Severity and case fatality rates of COVID-19: A systematic review, meta-analysis and an exploratory meta-regression of risk factors

Chathurika Dhanasekara MBBS, PhD, Shao-Hua Chin PhD, Chanaka N. Kahathuduwa MBBS, PhD


eTable 1. Keywords and Keyword Combinations Used to Screen the PubMed, Scopus, and Web of Science Electronic Databases

(covid-19) OR (((corona OR coronavirus)) AND wuhan) OR (2019 novel coronavirus infection) OR (COVID19) OR (coronavirus disease 2019) OR (coronavirus disease-19) OR (2019-nCoV disease) OR (2019 novel coronavirus disease) OR (2019-nCoV infection) OR (SARS-CoV-2)


eTable 2. Summary Statistics of All Covariates Used in the Univariate Meta-regression Analyses

Variable Events Total Studies Pooled Effect Size (95% CI) †
Fixed-effects Model Random-effects Model
Demographic Variables
Age (years) NA 2033 28 32.847 (32.344–33.350) 41.148 (32.737–49.558)
Age < 18 years 110 1349 22 0.082 (0.068–0.097) 0.025 (0.002–0.274)
Age > 60 years 178 975 15 0.183 (0.160–0.208) 0.064 (0.019–0.196)
Female 941 2033 28 0.463 (0.441–0.485) 0.466 (0.431–0.500)
Past Medical History
DM-2 123 1420 22 0.087 (0.073–0.102) 0.102 (0.069–0.148)
Hypertension 228 1090 19 0.209 (0.186–0.234) 0.120 (0.069–0.201)
Cardiac disease 127 1121 18 0.113 (0.096–0.133) 0.060 (0.029–0.120)
Chronic liver disease 23 926 18 0.025 (0.017–0.037) 0.010 (0.003–0.037)
Chronic kidney disease 12 926 18 0.013 (0.007–0.023) 0.013 (0.007–0.023)
Malignancy 34 1216 19 0.028 (0.020–0.039) 0.024 (0.014–0.040)
COPD 19 1014 12 0.019 (0.012–0.029) 0.018 (0.010–0.031)
Low immunity 2 236 3 0.008 (0.002–0.033) 0.008 (0.002–0.033)
Smoking 16 247 3 0.065 (0.040–0.103) 0.065 (0.040–0.103)
Pregnant 11 506 11 0.022 (0.012–0.039) 0.000 (0.000–0.386)
Presenting Symptoms
Asymptomatic 24 618 11 0.039 (0.026–0.057) 0.009 (0.001–0.084)
Fever 1310 1578 24 0.830 (0.811–0.848) 0.833 (0.778–0.877)
Cough 992 1656 25 0.599 (0.575–0.622) 0.619 (0.539–0.693)
Sore throat 121 909 16 0.133 (0.113–0.157) 0.131 (0.085–0.197)
Tachypnea 138 325 7 0.425 (0.372–0.479) 0.084 (0.010–0.461)
Dyspnea 245 1452 20 0.169 (0.150–0.189) 0.102 (0.053–0.186)
Myalgia 163 801 14 0.203 (0.177–0.233) 0.192 (0.123–0.288)
Fatigue 328 762 11 0.430 (0.396–0.466) 0.336 (0.198–0.508)
Headache 136 1253 16 0.109 (0.092–0.127) 0.103 (0.071–0.146)
Diarrhea 104 1288 21 0.081 (0.067–0.097) 0.078 (0.059–0.104)
Laboratory Investigations ‡
Nucleic acid test positive 1529 1617 22 0.946 (0.933–0.956) 1.000 (0.916–1.000)
Leukopenia 258 940 16 0.274 (0.247–0.304) 0.217 (0.111–0.380)
Leukocytosis 99 899 16 0.110 (0.091–0.132) 0.082 (0.048–0.137)
Thrombocytopenia 73 472 8 0.155 (0.125–0.190) 0.137 (0.078–0.229)
Lymphopenia 476 988 17 0.482 (0.451–0.513) 0.410 (0.289–0.543)
High LDH 220 526 9 0.418 (0.377–0.461) 0.433 (0.242–0.646)
Low Albumin 156 423 6 0.369 (0.324–0.416) 0.340 (0.063–0.797)
High CRP 650 930 17 0.699 (0.669–0.728) 0.668 (0.534–0.780)
Higºh ESR 193 245 4 0.788 (0.732–0.834) 0.795 (0.701–0.866)
High procalcitonin 152 594 12 0.256 (0.222–0.293) 0.175 (0.071–0.370)
High D-dimer 117 504 7 0.232 (0.197–0.271) 0.188 (0.095–0.338)
Radiological Features on CT Thorax
No lesion on CT 95 894 16 0.106 (0.088–0.128) 0.078 (0.035–0.165)
Patchy consolidation 231 551 11 0.419 (0.379–0.461) 0.418 (0.314–0.530)
Ground glass opacities 416 754 15 0.552 (0.516–0.587) 0.693 (0.487–0.843)
Peripheral distribution 177 229 6 0.773 (0.714–0.823) 0.849 (0.516–0.967)
Bilateral or > 3 lobe involvement 721 953 15 0.757 (0.728–0.783) 0.711 (0.575–0.817)

