Analyzing the effects of social distancing on the COVID-19 pandemic in Korea using mathematical modeling.

OBJECTIVES: During the 6 months since the first coronavirus disease 2019 (COVID-19) patient was diagnosed in Korea on January 20, 2020, various prevention and control measures have been implemented according to the COVID-19 epidemic pattern. Therefore, this study aimed to estimate the reproductive numbers (R) for each epidemic stage to analyze the effects of the preventive measures and to predict the COVID-19 transmission trends. METHODS: We estimated the transmission rates for each epidemic stage by fitting a COVID-19 transmission model, based on a deterministic mathematical model, to the data on confirmed cases. The effects of preventive measures such as social distancing by time period were analyzed, and the size and trends of future COVID-19 outbreaks were estimated. RESULTS: The value of R was 3.53 from February18, 2020 to February 28, 2020, and the mean R reduced to 0.45 from March 14, 2020 to April 29, 2020, but it significantly increased to 2.69 from April 30, 2020 to May13, 2020 and it was maintained at 1.03 from May 14, 2020 to July 23, 2020. CONCLUSIONS: According to the estimated R, it had fallen to below 1 and was maintained at that level owing to the isolation of infected persons by the public health authorities and social distancing measures followed by the general public. Then, the estimated R increased rapidly as the contact among individuals increased during the long holiday period from April 30, 2020 to May 5, 2020. Thereafter, the value of R dropped, with the continued use of preventive measures but remained higher than 1.00, indicating that the COVID-19 outbreak can be prolonged and develop into a severe outbreak at any time.

Counseling for Health: How Psychological Distance Influences Continuance Intention towards Mobile Medical Consultation.

As mobile healthcare services entered the public sight with high frequency during the COVID-19 pandemic, patients are increasingly recognizing the effectiveness of mobile medical consultation (MMC). Earlier studies have investigated what influences continuance intention (CI) towards MMC, but few studies have scrutinized it from the perspective of patients' psychological distance. We formulated a framework to examine the psychological factors influencing CI towards MMC by integrating the information systems continuance model and psychological distance theory. The framework was validated using the partial least squares structural equation modeling (PLS-SEM) approach and data from 475 MMC users in China. The empirical results revealed that immediacy, telepresence, intimacy, and substitutability were significant predictors of CI, while satisfaction mediated these pathways. Pandemic-induced anxiety positively moderated the effect of immediacy on satisfaction and the effect of satisfaction on CI. Practical implementations for MMC healthcare practitioners, designers, and marketers are drawn.

Non-Psychiatrist Healthcare Professionals? Attitudes Toward Patients with Mental Disorders: Lower Scores in Social Distance as a Fragile Facet of Public Stigma Against Depression.

BACKGROUND: The stigmatization by healthcare professionals (HP) of patients suffering from mental disorders is an important problem that interferes with the delivery of medical assistance. Social distancing by HP is an integral part of stigmatization, which differs between various mental disorders, as well as between psychiatrists (PSY) versus nonpsychiatrist healthcare professionals (NPHP). SUBJECTS AND METHODS: The study included 141 HP: PSY (n=20; 36.2±4.2 y.o.) and NPHP (n=121; 25.9±2.2 y.o.). The NPHP group included general practitioners (GP)/physicians (n=29; 20.6%), surgeons (n=19; 13.5%), obstetrician-gynecologists (n=26; 18.4%), neurologists (n=11; 7.8%), pediatricians (n=6; 4.3%), and other subspecialists (including urologists, tuberculosis specialists, ophthalmologists and dermatologists) (n=30; 21.3%). The modified Bogardus Social Distance Self-Assessment Scale (BSDS) was used to evaluate the indicators of social distance phenomena. The assessment was performed by HP for the following groups of patients with the following mental disorders: alcohol use disorder, bipolar disorder, depression, drug addiction, epilepsy, mental retardation, personality disorder, schizophrenia. All statistical calculations were performed using IBM SPSS-27 software (IBM Corp. 2021, licensed to Samara State Medical University). P-value ≤0.05 was determined as significant for the between-group (PSY vs NPHP) comparisons using a nonparametric Mann-Whitney U-test. RESULTS: Our data analysis showed that HP achieved varying social distance scores for patients depending on the type of mental disorder, but with common trends among PSY and NPHPs. The mean (SD) scores of social distance ranged from 3.65(1.50) for depression to 5.25 (1.74) for drug addiction in the PSY, versus 3.44 (1.69), 6.19 (1.37) in NPHP, respectively. As compared to PSY, mean BSDS total scores were greater in the NPHP group, notably in the obstetricians-gynecologist - 6.27(1.40), and GP - 6.62 (0.90) groups, with similar trends of differing attitudes appeared among pediatricians - 7.00 (0.01) - regarding drug addiction, whereas the neurologists demonstrated a tendency towards lower social distance in relation to patients with depression - 2.27 (1.68), and epilepsy - 2.82 (1.47). CONCLUSIONS: Social distance measures by PSY and NPHP groups in contemporary Russia were highest in relation to patients with drug addiction, and lowest scores for depression and epilepsy. Stigmatization among HPs seems to influence health care delivery to certain categories of patients, which calls for further investigation. Higher social distance scores for patients with drug addiction might be related to higher stigma and lack of compassion toward these patients. Conversely, lower scores of social distance and corresponding emotional acceptance of people with depression by HP might interfere in the timely diagnosis and availability of appropriate care at an early stage amenable to treatment. This might reflect the cultural context of depressive mentality in Russia, or elevated prevalence of depressive states among HP. We propose interventions aiming to destigmatize mental disorders by targeting particular subgroups of vulnerable patients and also certain representatives of HP community.

