Skip to main content

Table 2 Strain inter- and intra-observer reproducibility

From: Speckle tracking echocardiographically-based analysis of ventricular strain in children: an intervendor comparison

Measurements (n = 15)Mean difference ± SDICC (95% CI)Mean absolute difference ± SD% error Median (IQR)
Inter-observer
QLAB 10.5
  AP40.1 ± 1.50.98 (0.95, 0.99)1.15 ± 0.993.46 (0.98–7.79)
  SAXM0.8 ± 3.00.92 (0.79, 0.97)1.99 ± 2.255.83 (3.04–10.00)
QLAB 10.8-Low
  AP40.8 ± 2.20.95 (0.85, 0.98)1.90 ± 1.2211.38 (6.00–19.61)
  SAXM− 1.8 ± 2.50.95 (0.79, 0.98)2.36 ± 1.917.91 (2.95–10.76)
QLAB 10.8-Med
  AP40.5 ± 1.80.96 (0.90, 0.99)1.61 ± 0.769.14 (6.00–20.47)
  SAXM− 1.1 ± 2.60.96 (0.88, 0.98)2.25 ± 1.547.10 (4.07–12.64)
QLAB 10.8-High
  AP40.6 ± 1.80.96 (0.90, 0.99)1.60 ± 0.9810.74 (4.56–19.76)
  SAXM− 1.5 ± 2.70.95 (0.83, 0.98)2.49 ± 1.749.04 (4.78–11.99)
TomTec-LFR
  AP40.2 ± 4.50.80 (0.50, 0.93)3.55 ± 2.5917.17 (13.73–24.00)
  SAXM0.3 ± 3.10.95 (0.85, 0.98)2.26 ± 2.034.72 (3.40–19.88)
TomTec-HFR
  AP41.5 ± 2.70.91 (0.73, 0.97)2.58 ± 1.6215.53 (7.16–25.24)
  SAXM−2.9 ± 2.70.92 (0.42, 0.98)3.17 ± 2.3811.38 (5.34–17.89)
Intra-observer
QLAB 10.5
  AP40.6 ± 2.60.79 (0.49, 0.92)1.72 ± 2.023.19 (1.31–11.11)
  SAXM0.2 ± 1.80.94 (0.84, 0.98)1.21 ± 1.343.10 (1.09–6.52)
QLAB 10.8-Low
  AP40.7 ± 2.00.79 (0.49, 0.92)1.41 ± 1.592.70 (0.98–10.00)
  SAXM− 0.4 ± 2.00.94 (0.84, 0.98)1.75 ± 0.935.82 (3.43–8.64)
QLAB 10.8-Med
  AP40.8 ± 2.50.73 (0.37, 0.90)1.89 ± 1.807.55 (3.12–11.45)
  SAXM0.1 ± 2.60.90 (0.73, 0.97)2.07 ± 1.486.21 (2.62–10.46)
QLAB 10.8-High
  AP41.2 ± 2.50.73 (0.38, 0.90)2.00 ± 1.875.31 (3.73–14.99)
  SAXM0.1 ± 2.40.91 (0.75, 0.97)2.04 ± 1.065.56 (3.81–9.27)
TomTec-LFR
  AP42.1 ± 2.90.65 (0.16, 0.88)2.73 ± 2.2911.00 (4.12–19.45)
  SAXM− 1.0 ± 1.60.94 (0.79, 0.98)1.27 ± 1.362.47 (0.72–5.32)
TomTec-HFR
  AP41.0 ± 1.70.82 (0.49, 0.94)1.51 ± 1.265.18 (2.84–10.29)
  SAXM0.0 ± 2.00.93 (0.79, 0.97)1.47 ± 1.343.58 (0.34–6.45)
  1. Strain values are listed as %. % error is defined as the absolute difference |[Reader 2 − Reader1]|/[median of Reader 1 and Reader 2] × 100
  2. Abbreviations: AP4 Apical four-chamber view; CI Confidence Interval; ICC Intraclass Correlation; IQR Interquartile Range; QLAB 10.8 Low low quantification smoothness setting; QLAB 10.8 High high quantification smoothness setting; QLAB 10.8 Med medium quantification smoothness setting; SAXM short-axis mid papillary muscle level; SD Standard Deviation; TT-30 TomTec at 30 frames per second; TT-H TomTec at high frame rate