COVID-19 Reproduction Number (R(t))

This file contains data regarding a 7-day average of the estimated instantaneous reproduction number, R(t), of COVID-19 in Ottawa. The reproduction number, R, is the average number of secondary cases of disease caused by a single infected individual over his or her infectious period. R(t) values greater than 1 indicate the virus is spreading faster and each case infects more than one contact, and less than 1 indicates the spread is slowing and the epidemic is coming under control. <br /><br /> R(t) was calculated using the EpiEstim package, developed by Cori et al. (2013; DOI: 10.1093/aje/kwt133), in the R software environment for statistical computing and graphics. Accurate episode date was used as the time anchor and cases were assigned as having a local or travel-related source of infection. <br /><br /> <strong>Accuracy</strong>: Points of consideration for interpretation of the data: <br /><ul><li>Data are entered into and extracted by Ottawa Public Health from la Solution de gestion des cas et des contacts pour la santé publique (Solution GCC). The CCM is a dynamic disease reporting system that allows for ongoing updates; data represent a snapshot at the time of extraction and may differ from previous or subsequent reports.</li></ul><ul><li>As the cases are investigated and more information is available, the dates are updated.</li></ul><ul><li>A person’s exposure may have occurred up to 14 days prior to onset of symptoms. Symptomatic cases occurring in approximately the last 14 days are likely under-reported due to the time for individuals to seek medical assessment, availability of testing, and receipt of test results.</li></ul><ul><li>Confirmed cases are those with a confirmed COVID-19 laboratory result as per the Ministry of Health Public health management of cases and contacts of COVID-19 in Ontario. March 25, 2020 version 6.0.</li></ul><ul><li>Counts will be subject to varying degrees of underreporting due to a variety of factors, such as disease awareness and medical care seeking behaviours, which may depend on severity of illness, clinical practice, changes in laboratory testing, and reporting behaviours.</li></ul><ul><li>Surveillance testing for COVID-19 began in long term care facilities on April 25, 2020.</li></ul> <strong>Attributes</strong>: Data fields: <br /><ul><li>Date – the earliest of symptom onset, test or reported date for cases (YYYY-MM-DD H:MM).</li></ul><ul><li>Lower Bound - 95% Confidence Interval - lower bound of the 95% confidence interval for the 7-day average of the R(t) estimate. </li><li><p style='background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;'><span style='font-size:11.5pt; font-family:Helvetica, sans-serif; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;'>Upper Bound - 95% Confidence Interval<b> </b>- upper bound of the 95% confidence interval for the 7-day average of the R(t) estimate.</span></p></li></ul><ul><li>Estimate of R(t) (7 Day Average) - 7-day average of the estimated instantaneous reproduction number, R(t), of COVID-19 in Ottawa. </li></ul><div><ul><li><span style='font-family:Helvetica, sans-serif; font-size:11.5pt;'>Nowcasting Adjusted Cases by Episode Date – number of Ottawa residents with confirmed COVID-19 by episode date. Counts for the most recent 14 days represent a nowcasting adjusted estimate developed by R. Imgrund in 2020. The model uses linear regression to estimate the number of future cases expected to have an accurate episode date within that 14-day window.</span></li></ul><div><div><div> <strong>Update Frequency</strong>: As of March 2022, the dataset is no longer updated. Historical data only.<br /><br /> <strong>Contact</strong>: <a href='mailto:[e-mail]' rel='nofollow ugc'>OPH Epidemiology Team</a></div></div></div></div>