Table 1.
Descriptive statistics of articles and comments collected (all numbers are presented as “count (%)”)
| Overalla |
Editorials |
Letters |
||||
|---|---|---|---|---|---|---|
| Characteristic | Comments (n = 171 556) | Articles (n = 130 629) | Comments (n = 46 644) | Articles (n = 48 370) | Comments (n = 85 252) | Articles (n = 62 919) |
| Year of Publication | ||||||
| Before 1990 | 807 (0.47) | 1582 (1.21) | 48 (0.10) | 66 (0.14) | 723 (0.85) | 1431 (2.27) |
| 1990 to 1994 | 11 173 (6.51) | 9861 (7.55) | 2185 (4.68) | 2405 (4.97) | 8346 (9.79) | 7440 (11.82) |
| 1995 to 1999 | 17 219 (10.04) | 14 782 (11.32) | 4524 (9.70) | 5034 (10.41) | 11 374 (13.34) | 9652 (15.34) |
| 2000 to 2004 | 27 224 (15.87) | 22 661 (17.35) | 7871 (16.87) | 8433 (17.43) | 14 654 (17.19) | 11 871 (18.87) |
| 2005 to 2009 | 37 686 (21.97) | 30 714 (23.51) | 11 245 (24.11) | 12 084 (24.98) | 17 204 (20.18) | 13 998 (22.25) |
| 2010 to 2014 | 48 353 (28.18) | 35 221 (26.96) | 13 329 (28.58) | 13 752 (28.43) | 20 457 (24.00) | 13 616 (21.64) |
| 2015 to August 2018 | 29 027 (16.92) | 15 808 (12.10) | 7442 (15.95) | 6596 (13.64) | 12 494 (14.66) | 4911 (7.81) |
| Missing | 67 (0.04) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0.0 (0.0) | 0 (0.0) |
| Common Journalsb | ||||||
| The New England Journal of Medicine | 8471 (4.94) | 3449 (2.64) | 1981 (4.25) | 2338 (4.83) | 6242 (7.32) | 2635 (3.09) |
| Lancet (London) | 6298 (3.67) | 3306 (2.53) | 55 (0.12) | 96 (0.20) | 4381 (5.14) | 2279 (2.67) |
| JAMA | 3392 (1.98) | 1881 (1.44) | 1013 (2.17) | 1123 (2.32) | 2258 (2.65) | 1213 (1.42) |
| BMJ (Clinical research ed.) | 3030 (1.77) | 1787 (1.37) | 841 (1.80) | 893 (1.85) | 1896 (2.22) | 1021 (1.20) |
| Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology | 2502 (1.46) | 2163 (1.66) | 1080 (2.32) | 1239 (2.56) | 1355 (1.59) | 1012 (1.19) |
| Critical Care Medicine | 2610 (1.52) | 2014 (1.54) | 1788 (3.83) | 1787 (3.69) | 769 (0.90) | 520 (0.61) |
| The Journal of Urology | 2368 (1.38) | 1312 (1.00) | 863 (1.85) | 806 (1.67) | 498 (0.58) | 432 (0.51) |
| Journal of the American College of Cardiology | 2410 (1.40) | 1992 (1.52) | 1509 (3.24) | 1575 (3.26) | 876 (1.03) | 617 (0.72) |
| Circulation | 2144 (1.25) | 1819 (1.39) | 1055 (2.26) | 1103 (2.28) | 980 (1.15) | 745 (0.87) |
| Annals of Internal Medicine | 1958 (1.14) | 815 (0.62) | 361 (0.77) | 382 (0.79) | 771 (0.90) | 467 (0.55) |
| Common PT Termsc | ||||||
| Comment | 171 489 (99.96) | 924 (0.71) | 46 644 (100) | 78 (0.16) | 85 252 (100) | 753 (1.20) |
| Letter | 85 237 (49.68) | 1464 (1.12) | 2 (<0.01) | 77 (0.16) | 85 252 (100) | 1289 (2.05) |
| Editorial | 46 644 (27.19) | 410 (0.31) | 46 644 (100) | 46 (0.10) | 2 (<0.01) | 336 (0.53) |
| Journal article | 38 234 (22.29) | 128 646 (98.48) | 4 (<0.01) | 48 213 (99.68) | 4 (<0.01) | 61 204 (97.27) |
| Comparative study | 7252 (4.23) | 64 964 (49.73) | 1576 (3.38) | 22 418 (46.35) | 4626 (5.43) | 33 142 (52.67) |
| Review | 3469 (2.02) | 2856 (2.19) | 1862 (3.99) | 712 (1.47) | 85 (0.10) | 1612 (2.56) |
| Randomized controlled trial | 1052 (0.61) | 44 119 (33.77) | 143 (0.31) | 16 847 (34.83) | 703 (0.82) | 22 246 (35.36) |
| Clinical Trial | 1397 (0.81) | 31 582 (24.18) | 193 (0.41) | 11 208 (23.17) | 1057 (1.24) | 18 637 (29.62) |
| Multicenter Study | 278 (0.16) | 31 282 (23.95) | 59 (0.13) | 14 403 (29.78) | 128 (0.15) | 13 312 (21.16) |
| Evaluation Studies | 222 (0.13) | 9002 (6.89) | 34 (0.07) | 3093 (6.39) | 119 (0.14) | 4089 (6.50) |
| Common MeSH Headingsc | ||||||
| Humans | 152 748 (89.04) | 124 425 (95.25) | 44 278 (94.93) | 46 464 (96.06) | 81 070 (95.09) | 60 717 (96.50) |
