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It is now 567 days since the first COVID-19 case was reported in Nigeria. As at September 17, 2021 the confirmed cases are 202,249 with 2,649 (1.32%) fatalities, however, 189,608 (94.19%) have recovered leaving 9,039 (4.49%) active cases.

Based on equal days forecast, by April 07, 2023, Nigeria’s aggregate confirmed COVID-19 cases are forecast to be:

Unconstrained forecast of COVID-19 for Nigeria

Model Confirmed cases Recoveries Fatalities Active RMSE
Upper ARIMA 1,346,860 1,268,607 17,779 60,474 139
With knots 1,066,555 1,004,589 14,079 47,888 157
Without knots 489,384 460,951 6,460 21,973 373
Linear 288,837 272,055 3,813 12,969 366
Semilog 277,454 261,334 3,662 12,458 139
Essembled based on weight 247,778 233,382 3,271 11,125 387
Essembled with equal weight 175,658 165,453 2,319 7,887 271
Essembled based on weight of fit 152,298 143,449 2,010 6,838 1.6
Growth 3,533 3,328 47 159 163
Essembled based on summed weight -142,263 -133,998 -1,878 -6,388 380
Quadratic Polynomial -236,071 -222,355 -3,116 -10,600 200
Lower ARIMA -945,901 -890,945 -12,486 -42,471 133
Smooth Spline -1,720,366 -1,620,412 -22,709 -77,244 157

Constrained forecast of COVID-19 for Nigeria

Model Confirmed cases Recoveries Fatalities Active
ARIMA 95% 1,367,538 1,288,084 18,051.0 61,402
Without knots 95% 1,366,946 1,287,527 18,044.0 61,376
Essembled based on weight 95% 1,304,335 1,228,553 17,217.0 58,565
Essembled based on summed weight 95% 1,131,053 1,065,338 14,930.0 50,784
Essembled with equal weight 95% 860,375 810,387 11,357.0 38,631
Smooth Spline 95% 847,495 798,256 11,187.0 38,053
Essembled based on weight of fit 95% 580,498 546,771 7,663.0 26,064
With knots 95% 539,351 508,014 7,119.0 24,217
Linear 288,837 272,055 3,813.0 12,969
Semilog 277,454 261,334 3,662.0 12,458
Quadratic Polynomial 95% 93,753 88,306 1,238.0 4,210
Essembled based on weight of fit 80% 82,210 77,434 1,085.0 3,691
Essembled with equal weight 80% 77,040 72,564 1,017.0 3,459
Quadratic Polynomial 80% 70,369 66,281 929.0 3,160
Smooth Spline 80% 69,618 65,573 919.0 3,126
Essembled based on summed weight 80% 27,341 25,752 361.0 1,228
Essembled based on weight 80% 16,188 15,247 214.0 727
ARIMA 80% 5,839 5,500 77.0 262
Without knots 80% 4,400 4,144 58.0 198
Growth 3,533 3,328 47.0 159
With knots 80% 3 3 0.0 0

However, the actual forecast made by the various models on the last day i.e. April 07, 2023 is shown below:

Unconstrained forecasts on the last day

Constrained forecasts on the last day

Refer to Table 2 and Table 3 as well as Fig. 18-20 for more details on how the estimates and forecasts were obtained.

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The visuals below supports this facts, take a look!

Fig. 1a Daily observed cases of COVID-19 in Nigeria

Fig. 2 Perecentages and previous days differences of COVID-19 in Nigeria Starting from February 29, 2020 to September 17, 2021

Fig. 3 Cases recorded in percentages Starting from February 29, 2020 to September 17, 2021 (legend as Fig. 2)

Fig. 4 Cumulative cases and Forecast of COVID-19 cases in Nigeria Starting from September 18, 2021 to April 07, 2023

Fig. 4a Components of COVID-19 cases in Nigeria between February 29, 2020 and September 17, 2021

Fig. 5 Number of days since average recorded cases exceeded one in each State

Fig. 6 Daily confirmed Coronavirus cases, by number of the days since 1 first daily case recorded

Fig. 7 Number of days from February 29, 2020 to September 17, 2021 that cases were recorded in the States

Fig. 7a Numbers of States that COVID-19 cases were reported on daily basis

Fig. 7b Forecast of Numbers of States that may still be COVID-19 affected by April 07, 2023

