What Lessons from the First Wave Apply to a Second Wave of COVID-19?
During the current public health crisis, many agencies and media outlets are reporting COVID-19 health outcome information based on the overall populations. Basing decisions on overall COVID-19 case counts and mortality can be misleading and offer faulty guidance for delivering public health interventions to high risk populations. Such guidance is critical during the second and potentially more devastating wave of the pandemic. A University of Illinois School of Public Health and Purdue research team has been examining spatial and temporal patterns of COVID-19 mortality with a focus on the significant loss of life from COVID-19 among Long-Term Care Facility (LTCF) residents in contrast to mortality in the community residents of private households (non-LTCF). The team is using data from Cook County Illinois as a test case to illustrate the importance of visualizing outcome information correctly.
The goals of the study are:
• Improve the accuracy of commonly quoted COVID-19 mortality indicators;
• Gain a better understanding of spatial and temporal distribution of COVID-19 deaths;
• Examine the role of race, ethnicity, and socioeconomic status in COVID-19 mortality;
• Identify population and organizational parameters that can inform strategies for public health interventions.
Prioritizing the allocation of resources based on reliable information is a prerequisite of a successful mitigation strategy and immunization plan. Findings from our research have significant implications. The state and federal government face a series of policy decisions both due to the recent surge in positive cases and, when the time comes, the need to rationalize distribution of vaccines to high priority groups beyond healthcare workers and nursing home residents. The research team seeks to modify prevailing practices in order to derive reliable information that guides policy decisions. The team identified high-risk LTCFs and residential areas of Cook County from readily available, real-time mortality data.
Spatial Distribution of COVID-19 Mortality
Our research has identified distinctly different spatial patterns in COVID-19 between LTCFs and community households. Figure 1 displays the mapping of COVID-19 deaths by zip code among LTCF residents (left map) compared to deaths by zip code of non LTCF residents (right map).
Figure 1. Difference of Long-Term Care Facility (LTCF) Related Mortality and Household Population (HP)-Related Mortality rate per ZIP Code (as of July 31, 2020).
Characteristics of LTCFs and Neighborhoods Related to Mortality Rates
In preliminary analysis we found three neighborhood (zip code) characteristics influencing COVID-19 mortality among persons in the community: the percentage of minority group residents, the density of the population ( population per square mile) and socio-economic status (SES) The mortality rates in neighborhoods with high concentrations of African-American and Hispanic populations had the highest adjusted COVID-19 death rates. These findings are in line with other studies finding an elevated risk of COVID-19 in minority populations. 1,2
Higher population density is a well know predictor of disease exposure. Also generally lower socioeconomic and minority workforces are employed in service jobs, including in healthcare, increasing the likelihood of COVID-19 exposure of these groups. Thus, racial and economic population disparities in zip codes are likely increase the risk of severe COVID-19 mortality.
Rates of mortality in LTCFs were much more difficult to predict than household mortality. As shown in Figure 1, the rate of community mortality was unrelated to the rate among LTCFs in the same zip code. The percentage of non-white residents did not appear to be strongly correlated with LTCF mortality however the measure of race /ethnicity may need further refinement to verify this conclusion.
In our analysis of COVID-19 nursing facility data recorded by the Center for Medicare and Medicaid Services (CMS) 3, we found a correlation between the number of COVID-19 cases among nursing facility staff and cases among residents. Also, we found patterns over time in incidence of COVID-19 cases among nursing facility staff that paralleled the trend in cases among residents. These findings raises the possibility, suggested by other researchers, that the community COVID-19 incidence is related to LTCF incidence and mortality. 4,5
A number of causes may underlie this correlation. Staff of LTCFs living in the wider community, outside the zip code of the LTCF and perhaps in high risk neighborhoods, may be transmitting COVID-19 to LTCF residents.6 Simultaneously, LTCF facility staff may be contracting COVID-19 in the work setting and transmitting it back into the community. Another possible contributor to spread of COVID-19 in LTCFs is transfer of individuals between acute care hospitals and the LTCFs. According to CMS data, Cook County nursing facilities had over 190 weekly COVID-19 admissions from the hospital in June, a drop in admissions to 50/week from July – October. A sharp upward trend to 150 admissions/week was recorded in November.
