Findings from other components of the process evaluation, for example interview data, suggest that healthcare staff did not always document everything that they did [ 17], and therefore it is likely that a method of fidelity assessment based upon healthcare staff recording of activity underestimates the true level of fidelity to treatment delivery.
In a 120-min routine that included a variety of lifestyle tasks and sporting activities, the SWA significantly overestimated EE in moderate-intensity physical activity and underestimated EE in vigorous-intensity physical activity [ 30].
Notwithstanding this, for activity concentrations exceeding 1.5 MBq/mL, the recovered activity concentration underestimated the known value by 4% approximately, demonstrating that accurate quantitation of 90Y is possible if long scan time is performed and if partial volume effects are accurately compensated for.
In the uncorrected case, the average activity is underestimated by up to 13.4% compared to the reference scan.
When ignoring RF coil attenuation (uncorrected), the activity is underestimated, especially for regions in vicinity of the RF coil.
For the coronal plane closest to the RF coil, the average activity was underestimated by 25.3% compared to the reference scan.
For the uncorrected case, i.e., when the headphones were attached to the phantom but neglected during AC, the reconstructed activity was underestimated compared to CTAC, especially for transversal planes embraced by the headphones.
Trost et al. [ 25] demonstrated that not every activity can be adequately recorded by accelerometry and that especially free-living activities are underestimated in their energy expenditure and their intensity by accelerometry.
Also, as stated in a review by Shephard et al. (2003), responses from self-reported questionnaire can often be influenced by social desirability, resulting in overestimated physical activity levels and underestimated sedentary activities such as time spent watching television [ 31].
The activities are underestimated.