Coefficient estimates for number of states reporting COVID-19 daily

LinearSemilogGrowthSpline without knotsLinear splinesSpline with knotsARIMA
(Intercept)15.449 ****10.521 ****2.559 ****4.005 ****2.806 *   0.011          
(0.532)    (1.485)    (0.054)    (0.893)    (1.576)    (2.302)         
Series-0.007 ****         -0.000 **                                  
(0.002)             (0.000)                                    
log(Series)         0.589 **                                           
         (0.275)                                             
bs(Series, knots = NULL)1                           35.494 ****                       
                           (2.580)                           
bs(Series, knots = NULL)2                           -6.958 ****                       
                           (1.637)                           
bs(Series, knots = NULL)3                           10.092 ****                       
                           (1.410)                           
bs(DDPtable$Series, knots = c(30, 115, 247, 337, 420))1                                    -2.678                   
                                    (2.248)                  
bs(DDPtable$Series, knots = c(30, 115, 247, 337, 420))2                                    13.683 ****              
                                    (1.667)                  
bs(DDPtable$Series, knots = c(30, 115, 247, 337, 420))3                                    22.953 ****              
                                    (1.943)                  
bs(DDPtable$Series, knots = c(30, 115, 247, 337, 420))4                                    -1.005                   
                                    (1.723)                  
bs(DDPtable$Series, knots = c(30, 115, 247, 337, 420))5                                    29.444 ****              
                                    (1.762)                  
bs(DDPtable$Series, knots = c(30, 115, 247, 337, 420))6                                    -13.311 ****              
                                    (1.849)                  
bs(DDPtable$Series, knots = c(30, 115, 247, 337, 420))7                                    13.823 ****              
                                    (1.951)                  
bs(DDPtable$Series, knots = c(30, 115, 247, 337, 420))8                                    13.363 ****              
                                    (1.812)                  
bs(Series, knots = c(30, 247, 420))1                                             5.023 *        
                                             (2.841)         
bs(Series, knots = c(30, 247, 420))2                                             24.954 ****     
                                             (2.439)         
bs(Series, knots = c(30, 247, 420))3                                             10.542 ****     
                                             (2.812)         
bs(Series, knots = c(30, 247, 420))4                                             19.799 ****     
                                             (2.544)         
bs(Series, knots = c(30, 247, 420))5                                             -3.155          
                                             (2.679)         
bs(Series, knots = c(30, 247, 420))6                                             24.189 ****     
                                             (2.620)         
ma1                                                      -0.754 
                                                      (0.028)
nobs549         549         549         549         549         549         548     
r.squared0.027     0.008     0.008     0.307     0.758     0.440          
adj.r.squared0.025     0.007     0.007     0.303     0.754     0.434          
sigma6.227     6.286     0.636     5.266     3.125     4.746     3.192 
statistic15.154     4.604     4.632     80.344     211.497     70.942          
p.value0.000     0.032     0.032     0.000     0.000     0.000          
df1.000     1.000     1.000     3.000     8.000     6.000          
logLik-1782.039     -1787.239     -529.323     -1689.015     -1400.004     -1630.438     -1413.581 
AIC3570.077     3580.479     1064.646     3388.030     2820.009     3276.877     2831.161 
BIC3583.002     3593.403     1077.570     3409.570     2863.090     3311.341     2839.774 
deviance21208.678     21614.317     221.083     15112.550     5273.340     12208.495          
df.residual547.000     547.000     547.000     545.000     540.000     542.000          
nobs.1549.000     549.000     549.000     549.000     549.000     549.000     548.000 
**** p < 0.001; *** p < 0.01; ** p < 0.05; * p < 0.1.

