Individually optimal choices can be collectively disastrous in COVID-19 disease control.

BACKGROUND: The word 'pandemic' conjures dystopian images of bodies stacked in the streets and societies on the brink of collapse. Despite this frightening picture, denialism and noncompliance with public health measures are common in the historical record, for example during the 1918 Influenza pandemic or the 2015 Ebola epidemic. The unique characteristics of SARS-CoV-2-its high basic reproduction number (R0), time-limited natural immunity and considerable potential for asymptomatic spread-exacerbate the public health repercussions of noncompliance with interventions (such as vaccines and masks) to limit disease transmission. Our work explores the rationality and impact of noncompliance with measures aimed at limiting the spread of SARS-CoV-2. METHODS: In this work, we used game theory to explore when noncompliance confers a perceived benefit to individuals. We then used epidemiological modeling to predict the impact of noncompliance on control of SARS-CoV-2, demonstrating that the presence of a noncompliant subpopulation prevents suppression of disease spread. RESULTS: Our modeling demonstrates that noncompliance is a Nash equilibrium under a broad set of conditions and that the existence of a noncompliant population can result in extensive endemic disease in the long-term after a return to pre-pandemic social and economic activity. Endemic disease poses a threat for both compliant and noncompliant individuals; all community members are protected if complete suppression is achieved, which is only possible with a high degree of compliance. For interventions that are highly effective at preventing disease spread, however, the consequences of noncompliance are borne disproportionately by noncompliant individuals. CONCLUSIONS: In sum, our work demonstrates the limits of free-market approaches to compliance with disease control measures during a pandemic. The act of noncompliance with disease intervention measures creates a negative externality, rendering suppression of SARS-CoV-2 spread ineffective. Our work underscores the importance of developing effective strategies for prophylaxis through public health measures aimed at complete suppression and the need to focus on compliance at a population level.

A smartphone-smartcard platform for contingency management in an inner-city substance use disorder outpatient program.

Contingency management (CM) is an efficacious incentive-based intervention for promoting drug abstinence, but treatment providers have not widely adopted it. Smartphone and smart debit card technologies can deliver automated, patient-centered, high-fidelity CM and related services, including cognitive behavioral therapy and appointment reminders. This study evaluated clinical outcomes associated with an integrated smartphone-smartcard platform in an inner-city outpatient clinic. We enrolled adults with opioid use disorder (n = 85) over nine weeks, and they received CM services for four months. We retrospectively compared them to matched controls who received services at the same time, from the same provider at a similar, nearby clinic in the same city. The platform was associated with significantly higher rates of counseling appointment attendance in study months 2 to 4 (9.6%-18.0% increases) and an odds ratio of 4.84 for increased proportion of urine samples consistent with drug abstinence and adherence to prescribed medication, compared to controls at 120 days (P < 0.05). Overwhelmingly, participants reported that they found the platform acceptable. These results suggest that the platform is an effective method for remote delivery of CM services that could overcome key logistical barriers to widespread adoption of CM among treatment providers.