The effect of induced COVID-19-related fear on psychological distance and time perception.

Emotional experience can influence cognitive estimates such as perceived psychological distance and time judgements. These estimators are crucial in threatening situations like the COVID-19 pandemic because the subjective perception of the closeness of a potential infection might influence behaviour. However, to date it remains unclear how fear affects these estimates. We report on data from N = 183 participants collected in Germany during the summer of 2020, when a "second wave" of COVID-19 infections was still only on the horizon of public awareness. We induced COVID-19-related fear in members of one group and compared their estimates of psychological distance and time judgements to those of a neutral group. Fear induction influenced these conjoint estimates in the way that an increase in infection rates appeared farther away and of shorter duration. Mediation analysis revealed inverse effects of changes in valence and ratings of Fear of COVID-19 on psychological distance. Possible explanations for these effects are discussed.

Social distance mediates the association between fear of infection and better-off-dead beliefs about people living with HIV.

OBJECTIVES: The better-off-dead belief, the idea that death is preferable for people living with human immunodeficiency virus, is a highly devaluing attitude, but little is known about its determinants among the general population. Guided by the instrumental model of stigma, this study examined the contributive roles of fear of infection and social distance to this stigmatizing belief. METHODS: A total of 304 Chinese university students recruited in Guangzhou and Hong Kong responded to questionnaires assessing the better-off-dead belief, fear of infection and social distance. Structural equation modelling was used to test associations among the variables. RESULTS: Fear of infection and social distance were associated with higher levels of the better-off-dead belief. Social distance mediated the association between fear of infection and the better-off-dead belief. CONCLUSIONS: Fear of infection and social distance are determinants of the better-off-dead belief, with social distance serving as a mediator. This study highlights the importance of addressing fear and avoidance in future public health efforts to reduce the prevalence of the better-off-dead belief.

Social status and novelty drove the spread of online information during the early stages of COVID-19.

Access to online information has been crucial throughout the COVID-19 pandemic. We analyzed more than eight million randomly selected Twitter posts from the first wave of the pandemic to study the role of the author's social status (Health Expert or Influencer) and the informational novelty of the tweet in the diffusion of several key types of information. Our results show that health-related information and political discourse propagated faster than personal narratives, economy-related or travel-related news. Content novelty further accelerated the spread of these discussion themes. People trusted health experts on health-related knowledge, especially when it was novel, while influencers were more effective at propagating political discourse. Finally, we observed a U-shaped relationship between the informational novelty and the number of retweets. Tweets with average novelty spread the least. Tweets with high novelty propagated the most, primarily when they discussed political, health, or personal information, perhaps owing to the immediacy to mobilize this information. On the other hand, economic and travel-related information spread most when it was less novel, and people resisted sharing such information before it was duly verified.

SARS-CoV-2 transmission, the ambiguous role of children and considerations for the reopening of schools in the fall.

Tweetable abstract The reopening of schools in the fall entails risks given the controversies in pediatric COVID-19 pathogenesis and the ambiguous role of children in transmission.

Social Distance in COVID-19: Drawing the line between protective behavior and stigma manifestation.

