pharmacies And Drug Diversion During The Opioid Epidemic, Aljoscha Janssen, Xuan Zhang

Research Collection School Of Economics

This study investigates the role of retail pharmacy ownership in the opioid epidemic. Using data of prescription opioid orders, we show that compared with chain pharmacies, independent pharmacies dispense 39.1% more opioids and 60.5% more OxyContin. After an independent pharmacy becomes a chain pharmacy, opioid dispensing decreases. Using the OxyContin reformulation, which reduced non-medical demand but not the legitimate medical demand, we show that at least a third of the difference in the amount of OxyContin dispensed can be attributed to non-medical demand. We show that differences in competitive pressure and whether pharmacists own the pharmacy drive our estimates.

Life Satisfaction Changes And Adaptation In The Covid-19 Pandemic: Evidence From Singapore, Terence C. Cheng, Kim, Kanghyock Koh

Research Collection School Of Economics

We provide novel evidence on how COVID-19 affected overall life satisfaction using a monthly longitudinal survey of middle-aged and older Singaporeans. We study how the subjective well-being of individuals evolves over the course of 18 months including the outbreak of the pandemic, the implementation of the lockdown and the spike of cases due to the delta variant in a country where COVID-19 is controlled in a sustained manner. Using an event-study design framework, we find large declines in overall life satisfaction in the lead-up to and following the lockdown. Fifteen months after the outbreak of the pandemic, and 13 months …

Associations Of The Covid-19 Pandemic With Older Individuals' Healthcare Utilization And Self-Reported Health Status: A Longitudinal Analysis From Singapore, Sangnam Ahn, Seonghoon Kim, Kanghyock Koh

Research Collection School Of Economics

Background: The COVID–19 pandemic has challenged the capacity of healthcare systems around the world and can potentially compromise healthcare utilization and health outcomes among non-COVID–19 patients. Objectives: To examine the associations of the COVID-19 pandemic with healthcare utilization, out-of-pocket medical costs, and perceived health among middle-aged and older individuals in Singapore. Method: Utilizing data collected from a monthly panel survey, a difference-in-differences approach was used to characterize monthly changes of healthcare use and spending and estimate the probability of being diagnosed with a chronic condition and self-reported health status before and during the COVID-19 outbreak in 2020. Subjects: Data were …

The Intergenerational Mortality Tradeoff Of Covid-19 Lockdown Policies, Lin Ma, Gil Shapira, Damien De Walque, Quy-Toan Do, Jed Friedman, Andrei A. Levchenko

Research Collection School Of Economics

In lower-income countries, the economic contractions that accompany lockdowns to contain COVID-19 transmission can increase child mortality, counteracting the mortality reductions achieved by the lockdown. To formalize and quantify this effect, we build a macro-susceptible-infected-recovered model that features heterogeneous agents and a country-group-specific relationship between economic downturns and child mortality and calibrate it to data for 85 countries across all income levels. We find that in some low-income countries, a lockdown can produce net increases in mortality. The optimal lockdown that maximizes the present value of aggregate social welfare is shorter and milder in poorer countries than in rich ones.

Heterogeneous Health Effects Of Medical Marijuana Legalization: Evidence From Young Adults In The United States, Junxing Chay, Seonghoon Kim

Research Collection School Of Economics

Legalizing marijuana for medical purposes is a longstanding debate. However, evidence of marijuana's health effects is limited, especially for young adults. We estimate the health impacts of medical marijuana laws (MML) in the U.S. among young adults aged 18–29 years using the difference-in-differences method and data from the Behavioral Risk Factors Surveillance System. We find that having MMLs with strict regulations generate health gains, but not in states with lax regulations. Our heterogeneity analysis results indicate that individuals with lower education attainments, with lower household income and without access to health insurance coverage gain more health benefits from MML with …

Short-Term Impact Of Covid-19 On Consumption Spending And Its Underlying Mechanisms: Evidence From Singapore, Seonghoon Kim, Kanghyock Koh, Xuan Zhang

Research Collection School Of Economics

We examine the short-term impact of COVID-19 on consumption spending and labor market outcomes. Using monthly panel data of individuals mainly aged 50–70 in Singapore, we find that COVID-19 reduced consumption spending and labor market outcomes immediately after its outbreak, and its negative impact quickly evolved. At its peak, the pandemic reduced total household consumption spending by 22.8% and labor income by 5.9% in April. Probability of full-time work also went down by 1.2 pp and 6.0 pp in April and May, respectively, but employment and self-employment were only mildly affected. Our heterogeneity analysis indicates that the reduction in consumption …