† Effect size measure is mean for age. For all other variables, it is the proportion of individuals (i.e., events) out of total sample size.

‡ Biochemical parameters have been interpreted as low / high based on reference ranges considered in each study.


eTable 3. Results of All Univariate Meta-regression Analyses Examining the Moderator Effects of the Covariates on the Prevalence of Combined Severe or Critical Illness in COVID-19

Model Variable Coefficient† SE 95% CI Z p
Demographic Variables
1 Intercept –5.921 1.236 –8.344 to –3.498 –4.789 <0.001
Age 0.093 0.026 0.043 to 0.144 3.634 <0.001
k = 26, τ2 = 0.781, I2 = 88.428, QM = 13.206
2 Intercept –1.400 0.310 –2.006 to –9.794 –4.524 <0.001
Age < 18 years –3.450 1.287 –5.972 to –5.927 –2.680 0.007
k = 21, τ2 = 1.172, I2 = 91.709, QM = 7.182
3 Intercept –3.599 0.461 –4.502 to –2.695 –7.806 <0.001
Age > 60 years 8.367 1.720 4.997 to 11.738 4.866 <0.001
k = 15, τ2 = 0.573, I2 = 77.484, QM = 23.679
4 Intercept –0.491 1.196 –2.836 to 1.853 –0.411 0.681
Female –2.836 2.517 –7.769 to 2.397 –1.127 0.260
k = 26, τ2 = 1.771, I2 = 94.515, QM = 1.270
Past Medical History
5 Intercept –2.344 0.471 –3.267 to –1.421 –4.978 <0.001
DM-2 3.632 2.161 –0.603 to 7.868 1.681 0.093
k = 20, τ2 = 1.532, I2 = 93.418, QM = 2.826
6 Intercept –2.966 0.556 –4.056 to –1.877 –5.338 <0.001
Hypertension 8.381 2.456 3.567 to 13.194 3.413 <0.001
k = 17, τ2 = 1.009, I2 = 88.950, QM = 11.646
7 Intercept –2.112 0.476 –3.045 to –1.179 –4.436 <0.001
Cardiac disease 4.801 2.649 –0.392 to 9.993 1.812 0.070
k = 16, τ2 = 1.211, I2 = 91.573, QM = 3.283
8 Intercept –2.274 0.654 –3.555 to –5.992 –3.476 <0.001
Chronic liver disease 4.698 15.493 –25.668 to 35.064 0.303 0.762
k = 16, τ2 = 3.223, I2 = 94.655, QM = 0.092
9 Intercept –2.411 0.507 –3.405 to –1.417 –4.756 <0.001
Chronic kidney disease 21.831 10.504 1.244 to 42.419 2.078 0.038
k = 16, τ2 = 2.235, I2 = 93.455, QM = 4.320
10 Intercept –2.366 0.441 –3.230 to –1.501 –5.363 <0.001
Malignancy 24.845 10.920 3.442 to 46.247 2.275 0.023
k = 17, τ2 = 0.960, I2 = 89.464, QM = 5.176
11 Intercept –1.827 0.399 –2.609 to –1.345 –4.580 <0.001
COPD 27.432 12.227 3.467 to 51.397 2.243 0.025
k = 11, τ2 = 0.733, I2 = 91.466, QM = 5.033
12 Intercept –2.020 0.713 –3.416 to –5.623 –2.835 0.005