Temporal Patterns in Mortality
The adjustment of mortality rates for LTCF effects is not only relevant to accurately visualize the spatial situation but is also necessary to evaluate and forecast trends in mortality. To illustrate the importance of isolating LTCF trends, we present results using moving averages of mortality during the first COVID wave. During the first wave in the spring 2020 (see Figure 2), COVID-19 cases and mortality in LTCF (red) have lagged behind the COVID-19 spreads and deaths in the community (green). The time lag between the LTCF and HP losses, probably represents the lag in transmission from the community to LTCF. As seen in Figure 2, the LTCF related losses peaked at 40 losses per day after surpassing the community losses.
Figure 2 First wave characteristics of LTCF and HP related mortality depicted as a 14-days moving average.
By taking into account the characteristics of the first wave, we performed an early assessment of the second wave pattern. Figure 3 displays the 14-day moving average which depicts the community and LTCF related patterns of mortality. At the start, the almost parallel trajectories signify that the COVID-19 transmission pathway to the LTCF residents remained active during the early summer months. However, the latter part of the second wave graph raises serious concerns since after mid-October it is likely that the LTCF related mortality is entering an acceleration phase similar to the one seen during the first wave (see Figure 2).
Figure 3 Forecasted 2nd wave pattern of LTCF and community deaths (HP) depicted as a 14-days moving average.
As of November 25, 52% of LTCF deaths in Cook County are located 18 facilities and 10 ZIP codes. The losses in October were 2 per day; in November this loss was close to 8 per day. The risk is that the LTCF mortality trend will follow a pattern similar to the first wave and peak after the peak of the community mortality. Without a vaccine intervention and measures, the peak LTCF mortality rate raises serious concerns with a LTCFs death toll that greatly exceeds the 10 per day.
Strategies to Address a Possible Second Wave of COVID-19
From a policy point of view, the above findings raise a number of issues that demand immediate public health action. Such action is imperative in order to avoid seeing the losses climb to a 40 per day 5-day moving average seen in the first wave. The first wave put enormous strain on LTCFs under circumstances of staff shortages and limited access to PPE. 7 The LTCFs are probably in a better position now to contend with COVID-19 compared to March when the initial COVID-19 surge began. According to reports for the week ending November 15 (CMS data), all Cook County nursing facilities had access to COVID-19 testing for residents and staff. Yet, only 26% of facilities had testing at the point of care and only 3% of facilities could obtain same-day results.
Approximately three-fourths of nursing facilities did surveillance COVID-19 testing of asymptomatic staff or residents; the other one-fourth only tested when a person exhibited symptoms or had been in contact with a person having COVID-19. Over 95% of facilities reported having a 7-day supply of masks, eye protectors, and gowns. In addition, 91% of facilities reported no nursing staff shortages the week of November 15. However, it remains to be seen if staff shortages might arise in subsequent weeks with a new surge of COVID-19 cases.
Our findings suggest a two pronged approach aimed at breaking the cycle of transmission from community to LTCFs. Public health officials should re-double efforts to prevent a community surge through:
Clearly articulated policies for social distancing, face covering, and restricted access to high-risk setting for spread of COVID-19;
Targeted testing in hot-spot or likely to be hot-spot neighborhoods that are densely populated, low income, and have concentrations of minority groups;
Targeted interventions for vulnerable at-risk populations (with co-morbid conditions, advanced age, and residing in at-risk neighborhoods). When COVID-19 vaccines become available, they should be targeted to areas of the city at highest risk. These interventions should combine resources of health departments, Area Agency on Aging, and health systems to reach out to at risk individuals.
With regard to LTCFs, health system and public health agencies should devote resources to up-stream prevention of COVID-19 spread and mortality among LTCF residents before they are hospitalized and strain ICU capacity. The CDC 8, Illinois Department of Public Health 9, and other sources 10 have urged these actions:
Contact tracing of LTCF staff and residents;
Rapid testing of LTCF residents and staff;
Emergency nursing and medical support for burned out and depleted LTCF staff;
Transitional support between nursing facilities, hospitals, and community;
Vaccinate, as a priority, LTCF residents and all staff when COVID-19 vaccines become available.
The issue of priority vaccinations for high risk communities should also be addressed. LTCFs should receive financial and other resources to step up their mitigation efforts, including carefully controlled visitation, isolation, PPE, and other infection control practices.
Our analysis strongly supports these measures.