Jue Insight: Migration, Transportation Infrastructure, And The Spatial Transmission Of Covid-19 In China, Bingjing Li, Lin Ma

Research Collection School Of Economics

This paper evaluates the impacts of migration flows and transportation infrastructure on the spatial transmission of COVID-19 in China. Prefectures with larger bilateral migration flows and shorter travel distances with Hubei, the epicenter of the outbreak, experienced a wider spread of COVID-19. In addition, richer prefectures with higher incomes were better able to contain the virus at the early stages of community transmission. Using a spatial general equilibrium model, we show that around 28% of the infections outside Hubei province can be explained by the rapid development in transportation infrastructure and the liberalization of migration restrictions in the recent decade.

Economic Impact Of Targeted Government Responses To Covid-19: Evidence From The Large-Scale Cluster In Seoul, Kim, Kanghyock Koh, Jinwook Shin

Research Collection School Of Economics

We estimate the economic impact of South Korea's targeted responses to the first large-scale COVID-19 cluster in Seoul. We find that foot traffic and retail sales decreased only within a 300 meter radius of the cluster and recovered to its pre-outbreak level after four weeks. The reductions appear to be driven by temporary business closures rather than the risk avoidance behavior of the citizens. Our results imply that less intense, but more targeted COVID-19 interventions, such as pin-pointed, temporary closures of businesses, can be a low-cost alternative after lifting strict social distancing measures.

Does Precise Case Disclosure Limit Precautionary Behavior? Evidence From Covid-19 In Singapore, Aljoscha Janssen, Matthew H. Shapiro

Research Collection School Of Economics

Limiting the spread of contagious diseases can involve both government-managed and voluntary efforts. Governments have a number of policy options beyond direct intervention that can shape individuals’ responses to a pandemic and its associated costs. During its first wave of COVID-19 cases, Singapore was among a few countries that attempted to adjust behavior through the announcement of detailed case information. Singapore's Ministry of Health maintained and shared precise, daily information detailing local travel behavior and residences of COVID-19 cases. We use this policy along with device-level cellphone data to quantify how local and national COVID-19 case announcements trigger differential behavioral …

Change In Outbreak Epicentre And Its Impact On The Importation Risks Of Covid-19 Progression: A Modelling Study, Oyelola A. Adegboye, Adeshina I. Adekunle, Anton Pak, Ezra Gayawan, Denis H. Y. Leung, Diana P. Rojas, Emma S. Mcbryde, Damon P. Eisen

Research Collection School Of Economics

Background: The outbreak of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) that was first detected in the city of Wuhan, China has now spread to every inhabitable continent, but now the attention has shifted from China to other epicentres. This study explored early assessment of the influence of spatial proximities and travel patterns from Italy on the further spread of SARS-CoV-2 worldwide. Methods: Using data on the number of confirmed cases of COVID-19 and air travel data between countries, we applied a stochastic meta-population model to estimate the global spread of COVID-19. Pearson's correlation, semi-variogram, and Moran's Index were used to …

The Potential Impacts Of Covid-19 On The Global Value Chains: Gvc Positioning And Linkages, Gerald Foong, Pao-Li Chang

Research Collection School Of Economics

Apart from the public health crisis entailed by the Coronavirus Disease 2019 (COVID-19) pandemic, it has also propagated a pandemic-induced economic shock globally. One transmission channel is via the inter-country linkages arising from the trade in intermediate inputs, which is a pertinent characteristic of global value chains (GVCs), and resulting in a "supply-chain contagion" as termed by Baldwin and Tomiura (2020). In this paper, we propose measures of bilteral downstreamness and upstreamness, the extent of a country's GVC participation, and the position of a country in GVCs by leveraging upon the gross export decomposition framework as laid out by Borin …

Between Lives And Economy: Optimal Covid-19 Containment Policy In Open Economies, Wen-Tai Hsu, Hsuan-Chih Luke Lin, Yang Han

Research Collection School Of Economics

This paper studies optimal containment policy for combating a pandemic in an open-economy context. It does so via quantitative analyses using a model that incorporates a standard epidemiological compartmental model in a multi-country, multi-sector Ricardian model of international trade with full-fledged input-output linkages. We devise a novel approach in computing optimal national policies in the long run, and contrast these policies with a baseline in which countries maintain their current policies until vaccine availability. The welfare gains under optimal policies are asymmetric as the gains for the set of countries which should tighten up the containment measures are much larger …

