Health System
COVID-19 Questions & Myths
14. How should we interpret daily data updates to understand the threat of COVID-19?
People naturally tend to focus on the number of new cases; however, other pieces of information add understanding.
Current hospitalizations and deaths show how many are severely affected and indicate if the system is overwhelmed today. Currently, in Alberta 3-4% of COVID19 cases are hospitalized and 1% die, but 20-25% of the elderly require hospitalization and greater than 10% die. Public health restrictions are needed until the hospital system is able to resume full normal care for COVID-19 and non COVID-19 patients. Our capacity has expanded for COVID-19 patients by delaying less urgent care and increasing the patient care beds and workload of available health care workers.
Looking at the daily new cases trend reported by Alberta Health over 1-2 weeks informs us if hospitalization and deaths will increase or decrease. Patients entering hospital today typically first had symptoms 7-10 days ago, and likely tested positive 2-3 days into symptoms. In general, new daily cases should not exceed 300/day in Alberta to avoid overwhelming hospitals and impairing other care.
Next, we look at percent positivity. The percent positive is the percentage of all COVID-19 tests done that day that are actually positive (Johns Hopkins Bloomberg School of Public Health). This indicates how widespread infection is, and whether the total number of tests is sufficient. A high percent positive means that many community cases are being missed, and more testing should be done. For example, in some places one out of every five tests is positive (20% positivity) which suggests that there are many undetected cases. The World Health Organization recommends that governments shouldn’t consider reopening until there has been under 5% positivity for two weeks.
The R value also describes disease transmission trends. Also called the reproduction number, it describes whether community transmission is increasing, decreasing or staying the same. It tells us the average number of people that someone with COVID-19 will infect. If the R value is one this means on average one infected person will infect one other person and the outbreak will continue. If the R is greater than 1 the outbreak is growing. We look for a trend of the R value to be 0.8 or less before easing public health restrictions. BioMed Central published an article showing the R value of COVID-19 without restrictions in place early in the pandemic was usually in the range of 2 to 3, and that of seasonal influenza about 1.3.
References:
i. COVID-19 Testing: Understanding the “Percent Positive”, Johns Hopkins Bloomberg School of Public Health
ii. Cases in Alberta, Alberta Health
iii. Estimates of the reproduction number for seasonal, pandemic, and zoonotic influenza: a systematic review of the literature, Biggerstaff, & et al., BioMed Central
15. How many patients are in the hospital because of COVID-19 versus “WITH” COVID-19?
Based on emergency room diagnoses and admission data in Alberta, the majority of patients are admitted with severe viral pneumonia requiring oxygen treatment or admission to ICU for mechanical ventilation. A very small number of patients are admitted for other care and are discovered to have COVID-19 at or after admission. A study in the Canadian Medical Journal on the first wave found no COVID-19 cases in 1814 people admitted to three Alberta hospitals for non COVID causes.
16. Is the virus really threatening our healthcare capacity? We are supposed to have 3000 extra beds and more than 1000 extra ICU beds.
Yes. As of January 2021, COVID-19 patients require the equivalent of two large community hospitals and 10 community ICUs, on top of the usual care for patients with other medical and surgical problems. Alberta has less ICU bed capacity than most Canadian provinces at 7.9 ICU beds/100,000 population, following decades of hospital downsizing. In comparison, the number of ICU beds per 100,000 people in Quebec is 11.4, Nova Scotia 15 , the USA 25, and Germany 35 as per the “Critical Care Capacity in Canada: Results of a National Cross-Sectional Study”.
It is possible to provide extra ICU beds and life support equipment; however, impossible to rapidly create an experienced health care team of ICU doctors, nurses, and respiratory therapists for this number of beds. It takes six years after medical school to educate an ICU specialist and six months of training for a critical care nurse. Critically ill patients with COVID-19 require a highly trained team working at the bedside around the clock.
Reference:
i. Critical care capacity in Canada: results of a national cross-sectional study, Fowler RA et al.