Social stigma has long been defined by Ervin Goffman as an attribute that it is deeply discrediting and reduces the individual who bears it from a whole and usual person to a tarnished one, unfit to be included into the mainstream society.1 As stigma spans time and space and has been documented in other social species such as ants and chimpanzees, one might argue for its adaptive potential. Neuberg and colleagues2 have suggested that humans generate stigmas against threats to effective group functioning, with a notable case being infectious diseases. A similar explanation has been put forward by other researchers who consider stigma to have evolved from disease-avoidance mechanisms.3 Hence, it is not surprising that tuberculosis, HIV and leprosy have been surrounded by stigma and discrimination.4,5 More recently, people who had survived the 2013-2016 Ebola outbreak tackled social exclusion and unemployment after returning to their neighborhoods.6 Nowadays, the global community faces an unprecedented challenge of grappling with the COVID-19 pandemic. From the very outset, social distance measures were introduced in order to contain the spread of the virus, ranging from maintaining 1.5 meters physical distance to strict lockdowns. However, this may easily escalate into stigmatizing and discriminatory behaviours (desired social distance is a proxy of discrimination) against people who have suffered from COVID-19, their relatives and their caregivers, with the United Nations stating that "fear, rumours and stigma" are the key challenges surrounding COVID-19.7 Apart from the psychological distress experienced by the stigmatized individuals, due to anticipated stigma people might start concealing their illness, avoid or delay seeking medical advice or testing until they are seriously ill and be reluctant to collaborate with authorities on tracing contacts. Therefore, timely identifying stigma and addressing it is an integral part of an effective health response to the ongoing pandemic. In spite of its importance, research on COVID-19 related stigma is scarce. From the perspective of the stigmatized individuals, a study in China8 demonstrated that COVID-19 survivors faced heightened levels of overall stigma, social rejection, financial insecurity, internalized shame and social isolation, compared to healthy controls. From the perspective of the general population, a study in US9 substantiated low levels of anticipated stigma and stereotype endorsement; however, respondents who anticipated greater stigma were less likely to seek a COVID-19 test. It is therefore clear that the international literature is still on its infancy with respect to COVID-19 related stigma. In this context, in the First Department of Psychiatry, University of Athens, we conducted a survey on public attitudes to COVID-19 and to mental disorders. The study would inform the design and implementation of anti-stigma initiatives, funded by the Regional Governor of Attica. As physical distancing and social distancing are interwoven, with some researchers and practitioners using the terms interchangeably, and social distancing is also a protective public health measure against COVID-19, we enquired about attitudes and desired social distance from people who had recovered from COVID-19. Nonetheless, it merits noting that evidence from other diseases indicates that stigma may persist even after recovery.10 Moreover, rather than describing public attitudes overall, we were more interested in investigating where COVID-19 related stigma stands as compared to the most stigmatizing health condition to date, i.e., severe mental illness.11 Interestingly enough, which elements of severe mental illness render it the most stigmatized as compared to other conditions is still speculative: is it the fear of madness? the severity and the type of symptoms? the purported incurability or its chronicity? In our study, evidence from a convenience sample of 370 residents of Attica indicates that the general population holds more negative attitudes towards people who have recovered from COVID-19 than towards people with mental disorders. Nonetheless, respondents reported lower levels of desired social distance from recovered COVID-19 cases as compared to mental illness cases in social interactions of graded intimacy; however, the difference between the two groups was found to decrease as the level of intimacy decreased as well. In other words, desired social distance from COVID-19 cases is more easily discernible in transient social encounters, like talking to a stranger. It is therefore clear that social distance is still a public health protective measure rather than a stigma manifestation. For social encounters of greater intimacy, usually a sign of discriminatory behaviours, having recovered from COVID-19 is not a deterrent to interaction. Findings can be explained by the acute (non-chronic) nature of the disease, both in terms of symptoms as well as the 10-day period since symptom onset for being contagious. Nonetheless, with emerging evidence substantiating the notion of long COVID-19, defined as the persistence of symptoms for 3 weeks after infection,12 this might quickly change. Moreover, with many public health protective measures available, such as the use of mask, diagnostic testing and vaccination, people who become infected are more likely to be blamed for contracting the disease and thus deemed responsible for this, in line with the Attribution Theory.13 Specifically, overarching evidence from stigma research in many diseases/conditions indicates that when an illness or a social condition, such as economic disadvantage, is attributed to internal causes, as compared to external, lay people are more likely to hold stigmatizing attitudes.14-16 Therefore, as attitudes towards COVID-19 are worse compared to those towards people with mental illness, if tailored anti-stigma action is not undertaken, it is only a matter of time for prejudices to evolve into discriminatory behaviours, with devastating consequences on both the individuals and the course of the pandemic. Concomitantly, as severe mental illness is neither life threatening nor contagious, but COVID-19 is, it is interesting to explore how stigma is related to evolutionary mechanisms favouring adaptability and survival as well as which elements are the drivers of stigma development and establishment. Therefore, comparing and contrasting the stigma surrounding these conditions may shed light on the underpinnings of social stigma and facilitate effective interventions to reduce it and eventually eliminate it.