Covid-19, Lockdown, And The Dynamics Of Subjective Well-Being, Terence C. Cheng, Kim, Kanghyock Koh

Research Collection School Of Economics

We provide novel evidence on how the COVID-19 global health and economic crisis is affecting overall life satisfaction and domain-specific satisfaction using data from a monthly longitudinal survey of middle-aged and older Singaporeans. Using a difference-in-differences framework, we document large declines in overall life satisfaction and domain-specific satisfaction during the COVID-19 outbreak, except satisfaction with health. These declines coincide with the introduction of a nationwide lockdown, with life satisfaction remaining below its pre-pandemic levels even after the lockdown is lifted. We also find that individuals who report a drop in household income during the COVID-19 outbreak experience a decline in …

Spending Impact Of Covid-19 Stimulus Payments: Evidence From Card Transaction Data In South Korea, Kim, Kanghyock Koh, Wonjun Lyou

Research Collection School Of Economics

Various countries have implemented transfer programs to individuals since the Covid-19 outbreaks. However, the extent to which such transfers alleviate economic recessions is unclear. This paper analyzes a South Korean program, which provided vouchers redeemable only at small local businesses. We find that, due to the program, over 30% of households across all income groups increased their food and overall household spending, but the usage restriction may have affected consumer choice, distorting business competition. While the employment and sales of small businesses improved, the program’s fiscal sustainability is in question because of the large tax exemption.

Activation Of Trpa1 Nociceptor Promotes Systemic Adult Mammalian Skin Regeneration, Jenny J. Wei, Hali S. Kim, Casey A. Spencer, Donna Brennan-Crispi, Ying Zheng, Nicolette M. Johnson, Misha Rosenbach, Christopher Miller, Denis H. Y. Leung, George Cotsarelis, Thomas H. Leung

Research Collection School Of Economics

Adult mammalian wounds, with rare exception, heal with fibrotic scars that severely disrupt tissue architecture and function. Regenerative medicine seeks methods to avoid scar formation and restore the original tissue structures. We show in three adult mouse models that pharmacologic activation of the nociceptor TRPA1 on cutaneous sensory neurons reduces scar formation and can also promote tissue regeneration. Local activation of TRPA1 induces tissue regeneration on distant untreated areas of injury, demonstrating a systemic effect. Activated TRPA1 stimulates local production of interleukin-23 (IL-23) by dermal dendritic cells, leading to activation of circulating dermal IL-17–producing γδ T cells. Genetic ablation of …

Regional Prevalence Of Health Worker Absenteeism In Tanzania, Tomoki Fujii

Research Collection School Of Economics

Absenteeism of health workers in developing countries is common and can severely undermine the reliability of the health system. Therefore, it is important to understand where the prevalence of absenteeism is high. We develop a simple imputation method that combines a Service Delivery Indicators survey and a Service Provision Assessment survey to estimate the prevalence of absenteeism of health workers at the level of regions in Tanzania. The resulting estimates allow one to identify the regions in which the prevalence of absenteeism is significantly higher or lower than the national average and help policymakers determine priority areas for intervention.

Aging Suppresses Skin-Derived Circulating Sdf1 To Promote Full-Thickness Tissue Regeneration, Mailyn A. Nishiguchi, Casey A. Spencer, Denis H. Y. Leung, Thomas H. Leung

Research Collection School Of Economics

Physicians have observed that surgical wounds in the elderly heal with thinner scars than wounds in young patients. Understanding this phenomenon may reveal strategies for promoting scarless wound repair. We show that full-thickness skin wounds in aged but not young mice fully regenerate. Exposure of aged animals to blood from young mice by parabiosis counteracts this regenerative capacity. The secreted factor, stromal-derived factor 1 (SDF1), is expressed at higher levels in wounded skin of young mice. Genetic deletion of SDF1 in young skin enhanced tissue regeneration. In aged mice, enhancer of zeste homolog 2 (EZH2) and histone H3 lysine 27 …

Joint Spatial Time Series Epidemiological Analysis Of Malaria And Cutaneous Leishmaniasis Infection, O. A. Adegboye, M. Al-Saghir, Denis H. Y. Leung

