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Michael Wolfson

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  1. Posted May 4, 2020 Photo: Health worker performs a coronavirus throat swab test Sophisticated sampling strategy needed to adapt to evolving policies associated with gradual relaxation of physical distancing. Go to story
  2. May 4, 2020 Sophisticated sampling strategy needed to adapt to evolving policies associated with gradual relaxation of physical distancing. THE FEDERAL GOVERNMENT recently announced it will fund at least one million blood tests to track the novel coronavirus over the next two years. This is a step in the right direction. But is it enough? How do we know if we are testing the right number, and the right people, especially as the pressure to ease up on the lock down and isolation rules increases? The answer depends critically on why we need test results. A sophisticated sampling strategy is the only path forward at present. There simply is not enough resources to test everyone or even perform a simple random sample. Health worker performs a coronavirus throat swab test Perhaps half of those infected do not show more than very mild symptoms, if any. These individuals have greatly complicated efforts at epidemic control. If everyone infected with COVID-19 had symptoms, we could simply require them to self-isolate. Instead, we have to keep two meters from everyone and wear masks, because we cannot tell if they are infected but not showing it. Public health agencies clearly need to continue and expand testing for high risk populations, including front-line health care workers, personal support workers (PSWs) working in nursing homes, retirement residences and in home care, as well as the public health workers doing contact tracing. But we need to do better, with reliable real-time data on how many people in the population are, or have been, infected and where they are. Tests of current infections, with a lag of a few weeks, signal impending hospitalizations. That’s no longer good enough. It is essential to detect and isolate infected individuals quickly, and as many of their contacts as can be traced, if we want to relax the restrictions as quickly as possible. Blood tests as the government has just announced, can tell us how many people have been infected (though the amount of resulting immunity remains unknown). But these will likely be far below those needed for herd immunity, so low that significant relaxation of physical distancing would result in a surge of new infections—straining health care resources, causing more deaths, and requiring the reintroduction of draconian controls. To monitor adequately, the tests cannot cover only symptomatic individuals since this will miss the large asymptomatic or pre-symptomatic portion of the infected population. It matters who is tested. If it’s mainly individuals who live alone and are careful about physically isolating, most tests will be negative. For PSWs or meat processing plant workers, though, the same number of tests could find much higher rates of infection. To provide valid and useful results, testing needs to be based on sophisticated sampling, simple random samples will not work. A highly controversial Santa Clara study of how many residents have been infected shows the perils of poor sampling. For example, nursing homes need their own samples; indeed, every resident should be tested periodically for the time being. For the general population, though, a multi-pronged effort is needed, starting with new clusters of infection, including key groups such as front-line workers in shops that are re-opening. We also need to distinguish geographic regions within provinces, for example, different cities. Even though most of the public discussion has been about policies at the provincial level (and state level in the US), proper sampling, and relaxation policies, will need to target very real differences within provinces. In sum, we need a sophisticated sampling strategy for testing, and one that can adapt to evolving circumstances, not least as physical distancing and related policies are reduced. These data need to be accessible for statistical analysis not only locally, not only provincially, but also nationally, and of course they need to be securely handled and protected. Testing results, based on proper and extensive sampling, are fundamental to improving the model results shown on TV and used by governments to inform the relaxation of restrictions. This would allow us to return to a new normal—more quickly, and with lower risks of serious mistakes. Michael Wolfson, PhD, is a former assistant chief statistician at Statistics Canada and a member of the Centre for Health Law, Policy and Ethics at the University of Ottawa.
  3. Posted April 17, 2020 It’s time the federal government used its authority to create critical data infrastructure. Go to story
  4. It took the federal government until April 9 to publish projections of morbidity for COVID-19 in Canada CANADIANS ARE FINALLY BEGINNING TO SEE projections of COVID-19 cases, deaths and needs for intensive-care units from various provinces and the federal government. We are also starting to see simulations that look beyond the next month or two when, hopefully, epidemic curves are clearly flattening. Canada’s national data-collection capacity will be critical for the next stage of the pandemic, when relaxing of the stringent physical-distancing measures can begin. Yet our data-collection infrastructure is proving woefully inadequate. To be effective, an extraordinary and co-ordinated national effort is required, with much more extensive testing and real-time standardized reporting of results, from local to provincial to federal agencies. These data on the tests will be much more powerful for managing the pandemic if they also include pre-existing diseases and risk factors such as smoking. These kinds of data flows are obviously feasible with current computing and communication technologies. Indeed, they were feasible 20 years ago when the federal government created the Canada Health Infoway corporation and provided it with billions of dollars. One of its missions was to work with the provinces to develop interoperable real-time “outbreak detection” systems. Had these systems been in place even as late as last year, Canada would not have wasted critical weeks and months in reacting to COVID-19. And if these systems were in place now, we could manage relaxing the current lockdown phase with “smart quarantine” and reap the major benefits of returning the economy to normalcy at a faster rate. So why do we still not have this real-time standardized data-reporting capacity? One blockage is the constitutional conflict over jurisdiction; the provinces claim almost exclusive jurisdiction over health care. The federal government also plays a substantial role, spending billions on health research and fiscal transfers to the provinces and regulating drugs and devices – on top of the billions given to Infoway – but it has been too timid to use all its powers much beyond ineffectual cajoling. Another blockage is fear of transparency. It