Determinants of SARS-CoV-2 Infection in the Older Adult Population: Data From the LOST in Lombardia Study (preprint)

Most COVID-19-related fatalities occurred among older adults, however to date, evidence on determinants of SARS-CoV-2 infection in this population is limited and mostly based on case series without a comparison group. A telephone-based cross-sectional study was conducted in November 2020 on a representative sample of 4,400 Italians aged ≥65 years residing in the Lombardy region. We determined the prevalence of a history of SARS-CoV-2 infection in the period between the beginning of the pandemic and the time of the interview. Thorough unconditional multiple logistic regression models, we estimated odds ratios (OR) of SARS-CoV-2 infection and the corresponding 95% confidence intervals (CI). We also evaluated if the infection was a determinant of a worsening in mental health wellbeing. Overall, 4.9% of participants reported a history of SARS-CoV-2 infection. No significant relationship between sex and SARS-CoV-2 infection was observed. SARS-CoV-2 infection was less frequently reported in subjects aged ≥70 (OR=0.55; 95% 0.41-0.74) compared to 65-69 years. No trend was observed after 70 years of age. Those with at least one chronic condition reported a lower infection rate compared to healthy subjects (OR=0.68 95% CI: 0.49-0.93). Separated/divorced participants less frequently reported infection than married/cohabiting ones (OR=2.33 95% CI: 1.29-4.20). Self-reported history of SARS-CoV-2 infection resulted being a determinant of an increase in depressive symptoms (OR=1.57; 95% CI: 1.17-2.10). This first large representative study of people aged 65 years or over suggests that in Italy the oldest subjects and those having chronic conditions less frequently expose themselves to SARS-CoV-2 infection during the pandemic.

Does COVID-19 vaccination improve mental health? A difference-in-difference analysis of the UnderstandingCoronavirus in America study (preprint)

BackgroundMental health problems increased during the COVID-19 pandemic. Knowledge that one is less at risk after being vaccinated may alleviate distress, but this hypothesis remains unexplored. Here we test whether psychological distress declined in those vaccinated against COVID-19 in the US and whether changes in perceived risk mediated any association. MethodsA nationally-representative cohort of U.S. adults (N=5,792) in the Understanding America Study were interviewed every two weeks from March 2020 to June 2021 (28 waves). Difference-in-difference regression tested whether getting vaccinated reduced distress (PHQ-4 scores), with mediation analysis used to identify potential mechanisms, including perceived risks of infection, hospitalization, and death. ResultsVaccination was associated with a 0.09 decline in distress scores (95% CI:-0.62 to -0.35) (0-12 scale), a 5.7% relative decrease compared to mean scores in the wave prior to vaccination. Vaccination was also associated with an 8.44 percentage point reduction in perceived risk of infection (95% CI:-9.15% to -7.73%), a 7.44-point reduction in perceived risk of hospitalization (95% CI:-8.07% to -6.82%), and a 5.03-point reduction in perceived risk of death (95% CI:-5.57% to -4.49%). Adjusting for risk perceptions decreased the vaccination-distress association by two-thirds. Event study models suggest vaccinated and never vaccinated respondents followed similar PHQ-4 trends pre-vaccination, diverging significantly post-vaccination. Analyses were robust to individual and wave fixed effects, time-varying controls, and several alternative modelling strategies. Results were similar across sociodemographic groups. ConclusionReceiving a COVID-19 vaccination was associated with declines in distress and perceived risks of infection, hospitalization, and death. Vaccination campaigns could promote these additional benefits of being vaccinated.

Changing probability of experiencing food insecurity by socioeconomic and demographic groups during the COVID-19 pandemic in the UK (preprint)

Background: Food supply concerns have featured prominently in the UK response to the COVID-19 pandemic. We assess changes in food insecurity in the UK population from April to July 2020. Method: We analyze 11,095 respondents from the April through July waves of the Understanding Society COVID-19 longitudinal study survey linked with Wave 9 of the UK Understanding Society study. Food insecurity was defined as having used a food bank in the last 4 weeks; being hungry but not eating in the last week; or not able to eat healthy and nutritious food in the last week. Unadjusted estimates to examine changes in population prevalence and logistic regression were used to assess the association between employment transitions and food insecurity. Findings: The prevalence of reporting at least one form of food insecurity rose from 7.1% in April to 20.2% by July 2020. Some of the largest increases were among Asian respondents (22.91 percentage points), the self-employed (15.90 percentage points), and 35-44-year-olds (17.08 percentage points). In logistic regression models, those moving from employment to unemployment had higher odds of reporting food insecurity relative to furloughed individuals (OR=2.23; 95% CI: 1.20 to 4.13) and to the persistently employed (OR=2.38; 95% CI: 1.33 to 4.27), adjusting for sociodemographic characteristics. Furloughed individuals did not differ significantly in their probability of experiencing food insecurity compared to the persistently employed (OR=1.07; 95% CI: 0.83 to 1.37). Interpretation: Food insecurity has increased substantially in the UK. Steps are needed to provide subsidies or food support to vulnerable groups.

Using volunteered geographic information to assess mobility in the COVID-19 pandemic context: cross-city time series analysis of 41 cities in 22 countries from March 2nd to 26th 2020 (preprint)

Objectives: Restricting mobility is a central aim for lowering contact rates and preventing COVID-19 transmission. Yet the impact on mobility of different non-pharmaceutical countermeasures in the earlier stages of the pandemic is not well-understood. Design: Trends were evaluated using Citymapper’s mobility index covering 2 nd to 26 th March 2020, expressed as percentages of typical usage periods from 0% as the lowest and 100% as normal. China and India were not covered. Multivariate fixed effects models were used to estimate the association of policies restricting movement on mobility before and after their introduction. Policy restrictions were assessed using the Oxford COVID-19 Government Response Stringency Index as well as measures coding the timing and degree of school and workplace closures, transport restrictions, and cancellation of mass gatherings. Setting: 41 cities worldwide Main outcome measures: Citymapper’s mobility index Results: : Mobility declined in all major cities throughout March. Larger declines were seen in European than Asian cities. The COVID-19 Government Response Stringency Index was strongly associated with declines in mobility (r = -0.75, p<0.001). After adjusting for time-trends, we observed that implementing non-pharmaceutical countermeasures was associated with a decline of mobility of 10.0% for school closures (95% CI: 4.36% to 15.7%), 15.0% for workplace closures (95% CI: 10.2% to 19.8%), 7.09% for cancelling public events (95% CI: 1.98% to 12.2%), 18.0% for closing public transport (95% CI: 6.74% to 29.2%), 13.3% for restricting internal movements (95% CI: 8.85% to 17.8%) and 5.30% for international travel controls (95% CI: 1.69 to 8.90). In contrast, as expected, there was no association between population mobility changes and fiscal or monetary measures or emergency healthcare investment. Conclusions: : Understanding the effect of public policy on mobility in the early stages is crucial to slowing and reducing COVID-19 transmission. By using Citymapper’s mobility index, this work provides the first evidence about trends in mobility and the impacts of different policy interventions, suggesting that closure of public transport, workplaces and schools are particularly impactful. Summary: box What is already known on this topic? Governments across the global are experimenting with a range of policy interventions to restrict movement in populations. Yet their impact is not well understood. There is an urgent need to understand how alternative policy approaches to restricting movement can impact on population mobility trends. What this study adds Our study finds that policy restrictions markedly reduced population-wide mobility. Closing public transport, workplaces and schools have among the largest associations with mobility declines.