Research Collection School Of Economics

Malaria and leishmaniasis are among the two most important health problems of many developing countries especially in the Middle East and North Africa. It is common for vector-borne infectious diseases to have similar hotspots which may be attributed to the overlapping ecological distribution of the vector. Hotspot analyses were conducted to simultaneously detect the location of local hotspots and test their statistical significance. Spatial scan statistics were used to detect and test hotspots of malaria and cutaneous leishmaniasis (CL) in Afghanistan in 2009. A multivariate negative binomial model was used to simultaneously assess the effects of environmental variables on malaria …

Hospital-Skilled Nursing Facility Referral Linkage Reduces Readmission Rates Among Medicare Patients Receiving Major Surgery, Andrew J. Schoenfeld, Xuan Zhang, David C. Grabowski, Vincent Mor, Joel S. Weissman, Momotazur Rahman

Research Collection School Of Economics

BACKGROUND:In the health reform era, rehospitalization after discharge may result in financial penalties to hospitals. The effect of increased hospital-skilled nursing facility (SNF) linkage on readmission reduction after surgery has not been explored.METHODS:To determine whether enhanced hospital-SNF linkage, as measured by the proportion of surgical patients referred from a hospital to a particular SNF, would result in reduced 30-day readmission rates for surgical patients, we used national Medicare data (2011-2012) and evaluated patients who underwent 1 of 5 operative procedures (coronary artery bypass grafting [CABG], hip fracture repair, total hip arthroplasty, colectomy, or lumbar spine surgery). Initial evaluation was performed …

Shrinkage Empirical Likelihood Estimator In Longitudinal Analysis With Time-Dependent Covariates: Application To Modeling The Health Of Filipino Children, Denis H. Y. Leung, Dylan S. Small, Jing Qin, Min Zhu

Research Collection School Of Economics

The method of generalized estimating equations (GEE) is a popular tool for analysing longitudinal (panel) data. Often, the covariates collected are time-dependent in nature, for example, age, relapse status, monthly income. When using GEE to analyse longitudinal data with time-dependent covariates, crucial assumptions about the covariates are necessary for valid inferences to be drawn. When those assumptions do not hold or cannot be verified, Pepe and Anderson (1994, Communications in Statistics, Simulations and Computation 23, 939–951) advocated using an independence working correlation assumption in the GEE model as a robust approach. However, using GEE with the independence correlation assumption may …

Efficient Parameter Estimation In Longitudinal Data Analysis Using A Hybrid Gee Method, Denis H. Y. Leung, You Gan Wang, Min Zhu

Research Collection School Of Economics

The method of generalized estimating equations (GEEs) provides consistent estimates of the regression parameters in a marginal regression model for longitudinal data, even when the working correlation model is misspecified (Liang and Zeger, 1986). However, the efficiency of a GEE estimate can be seriously affected by the choice of the working correlation model. This study addresses this problem by proposing a hybrid method that combines multiple GEEs based on different working correlation models, using the empirical likelihood method (Qin and Lawless, 1994). Analyses show that this hybrid method is more efficient than a GEE using a misspecified working correlation model. …

Multiple Testing To Establish Superiority/Equivalence Of A New Treatment Compared With K Standard Treatments For Unbalanced Designs, Koon Shing Kwong, Siu Hung Cheung, Wai-Sum Chan

Research Collection School Of Economics

In clinical studies, multiple superiority/equivalence testing procedures can be applied to classify a new treatment as superior, equivalent (same therapeutic effect), or inferior to each set of standard treatments. Previous stepwise approaches (Dunnett and Tamhane, 1997, Statistics in Medicine 16, 2489–2506; Kwong, 2001, Journal of Statistical Planning and Inference 97, 359–366) are only appropriate for balanced designs. Unfortunately, the construction of similar tests for unbalanced designs is far more complex, with two major difficulties: (i) the ordering of test statistics for superiority may not be the same as the ordering of test statistics for equivalence; and (ii) the correlation structure …

A Semi-Parametric Two-Component Compound Mixture Model And Its Application To Estimating Malaria Attributable Fractions, Jing Qin, Denis H. Y. Leung

Research Collection School Of Economics

Malaria remains a major epidemiologic problem in many developing countries. Malaria is defined as the presence of parasites and symptoms (usually fever) due to the parasites. In endemic areas, an individual may have symptoms attributable either to malaria or to other causes. From a clinical viewpoint, it is important to correctly diagnose an individual who has developed symptoms so that the appropriate treatments can be given. From an epidemiologic and economic viewpoint, it is important to determine the proportion of malaria-affected cases in individuals who have symptoms so that policies on intervention program can be developed. Once symptoms have developed …

