Table. Proportion of Observed Overdose Deaths in Excess of the Number Forecasted With ARIMA Models in the US From March 8, 2020, to December 31, 2020a.
Modelb | Model type | Total deaths observed, No. | Total deaths forecasted, No. (lower and upper prediction limits)c | Proportion of deaths observed to deaths forecasted (lower and upper prediction limits)c |
---|---|---|---|---|
ARIMA (7,1,10) | Initial | 72 643 | 65 386 (57 269-73 503) | 1.11 (1.28-0.98) |
ARIMA (9,1,6) | Final | 72 643 | 65 042 (56 778-73 306) | 1.12 (1.28-0.99) |
Abbreviation: ARIMA, autoregressive integrated moving average.
Data from Connecticut and North Carolina were excluded from the analysis.
The 2 models showed similar performance and are thus presented side by side.
The prediction limits are for the forecasts generated by each model.