Table 1.

The actual, predicted number using the time series method and percentage change of chest-related procedures in 2020.

2020	Chest X-rays			CT Chests			US Chests			Interventional Radiology
	Actual	Predicted*	% change	Actual	Predicted*	% change	Actual	Predicted*	% change	Actual	Predicted*	% change
Jan	162,185	170,811	−5.05	7,828	8,413	−6.96	13	16	−16.51	180	211	−14.65
Feb	129,066	154,692	−16.57	5,429	7,668	−29.20	12	16	−26.11	147	179	−17.83
Mar	142,525	173,219	−17.72	7,848	8,761	−10.42	5	15	−67.19	211	224	−5.61
Apr	129,669	159,359	−18.63	7,182	7,739	−7.20	9	10	−12.11	207	190	8.82
May	140,276	166,580	−15.79	8,354	8,594	−2.80	8	19	−56.92	189	212	−10.94
Jun	146,924	158,344	−7.21	9,065	8,361	8.43	14	18	−20.32	219	194	13.15
Jul	149,828	165,895	−9.69	8,403	8,770	−4.18	7	18	−60.16	235	224	5.12
Aug	141,393	162,393	−12.93	8,372	9,195	−8.96	12	15	−17.64	240	240	0.19
Sep	146,512	153,307	−4.43	9,513	8,601	10.60	9	17	−46.78	221	224	−1.44
Oct	147,334	158,694	−7.16	8,624	8,587	0.43	6	16	−62.29	165	215	−23.22
Nov	154,940	158,854	−2.46	9,540	9,035	5.59	6	21	−71.31	223	218	2.35
Dec	161,229	165,331	−2.48	9,534	8,535	11.70	20	20	2.20	235	191	23.33
Total	1,751,881	1,947,479	−10.04	99,692	102,261	−2.51	121	199	−39.16	2,472	2,520	−1.90
Stationary R–squared		0.727			0.814			0.836			0.843
R–squared		0.650			0.742			0.446			0.684
RMSE		5148.005			318.861			4.215			15.162
MAPE		2.562			3.056			15.704			6.823
MAE		3930.920			239.558			3.384			11.893
MaxAPE		10.175			8.505			49.340			17.637
MaxAE		14593.800			616.880			8.420			34.263
Normalised BIC		17.391			11.828			3.176			5.736

RMSE, Root mean square error; MAE, Mean absolute error; MaxAPE, Maximum absolute percentage error; MaxAE, Maximum absolute error; Normalised BIC, Normalised Bayesian information criterion.

^*The predicted values were rounded to nearest integer, and the percentage change was based on the full digits of the predicted value.