Low immunity 66.920 78.023 –86.003 to 219.842 0.858 0.391
k = 3, τ2 = 0.733, I2 = 71.082, QM = 0.736
13 Intercept –8.862 6.638 –21.872 to 4.148 –1.335 0.182
Smoking 127.878 101.797 –71.641 to 327.397 1.256 0.209
k = 3, τ2 = 0.048, I2 = 50.308, QM = 1.578
14 Intercept –2.088 0.618 –3.299 to –2.876 –3.377 <0.001
Pregnant –4.395 6.052 –16.256 to 7.466 –0.726 0.468
k = 10, τ2 = 2.133, I2 = 90.869, QM = 0.527
Presenting Symptoms
15 Intercept –1.287 0.486 –2.240 to –2.334 –2.647 0.008
Asymptomatic –5.774 4.980 –15.534 to 3.987 –1.159 0.246
k = 11, τ2 = 1.549, I2 = 92.081, QM = 1.344
16 Intercept –8.760 2.003 –12.685 to –4.835 –4.374 <0.001
Fever 8.772 2.378 4.111 to 13.432 3.689 <0.001
k = 23, τ2 = 0.641, I2 = 86.409, QM = 13.607
17 Intercept –3.308 0.987 –5.242 to –1.374 –3.353 <0.001
Cough 2.736 1.492 –0.187 to 5.665 1.834 0.067
k = 24, τ2 = 1.280, I2 = 92.822, QM = 3.365
18 Intercept –1.698 0.456 –2.590 to –7.854 –3.725 <0.001
Sore throat –0.410 1.971 –4.272 to 3.452 –0.208 0.835
k = 15, τ2 = 1.035, I2 = 89.939, QM = 0.043
19 Intercept –3.773 1.205 –6.134 to –1.411 –3.131 0.002
Tachypnea 5.104 2.616 –0.023 to 19.231 1.951 0.051
k = 7, τ2 = 1.774, I2 = 89.572, QM = 3.806
20 Intercept –1.997 0.354 –2.691 to –1.322 –5.636 <0.001
Dyspnea 3.056 1.392 0.327 to 5.784 2.195 0.028
k = 19, τ2 = 0.680, I2 = 88.759, QM = 4.817
21 Intercept –2.227 0.749 –3.695 to –6.758 –2.972 0.003
Myalgia 3.541 2.648 –1.648 to 8.731 1.338 0.181
k = 13, τ2 = 1.323, I2 = 91.941, QM = 1.789
22 Intercept –2.466 0.685 –3.809 to –1.124 –3.600 <0.001
Fatigue 2.702 1.388 –0.018 to 5.421 1.947 0.052
k = 11, τ2 = 0.730, I2 = 87.246, QM = 3.791
23 Intercept –0.803 0.471 –1.727 to 1.129 –1.705 0.088
Headache –5.361 3.194 –11.621 to 4.899 –1.679 0.093
k = 15, τ2 = 1.153, I2 = 93.398, QM = 2.817
24 Intercept –2.590 0.566 –3.699 to –1.482 –4.579 <0.001
Diarrhea 11.680 5.237 1.415 to 21.944 2.230 0.026
k = 20, τ2 = 1.139, I2 = 91.537, QM = 4.974
Laboratory Investigations ‡
25 Intercept –0.521 0.404 –1.311 to 8.272 –1.291 0.197
Nucleic acid test positive –1.370 0.423 –2.199 to –9.545 –3.235 0.001
k = 21, τ2 = 1.477, I2 = 94.363, QM = 10.464
26 Intercept –1.904 0.734 –3.343 to –3.465 –2.594 0.009
Leukopenia –0.357 1.926 –4.132 to 3.418 –0.185 0.853
