Background Whilst evidence of use of face masks in reducing COVID-19 cases is increasing, the impact of mandatory use across a large population has been difficult to assess. Introduction of mandatory mask use on July 22, 2020 during a resurgence of COVID-19 in Melbourne, Australia created a situation that facilitated an assessment of the impact of the policy on the epidemic growth rate as its introduction occurred in the absence of other changes to restrictions. Methods and findings Exponential epidemic growth or decay rates in daily COVID-19 diagnoses were estimated using a non-weighted linear regression of the natural logarithm of the daily cases against time, using a linear spline model with one knot (lspline package in R v 3.6.3). The model’s two linear segments pivot around the hinge day, on which the mask policy began to take effect, 8 days following the introduction of the policy. We used two forms of data to assess change in mask usage: images of people wearing masks in public places obtained from a major media outlet and population-based survey data. Potential confounding factors (including daily COVID-19 tests, number of COVID-19 cases among population subsets affected differentially by the mask policy–e.g., healthcare workers) were examined for their impact on the results. Daily cases fitted an exponential growth in the first log-linear segment (k = +0.042, s.e. = 0.007), and fitted an exponential decay in the second (k = -0.023, s.e. = 0.017) log-linear segment. Over a range of reported serial intervals for SARS-CoV-2 infection, these growth rates correspond to a 22–33% reduction in an effective reproduction ratio before and after mandatory mask use. Analysis of images of people in public spaces showed mask usage rose from approximately 43% to 97%. Analysis of survey data found that on the third day before policy introduction, 44% of participants reported “often” or “always” wearing a mask; on the fourth day after, 100% reported “always” doing so. No potentially confounding factors were associated with the observed change in growth rates. Conclusions The mandatory mask use policy substantially increased public use of masks and was associated with a significant decline in new COVID-19 cases after introduction of the policy. This study strongly supports the use of masks for controlling epidemics in the broader community.

Promoting the use of contact tracing technology will be an important step in global recovery from the COVID-19 pandemic. Across two studies, we assessed two messaging strategies as motivators of intended contact tracing uptake. In one sample of 1117 Australian adults and one sample of 888 American adults, we examined autonomy-supportive and controlling message framing and the presence or absence of information safety as predictors of intended contact tracing application uptake, using an online randomized 2 × 2 experimental design. The results suggested that the provision of data safety assurances may be key in affecting people’s intentions to use contact tracing technology, an effect we found in both samples regardless of whether messages were framed as autonomy-supportive or controlling. Those in high information safety conditions consistently reported higher intended uptake and more positive perceptions of the application than those in low information safety conditions. In Study 2, we also found that perceptions of government legitimacy related positively to intended application uptake, as did political affiliation. In sum, individuals appeared more willing to assent to authority regarding contact tracing insofar as their data safety can be assured. Yet, public messaging strategies alone may be insufficient to initiate intentions to change behavior, even in these unprecedented circumstances.

No abstract

Promoting the use of contact tracing technology will be an important step in global recovery from the COVID-19 pandemic. The current study assesses two messaging strategies as motivators of contact tracing use. In a sample of 1117 Australian adults (Mage = 50.17, SDage = 17.46) we examined autonomy-supportive and controlling message framing and the presence or absence of information safety as predictors of intended contact tracing application uptake. Using an online randomized experimental design, we found that autonomy-supportive and controlling message framing did not differentially affect intended uptake. However, there was a main effect of information safety. Those in high information safety conditions reported higher intentions to use the application and to recommend it to others than those in low information safety conditions, regardless of message framing. In these unprecedented circumstances, Australians appeared more willing to assent to authority regarding contact tracing insofar as their data safety can be assured.

BackgroundWhilst evidence of use of face masks in reducing COVID-19 cases is increasing, the impact of mandatory use across a large population has been difficult to assess. Introduction of mandatory mask use on July 22, 2020 during a resurgence of COVID-19 in Melbourne, Australia created a situation that facilitated an assessment of the impact of the policy on the epidemic growth rate as its introduction occurred in the absence of other changes to restrictions.

PurposeThis study aimed to examine (1) whether confidence in political and health authorities predicted intention to adopt recommended health-protective behaviours and (2) whether age, gender and education level moderated the relationship between confidence in political and health authorities and health protective-behaviours (download the COVIDSafe app, wear a face mask and stay at home).Design/methodology/approachThis study assessed 1,206 Australians using an online survey. Participants answered questions regarding their confidence in political and health authorities and intention to adopt health-protective measures.FindingsConfidence in health and political authorities predicted intention to stay home and intention to download the COVIDSafe app, but not to wear a face mask in public spaces. Age moderated the relationship between confidence in authorities and intention to stay home (i.e. among respondents with less than 54 years old, confidence in authorities was associated with higher intention to stay home). Further, age and education level moderated the relationship between confidence in authorities and intention to download the COVIDSafe app (i.e. among older respondents and those with a university degree or higher, confidence in authorities was more strongly associated with higher intention to download the COVIDSafe app). The interaction between confidence and education predicted adoption of mask-wearing (i.e. among participants with a university degree or higher, more confidence in authorities was associated with higher intention to wear a mask in public spaces).Originality/valueOur findings can inform the development of targeted communications to increase health-protective behaviours at early stages of future pandemics.

Transitioning toward more plant-based diets can alleviate health and sustainability challenges. However, research on interventions that influence animal-product consumption remains fragmented and inaccessible to researchers and practitioners. We conducted an overview of systematic reviews, also known as a meta-review. We searched five databases for reviews that examined interventions that influence (increase or decrease) the consumption of animal products. We quantitatively summarised results using individual studies' directions of effect because reviews rarely reported effect sizes of primary studies. We also discussed the contexts in which the evidence for interventions appeared strongest in light of the broader literature on behaviour change. Eighteen systematic reviews met inclusion criteria, 12 of which examined interventions intended to decrease animal-product consumption and 6 of which examined interventions intended to increase animal-product consumption. In total, only two reviews conducted quantitative meta-analyses. Across all reviews, vote counting based on the direction of individual studies’ estimates indicated that providing information on the environmental impact of meat consumption may reduce consumption, with 10 of 11 estimates suggesting reduced consumption (91% [95% CI 62.3%, 98.4%]; p = .012). Providing information on the health consequences of meat consumption, emphasising social norms, and reducing meat portion sizes also appeared promising, albeit with more limited strength of evidence. Reviews examining interventions that decreased consumption predominately focused on meat (10/12 reviews). Future reviews should conduct quantitative syntheses where appropriate and could more frequently examine interventions that influence the consumption of animal products other than meat.

Many charities rely on donations to support their work addressing some of the world’s most pressing problems. We conducted a meta-review to determine what interventions work to increase charitable donations. We found 21 systematic reviews incorporating 1339 primary studies and over 2,139,938 participants. Our meta-meta-analysis estimated the average effect of an intervention on charitable donation size and incidence: r = 0.08 (95% CI [0.03, 0.12]). Due to limitations in the included systematic reviews, we are not certain this estimate reflects the true overall effect size. The most robust evidence found suggests charities could increase donations by (1) emphasising individual beneficiaries, (2) increasing the visibility of donations, (3) describing the impact of the donation, and (4) enacting or promoting tax-deductibility of the charity. We make recommendations for improving primary research and reviews about charitable donations, and how to apply the meta-review findings to increase charitable donations.