Differential impact of physical distancing strategies on social contacts relevant for the spread of SARS-CoV-2: evidence from a cross-national online survey, March-April 2020.

OBJECTIVES: We investigate changes in social contact patterns following the gradual introduction of non-pharmaceutical interventions and their implications for infection transmission in the early phase of the pandemic. DESIGN, SETTING AND PARTICIPANTS: We conducted an online survey based on targeted Facebook advertising campaigns across eight countries (Belgium, France, Germany, Italy, the Netherlands, Spain, UK and USA), achieving a sample of 51 233 questionnaires in the period 13 March-12 April 2020. Poststratification weights based on census information were produced to correct for selection bias. OUTCOME MEASURES: Participants provided data on social contact numbers, adoption of protective behaviours and perceived level of threat. These data were combined to derive a weekly index of infection transmission, the net reproduction number [Formula: see text] . RESULTS: Evidence from the USA and UK showed that the number of daily contacts mainly decreased after governments issued the first physical distancing guidelines. In mid-April, daily social contact numbers had decreased between 61% in Germany and 87% in Italy with respect to pre-COVID-19 levels, mostly due to a contraction in contacts outside the home. Such reductions, which were uniform across age groups, were compatible with an [Formula: see text] equal or smaller than one in all countries, except Germany. This indicates lower levels of infection transmission, especially in a period of gradual increase in the adoption rate of the face mask outside the home. CONCLUSIONS: We provided a comparable set of statistics on social contact patterns during the COVID-19 pandemic for eight high-income countries, disaggregated by week and other demographic factors, which could be leveraged by the scientific community for developing more realistic epidemic models of COVID-19.

Behaviours and attitudes in response to the COVID-19 pandemic: insights from a cross-national Facebook survey.

BACKGROUND: In the absence of medical treatment and vaccination, individual behaviours are key to curbing the spread of COVID-19. Here we describe efforts to collect attitudinal and behavioural data and disseminate insights to increase situational awareness and inform interventions. METHODS: We developed a rapid data collection and monitoring system based on a cross-national online survey, the "COVID-19 Health Behavior Survey". Respondent recruitment occurred via targeted Facebook advertisements in Belgium, France, Germany, Italy, the Netherlands, Spain, the United Kingdom, and the United States. We investigated how the threat perceptions of COVID-19, the confidence in the preparedness of organisations to deal with the pandemic, and the adoption of preventive and social distancing behaviours are associated with respondents' demographic characteristics. RESULTS: We analysed 71,612 questionnaires collected between March 13-April 19, 2020. We found substantial spatio-temporal heterogeneity across countries at different stages of the pandemic and with different control strategies in place. Respondents rapidly adopted the use of face masks when they were not yet mandatory. We observed a clear pattern in threat perceptions, sharply increasing from a personal level to national and global levels. Although personal threat perceptions were comparatively low, all respondents significantly increased hand hygiene. We found gender-specific patterns: women showed higher threat perceptions, lower confidence in the healthcare system, and were more likely to adopt preventive behaviours. Finally, we also found that older people perceived higher threat to themselves, while all respondents were strongly concerned about their family. CONCLUSIONS: Rapid population surveys conducted via Facebook allow us to monitor behavioural changes, adoption of protective measures, and compliance with recommended practices. As the pandemic progresses and new waves of infections are a threatening reality, timely insights from behavioural and attitudinal data are crucial to guide the decision-making process. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1140/epjds/s13688-021-00270-1.

Addressing Public Health Emergencies via Facebook Surveys: Advantages, Challenges, and Practical Considerations.

Surveys of the general population can provide crucial information for designing effective nonpharmaceutical interventions to tackle public health emergencies, such as the COVID-19 pandemic. Yet, conducting such surveys can be difficult, especially when timely data collection is required. In this viewpoint paper, we discuss our experiences with using targeted Facebook advertising campaigns to address these difficulties in relation to the COVID-19 pandemic. We describe central advantages, challenges, and practical considerations. This includes a discussion of potential sources of bias and how they can be addressed.

Ability and mobility: The relative influence of skills and social origin on social mobility.

The recent PIACC data offer us the first ever opportunity to identify the relative salience of abilities versus social origin in comparative social mobility research. Sampling 21 countries, we identify the degree of meritocratic selection by estimating the relative influence of social origin versus individual cognitive and social skills. We pay particular attention to the possibility of skills combinations as regards both upward and downward mobility. Social skills may compensate for weak cognitive abilities, or vice-versa; and what are the added effects of commanding strong skills on both counts? This is, as far as we know, the first time that comparative mobility research has examined such skills-complementarities. As in previous research we, too, uncover a significantly more egalitarian mobility pattern in the Nordic countries. This however obtains also for Canada and the Netherlands. A unique feature of Scandinavia is its asymmetric profile: significant upward mobility for those of low social origin, but surprisingly little downward mobility among those of privileged origins. Contrary to expectations, this cannot be ascribed to skills compensation. We find, however, that social skills play an important role for upward mobility among low-SES sons.