k = 15, τ2 = 2.855, I2 = 96.044, QM = 0.034
27 Intercept –3.166 0.857 –4.845 to –1.487 –3.696 <0.001
Leukocytosis 8.608 5.659 –2.482 to 19.699 1.521 0.128
k = 15, τ2 = 2.690, I2 = 95.111, QM = 2.314
28 Intercept –3.945 1.260 –6.414 to –1.476 –3.132 0.002
Thrombocytopenia 10.488 5.507 –0.306 to 21.282 1.904 0.057
k = 8, τ2 = 2.917, I2 = 94.454, QM = 3.627
29 Intercept –3.871 0.840 –5.518 to –2.224 –4.607 <0.001
Lymphopenia 4.734 1.574 1.649 to 7.823 3.008 0.003
k = 16, τ2 = 1.213, I2 = 90.850, QM = 9.046
30 Intercept –4.437 0.686 –5.781 to –3.192 –6.467 <0.001
High LDH 5.769 1.164 3.488 to 8.054 4.957 <0.001
k = 9, τ2 = 0.278, I2 = 58.546, QM = 24.572
31 Intercept –1.507 0.734 –2.945 to –5.869 –2.053 0.040
Low Albumin 1.299 1.384 –1.414 to 4.312 0.938 0.348
k = 6, τ2 = 1.210, I2 = 89.774, QM = 0.880
32 Intercept –4.645 1.018 –6.641 to –2.649 –4.562 <0.001
High CRP 4.688 1.392 1.959 to 7.417 3.367 <0.001
k = 16, τ2 = 0.697, I2 = 85.579, QM = 11.335
33 Intercept 2.608 6.597 –10.323 to 15.538 0.395 0.693
High ESR –5.846 8.398 –22.305 to 11.613 –0.696 0.486
k = 4, τ2 = 1.636, I2 = 84.528, QM = 0.485
34 Intercept –2.535 0.965 –4.427 to –0.643 –2.626 0.009
High procalcitonin 1.146 2.476 –3.707 to 5.999 0.463 0.644
k = 11, τ2 = 3.562, I2 = 95.576, QM = 0.214
35 Intercept –2.962 0.289 –3.528 to –2.395 –10.253 <0.001
High D-dimer 6.110 0.830 4.484 to 7.736 7.365 <0.001
k = 7, τ2 = 0.000, I2 = 0.000, QM = 54.243
Radiological Features on CT Thorax
36 Intercept –1.016 0.468 –1.932 to –8.798 –2.170 0.030
No lesions on CT –10.053 3.413 –16.743 to –3.363 –2.945 0.003
k = 15, τ2 = 1.239, I2 = 89.806, QM = 8.675
37 Intercept –2.639 1.142 –4.878 to –2.461 –2.311 0.021
Patchy consolidations 1.121 2.265 –3.318 to 5.559 0.495 0.621
k = 10, τ2 = 1.261, I2 = 88.147, QM = 0.245
38 Intercept –2.231 1.134 –4.454 to –7.938 –1.967 0.049
Ground glass opacities 0.089 1.650 –3.144 to 3.322 0.054 0.957
k = 14, τ2 = 2.583, I2 = 94.256, QM = 0.003
39 Intercept –6.172 3.565 –13.159 to 7.816 –1.731 0.083
Peripheral distribution 3.966 3.959 –3.794 to 11.725 1.002 0.317
k = 6, τ2 = 1.767, I2 = 83.815, QM = 1.003
40 Intercept –4.974 1.267 –7.457 to –2.492 –3.927 <0.001
Bilateral or > 3 lobe involvement 4.435 1.627 1.246 to 7.624 2.725 0.006
k = 14, τ2 = 0.696, I2 = 87.270, QM = 7.428

