Table 1.
Effects of Data Clustering Due to Dependency in Observations, Namely 3 EF Estimates in the Same Patient
| All 3 Estimates | Estimate 1 | Estimate 2 | Estimate 3 | ||
|---|---|---|---|---|---|
| Linear regression | r value | 0.95 | 0.94 | 0.94 | 0.95 |
| P value | 0.0000 | 0.0000 | 0.0000 | 0.0000 | |
| 95% CI | (0.938–0.96) | (0.912–0.959) | (0.912–0.959) | (0.926–0.966) | |
| Intraclass correlation | ICC | 0.92 | 0.92 | 0.92 | 0.93 |
| 95% CI | (0.900–0.936) | (0.883–0.946) | (0.883–0.946) | (0.897–0.953) | |
| Bland-Altman analysis | Bias | 1.0 | 1.1 | 0.8 | 1.1 |
| LOA (2SD) | 12.1 | 12.2 | 12.4 | 11.7 |
Results of linear regression and Bland-Altman analysis (both against the reference values), performed for all 3 estimates combined vs each of the 3 estimates separately. See text for details. EF indicates ejection fraction; ICC, indicates intraclass correlation; LOA, limits of agreement.