Estimating the Growth Rate and Doubling Time for Short-Term Prediction and Monitoring Trend During the COVID-19 Pandemic with a SAS Macro

Stanley Xu; Christina Clarke; Susan Shetterly; Komal Narwaney

We estimated a series of growth rates using RGCA with a length of 7 days. The estimated growth rates and 95% CIs were plotted over time using the mid-day of a 7 day period ( Figure 1 ). The growth rate peaked with a value of 56.2% at the mid-day of March 18 th for the period March 15 th and March 21 st . Between March 18 th and April 1 st , although the growth rate continuously decreased, the daily number of hospitalizations increased because of positive growth rates. We started to observe negative growth rates after April 1 st , except for a positive growth rate on April 9 th . The growth rate reached its minimum at the mid-day of April 5 th (period April 2 nd -April 8 th ) with a value of -19.2%. The growth rate then increased after April 5 th . Note that a negative growth rate represents a reduction in number of hospitalizations.