Adrenocortical Adenoma And Carcinoma: Histopathological And Molecular Comparative Analysis, A. Stojadinovic, M. F. Brennan, A. Hoos, A. Omeroglu, Denis H. Y. Leung, M. Dudas, A. Nissan, C. Cordon-Cardo, R.A. Ghossein

Research Collection School Of Economics

We compared histomorphological features and molecular expression profiles of adrenocortical adenomas (ACAd) and carcinomas (ACCa). A critical histopathological review (mean, 11 slides per patient) was conducted of 37 ACAd and 67 ACCa. Paraffin-embedded tissue cores of ACAd (n = 33) and ACCa (n = 38) were arrayed in triplicate on tissue microarrays. Expression profiles of p53, mdm-2, p21, Bcl-2, cyclin D1, p27, and Ki-67 were investigated by immunohistochemistry and correlated with histopathology and patient outcome using standard statistical methodology. Median follow-up period was 5 years. Tumor necrosis, atypical mitoses, and >1 mitosis per 50 high-power fields were factors that were …

Factors Influencing Treatment Patterns In Breast Cancer Patients Age 75 And Over, Arti Hurria, Denis H. Y. Leung, Kathleen Trainor, Patrick Borgen, Larry Norton, Clifford Hudis

Research Collection School Of Economics

To retrospectively determine the factors influencing treatment decisions in older breast cancer patients at a single center. Experimental Design: 216 patients age > or = 75 seen in post-treatment follow-up between January, 1997 and June, 2000 were identified in the Memorial Sloan-Kettering breast cancer database. Eligible patients were > or = 75 years old at diagnosis, had a diagnosis of stage I, II, or III breast cancer, and received their follow-up care at Memorial Sloan Kettering Cancer Center. A retrospective chart review was performed. Patients were stratified by: (1) prognostic factors (age (75-79 or > or = 80), Charlson comorbidity score, tumor size, …

Antifibrinolytic Therapy And Perioperative Blood Loss In Cancer Patients Undergoing Major Orthopedic Surgery, David Amar, Florence M. Grant, Hao Zhang, Patrick J. Boland, Denis H. Y. Leung, John A. Healey

Research Collection School Of Economics

Background: Aprotinin has been reported to reduce blood loss and transfusion requirements in patients having major orthopedic operations. Data on whether epsilon amino-caproic acid (EACA) is effective in this population are sparse.

Methods: Sixty-nine adults with malignancy scheduled for either pelvic, extremity or spine surgery during general anesthesia entered this randomized, double-blind, placebo-controlled trial, and received either intravenous aprotinin (n = 23), bolus of 2 x 10(6) kallikrein inactivator units (KIU), followed by an infusion of 5 x 10(5) KIU/h, or EACA (n = 22), bolus of 150 mg/kg, followed by a 15 mg/kg/h infusion or saline placebo (n = …

Isotonic Designs For Phase I Trials, Denis H. Y. Leung, You-Gan Wang

Research Collection School Of Economics

The purpose of a phase I trial in cancer is to determine the level (dose) of the treatment under study that has an acceptable level of adverse effects. Although substantial progress has recently been made in this area using parametric approaches, the method that is widely used is based on treating small cohorts of patients at escalating doses until the frequency of toxicities seen at a dose exceeds a predefined tolerable toxicity rate. This method is popular because of its simplicity and freedom from parametric assumptions. In this paper, we consider cases in which it is undesirable to assume a …

Clinical Significance Of Molecular Expression Profiles Of Hürthle Cell Tumors Of The Thyroid Gland Analyzed Via Tissue Microarrays, A. Hoos, A. Stojadinovic, B. Singh, M. Dudas, Denis H. Y. Leung, A. Shaha

Research Collection School Of Economics

Hürthle cell tumors are rare thyroid neoplasms for which disease biology is poorly understood and diagnosis of carcinoma can be challenging. The aim of the study was to characterize molecular expression profiles of Hürthle cell tumors and to determine the clinical significance of identified phenotypes. Paraffin-embedded tissue cores of normal thyroid (n = 18), and histopathologically well-defined Hürthle cell adenomas (n = 27), Hürthle cell tumors of unknown malignant behavior (n = 7), and minimally (n = 14) and widely (n = 21) invasive Hürthle cell carcinomas were arrayed in triplicate on tissue microarrays. Expression profiles of p53, mdm-2, p21, …