To the Editor: In their study of the relationship of physical fitness and body mass index to cardiac disease in women, Dr Wessel and colleagues1 incorrectly converted the Duke Activity Status Index (DASI) score to peak metabolic equivalent tasks (METs). The Methods state that the actual score from the DASI questionnaire can be divided by 3.5 to estimate METs. However, the original article on the development of the DASI2 states that weighting of items in the index was based on known metabolic costs, but the sum of the weighted answers must then be converted to VO2 peak in mL/kg per minute using the equation VO2 peak = 0.43 × DASI score + 9.6. METs can then be calculated by dividing the estimated VO2 peak by 3.5.
Converting directly from DASI score to METs, as in the study by Wessel and colleagues, overestimates METs. This is important, as the study used a DASI score of 25 or greater as the criterion for placement in the fit group, under the assumption that this score is equivalent to 7 or more METs. A DASI score of 25 converts to only 5.8 METs, calculated by converting the DASI score to a VO2 peak of 20.35 mL/kg per minute and dividing by 3.5. Therefore, the cutoff used to define fit and unfit groups in this study was actually 5.8 METs.
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
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