Impact of the COVID-19 pandemic on inbound air travel to Canada–Supplemental

CCDR

Volume 50-3/4, March/April 2024: Innovations in Public Health Surveillance

Impact of the COVID-19 pandemic on inbound air travel to Canada—Supplemental material

Vanessa Gabriele-Rivet, Erin Rees, Afnan Rahman, Rachael M Milwids

This document reports output from the null hypothesis (H0) and interrupted time series (ITS) analysis models for residual diagnostics and model estimates.

Null hypothesis (H0) model

Figure S1: Residual check for null hypothesis (H0) model SARIMA (0,1,1) x (1,0,0)12

Figure S1

Figure S1 - Text description

The figure shows output from the null hypothesis (H0) model residuals as a time series, autocorrelation function (ACF) and a histogram. Residuals should appear random (i.e., white noise) in models that adequately capture trends, including temporal trends. Output from the residual time series appears mostly random except for a steep trough shortly after 2020. In the ACF plot, there is no statistically significant autocorrelation in residuals at the assessed time lags. The histogram suggests the residuals are mostly random by having a close to normal distribution shape.


Table S1: Results from final null hypothesis (H0) model SARIMA (0,1,1) x (1,0,0)12
Parameter Coefficient Standard error 95% confidence interval
ma1 0.3619 0.1220 0.1228 0.6011
sar1 0.3811 0.1159 0.1538 0.6083
Table S1 - Abbreviation

Abbreviation: SARIMA, seasonal autoregressive integrated moving average

Interrupted time series (ITS) model

Figure S2: Residual check for final interrupted time series (ITS) model SARIMA (2,0,0) x (2,1,0)12

Figure S2

Figure S2 - Text description

The figure shows output from the interrupted time series (ITS) model residuals as a time series, autocorrelation function (ACF) and a histogram. Residuals should appear random (i.e., white noise) in models that adequately capture trends, including temporal trends. Output from the residual time series appears mostly random for the pandemic and the pre-pandemic periods, separately. However, differences in the range of residuals between both periods suggest that the model does not adequately account for differences in the magnitude of seasonal patterns between both periods. In the ACF plot, there is no statistically significant autocorrelation in residuals at the assessed time lags. The histogram suggests the residuals are mostly random by having a close to normal distribution shape.


Table S2: Results from final interrupted time series (ITS) model SARIMA (2,0,0) x (2,1,0)12
Parameter Coefficient Standard error 95% confidence interval
ar1 0.9669 0.1233 0.7252 1.2086
ar2 −0.3311 0.1250 −0.5761 −0.0860
sar1 −0.1557 0.1456 −0.4411 0.1297
sar2 −0.4073 0.1399 −0.6815 −0.1330
drift 11,092.7 4,797.6 1,689.6 20,495.8
step March 2020 −1,001,994.3 107,500.9 −1,212,692.2 −791,296.4
step April 2020 −1,773,160.7 97,668.4 −1,964,587.3 −1,581,734.1
ramp August 2021 112,626.7 10,689.9 91,674.9 133,578.6
Table S2 - Abbreviation

Abbreviation: SARIMA, seasonal autoregressive integrated moving average

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