† Coefficients represent logit-transformed proportions; positive coefficients suggest increased risk and negative coefficients suggest decreased risk.

‡ Biochemical parameters have been interpreted as low / high based on reference ranges considered in each study.


eTable 4. Results of All Univariate Meta-regression Analyses Examining the Moderator Effects of the Covariates on the Prevalence Critical Illness in COVID-19

Model Variable Coefficient† SE 95% CI Z p
Demographic Variables
1 Intercept –8.153 2.031 –12.134 to –4.173 –4.014 <0.001
Age 0.115 0.041 0.033 to 6.196 2.774 0.006
k = 24, τ2 = 1.094, I2 = 85.333, QM = 7.694
2 Intercept –2.407 0.527 –3.440 to –1.374 –4.567 <0.001
Age < 18 years –7.526 6.892 –21.034 to 5.981 –1.092 0.275
k = 18, τ2 = 1.635, I2 = 87.100, QM = 1.193
3 Intercept –5.479 0.884 –7.211 to –3.747 –6.200 <0.001
Age > 60 years 8.868 2.647 3.678 to 14.757 3.349 <0.001
k = 13, τ2 = 0.981, I2 = 69.156, QM = 11.219
4 Intercept –1.157 1.429 –3.957 to 1.644 –0.809 0.418
Female –3.934 3.082 –9.975 to 2.157 –1.276 0.202
k = 24, τ2 = 1.890, I2 = 90.774, QM = 1.629
Past Medical History
5 Intercept –2.712 0.510 –3.711 to –1.713 –5.319 <0.001
DM-2 0.581 2.220 –3.770 to 4.932 0.262 0.794
k = 19, τ2 = 1.405, I2 = 89.782, QM = 0.068
6 Intercept –4.091 0.676 –5.416 to –2.765 –6.050 <0.001
Hypertension 8.385 2.518 3.450 to 13.321 3.330 <0.001
k = 17, τ2 = 0.615, I2 = 74.934, QM = 11.090
7 Intercept –3.386 0.657 –4.674 to –2.597 –5.150 <0.001
Cardiac disease 6.745 2.970 0.924 to 12.565 2.271 0.023
k = 15, τ2 = 1.058, I2 = 86.342, QM = 5.158
8 Intercept –2.632 0.494 –3.600 to –1.664 –5.329 <0.001
Chronic liver disease –1.965 11.525 –24.553 to 21.623 –0.170 0.865
k = 15, τ2 = 1.332, I2 = 84.529, QM = 0.029
9 Intercept –2.850 0.463 –3.757 to –1.944 –6.161 <0.001
Chronic kidney disease 11.613 8.335 –4.722 to 27.949 1.393 0.163
k = 15, τ2 = 1.185, I2 = 84.105, QM = 1.942
10 Intercept –2.718 0.428 –3.556 to –1.886 –6.355 <0.001
Malignancy 20.308 9.919 0.866 to 39.752 2.047 0.041
k = 16, τ2 = 0.497, I2 = 75.460, QM = 4.191
11 Intercept –2.140 0.468 –3.057 to –1.223 –4.573 <0.001
COPD –3.422 14.786 –32.402 to 25.557 –0.231 0.817
k = 11, τ2 = 1.028, I2 = 89.416, QM = 0.054
Presenting Symptoms
12 Intercept –3.186 1.049 –5.243 to –1.129 –3.036 0.002
Asymptomatic –9.113 12.896 –34.389 to 16.162 –0.707 0.480
k = 9, τ2 = 4.359, I2 = 90.352, QM = 0.499
13 Intercept –10.098 3.624 –17.201 to –2.995 –2.786 0.005
Fever 8.525 4.236 0.224 to 16.827 2.013 0.044
k = 20, τ2 = 1.946, I2 = 89.018, QM = 4.051
14 Intercept –4.429 1.361 –7.096 to –1.762 –3.255 0.001
Cough 2.421 2.119 –1.732 to 6.574 1.142 0.253
k = 21, τ2 = 2.096, I2 = 90.704, QM = 1.305
15 Intercept –2.901 0.617 –4.110 to –1.693 –4.706 <0.001
Sore throat –0.011 2.573 –5.054 to 5.733 –0.004 0.997
k = 14, τ2 = 1.552, I2 = 87.761, QM = 0.000
16 Intercept –6.493 3.574 –13.498 to 6.513 –1.816 0.069
Tachypnea 4.139 6.653 –8.901 to 17.179 0.622 0.534
k = 7, τ2 = 9.745, I2 = 92.103, QM = 0.387
17 Intercept –3.919 0.701 –5.293 to –2.546 –5.592 <0.001
Dyspnea 5.263 2.589 0.187 to 19.339 2.033 0.042