Alcohol Use as a Function of Physical Activity and Golfing Motives in a National Sample of United States Golfers.

Alcohol and physical inactivity are risk factors for a variety of cancer types. However, alcohol use often co-occurs with physical activity (PA), which could mitigate the cancer-prevention benefits of PA. Alcohol is integrated into the culture of one of the most popular physical activities for adults in the United States (U.S.), golf. This study examined how alcohol use was associated with total PA, golf-specific PA, and motives for golfing in a national sample of golfers in the U.S. Adult golfers (n = 338; 51% male, 81% White, 46 ± 14.4 years) self-reported alcohol use, golfing behavior and motives, and PA. Most (84%) golfers consumed alcohol, averaging 7.91 servings/week. Golf participation, including days/week, holes/week, and practice hours/week, was not associated with alcohol use. Golfers with stronger social motives were 60% more likely to consume alcohol. Weekly walking (incident risk ratio (IRR) = 7.30), moderate-to-vigorous PA (MVPA; IRR = 5.04), and total PA (IRR = 4.14) were associated with more alcohol servings/week. Golfers' alcohol use may be higher than the general adult population in the U.S. and contributes 775 extra kilocalories/week, a surplus that may offset PA-related energy expenditure and cancer-protective effects. Alcohol use interventions targeting golfers may facilitate weight loss and reduce cancer risk, especially for golfers motivated by social status.

Health care worker burnout during the COVID-19 pandemic: A cross-sectional survey study in Saudi Arabia.

OBJECTIVES: To estimate the prevalence of burnout among health care workers (HCWs) who are working in Saudi Arabia during the Coronavirus disease 2019 (COVID-19) pandemic, and explore individual and work-related factors associated with burnout in this population. METHODS: In this cross-sectional study conducted between June to August of 2020, we invited HCWs through social channels to complete a questionnaire. The questionnaire inquired about demographics, factors related to burnout, and used the Copenhagen Burnout Inventory scale to indicate burnout. A total of 646 HCWs participated. RESULTS: The mean (SD) age of participants was 34.1 (9.5) years. Sixty-one percent were female. The prevalence of burnout among HCWs was 75%. Significant factors associated with burnout were age, job title, years of experience, increased working hours during the pandemic, average hours of sleep per day, exposure to patients with COVID-19, number of times tested for COVID-19, and perception of being pushed to deal with COVID-19 patients. CONCLUSION: Health care workers as frontline workers, face great challenges during this pandemic, because of the nature of their work. Efforts should be made to promote psychological resilience for HCWs during pandemics. This study points out the factors that should be invested in and the factors that may not be influential.

The Social Distance Scale (v1): A Screening Instrument to Assess Patient Adherence to Prevention Strategies during Pandemics.

BACKGROUND: This paper describes the development of a brief self-report screening measure of adherence to social distancing and self-protective behaviors in pandemic situations. Items measured behaviors currently established as primary strategies to prevent and reduce the spread of the COVID-19 infection. METHODS: An item pool of 29 questions was generated with the aim of estimating the frequency of specific behaviors and were written to avoid confounding the description of behavioral actions with evaluative judgements. Responses were collected from 401 young adults using an anonymous online survey. RESULTS: An Exploratory Factor Analysis was conducted with the purpose of item reduction and subscale development. A 14-item Social Distance Scale emerged, consisting of four subscales: Isolation from Community (IC), Work from Home (WH), Family Contact (FC), and Protective Behaviors (PB). The initial psychometric evaluation of the scales indicated adequate internal consistency and test-retest reliability. (4) Conclusions: The Social Distance Scale (v1) is a promising new instrument which may be applied at the population or individual level. It may be used in conjunction with COVID-19 testing to measure interactions between social distancing factors and transmission. In addition, a reliable screening measure has utility for health service providers to assess patient risk and to provide educational/counseling.

Model-based analysis on social acceptability and feasibility of a focused protection strategy against the COVID-19 pandemic.