Using Mapping to Target Interventions
The analytical framework developed by our team, provides a better visualization of the areas which will be significantly impacted during the second wave. This visualization can assist policymakers address the high risk areas which are different than those during the first wave. This difference is seen in Figures 4 and 5 where 1st wave data is compared to 2nd wave data for the LTCF and HP residents. For the household population (HP), Figure 4, the majority of high death rate areas are concentrated in the periphery of the City whereas the comparable 1st wave areas were concentrated in the south and south east section.
Figure 4 HP-related death rates (per 100,000 population) for the 1st wave (ending 4.18.20) and 2nd wave (starting 9.27.20).
The LTCF distribution is significantly different and the majority high death rate areas are concentrated in the North West part of Cook County whereas the comparable 1st wave areas where concentrated in the South West (see Figure 5).
Figure 5. LTCF-related death rates (per 100,000 population living in group quarters) for the 1st wave (ending 4.18.20) and 2nd wave (starting 9.27.20).
Conclusions
Prevailing practices which rely on aggregate population analysis and visualization can be misleading. We have shown how Information on spatial and temporal patterns in COVID-19 mortality can guide policies to address high priority areas in Cook County. By focusing on high-risk LTCFs and high risk residential areas, intervention measures can be implemented to minimize COVID-19 spread and subsequent mortality. When COVID-19 vaccines become available, they should be distributed to the same high-risk populations. Although the case discussed here focused on Cook County, the basic approach can effectively be applied on a state wide level.
Detailed findings, additional tables, maps and figures are available at:
https://storymaps.arcgis.com/stories/55a419ee24744a7698e9877f73384023
https://storymaps.arcgis.com/stories/962fe31af7f04a43832d6de375cd6ca7
References
1. Selden TM, Berdahl TA. COVID-19 And Racial/Ethnic Disparities In Health Risk, Employment, And Household Composition: Study examines potential explanations for racial-ethnic disparities in COVID-19 hospitalizations and mortality. Health Affairs. 2020;39(9):1624-1632.
2. Figueroa JF, Wadhera RK, Lee D, Yeh RW, Sommers BD. Community-Level Factors Associated With Racial And Ethnic Disparities In COVID-19 Rates In Massachusetts: Study examines community-level factors associated with racial and ethnic disparities in COVID-19 rates in Massachusetts. Health affairs. 2020:10.1377/hlthaff. 2020.01040.
3. Centers for Medicare and Medicaid Services. COVID-19 Nursing Home Data. https://data.cms.gov/stories/s/COVID-19-Nursing-Home-Data/bkwz-xpvg. Published 2020.
4. Sugg MM, Spaulding TJ, Lane SJ, et al. Mapping community-level determinants of COVID-19 transmission in nursing homes: A multi-scale approach. Science of the Total Environment. 2020;752:141946.
5. Nguyen LH, Drew DA, Graham MS, et al. Risk of COVID-19 among front-line health-care workers and the general community: a prospective cohort study. The Lancet Public Health. 2020;5(9):e475-e483.
6. Chen MK, Chevalier JA, Long EF. Nursing home staff networks and COVID-19. National Bureau of Economic Research;2020. 0898-2937.
7. McGarry BE, Grabowski DC, Barnett ML. Severe staffing and personal protective equipment shortages faced by nursing homes during the COVID-19 pandemic: Study examines staffing and personal protective equipment shortages faced by nursing homes during the COVID-19 pandemic. Health Affairs. 2020;39(10):1812-1821.
8. Centers for Disease Control and Prevention. COVID-19 Nursing Homes and Long-Term Care Facilities. https://www.cdc.gov/coronavirus/2019-ncov/hcp/nursing-home-long-term-care.html. Published 2020. Accessed November 22 2020.
9. Illinois Department of Public Health. Long-Term Care Facilties Guidance. https://www.dph.illinois.gov/topics-services/diseases-and-condition HYPERLINK "https://www.dph.illinois.gov/topics-services/diseases-and-conditions/diseases-a-z-list/coronavirus/long-term-care-guidance"s/diseases-a-z-list/coronavirus/long-term-care-guidance. Published 2020. Accessed November 22 2020.
10. McGilton KS, Escrig-Pinol A, Gordon A, et al. Uncovering the devaluation of nursing home staff during COVID-19: are we fuelling the next health care crisis? Journal of the American Medical Directors Association. 2020;21(7):962-965.