has taken strong public pressure for governments to begin providing even limited epidemic-curve projections on which their policies are based. Of course, we need to ensure patients’ sensitive health data remain confidential except as needed in their circle of care. However, as the Council of Canadian Academies noted in its 2015 report, data custodians too often use privacy concerns to block access, stymieing major benefits of health research and, in the current emergency, support for both smart quarantine and much better modelling and projections. What can we do about these completely unacceptable blockages? There are several places to start. The Canadian Medical Association can offer strong leadership by supporting real-time interoperable data not only for their own interests and individual patient care, but also for broader health-system uses, not least for epidemic detection and management. The private-sector vendors of electronic medical-record systems can immediately cease their profit-capturing data blockages and allow their software to interoperate in real-time with those of other vendors and government systems. Provincial governments can agree quickly on more in-depth and uniform data standards for hospitals, labs and physicians so that, along with the federal government, they can quickly and unambiguously assemble these data, especially virus-testing results. Privacy commissioners need to alleviate the excessive concerns over privacy around health data, to rise above responding only to complaints, and to make it clear that – especially in this emergency situation – they support essential data flows, provided that basic privacy protections are in place. The Public Health Agency of Canada and the provinces can open up their data beyond a few pages to the energy and creativity of Canada’s excellent university-based health researchers and modellers and support the CIHR-funded pan-Canadian network. In turn, Statistics Canada can expedite a virtual form of its Research Data Centres so that bona fide health researchers can access much higher-quality data with appropriate privacy protections. The federal government must assert its leadership and authority, using its constitutional powers, to set critical national standards and enforce the collection, sharing and use of public-health data – and finally bring Canada into the 21st century of critical data infrastructure. Michael Wolfson, PhD, is a former assistant chief statistician at Statistics Canada and a member of the Centre for Health Law, Policy and Ethics at the University of Ottawa.
  5. March 25, 2020 IT'S TAKEN TOO LONG for many governments, including Canada’s, to recognize the seriousness of the Corona virus pandemic when even days of delay can have large effects on the ultimate death toll. It is only now that our governments are recognizing that successfully flattening the epidemic curve means that we could be self-isolating for more than just a month or two. It is not too soon to start planning for the phase after, when it is time to begin relaxing the social distancing measures. If this relaxation is not done very carefully, the epidemic will simply resume. During the 1918 Spanish flu epidemic, which killed tens of millions world-wide, some cities like St. Louis quickly instituted rigorous social distancing while others, like Philadelphia, did not. Both had resumptions of the epidemic after their social distancing and quarantine efforts were relaxed. At present, a major issue is that we do not even know, in Canada and in most other countries, how many individuals are infected. We know how many cases have been reported, but these tend to be individuals with more than very mild symptoms. Various studies have estimated that for every reported case, there could be anywhere from 10 to 100 unreported cases. It is possible to successfully limit the spread of the virus, as we can see in Wuhan, Singapore, Taiwan and South Korea, and to avoid the catastrophe unfolding in parts of Italy, where doctors are now having to decide who among their gravely ill patients can have their life saved with a ventilator. But how will we know when and how to begin relaxing the very stringent social distancing measures now being implemented, and allow Canadians to safely resume their daily lives without fear of getting sick, and without the risk of infecting anyone else? For evidence informed public health policy, we need accurate information. There is an international movement to develop smart phone apps that, with big data analytics, could provide critically needed real-time information to help track the pandemic. But serious options quickly run into questions of protecting personal privacy, especially with the public’s growing concerns about the behaviours of high-tech firms like Google, Facebook, Amazon and Twitter. So, is there a way, in Canada, for us to be both sensitive to very real concerns about personal privacy and be able to use the obvious potential of social media-type apps? In principle, individuals with immunity, could be issued a “green card” authorizing them to resume fully all their social activities. On the other hand, those who are infected would have a “red card,” while those who are still susceptible would be in a “yellow” state. In fact, China is implementing a system like this using a smart phone app already. If your phone shows red, your freedom is highly restricted. Obviously in Canada, surveillance measures would have to be compliant with protections guaranteed under the Canadian Charter of Rights & Freedoms and relevant federal and provincial privacy laws. But there would be major benefits to developing this kind of data infrastructure to manage both the current and subsequent phases of the pandemic. Public health policy and implementation need smart ways to manage the relaxation of COVID-19 containment measures. This includes being able quickly, in real time, to identify clusters of new infections and isolate them; and to monitor people arriving from outside the country in case they become infectious. It will also be necessary to monitor the movements of any already infected individuals in order to enforce their isolation as the large pool of Canadians who would still be susceptible to infection return to more normal social life. Canada’s current infectious disease surveillance data flows are simply not up to the standards of countries like Taiwan. Still, there are very serious trade-offs here. The more detailed the data collected, the more sophisticated the evidence that can be produced to inform smart public health policy. But at the same time, more detailed data collection will be more invasive of individual privacy. Being able to deploy this kind of real-time geographically detailed infectious disease surveillance requires serious planning by Canadian governments and key researchers now. It is not too soon to begin discussing where to strike the right balance. Michael Wolfson, PhD, is a former assistant chief statistician at Statistics Canada and a member of the Centre for Health Law, Policy and Ethics at the University of Ottawa.
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