This paper studies the social acceptability and feasibility of a focused protection strategy against coronavirus disease 2019 (COVID-19). We propose a control scheme to develop herd immunity while satisfying the following two basic requirements for a viable policy option. The first requirement is social acceptability: the overall deaths should be minimized for social acceptance. The second is feasibility: the healthcare system should not be overwhelmed to avoid various adverse effects. To exploit the fact that the disease severity increases considerably with age and comorbidities, we assume that some focused protection measures for those high-risk individuals are implemented and the disease does not spread within the high-risk population. Because the protected population has higher severity ratios than the unprotected population by definition, the protective measure can substantially reduce mortality in the whole population and also avoid the collapse of the healthcare system. Based on a simple susceptible-infected-recovered model, social acceptability and feasibility of the proposed strategy are summarized into two easily computable conditions. The proposed framework can be applied to various populations for studying the viability of herd immunity strategies against COVID-19. For Japan, herd immunity may be developed by the proposed scheme if [Formula: see text] and the severity rates of the disease are 1/10 times smaller than the previously reported value, although as high mortality as seasonal influenza is expected.

Social distancing, use of face masks and hand washing among participants in the Brazilian Longitudinal Study of Aging: the ELSI-COVID-19 initiative. / Distanciamento social, uso de máscaras e higienização das mãos entre participantes do Estudo Longitudinal da Saúde dos Idosos Brasileiros: iniciativa ELSI-COVID-19.

The aim of the study was to examine the prevalence of social distancing, the use of face masks and hand washing when leaving home among Brazilian adults aged 50 or over. Data from 6,149 telephone interviews were used, conducted between May 26 and June 8, 2020 among participants in the Brazilian Longitudinal Study of Aging (ELSI-Brazil). Social distancing was defined by not having left home in the last seven days. Only 32.8% of study participants did not leave home during the period considered, 36.3% left between one and two times, 15.2% between three and five times and 15.7% left every day. The main reasons for leaving home were to buy medicine or food (74.2%), to work (25.1%), to pay bills (24.5%), for health care (10.5%), to exercise (6.2%), and to meet family or friends (8.8%). Among those who left home, 97.3% always wore face masks and 97.3% always performed hand washing. Women left home less often than men. Men left home more often to work and exercise while women left home more often to seek healthcare. Men (odds ratio - OR = 1.84), those with higher education (OR = 1.48 and 1.95 for 5-8 and 9 years, respectively) and urban residents (OR = 1.54) left home more frequently to perform essential activities, regardless of age or other characteristics. Results show low adherence to social distancing, but high prevalence in the reported use of face masks and hand washing.

O objetivo do estudo foi examinar a prevalência do distanciamento social, do uso de máscaras e da higienização das mãos ao sair de casa entre adultos brasileiros com 50 anos ou mais de idade. Foram utilizados dados de 6.149 entrevistas telefônicas, conduzidas entre 26 de maio e 8 junho de 2020 dentre os participantes do Estudo Longitudinal da Saúde dos Idosos Brasileiros (ELSI-Brasil). O distanciamento social foi definido por não ter saído de casa nos últimos 7 dias. Somente 32,8% dos participantes do estudo não saíram de casa no período considerado, 36,3% saíram entre 1 e 2 vezes, 15,2% entre 3 a 5 vezes e 15,7% saíram todos os dias. As principais razões para sair de casa foram comprar remédios ou alimentos (74,2%), trabalhar (25,1%), pagar contas (24,5%), atendimento dem saúde (10,5%), fazer exercícios (6,2%) e encontrar familiares ou amigos (8,8%). Entre os que saíram de casa, 97,3% usaram sempre máscaras faciais e 97,3% sempre higienizaram as mãos. As mulheres saíram menos de casa que os homens. Esses saíram com mais frequência para trabalhar e fazer exercícios. Elas saíram mais para atendimento em saúde. Os homens (odds ratio - OR =1,84) aqueles com escolaridade mais alta (OR = 1,48 e 1,95 para 5-8 e 9 anos, respectivamente) e os residentes em áreas urbanas (OR = 1,54) saíram mais para realizar atividades essenciais, independentemente da idade e de outros fatores relevantes. Os resultados mostram baixa adesão ao distanciamento social, mas altas prevalências nos usos de máscaras e higienização das mãos.

