I've been curious about the efficacy of social distancing for a while. However, here's my problem: I don't really care about models. Models are, in my estimation, just guesses. Here's the abstract of a paper:
This paper develops and implements a method to monetize the impact of moderate social distancing on deaths from COVID-19. Using the Ferguson et al. (2020) simulation model of COVID-19’s spread and mortality impacts in the United States, we project that 3-4 months of moderate distancing beginning in late March 2020 would save 1.7 million lives by October 1. Of the lives saved, 630,000 are due to avoided overwhelming of hospital intensive care units. Using the projected age-specific reductions in death and age-varying estimates of the United States Government’s value of a statistical life, we find that the mortality benefits of social distancing are about $8 trillion or $60,000 per US household. Roughly 90% of the monetized benefits are projected to accrue to people age 50 or older. Overall, the analysis suggests that social distancing initiatives and policies in response to the COVID-19 epidemic have substantial economic benefits.
Then, I went to the Ferguson study. I was looking for the formulas the model was based on, but, instead found this:
We assumed an incubation period of 5.1 days . Infectiousness is assumed to occur from 12 hours prior to the onset of symptoms for those that are symptomatic and from 4.6 days after infection in those that are asymptomatic with an infectiousness profile over time that results in a 6.5-day mean generation time. Based on fits to the early growth-rate of the epidemic in Wuhan, we make a baseline assumption that R0=2.4 but examine values between 2.0 and 2.6.
But some in China have been skeptical of the accuracy of the official tally, particularly given Wuhan’s overwhelmed medical system, authorities’ attempts to cover up the outbreak in its initial stages, and multiple revisions to the way official cases are counted. Residents on social media have demanded disciplinary action against top Wuhan officials.
Okay, so garbage in garbage out. Anyone, I wanted to see what happened in real life with social distancing. One comment is that nothing I found showed any second order effects (e.g., depression). But, here's a summary from a paper in the National Collaborating Centre for Infectious Diseases:
A study by Copeland et al. provided such an opportunity in the context of the early stages of 2009 pH1N1 in Texas, USA. Two adjacent counties within the Dallas/Fort Worth metropolitan area, with similar demographic and epidemiologic characteristics.
Copeland et al. found evidence that school closure reduced self-reported ARI and emergency visits related to influenza. Their analysis demonstrates that, while ARI increased in both intervention and control groups from before to during school closure ([Intervention Community]: 0.6% before to 1.2% during; [Control Community]: 0.4% before to 1.5% during), increases were 45% lower in the intervention community.
Emergency department visits showed similar improvements associated with school closure. Prior to school closures, the percentage of daily visits to emergency departments attributed to influenza was similar in the two communities. Rates increased from before to during school closures in both communities ([Intervention Community]: 2.8%- 4.4%; [Control Community]: 2.9%- 6.2%), though again the control community saw greater, and more than two-fold increases. Most of the difference between communities was attributed to differences in the school-aged population.
So, an improvement in school closures. Many things are missing. The infection rate continued to increase after schools closed. But, still, an improvement.
An observational study by Awofisayo et al. described a risk-based approach to decision-making developed and implemented during the 2009 influenza H1N1 pandemic in a hard-hit region of West Midlands, England. In the absence of definitive guidance on triggers for school closure, the Health Protection Agency (HPA) together with several stakeholders, sought a method to use available evidence to guide a coordinated response during the ‘containment phase’ of the pandemic, when the greatest priority was to limit the spread of influenza.
Although this study was not designed to assess the effectiveness of school closures, the authors observed that the reactive approach employed, usually of short duration, and in a context of a rapidly accelerating outbreak, likely had minimal impact on containing the spread of influenza in the region. As well, anecdotal reports indicated that benefits of closures may have been negated by a compensatory shift in children’s social interactions from schools to the community.
Here, it was ineffective. However, anecdotally, it might have worked if children complied.
A study by McVernon et al. . . . was based on anonymous telephone and online surveys completed by parents whose children attended schools that had been closed as a public health measure in the early stages of the influenza H1N1 pandemic in the state of Victoria, Australia. Victoria’s policies at this time called for closures in schools that had multiple confirmed cases in different classes, where the recommended minimum duration of closure was seven days from the date the last confirmed case attended school. Influenza cases and their family members were asked to remain at home and refrain from contact with others.
McVernon and colleagues found high levels of compliance with quarantine, at both individual and household levels, and particularly high compliance in households with a case of influenza. Of those who were quarantined, household members stayed at home for more than 94 percent (95% CI, 92.8–95.9) of the recommended period. Most respondents (88%) stayed at home for the entire recommended time. Household level compliance was also high, with 84.5% (95% CI, 79.3–88.5) or 250 of the 301 participating households reporting full compliance.
[A] less expected finding by McVernon and colleagues was the extent of variability in the quarantine recommendations given to families, which reflected public health system challenges in consistent implementation of closures. The authors suggest that irregular practice rather than public compliance may undermine the effectiveness of school closures.
Reading this, and this might be a stretch, it feels like public trust in institutions is a big factor in whether or not social distancing takes place. When there is a lack of trust in institutions or divisions in those institutions it won't happen.
I wanted to include a couple of summary items though, too:
Cost-effectiveness of school closure improves with higher transmission rates, longer duration of a pandemic, and greater severity.
Relative to other measures, such as immunization, school closures are much less cost effective.
Neither short- nor long-term school closures (nor other social distancing measures) when used alone, are cost-effective.
I actually find this interesting, I haven't drawn any conclusions. The only conclusion I'm leaning towards is that without trust in institutions society breaks down. However, quite frankly, I don't think those institutions have earned our trust.