Properties of the estimated coefficients

Linear Semilog Growth Spline with knots Linear splines Spline without knots Smooth spline ARIMA
Absolute Error 2800 2900 6200 2100 1300 2400 1100 1300
Absolute Percent Error 440 420 420 230 140 280 120 130
Accuracy 0 0 0 0 0 0 0 0
Adjusted R Square 0.025 0.0065 0.0066 0.43 0.75 0.3 0 0
Akaike’s Information Criterion AIC 3600 3600 1100 3300 2800 3400 0 2800
Allen’s Prediction Sum-Of-Squares (PRESS, P-Square) 0 0 0 0 0 0 0 0
Area under the ROC curve (AUC) 0.87 0.13 0.87 0.033 0.048 0.023 0.015 0.028
Average Precision at k 0 0 0 0 0 0 0 0
Bias 0.00000000000000033 0.00000000000000006 11 -0.00000000000000021 0.000000000000000097 -0.000000000000000033 0.0000000000000008 0.11
Brier score 40 40 200 20 10 30 8 10
Classification Error 1 1 1 1 1 1 1 1
F1 Score 0 0 0 0 0 0 0 0
fScore 0 0 0 0 0 0 0 0
GINI Coefficient 0.2 -0.2 0.2 0.6 0.9 0.6 0.9 0.9
kappa statistic 0 0 0 0 0 0 0 0
Log Loss Inf Inf Inf Inf Inf Inf Inf Inf
Mallow’s cp 2 2 2 7 9 4 0 0
Matthews Correlation Coefficient 0 0 0 0 0 0 0 0
Mean Log Loss Inf Inf Inf Inf Inf Inf Inf Inf
Mean Absolute Error 5.2 5.3 11 3.9 2.3 4.4 2.1 2.4
Mean Absolute Percent Error 0.8 0.77 0.77 0.42 0.26 0.51 0.21 0.24
Mean Average Precision at k 0 0 0 0 0 0 0.17 0
Mean Absolute Scaled Error 1.8 1.9 4 1.4 0.83 1.5 0.73 0.85
Median Absolute Error 4.9 5.1 12 3.4 1.9 3.9 1.6 2
Mean Squared Error 39 39 160 22 9.6 28 7.8 10
Mean Squared Log Error 0.31 0.31 2 0.15 0.074 0.19 0.053 0.068
Model turning point error 330 297 330 306 304 312 304 405
Negative Predictive Value 0 0 0 0 0 0 0 0
Percent Bias -0.55 -0.51 0.72 -0.21 -0.1 -0.29 -0.081 -0.068
Positive Predictive Value 0 0 0 0 0 0 0 0
Precision NaN NaN NaN NaN NaN NaN NaN NaN
R Square 0.027 0.0083 0.0084 0.44 0.76 0.31 0 0
Relative Absolute Error 0.97 1 2.1 0.73 0.44 0.82 0.39 0.45
Recall 15 12 2.5 3 3.4 5.8 2.7 2.2
Root Mean Squared Error 6.2 6.3 13 4.7 3.1 5.2 2.8 3.2
Root Mean Squared Log Error 0.56 0.56 1.4 0.39 0.27 0.43 0.23 0.26
Root Relative Squared Error 0.99 1 2 0.75 0.49 0.83 0.44 0.51
Relative Squared Error 0.97 0.99 4.2 0.56 0.24 0.69 0.2 0.26
Schwarz’s Bayesian criterion BIC 3600 3600 1100 3300 2900 3400 0 2800
Sensitivity 0 0 0 0 0 0 0 0
specificity 0 0 0 0 0 0 0 0
Squared Error 21000 22000 91000 12000 5300 15000 4300 5600
Squared Log Error 170 170 1100 82 41 100 29 37
Symmetric Mean Absolute Percentage Error 0.42 0.44 1.3 0.33 0.22 0.36 0.18 0.21
Sum of Squared Errors 21000 22000 91000 12000 5300 15000 4300 5600
True negative rate 0 0 0 0 0 0 0 0
True positive rate 0 0 0 0 0 0 0 0

Fig. 8 Number of days the last COVID19 case was recorded as at September 17, 2021

Fig. 9 Diverging Bars of COVID-19 cases in the States (normalised)


Fig. 10 Monthly summary of COVID19 cases in the States

Fig. 11 Daily recorded cases of COVID19 in the States

Fig. 12 Number of days since average recorded cases exceeded one in each geo-political zone

Fig. 13 Number of days from February 29, 2020 to September 17, 2021 that cases were recorded in the Zones

Fig. 14 Monthly summary of COVID19 cases in the Zones

Table 1 Regression estimates of factors that might have stressed Nigeria’s economy within the period of the COVID-19 pandemic

