Time-Series Analysis of Continuously Monitored Blood Glucose: The Impacts of Geographic and Daily Lifestyle Factors

Table 4

ARIMA blood glucose modeling results, single participant (, ).

Variables	Lag^a	Estimate		Sig.
Previous BG readings	Lag 1	−0.61	−18.3	0.000
	Lag 2	−0.28	−7.28	0.000
	Lag 3	−0.22	−5.71	0.000
	Lag 4	−0.27	−7.93	0.000
Exercise time in last 5 min	Lag 0	0.00	−3.75	0.000
	Lag 1		2.54	0.011
Trip-automobile time in last 5 min	Lag 0		4.07	0.000
	Lag 4		−2.49	0.013

Outputs are displayed similar to other multivariate models (overall , variables entering model) but with the addition of one distinct feature: the time “lag” with which BG was significantly autocorrelated with the variable. A lag of 1 indicates autocorrelation of BG with the explanatory value in the preceding 5-minute interval, whilst higher lags indicate associated autocorrelation further back in time. A single explanatory variable can have multiple lagged effects, listed in sequence in the output with separate estimates.