Because of the staged entry of participants, we evaluated two time variables: calendar date (proxy for unmeasured confounders) and day of study for a specific subject (possibly related to fatigue).
Under the amendments, laboratories like hers must be certified before they can perform tests for the general public, and their performance is evaluated three times a year by the College of American Pathologists.
Corrosion was evaluated four times a year performing visual observations (rust, cracks, delamination) and electrochemical measurements from which corrosion rates were calculated.
Odor intensity (ratings 0 5) and environmental factors, including meteorological condition, PM10, PM2.5, total volatile organic compounds (TVOCs), ammonia and reduced sulfides, were evaluated six times daily.
The residents in the experimental and control groups were evaluated three times: at the beginning of the program (1996), 1 year (1997) and 2 years (1998) later.
A total of 41 nurses were randomly allocated to three groups, which were separately trained, and all were evaluated four times at three-month intervals (before intervention, between each intervention, and after the last intervention).
The blood glucose levels were evaluated three times a week for the appropriate level of blood glucose control and animals were treated accordingly.
The repeated sprint ability was also evaluated three times: during Ex1, during Ex2, and at 24 h during post-exercise period (Fig. 1).
Scores of subjective fatigue and vitality were evaluated six times (before Ex1, immediately after Ex1, before Ex2, immediately after Ex2, 4 h after Ex2, 24 h after the onset of Ex1) using a 100-mm visual analogue scale (VAS), where 0 mm represented "no fatigue (or "filled vitality") at all" and 100 mm represented "unbearable fatigue (or "no vitality at all")" [21].
