Table 2.
Distribution of all Clinical Articles (n = 985) by Study Type and Level of Evidence, by Year of Publication
| Study Type | Clinical Articles (n = 985)a | ||||||
| 1994 | 1999 | 2004 | 2009 | 2014 | 2019 | P Value | |
| Clinical | |||||||
| Therapeutic | 61 (54.0) | 71 (62.3) | 99 (60.0) | 151 (74.8) | 135 (65.9) | 127 (68.3) | <0.01b |
| Prognostic | 44 (38.9) | 34 (29.8) | 53 (32.1) | 35 (17.3) | 43 (21.0) | 43 (21.0) | <0.01b |
| Diagnostic | 8 (7.1) | 7 (6.1) | 12 (7.3) | 16 (7.9) | 23 (11.2) | 14 (7.5) | 0.59b |
| Economic | 0 (0.0) | 2 (1.8) | 1 (0.6) | 0 (0.0) | 4 (1.9) | 2 (1.1) | 0.23c |
| LOE | |||||||
| I | 4 (3.5) | 2 (1.8) | 10 (6.1) | 7 (3.5) | 13 (6.3) | 12 (6.5) | 0.29c |
| II | 6 (5.3) | 5 (4.4) | 13 (7.9) | 12 (5.9) | 27 (13.2) | 29 (15.6) | <0.01b |
| III | 18 (15.9) | 14 (12.3) | 38 (23.0) | 41 (20.3) | 60 (29.3) | 66 (35.5) | <0.01b |
| IV | 47 (41.6) | 55 (48.2) | 62 (37.6) | 86 (42.6) | 71 (34.6) | 70 (37.6) | 0.21b |
| V | 38 (33.6) | 38 (33.3) | 42 (25.4) | 56 (27.7) | 34 (16.6) | 9 (4.8) | <0.01b |
LOE = level of evidence. All bolded p-values = 0.01.
a
Values displayed as n (%).
b
Chi squared analysis.
c
Fisher exact test.