The study subgroups of each city collected and checked measurements and questionnaires under the direction of the Beijing Steering Committee that ultimately performed data entry and statistical analysis.
Fig. 3 Examples of viewing and checking measurement data in UDECON for (a) X-, Y-, and Z-axis intensity on multiple plots; (b) declination, inclination, and total intensity on multiple plots; and (c) total intensity on a single plot.
A crucial first step therefore is assessing model fit and checking measurement invariance.
Finally, we double-checked measurements in which migration was apparent, to be sure that this was not caused by a measurement error.
We checked for measurement invariance of the latent factor 'alcohol involvement' between the five time-points.
The performance of the instruments was checked and measurement tools monitoring were done.
At each centre, the same tonometer was used throughout the study, and the calibration was checked every measurement day.
Spot-check measurement of tracheal pressure were taken by introducing a pressure measuring catheter into the trachea via the lumen of the ETT, as described in detail elsewhere [ 20].
Tailpipe emission parameters were derived from road tunnel measurements throughout the United States and were checked using measurements on vehicles run on dynamometer test beds (Beyea et al. 2008).
Further criticism concerns the comparability with other studies on balance ability, due to limitations of the S3-Check measurement system, which does not allow for testing different sensory conditions (e.g. eyes open vs. eyes closed, stable vs. instable ground).
