Table 4. Systematic review: 74 plasma miRNA publications July 1, 2013—June 30, 2014.
| Methodologic Parameter Assessed | Number of studies (% of total 74 manuscripts reviewed) |
|---|---|
| Time of Plasma Extraction | |
| ≤ 2h | 44 (59.5) |
| >2h | 8 (10.8) |
| Not Stated | 22 (29.7) |
| Method RNA Extraction + | |
| Trizol | 13 (17.6) |
| miRNeasy | 25 (33.8) |
| mirVana | 30 (40.5) |
| Not Stated/Other | 8 (10.8) |
| Type of miRNA used | |
| Total miRNA | 72 (97.3) |
| Exosomal miRNA | 2 (2.7) |
| Cycle Threshold Bar Setting | |
| Fixed | 2 (2.7) |
| Variable | 1 (1.4) |
| Not Listed | 71 (95.9) |
| miRNA Quantification * | |
| External reference | 31 (41.9) |
| Internal reference | 32 (43.2) |
| Not specified | 12 (16.2) |
| Statistical Analysis Described ψ | 74 (100) |
| t-test | 30 (40.5) |
| Mann-Whitney | 29 (39.2) |
| Receiver operating characteristic (ROC) curves | 24 (32.4) |
| Wilcoxon | 16 (21.6) |
| ANOVA | 12 (16.2) |
| Other | 14 (18.9) |
+ Some manuscripts utilized more than one method of RNA extraction.
* Some manuscripts used both an internal and external reference.
ψ Many manuscripts used multiple methods of statistical analysis.