On June 28, 2022, Journal Citation Reports 2021 was released, which is also the first time that Covid19-related publications have been included in the calculation of Journal Impact Factor (JIF). Journals in medical fields like infectious diseases, critical care, public health have significant increase in JIF. Here, by excluding the citations from and to Covid19-related papers, we identified the top 10 medical journals having the largest contribution of Covid-related papers on JIF as shown in Table 1 . Prestigious medical journals are included in these identified journals. Averagely, Covid-related papers contribution rate is about 50% on the JIF of these 10 journals (with 7 journals having more than 50%). For example, Covid-related papers contribute 108.5 to the JIF of Lancet and boost it over 200 for the first time. The Covid-19 is a huge challenge to our life and scientific research, and it also raises an unprecedented challenge to our scientific research evaluation system, especially to the quantitative evaluation system, e.g., how to deal with the dominance of Covid-related papers in highly-cited papers, the new citation elites due to publications of Covid-related papers, the ranking boost of scientific journals and institutions.
Table 1. Top 10 journals having the largest contribution of Covid-related papers1 to JIF. |
| Index | Journal | JIF2021 | JIF2021 w/o Covid2 | Contribution of Covid3 | Percentage4 |
|---|---|---|---|---|---|
| 1 | Lancet | 202.7 | 94.2 | 108.5 | 53.5% |
| 2 | JAMA J AM MED ASSOC | 157.3 | 63.8 | 93.6 | 59.5% |
| 3 | NEW ENGL J MED | 176.1 | 96.2 | 79.9 | 45.4% |
| 4 | LANCET RESP MED | 102.6 | 40.7 | 62.0 | 60.4% |
| 5 | LANCET INFECT DIS | 71.4 | 23.8 | 47.6 | 66.7% |
| 6 | BMJ BRIT MED J | 93.3 | 47.5 | 45.9 | 49.2% |
| 7 | LANCET PSYCHIAT | 77.1 | 33.1 | 44.0 | 57.1% |
| 8 | LANCET PUBLIC HEALTH | 72.4 | 30.6 | 41.8 | 57.7% |
| 9 | NAT REV IMMUNOL | 108.6 | 68.2 | 40.4 | 37.2% |
| 10 | J INFECTION | 38.6 | 8.8 | 29.8 | 77.2% |
1Covid-related papers are identified as papers with 'covid', 'sars-cov', 'coronavirus', and 'ncov' in title. 2JIF2021 w/o Covid=$\frac{\text { Total } \text { Citations }-\text { Citations from/to } \text { covid }-\text { related papers }}{\text { Citableltem }-\text { covid }-\text { related }-\text { CitableItem }}$ 3Contribution of Covid =JIF 2021-JIF 2021 w/o Covid 4Percentage =$\frac{\text { Contribution of Covid }}{J I F 2021}$ |