k = 17, τ2 = 1.935, I2 = 90.510, QM = 4.131
18 Intercept –2.954 0.729 –4.382 to –1.526 –4.055 <0.001
Myalgia 2.311 2.833 –3.241 to 7.864 0.816 0.415
k = 13, τ2 = 1.128, I2 = 82.759, QM = 0.666
19 Intercept –5.730 1.452 –8.575 to –2.884 –3.947 <0.001
Fatigue 6.841 3.255 0.462 to 13.221 2.102 0.036
k = 9, τ2 = 1.883, I2 = 75.036, QM = 4.418
20 Intercept –2.093 0.707 –3.478 to –4.718 –2.962 0.003
Headache –7.333 6.010 –19.113 to 4.446 –1.220 0.222
k = 15, τ2 = 1.972, I2 = 92.662, QM = 1.489
21 Intercept –3.018 0.673 –4.337 to –1.699 –4.485 <0.001
Diarrhea 4.228 5.997 –7.525 to 15.981 0.705 0.481
k = 18, τ2 = 1.279, I2 = 86.591, QM = 0.497
Laboratory Investigations ‡
22 Intercept –728.908 26694.139 –53048.459 to 51594.644 –0.027 0.978
Nucleic acid test positive 725.702 26694.139 –51593.849 to 53945.253 0.027 0.978
k = 18, τ2 = 2.861, I2 = 94.023, QM = 0.001
23 Intercept –2.923 0.688 –4.272 to –1.575 –4.249 <0.001
Leukopenia –0.149 1.679 –3.440 to 3.141 –0.089 0.929
k = 15, τ2 = 1.763, I2 = 87.768, QM = 0.008
24 Intercept –3.734 0.742 –5.189 to –2.279 –5.030 <0.001
Leukocytosis 6.462 4.651 –2.655 to 15.578 1.389 0.165
k = 15, τ2 = 1.617, I2 = 83.727, QM = 1.930
25 Intercept –3.319 0.906 –5.095 to –1.543 –3.663 <0.001
Thrombocytopenia 4.623 3.915 –3.049 to 12.296 1.181 0.238
k = 8, τ2 = 1.198, I2 = 85.576, QM = 1.395
26 Intercept –4.303 0.979 –6.222 to –2.383 –4.393 <0.001
Lymphopenia 3.533 1.996 –0.378 to 7.444 1.770 0.077
k = 15, τ2 = 1.264, I2 = 81.627, QM = 3.134
27 Intercept –3.882 0.707 –5.267 to –2.496 –5.491 <0.001
High LDH 3.392 1.137 1.164 to 5.621 2.984 0.003
k = 8, τ2 = 0.315, I2 = 51.385, QM = 8.904
28 Intercept –2.131 0.308 –2.735 to –1.527 –6.914 <0.001
Low Albumin 0.994 0.517 –0.019 to 2.318 1.923 0.055
k = 5, τ2 = 0.081, I2 = 27.279, QM = 3.697
29 Intercept –6.561 1.654 –9.803 to –3.319 –3.967 <0.001
High CRP 5.696 2.155 1.471 to 9.921 2.642 0.008
k = 14, τ2 = 0.741, I2 = 74.102, QM = 6.983
30 Intercept –2.584 0.805 –4.161 to –1.936 –3.209 0.001
High procalcitonin –6.018 4.132 –14.116 to 2.081 –1.456 0.145
k = 10, τ2 = 2.030, I2 = 78.770, QM = 2.121
31 Intercept –3.367 0.736 –4.808 to –1.925 –4.577 <0.001
High D-dimer 6.185 2.671 0.950 to 11.421 2.315 0.021
k = 5, τ2 = 0.221, I2 = 39.400, QM = 5.361
Radiological Features on CT Thorax
32 Intercept –2.481 0.621 –3.698 to –1.265 –3.998 <0.001
No lesions on CT –6.518 3.726 –13.821 to 2.786 –1.749 0.080
k = 14, τ2 = 1.473, I2 = 79.098, QM = 3.059
33 Intercept –2.430 1.574 –5.514 to 9.656 –1.544 0.123
Patchy consolidations –2.949 3.633 –10.070 to 4.171 –0.812 0.417
k = 10, τ2 = 2.026, I2 = 77.274, QM = 0.659
34 Intercept –1.955 0.893 –3.705 to –6.204 –2.188 0.029
Ground glass opacities –1.912 1.387 –4.630 to 8.856 –1.379 0.168
k = 14, τ2 = 1.354, I2 = 81.205, QM = 1.901
35 Intercept –5.393 3.288 –11.838 to 1.452 –1.640 0.101
Peripheral distribution 1.619 3.529 –5.297 to 8.536 0.459 0.646
k = 5, τ2 = 0.617, I2 = 32.942, QM = 0.211
36 Intercept –4.371 1.735 –7.772 to –1.978 –2.519 0.012
Bilateral or > 3 lobe involvement 1.857 2.445 –2.935 to 6.657 0.759 0.448
k = 12, τ2 = 1.547, I2 = 84.184, QM = 0.577

