Table 4.
Comparison of studies that used the two major types of ISI classifications
| Study characteristics | Number of studies using a particular type of ISI classification (%) | |
|---|---|---|
| L2 classification | Q3 classification | |
| Total number of studies | 10 | 6 |
| Prospective | 6 (60.0) | 4 (66.6) |
| Retrospective | 4 (40.0) | 2 (33.3) |
| Blinding of assessors | 4 (40.0)a | 2 (33.3) |
| Uniform surgical procedure performed | 4 (40.0) | 5 (83.3) |
| Multivariate analysis used | 2 (20.0) | 3 (50.0)b |
| Type of ISI correlated with outcome | 4 (40.0) | 4 (66.6) |
| Type of ISI was an independent predictor of outcome | 1 (10.0) | 3 (50.0) |
| Classes of evidence (Class I/II) | 0/10 | 1/5 |
Q3 classification—type 0, no ISI; type 1, faint, fuzzy border; type 2, intense, well-defined border
L2 classification—type 0, no ISI; type 1, focal/single segment ISI; type 2, multisegmental ISI
aOnly one assessor was blinded in the study by Papadopoulos et al. [26]
bIn the study by Chen et al. [5], ANCOVA was used to identify the independent predictive value of ISI. All other studies used the multiple regression analyses