El objetivo del estudio fue examinar la prevalencia del distanciamiento social, uso de mascarillas e higienización de las manos al salir de casa entre adultos brasileños con 50 años o más de edad. Se utilizaron datos de 6.149 entrevistas telefónicas, realizadas entre el 26 de mayo y el 8 junio de 2020 entre los participantes del Estudio Brasileño Longitudinal del Envejecimiento (ELSI-Brasil por sus siglas en portugués). El distanciamiento social fue definido por no haber salido de casa en los últimos 7 días. Solamente un 32,8% de los participantes del estudio no salieron de casa en el período considerado, 36,3% salieron entre 1 y 2 veces, 15,2% entre 3 a 5 veces y 15,7% salieron todos los días. Las principales razones para salir de casa fueron comprar medicamentos o alimentos (74,2%), trabajar (25,1%), pagar cuentas (24,5%), atención en salud (10,5%), hacer ejercicios (6,2%) y encontrar con familiares o amigos (8,8%). Entre los que salieron de casa, un 97,3% usaron siempre mascarillas faciales y un 97,3% higienizaron siempre las manos. Las mujeres salieron menos de casa que los hombres. Estos salieron con más frecuencia para trabajar y para hacer ejercicio. Ellas salieron más para la atención en salud. Los hombres (odds ratio - OR = 1,84), los con escolaridad más alta (OR = 1,48 y 1,95 para 5-8 y 9 años) y los residentes en áreas urbanas (OR = 1,54) salieron más para realizar actividades esenciales, independientemente de la edad y de otros factores relevantes. Los resultados muestran una baja adhesión al distanciamiento social, pero altas prevalencias en el uso de mascarillas e higienización de las manos.

Assessment of Social Distancing for Controlling COVID-19 in Korea: An Age-Structured Modeling Approach.

The outbreak of the novel coronavirus disease 2019 (COVID-19) occurred all over the world between 2019 and 2020. The first case of COVID-19 was reported in December 2019 in Wuhan, China. Since then, there have been more than 21 million incidences and 761 thousand casualties worldwide as of 16 August 2020. One of the epidemiological characteristics of COVID-19 is that its symptoms and fatality rates vary with the ages of the infected individuals. This study aims at assessing the impact of social distancing on the reduction of COVID-19 infected cases by constructing a mathematical model and using epidemiological data of incidences in Korea. We developed an age-structured mathematical model for describing the age-dependent dynamics of the spread of COVID-19 in Korea. We estimated the model parameters and computed the reproduction number using the actual epidemiological data reported from 1 February to 15 June 2020. We then divided the data into seven distinct periods depending on the intensity of social distancing implemented by the Korean government. By using a contact matrix to describe the contact patterns between ages, we investigated the potential effect of social distancing under various scenarios. We discovered that when the intensity of social distancing is reduced, the number of COVID-19 cases increases; the number of incidences among the age groups of people 60 and above increases significantly more than that of the age groups below the age of 60. This significant increase among the elderly groups poses a severe threat to public health because the incidence of severe cases and fatality rates of the elderly group are much higher than those of the younger groups. Therefore, it is necessary to maintain strict social distancing rules to reduce infected cases.

Estimating the impact of physical distancing measures in containing COVID-19: an empirical analysis.

BACKGROUND: Epidemic modelling studies predict that physical distancing is critical in containing COVID-19. However, few empirical studies have validated this finding. Our study evaluates the effectiveness of different physical distancing measures in controlling viral transmission. METHODS: We identified three distinct physical distancing measures with varying intensity and implemented at different times-international travel controls, restrictions on mass gatherings, and lockdown-type measures-based on the Oxford COVID-19 Government Response Tracker. We also estimated the time-varying reproduction number (Rt) for 142 countries and tracked Rt temporally for two weeks following the 100th reported case in each country. We regressed Rt on the physical distancing measures and other control variables (income, population density, age structure, and temperature) and performed several robustness checks to validate our findings. FINDINGS: Complete travel bans and all forms of lockdown-type measures have been effective in reducing average Rt over the 14 days following the 100th case. Recommended stay-at-home advisories and partial lockdowns are as effective as complete lockdowns in outbreak control. However, these measures have to be implemented early to be effective. Based on the observed median timing across countries worldwide, lockdown-type measures are considered early if they were instituted about two weeks before the 100th case and travel bans a week before detection of the first case. INTERPRETATION: A combination of physical distancing measures, if implemented early, can be effective in containing COVID-19-tight border controls to limit importation of cases, encouraging physical distancing, moderately stringent measures such as working from home, and a full lockdown in the case of a probable uncontrolled outbreak.