How does VDH Count COVID-19-Associated Deaths?

The Virginia Department of Health (VDH) counts the number of deaths associated with COVID-19 to understand the impact of the COVID-19 pandemic. VDH is drawing on experience counting deaths for other reportable conditions to be as accurate as possible. For some health conditions, there is a national standard for how to count deaths as disease-associated mortality. Influenza-associated pediatric mortality and RSV-associated mortality are good examples. For other conditions, the national standard for which situations get counted applies to the case itself. Identifying which cases result in death becomes part of the case investigation. This might occur through review of a medical record, discussion with the patient’s healthcare provider, or through review of the patient’s death certificate. 

The COVID-19 standardized case definition outlines which cases and deaths get counted. VDH counts a COVID-19-associated death if it meets one of the three criteria below:

  1. During the case investigation, the case investigator determined that the patient passed away due to COVID-19. This may occur through the review of the patient’s medical record, talking with the patient’s healthcare provider, or talking with the patient’s family.
  2. VDH receives a death certificate that matches a known confirmed or probable case of COVID-19 and either:
    • The death certificate specifically lists COVID-19 or SARS-CoV-2 as the primary or contributing factor in death, or
    • The death certificate lists a directly related cause of death (examples include Acute Respiratory Distress Syndrome, viral pneumonia, and hypoxic respiratory failure), the death occurred within 60 days of the patient becoming sick, and there’s no evidence of recovery between the date the patient became sick and the date of death.
  3. VDH receives a death certificate that does not match a known confirmed or probable case of COVID-19 and the death certificate specifically lists COVID-19 or SARS-CoV-2 as the primary or contributing cause of death. These situations are entered as new probable cases that resulted in death.

Even for known confirmed and probable COVID-19 cases, if a death certificate lists an alternative cause of death that better fully explains the patient’s death, VDH does not count that person as a COVID-19-associated death. Examples include suicide, gunshot wounds, motor vehicle accidents, and drug overdose. VDH only counts people who died as a result of COVID-19, not people who died of another more directly related cause while also having COVID-19.

Many deaths that VDH reviews are people that have underlying conditions like diabetes, heart disease, or dementia. VDH only counts people as COVID-19-associated deaths if the person’s medical record, healthcare provider, or official death certificate indicates that they died due to COVID-19 or as a result of an acute respiratory complication related to COVID-19. If a person with COVID-19 dies and their healthcare provider does not tell us the death was COVID-19-related and the death certificate lists something like cancer or end stage renal failure as the only cause of death, then VDH does not count that death as COVID-19-associated.

VDH does count deaths among people with underlying conditions where the death certificate specifically lists that COVID-19 as the primary or contributing cause of death. Many of these death certificates also list the underlying condition. In these situations, it is likely that the COVID-19 infection worsened the underlying condition and the two together contributed to the patient’s death. 

Some helpful things to remember about COVID-19-associated deaths:

  • Death is one possible outcome of a COVID-19 infection. The number of deaths reported by VDH is a subset of the total number of COVID-19 cases.
  • Probable deaths are deaths that occurred in persons classified as probable COVID-19 cases.
  • There is a delay between a rise in cases and a corresponding rise in deaths.
    • This is partly due to the progression of the disease – on average, death occurs a week or more after a person becomes sick with COVID-19.
    • Each death certificate is reviewed carefully according to stringent criteria by a subject matter expert which takes additional time. 
  • Graphs showing the number of deaths reported by day does not represent when a death occurred.
  • There is the option to view VDH’s data on COVID-19-associated deaths by the date of death here, which is a more accurate representation of when death occurred than looking at deaths by the day they were reported.

 

*Originally posted on January 11, 2021.

Quality Assurance Steps for COVID-19 Data

During the COVID-19 response in Virginia, the Virginia Department of Health (VDH) is reporting public health data in more detail and more quickly than ever before. VDH routinely performs ongoing and comprehensive quality assurance on COVID-19 cases, hospitalizations, and deaths, including those that have been previously reported to VDH. Performing data quality assurance, such as checking for correct addresses, re-classifying cases to align with national case definitions, and other efforts, is important for public health. It helps make sure that data that are reported and presented are as accurate and timely as possible. The data quality assurance steps VDH takes are not new. Public health professionals perform these data quality steps for many health conditions in addition to COVID-19. Because of these steps, it is important to note that all data are preliminary and subject to change.

Checking for Locality of Residence:

One of the data quality assurance steps that VDH takes is checking for correct addresses. VDH initially assigns a case to a locality (county or independent city) based on the patient’s residential ZIP code. In Virginia, some ZIP codes cross between multiple localities. Upon further review of the case, which includes applying geocoding to the residential address, VDH may determine the original locality assigned to the case is not correct. In these scenarios, the case will be re-assigned to the appropriate locality, which may result in a negative count for the original locality and a positive case count in the re-assigned locality.

Classifying a COVID-19 Case: 

To determine if a person should be counted as a COVID-19 case, VDH uses criteria outlined in a national case surveillance definition by the Centers for Disease Control and Prevention (CDC). Disease surveillance is foundational to public health practice. It helps understand diseases and their spread and informs appropriate actions to control outbreaks. VDH performs several steps to ensure each COVID-19 case reported in a Virginia resident meets these specified criteria.

Not every COVID-19 case involves a positive test, and not every positive test reported to VDH is counted as a COVID-19 case. Some cases are counted because they show symptoms of COVID-19 and had close contact to another known COVID-19 case as described in the national case surveillance definition. Additionally, there are people in Virginia who have been tested more than once for COVID-19. Some of these people are in higher risk settings such as healthcare or nursing homes, and others are known COVID-19 cases who needed negative tests to return to their normal routine. When a person is tested many times over the course of their COVID-19 infection, VDH reviews all the test results to ensure multiple positive test results for the same infection in one person are not counted as multiple COVID-19 cases. However, there are instances where a person may be counted as more than one COVID-19 case. This may happen when a person tests positive again more than 90 days from the first test, or when a person tests positive for COVID-19 with a different SARS-CoV-2 variant, which could indicate potential re-infection. 

The data quality steps described above may result in changes to the number of cases, hospitalizations, and deaths in your community or within the state. Negative numbers in case counts by report date on the VDH COVID-19 data dashboards may be observed as quality assurance steps are completed. The dashboards most likely to be impacted are: Locality and Level of Community Transmission.

 

*Originally posted on June 17, 2021.

Imputing Missing Race and Ethnicity Data in COVID-19 Cases

Health equity is a cornerstone of public health. This is especially true during the COVID-19 pandemic when many populations are suffering from both the health and economic consequences of the disease. Good information on disparities in disease incidence, outcomes, and social and economic consequences, is necessary to guide and develop an appropriate response. However, efforts to study these disparities have been hampered by missing data. Almost a quarter of confirmed cases are missing race and ethnicity data.  Accounting for this missing data is essential to understanding COVID-19 and to facilitate research into health disparities. Social Epidemiologists from the Office of Health Equity used imputation techniques to estimate race and ethnicity for cases missing that data. 

The methodology, along with the results of the first run, are summarized in the attached PDF. These will be updated with more recent data shortly, and monthly thereafter. This data is intended for research purposes and to assist understanding of COVID-19-related health disparities. The COVID-19 Daily Dashboard will continue to report the unimputed data, including the number of cases not reported. Virginia Department of Health Surveillance and Investigations staff continue to pursue multiple strategies to fill in missing data.

Imputing Missing Race and Ethnicity Data in COVID-19 Cases