† Coefficients represent logit-transformed proportions; positive coefficients suggest increased risk and negative coefficients suggest decreased risk.

‡ Biochemical parameters have been interpreted as low / high based on reference ranges considered in each study.


eTable 5. Results of All Univariate Meta-regression Analyses Examining the Moderator Effects of the Covariates on the Mortality Rate Among in COVID-19

Model Variable Coefficient† SE 95% CI Z p
Demographic Variables
1 Intercept –13.847 2.681 –19.101 to –8.593 –5.165 <0.001
Age 0.198 0.052 0.096 to 9.299 3.838 <0.001
k = 25, ττ2 = 0.506, I2 = 50.639, QM = 14.733
2 Intercept –3.250 0.553 –4.334 to –2.166 –5.874 <0.001
Age < 18 years –39.307 18.722 –76.002 to –2.613 –2.100 0.036
k = 20, τ2 = 0.755, I2 = 57.711, QM = 4.408
3 Intercept –6.156 1.012 –8.140 to –4.172 –6.081 <0.001
Age > 60 years 7.499 2.949 1.720 to 13.278 2.543 0.011
k = 14, τ2 = 0.731, I2 = 44.403, QM = 6.468
4 Intercept –4.422 1.938 –8.221 to –3.623 –2.281 0.023
Female –0.868 3.930 –8.570 to 6.834 –0.221 0.825
k = 25, τ2 = 2.986, I2 = 84.794, QM = 0.049
Past Medical History
5 Intercept –3.966 0.865 –5.660 to –2.271 –4.587 <0.001
DM-2 –4.139 4.769 –13.485 to 5.257 –0.868 0.385
k = 19, τ2 = 2.493, I2 = 85.131, QM = 0.754
6 Intercept –4.843 0.937 –6.680 to –3.396 –5.167 <0.001
Hypertension 6.070 3.098 –0.002 to 12.143 1.959 0.050
k = 17, τ2 = 0.818, I2 = 62.909, QM = 3.839
7 Intercept –5.658 1.528 –8.653 to –2.663 –3.703 <0.001
Cardiac disease 6.298 5.635 –4.746 to 17.343 1.118 0.264
k = 16, τ2 = 3.590, I2 = 87.325, QM = 1.249
8 Intercept –5.096 1.329 –7.701 to –2.491 –3.833 <0.001
Chronic liver disease 2.410 21.686 –40.093 to 44.913 0.111 0.912
k = 17, τ2 = 3.515, I2 = 84.824, QM = 0.012
9 Intercept –4.976 1.169 –7.267 to –2.685 –4.256 <0.001
Chronic kidney disease –4.095 24.503 –52.120 to 43.938 –0.167 0.867
k = 17, τ2 = 3.415, I2 = 85.031, QM = 0.028
10 Intercept –5.202 1.169 –7.492 to –2.912 –4.452 <0.001
Malignancy 25.193 22.794 –19.482 to 69.869 1.105 0.269
k = 18, τ2 = 2.874, I2 = 86.440, QM = 1.222
11 Intercept –4.718 1.206 –7.081 to –2.355 –3.913 <0.001
COPD 11.975 37.673 –61.863 to 85.813 0.318 0.751
k = 10, τ2 = 3.332, I2 = 90.202, QM = 0.101
Presenting Symptoms
12 Intercept –3.582 0.815 –5.179 to –1.985 –4.397 <0.001
Asymptomatic –22.825 23.869 –69.607 to 23.957 –0.956 0.339
k = 10, τ2 = 0.832, I2 = 53.265, QM = 0.914
13 Intercept –16.665 6.768 –29.930 to –3.401 –2.462 0.014
Fever 13.979 7.552 –0.823 to 28.781 1.851 0.064
k = 21, τ2 = 2.575, I2 = 81.750, QM = 3.426
14 Intercept –4.380 1.630 –7.574 to –1.186 –2.688 0.007
Cough –0.590 2.693 –5.867 to 4.688 –0.219 0.827
k = 22, τ2 = 2.526, I2 = 79.906, QM = 0.048
15 Intercept –4.031 1.764 –7.488 to –9.574 –2.285 0.022
Sore throat –12.722 13.745 –39.662 to 14.219 –0.926 0.355
k = 14, τ2 = 3.976, I2 = 82.831, QM = 0.857
16 Intercept –4.512 1.018 –6.507 to –2.518 –4.434 <0.001
Tachypnea 3.019 2.240 –1.371 to 7.419 1.348 0.178
k = 6, τ2 = 0.000, I2 = 0.000, QM = 1.816
17 Intercept –5.384 0.963 –7.272 to –3.497 –5.592 <0.001
Dyspnea 5.208 2.959 –0.592 to 11.528 1.760 0.078