COVID19PMSInflationTeledensityBirth ratePopulation
(Intercept)169.543     2975.129     -475.232 *** -275.360     -36.492 ****15.452 ****
(370.172)    (1855.122)    (153.519)    (519.286)    (5.741)    (0.268)    
PMSprice-0.139 ****         0.089 ****0.217 ****0.003 **  -0.001 *   
(0.033)             (0.011)    (0.038)    (0.001)    (0.000)    
Inflation1.327 *** 9.179 ****         -1.957 ****-0.045 ****0.014 *** 
(0.353)    (1.145)             (0.470)    (0.009)    (0.004)    
Teledensity0.605 ****3.220 ****-0.283 ****         -0.008     0.002     
(0.100)    (0.563)    (0.068)             (0.005)    (0.002)    
`Birth rate`12.393     105.864 **  -13.895 ****-16.411              0.324 ****
(8.161)    (38.360)    (2.890)    (11.584)             (0.045)    
Population-15.626     -215.033 *   32.716 *** 24.907     2.425 ****         
(23.719)    (116.989)    (9.440)    (33.210)    (0.338)             
COVID19         -4.063 ****0.379 *** 1.197 ****0.011     -0.002     
         (0.956)    (0.101)    (0.197)    (0.008)    (0.003)    
nobs20         20         20         20         20         20         
r.squared0.773     0.895     0.940     0.834     0.860     0.850     
adj.r.squared0.692     0.858     0.918     0.775     0.810     0.796     
sigma1.222     6.612     0.653     1.718     0.037     0.014     
statistic9.552     23.910     43.671     14.102     17.210     15.808     
p.value0.000     0.000     0.000     0.000     0.000     0.000     
df5.000     5.000     5.000     5.000     5.000     5.000     
logLik-28.817     -62.589     -16.280     -35.636     41.086     61.205     
AIC71.633     139.178     46.559     85.273     -68.171     -108.410     
BIC78.603     146.148     53.529     92.243     -61.201     -101.440     
deviance20.895     612.023     5.964     41.326     0.019     0.003     
df.residual14.000     14.000     14.000     14.000     14.000     14.000     
nobs.120.000     20.000     20.000     20.000     20.000     20.000     
**** p < 0.001; *** p < 0.01; ** p < 0.05; * p < 0.1.

Fig. 15 COVID-19, inflation, PMS price, Teledensity and birth rate in Nigeria

Fig. 15 Relationship between COVID-19, inflation, PMS price, Teledensity and birth rate in Nigeria

Table 2 The coefficient estimates of the various models for forecasting of COVID-19 for Nigeria1