| Female | 56 236 (32.78) | 98 816 (75.65) | 14 966 (32.09) | 38 294 (79.17) | 28 900 (33.90) | 47 215 (75.04) |
| Male | 48 847 (28.47) | 94 622 (72.44) | 13 889 (29.78) | 37 732 (78.01) | 23 352 (27.39) | 43 673 (69.41) |
| Treatment outcome | 9730 (5.67) | 31 215 (23.90) | 3463 (7.42) | 12 546 (25.94) | 4724 (5.54) | 13 291 (21.12) |
| Animals | 8586 (5.00) | 7957 (6.09) | 2865 (6.14) | 2641 (5.46) | 3031 (3.56) | 2725 (4.33) |
| Middle aged | 4437 (2.59) | 72 855 (55.77) | 1008 (2.16) | 29 897 (61.81) | 2843 (3.33) | 34 318 (54.54) |
| Adult | 5559 (3.24) | 60 236 (46.11) | 1258 (2.70) | 21 346 (44.13) | 3422 (4.01) | 30 625 (48.67) |
| Aged | 4825 (2.81) | 56 418 (43.19) | 1290 (2.77) | 23 874 (49.36) | 2898 (3.40) | 26 043 (41.39) |
| Prospective studies | 1455 (0.85) | 24 878 (19.04) | 264 (0.01) | 10 381 (21.46) | 963 (1.13) | 12 279 (19.52) |
| Adolescent | 2572 (1.50) | 20 860 (15.97) | 699 (1.50) | 7096 (14.67) | 1396 (1.64) | 10 269 (16.32) |
| Missing | 67 (0.04) | 0 (0.00) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Common Major MeSH Headingsc | ||||||
| Antineoplastic Combined Chemotherapy Protocols/* therapeutic use | 1878 (1.09) | 2134 (1.63) | 543 (1.16) | 913 (1.89) | 887 (1.04) | 915 (1.45) |
| Stents* | 1151 (0.67) | 1102 (0.84) | 506 (1.08) | 596 (1.23) | 404 (0.47) | 322 (0.51) |
| Quality of Life* | 1107 (0.65) | 1208 (0.92) | 370 (0.79) | 528 (1.09) | 480 (0.56) | 460 (0.73) |
| Anti-Bacterial Agents/* therapeutic use | 1096 (0.64) | 868 (0.66) | 290 (0.62) | 304 (0.63) | 632 (0.74) | 475 (0.75) |
| Antineoplastic Agents/* therapeutic use | 990 (0.58) | 849 (0.65) | 288 (0.62) | 330 (0.68) | 435 (0.51) | 329 (0.52) |
| Hypertension/* drug therapy | 893 (0.52) | 843 (0.65) | 296 (0.63) | 387 (0.80) | 425 (0.50) | 350 (0.56) |
| Myocardial Infarction/* therapy | 881 (0.51) | 789 (0.60) | 448 (0.96) | 537 (1.11) | 330 (0.39) | 263 (0.42) |
| Breast Neoplasms/* drug therapy | 854 (0.50) | 773 (0.59) | 265 (0.57) | 361 (0.75) | 460 (0.54) | 370 (0.59) |
| Antibodies, Monoclonal/* therapeutic use | 777 (0.45) | 733 (0.56) | 232 (0.50) | 326 (0.67) | 378 (0.44) | 333 (0.53) |
| Asthma/* drug therapy | 712 (0.42) | 685 (0.52) | 226 (0.48) | 291 (0.60) | 431 (0.51) | 371 (0.59) |
| Missing | 67 (0.04) | 0 (0.00) | 0 (0.00) | 0 (0.00) | 0 (0.00) | 0 (0.00) |
| Commonly Listed Funding Sources | ||||||
| Research Support, Non-US Gov’t | 5971 (3.48) | 61 824 (47.33) | 2314 (4.96) | 24 842 (51.36) | 2050 (2.40) | 27 263 (43.33) |
| Research Support, NIH, Extramural | 2564 (1.49) | 12 292 (9.41) | 1374 (2.95) | 5544 (11.46) | 376 (0.44) | 3822 (6.07) |
| Research Support, US Gov’t, PHS | 798 (0.47) | 8883 (6.80) | 442 (0.95) | 3658 (7.56) | 97 (0.11) | 4324 (6.87) |
| Research Support, US Gov’t, Non-PHS | 451 (0.26) | 3530 (2.70) | 194 (0.42) | 1290 (2.67) | 72 (0.08) | 1412 (2.24) |
| Research Support, NIH, Intramural | 120 (0.07) | 536 (0.41) | 57 (0.12) | 202 (0.42) | 16 (0.02) | 168 (0.27) |
Abbreviations: MeSH, medical subject headings; NIH, National Institutes of Health; PT, publication type; PHS, Public Health Service.
a
The sum of all comments is not expected to equal the sum of editorials and letters, because not all comments are indexed into 1 of those 2 categories.
b
Journal names were used as presented from extraction; the list of common journals was selected based on comments first (overall).
c
When selecting common PT terms, MeSH headings, and major MeSH headings, the top 5 for comments (overall) was selected first, followed by the top 5 for articles (overall) that did include terms from the prior selection. For PT terms, those related to research support (eg, “Research Support, Non-US Gov’t”) were listed as a separate category from the PT term list.