k = 17, τ2 = 1.833, I2 = 78.737, QM = 3.097
18 Intercept –5.809 1.825 –9.386 to –2.232 –3.183 0.001
Myalgia 3.859 5.323 –6.575 to 14.292 0.725 0.469
k = 13, τ2 = 3.173, I2 = 78.683, QM = 0.525
19 Intercept –4.991 0.697 –6.357 to –3.625 –7.162 <0.001
Fatigue 2.601 1.314 0.025 to 5.178 1.979 0.048
k = 10, τ2 = 0.000, I2 = 0.000, QM = 3.917
20 Intercept –3.100 0.975 –5.010 to –1.189 –3.180 0.001
Headache –13.603 10.138 –33.474 to 6.268 –1.342 0.180
k = 15, τ2 = 2.078, I2 = 83.381, QM = 1.800
21 Intercept –5.158 1.600 –8.294 to –2.223 –3.224 0.001
Diarrhea 0.674 12.728 –24.272 to 25.629 0.053 0.958
k = 18, τ2 = 4.168, I2 = 87.268, QM = 0.003
Laboratory Investigations ‡
22 Intercept –277.080 203424.495 –398981.762 to 398427.693 –0.001 0.999
Nucleic acid test positive 272.246 203424.495 –398432.438 to 398976.929 0.001 0.999
k = 18, τ2 = 2.967, I2 = 85.532, QM = 0.000
23 Intercept –5.304 2.008 –9.239 to –1.369 –2.642 0.008
Leukopenia –2.851 4.864 –12.385 to 6.682 –0.586 0.558
k = 14, τ2 = 7.059, I2 = 89.937, QM = 0.344
24 Intercept –7.326 1.868 –10.987 to –3.665 –3.922 <0.001
Leukocytosis 20.497 7.588 5.624 to 35.369 2.701 0.007
k = 14, τ2 = 0.790, I2 = 55.410, QM = 7.296
25 Intercept –5.628 2.680 –10.880 to –3.375 –2.100 0.036
Thrombocytopenia –2.645 12.249 –26.652 to 21.362 –0.216 0.829
k = 8, τ2 = 7.292, I2 = 89.313, QM = 0.047
26 Intercept –10.089 4.017 –17.961 to –2.216 –2.512 0.012
Lymphopenia 8.553 6.098 –3.398 to 24.574 1.403 0.161
k = 15, τ2 = 6.297, I2 = 87.338, QM = 1.967
27 Intercept –9.907 3.336 –16.444 to –3.369 –2.970 0.003
High LDH 8.923 4.123 0.842 to 17.604 2.164 0.030
k = 9, τ2 = 0.938, I2 = 46.607, QM = 4.684
28 Intercept –6.740 1.325 –9.336 to –4.143 –5.088 <0.001
Low Albumin 4.782 1.433 1.973 to 7.591 3.337 <0.001
k = 6, τ2 = 0.000, I2 = 0.000, QM = 11.136
29 Intercept –22.970 10.385 –43.324 to –2.616 –2.212 0.027
High CRP 23.196 11.885 –0.097 to 46.499 1.952 0.051
k = 15, τ2 = 1.120, I2 = 63.919, QM = 3.809
30 Intercept –6.882 4.270 –15.250 to 1.486 –1.612 0.107
High procalcitonin –12.881 22.821 –57.609 to 31.847 –0.564 0.572
k = 10, τ2 = 11.734, I2 = 89.835, QM = 0.319
Radiological Features on CT Thorax
32 Intercept –2.321 0.316 –2.939 to –1.791 –7.344 <0.001
No lesions on CT –1941.342 3948.493 –9680.245 to 5797.561 –0.492 0.623
k = 13, τ2 = 0.000, I2 = 0.000, QM = 0.242
33 Intercept –4.454 2.631 –9.609 to 2.702 –1.693 0.090
Patchy consolidations –1.290 5.246 –11.572 to 8.992 –0.246 0.806
k = 9, τ2 = 2.859, I2 = 72.114, QM = 0.060
34 Intercept –1.341 1.554 –4.387 to 1.746 –0.863 0.388
Ground glass opacities –8.374 5.039 –18.250 to 1.552 –1.662 0.097
k = 13, τ2 = 2.225, I2 = 77.488, QM = 2.762
35 Intercept –9.953 4.723 –19.210 to –2.695 –2.107 0.035
Bilateral or > 3 lobe involvement 7.011 6.069 –4.883 to 18.956 1.155 0.248
k = 12, τ2 = 3.840, I2 = 86.622, QM = 1.335

† Coefficients represent logit-transformed proportions; positive coefficients suggest increased risk and negative coefficients suggest decreased risk.

‡ Biochemical parameters have been interpreted as low / high based on reference ranges considered in each study.