LinearSemilogGrowthSpline without knotsSpline with knotsARIMAQuardratic polynomialEssembled based on weightEssembled based on summed weight
(Intercept)280.209 ****-118.017     4.541 ****-132.578 **  -3.333          46.925     38.847  -1.736     
(32.601)    (88.858)    (0.131)    (61.329)    (62.794)         (47.255)    (146.654) (19.438)    
Day0.269 ***          0.002 ****                       2.729 ****               
(0.099)             (0.000)                           (0.384)                   
log(Day)         88.772 ****                                                        
         (16.346)                                                            
bs(Day, knots = NULL)1                           1245.435 ****                                      
                           (177.199)                                          
bs(Day, knots = NULL)2                           196.414 *                                         
                           (112.441)                                          
bs(Day, knots = NULL)3                           516.899 ****                                      
                           (96.842)                                          
bs(Day, knots = BREAKS)1                                    5.086                                  
                                    (121.394)                                 
bs(Day, knots = BREAKS)2                                    13.093                                  
                                    (78.637)                                 
bs(Day, knots = BREAKS)3                                    843.779 ****                             
                                    (90.146)                                 
bs(Day, knots = BREAKS)4                                    170.515 **                               
                                    (76.586)                                 
bs(Day, knots = BREAKS)5                                    201.752 **                               
                                    (83.882)                                 
bs(Day, knots = BREAKS)6                                    -81.410                                  
                                    (78.919)                                 
bs(Day, knots = BREAKS)7                                    2036.208 ****                             
                                    (78.519)                                 
bs(Day, knots = BREAKS)8                                    -273.019 ****                             
                                    (78.962)                                 
bs(Day, knots = BREAKS)9                                    45.325                                  
                                    (91.864)                                 
bs(Day, knots = BREAKS)10                                    478.647 ****                             
                                    (89.701)                                 
bs(Day, knots = BREAKS)11                                    634.786 ****                             
                                    (81.532)                                 
ar1                                             1.012                         
                                             (0.061)                        
ar2                                             -0.196                         
                                             (0.053)                        
ma1                                             -1.739                         
                                             (0.046)                        
ma2                                             0.814                         
                                             (0.036)                        
I(Day^2)                                                  -0.004 ****               
                                                  (0.001)                   
fitf                                                           1.098  -0.120     
                                                           (7.519) (0.079)    
fit0f                                                           0.029  -0.008     
                                                           (0.986) (0.086)    
fit1f                                                           -0.497  1.291 ****
                                                           (6.444) (0.125)    
fitpif                                                           -0.380  0.007     
                                                           (1.230) (0.099)    
fitaf                                                           0.383  -0.166 *   
                                                           (5.700) (0.093)    
fitf:fit0f                                                           -0.007           
                                                           (0.023)          
fitf:fit1f                                                           0.021           
                                                           (0.020)          
fit0f:fit1f                                                           0.013           
                                                           (0.026)          
fitf:fitpif                                                           -0.003           
                                                           (0.017)          
fit0f:fitpif                                                           0.001           
                                                           (0.002)          
fit1f:fitpif                                                           -0.009           
                                                           (0.020)          
fitf:fitaf                                                           -0.059           
                                                           (0.036)          
fit0f:fitaf                                                           -0.007           
                                                           (0.020)          
fit1f:fitaf                                                           0.038           
                                                           (0.034)          
fitpif:fitaf                                                           0.013           
                                                           (0.016)          
fitf:fit0f:fit1f                                                           -0.000           
                                                           (0.000)          
fitf:fit0f:fitpif                                                           0.000           
                                                           (0.000)          
fitf:fit1f:fitpif                                                           -0.000           
                                                           (0.000)          
fit0f:fit1f:fitpif                                                           -0.000           
                                                           (0.000)          
fitf:fit0f:fitaf                                                           0.000 *         
                                                           (0.000)          
fitf:fit1f:fitaf                                                           0.000           
                                                           (0.000)          
fit0f:fit1f:fitaf                                                           -0.000           
                                                           (0.000)          
fitf:fitpif:fitaf                                                           0.000           
                                                           (0.000)          
fit0f:fitpif:fitaf                                                           -0.000           
                                                           (0.000)          
fit1f:fitpif:fitaf                                                           -0.000           
                                                           (0.000)          
fitf:fit0f:fit1f:fitpif                                                           0.000           
                                                           (0.000)          
fitf:fit0f:fit1f:fitaf                                                           -0.000           
                                                           (0.000)          
fitf:fit0f:fitpif:fitaf                                                           -0.000 *         
                                                           (0.000)          
fitf:fit1f:fitpif:fitaf                                                           -0.000           
                                                           (0.000)          
fit0f:fit1f:fitpif:fitaf                                                           0.000           
                                                           (0.000)          
fitf:fit0f:fit1f:fitpif:fitaf                                                           -0.000           
                                                           (0.000)          
nobs567         567         567         567         567         566     567         567      567         
r.squared0.013     0.050     0.042     0.116     0.825          0.084     0.884  0.873     
adj.r.squared0.011     0.048     0.040     0.111     0.822          0.081     0.877  0.872     
sigma387.626     380.333     1.555     367.508     164.599     157.540 373.756     136.730  139.330     
statistic7.334     29.494     24.762     24.571     238.101          25.801     131.125  773.763     
p.value0.007     0.000     0.000     0.000     0.000          0.000     0.000  0.000     
df1.000     1.000     1.000     3.000     11.000          2.000     31.000  5.000     
logLik-4182.880     -4172.110     -1053.747     -4151.655     -3692.165     -3665.518 -4161.717     -3576.581  -3600.714     
AIC8371.760     8350.221     2113.494     8313.310     7410.330     7341.035 8331.434     7219.162  7215.428     
BIC8384.781     8363.242     2126.515     8335.012     7466.755     7362.728 8348.796     7362.394  7245.811     
deviance84893620.260     81729086.991     1365.673     76039856.291     15036516.318          78787166.131     10001930.986  10890631.588     
df.residual565.000     565.000     565.000     563.000     555.000          564.000     535.000  561.000     
nobs.1567.000     567.000     567.000     567.000     567.000     566.000 567.000     567.000  567.000     
**** p < 0.001; *** p < 0.01; ** p < 0.05; * p < 0.1.

Table 3 Various selection criteria for the estimated models2

Linears Semilogs Growths Spline with knots Spline without knots Smooth spline ARIMA Quardratic polynomial Essembled equal weight Essembled on weight Essembled summed weight Essembled weight of fit
Absolute Error 160000 160000 200000 61000 150000 44000 51000 160000 200000 44000 45000 200000
Absolute Percent Error Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf
Accuracy 0 0 0 0 0 0 0 0 0.032 0 0 0.032
Adjusted R Square 0.011 0.048 0.04 0.82 0.11 0 0 0.081 0 0.88 0.87 0
Akaike’s Information Criterion AIC 8400 8400 2100 7400 8300 0 7300 8300 0 7200 7200 0
Allen’s Prediction Sum-Of-Squares (PRESS, P-Square) 0 0 0 0 0 0 0 0 0 0 0 0
Area under the ROC curve (AUC) 0.008 0.008 0.008 0.088 0.008 0.008 0.016 0.008 0.008 0.032 0.008 0.008
Average Precision at k 0 0 0 0 0 0 0 0 0.5 0 0 0.5
Bias -0.0000000000000064 -0.000000000000032 350 0.0000000000000082 -0.000000000000011 0.00000000000026 1.5 0.000000000000023 360 0.00000000000000042 -0.0000000000000016 360
Brier score 100000 100000 300000 30000 100000 20000 20000 100000 NaN 20000 20000 10000000
Classification Error 1 1 1 1 1 1 1 1 1 1 1 1
F1 Score 0 0 0 0 0 0 0 0 0 0 0 0
fScore 0 0 0 0 0 0 0 0 0 0 0 0
GINI Coefficient 0.1 0.1 0.1 0.9 0.3 1 0.9 0.4 0.9 1 1 0.9
kappa statistic 0 0 0 0 0 0 0 0 NaN 0 0 NaN
Log Loss Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf
Mallow’s cp 2 2 2 8.9 4 0 0 3 0 0 6 0
Matthews Correlation Coefficient 0 0 0 0 0 0 0 0 NaN 0 0 NaN
Mean Log Loss Inf Inf Inf Inf Inf Inf Inf Inf NaN Inf Inf NaN
Mean Absolute Error 290 280 350 110 270 78 90 290 NaN 77 79 800
Mean Absolute Percent Error Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf
Mean Average Precision at k 0 0 0 0 0 0.5 0 0 0 0 0 0
Mean Absolute Scaled Error 2.7 2.6 3.3 1 2.5 0.74 0.86 2.7 3.4 0.73 0.75 3.4
Median Absolute Error 250 220 210 75 250 35 43 270 110 41 38 150
Mean Squared Error NA NA NA NA NA NA NA NA NaN NA NA 12000000
Mean Squared Log Error 3 NaN 13 NaN NaN NaN 0.26 2.4 29 NaN NaN 29
Model turning point error 288 288 288 279 290 275 380 281 348 257 236 344
Negative Predictive Value 0 0 0 0 0 0 0 0 0 0 0 0
Percent Bias -Inf NaN -Inf NaN NaN NaN -Inf -Inf NaN NaN NaN NaN
Positive Predictive Value 0 0 0 0 0 0 0 0 0 0 0 0
Precision NaN NaN NaN NaN NaN NaN NaN NaN 0 NaN NaN 0
R Square 0.013 0.05 0.042 0.83 0.12 0 0 0.084 0 0.88 0.87 0
Relative Absolute Error 0.99 0.96 1.2 0.37 0.92 0.27 0.31 0.98 0.47 0.27 0.27 0.63
Recall 280 -12 4.6 -2 -100 -0.19 0.5 63 0 4.3 -0.59 0
Root Mean Squared Error NA NA NA NA NA NA NA NA NaN NA NA 3400
Root Mean Squared Log Error 1.7 NaN 3.7 NaN NaN NaN 0.51 1.6 5.3 NaN NaN 5.3
Root Relative Squared Error 0.99 0.97 1.3 0.42 0.94 0.36 0.4 0.96 1.4 0.34 0.36 1.4
Relative Squared Error 0.99 0.95 1.8 0.17 0.88 0.13 0.16 0.92 1.8 0.12 0.13 1.8
Schwarz’s Bayesian criterion BIC 8400 8400 2100 7500 8300 0 7400 8300 0 7400 7200 0
Sensitivity 0 0 0 0 0 0 0 0 0.5 0 0 0.5
specificity 0 0 0 0 0 0 0 0 0 0 0 0
Squared Error 85000000 82000000 160000000 15000000 76000000 11000000 14000000 79000000 160000000 10000000 11000000 160000000
Squared Log Error 1700 NaN 7600 NaN NaN NaN 150 1400 16000 NaN NaN 16000
Symmetric Mean Absolute Percentage Error 0.89 0.88 1.8 0.59 0.85 0.34 0.4 0.91 0.6 0.37 0.36 0.7
Sum of Squared Errors 85000000 82000000 160000000 15000000 76000000 11000000 14000000 79000000 160000000 10000000 11000000 160000000
True negative rate 0 0 0 0 0 0 0 0 0 0 0 0
True positive rate 0 0 0 0 0 0 0 0 0 0 0 0

Fig. 18 Models of COVID-19 Cases using ensemble technology

Fig. 19 Equal duration forecast of COVID-19 Cases from the ensemble models using a native plotting method

Fig. 20 Unconstrained forecast of COVID-19 cases in Nigeria Starting from September 18, 2021 to April 07, 2023 using a more advaced plotting method

Fig. 20a

Fig. 20b Constrained forecast of COVID-19 cases in Nigeria Starting from September 18, 2021 to April 07, 2023 using a more advaced plotting method

Fig. 20b Lagged forecasts (1-14 days) of COVID-19 cases in Nigeria

Table 4 Summary of the dynamic COVID-19 forecasts
Model Sep 05, 21 - Mar 11, 23 Sep 12, 21 - Mar 25, 23 Sep 15, 21 - Mar 31, 23 Sep 16, 21 - Apr 02, 23 Sep 17, 21 - Apr 04, 23 Sep 18, 21 - Apr 06, 23
Without knots 244613 413515 446360 463311 463540 486447
Smooth Spline 3462771 2544669 1827374 1689162 1371793 1327628
With knots -1050368 -373943 -1489237 -1316597 -1983981 -1304816
Quadratic Polynomial -305855 -255514 -247231 -242266 -243256 -236121
Lower ARIMA -839128 -798187 -879781 -879412 -942191 -902238
Upper ARIMA 1363682 1428825 1373444 1381459 1342851 1377018
Essembled with equal weight 257423 326777 219645 197036 179852 158637
Essembled based on weight 261975 544769 436140 394743 473424 353491
Essembled based on summed weight -35515 -80576 -52924 -61714 -29933 -65088
Essembled based on weight of fit 183708 234242 175520 163216 153972 141763
Table 3 RMSE of the models in the dynamic forecasts
Model Sep 05, 21 - Mar 11, 23 Sep 12, 21 - Mar 25, 23 Sep 15, 21 - Mar 31, 23 Sep 16, 21 - Apr 02, 23 Sep 17, 21 - Apr 04, 23 Sep 18, 21 - Apr 06, 23
Without knots 368.79 368.21 367.32 367.04 366.73 366.53
Smooth Spline 158.68 160.72 161.93 161.96 162.6 162.48
With knots 138.57 139.5 139.43 139.33 139.22 139.35
Quadratic Polynomial 372.75 373.91 373.39 373.3 373 373.05
Lower ARIMA 156.13 156.95 156.84 156.7 156.84 156.84
Upper ARIMA 156.13 156.95 156.84 156.7 156.84 156.84
Essembled with equal weight 199.49 200.19 200.06 199.95 199.94 199.92
Essembled based on weight 412.36 410.59 409.56 409.12 408.88 408.5
Essembled based on summed weight 387.21 385.44 384.38 384.03 383.71 383.38
Essembled based on weight of fit 203.41 199.58 199.14 198.79 198.98 198.49

Fig. 21 Percentage of COVID19 cases that resulted into casualty per State as at September 17, 2021

Fig. 22 Percentage of COVID19 cases that recovered per State as at September 17, 2021

Fig. 23 Percentage of recoveries and deaths from COVID19 cases per Zone as at September 17, 2021

Fig. 24 Distribution of COVID19 in the States as at September 17, 2021


  1. Note that Smooth spline does not estimate coefficients and other model-characteristic statistics↩︎

  2. Multiclass Area Under the Curve (MAUC) is the mean of the various AUC estimated from the same data↩︎