An Activity Index for Raw Accelerometry Data and Its Comparison with Other Activity Metrics - Fig 6

<p>The “receiver operating characteristic” (ROC) curves of Activity Index (AI), activity count (AC), AC with Low Frequency Extension (LFE) and Euclidean Norm Minus One (ENMO) to predict whether metabolic equivalents (MET) is smaller or greater than 3 (A) and 1.5 (B), and whether MET is bigger than 1.5 but smaller than 3 (C). The ROC curves for AI, AC and ENMO are solid, dashed and dotted, respectively, while AC with and without LFE are rendered in purple and orange. The corresponding area under the curve (AUC) of each ROC curve is given in the legend section.</p

An Activity Index for Raw Accelerometry Data and Its Comparison with Other Activity Metrics - Fig 5

<p>Scatterplots of metabolic equivalents (METs) versus Activity Index (AI) (A), activity count (AC) (B), AC with Low Frequency Extension (LFE) (C) and Euclidean Norm Minus One (ENMO) (D). MET is on <i>x</i>-axis for all four plots, while AI, AC, AC (LFE) and ENMO are on the <i>y</i>-axis in (A), (B), (C) and (D), respectively. Each point in the figure represents a participant's median METs during a certain activity (rendered in different colors) versus the median AI, AC or ENMO while he/she was performing the same activity.</p

A general framework for accelerometer-related studies.

<p>The left panel illustrates two general data types: raw data and summary measures. The right panel shows 4 common research interests. The mid panel contains 6 common analysis pathways between the data and the research interests.</p

The “receiver operating characteristic” (ROC) curves for distinguishing four pairs of activity types, using Activity Index (AI, solid curves) or activity count (AC, dashed curves in different color for AC with and without Low Frequency Extension (LFE)) or Euclidean Norm Minus One (ENMO, dotted curves), respectively.

<p>The corresponding area under the curve (AUC) of each ROC curve is given in the legend section.</p

Summary Statistics of AI, AC, AC (LFE), and ENMO of each activity.

<p>Summary Statistics of AI, AC, AC (LFE), and ENMO of each activity.</p

Comparison of the boxplots of Activity Index (AI), activity count (AC), AC with Low Frequency Extention (LFE) and Euclidean Norm Minus One (ENMO) during different types of activities.

<p>Outliers outside of the upper and lower whiskers are omitted. Each type of summary metric from all the participants were pooled together and plotted according to the type of activity.</p

Minutes in Sedentary Bouts^a, Per Day.

<p>^a Variables computed using daily-level data.</p><p>^b Means are adjusted for accelerometer wear time, physical functioning, depression, cognitive functioning, as well as age and gender where appropriate.</p><p>^c p-values were derived from F tests following linear mixed models that regressed sedentary time on measures of age, gender, physical functioning, cognitive functioning, depression and accelerometer wear time; Kenward-Roger approximations were used to estimate the denominator degrees of freedom.</p><p>Minutes in Sedentary Bouts<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0136161#t003fn001" target="_blank">^a</a>, Per Day.</p

Sedentary minutes accumulated in bouts of various lengths for each one hour period between 06:00 and 22:59.

<p>The number of sedentary minutes spent in bouts of (a) 1+, (b) 5+, (c) 10+, (d) 20+, (e) 30+, and (f) 60+ minutes are plotted across hours of the day for men and women.</p

Number of sedentary bouts started during each one hour period between 06:00 to 22:59.

<p>The number of (a) 1+, (b) 5+, (c) 10+, (d) 20+, (e) 30+, and (f) 60+ minute bouts are plotted across hours of the day for men and women.</p

Change in FMD during sitting conditions.

<p>Condition-associated change in FMD is represented by the ratio of FMD 2 (end of sitting period) to FMD 1 (baseline) and are shown by group (Panels A and B) and by individual (Panels C and D) using raw data (Panels A and C) and allometrically scaled data (Panels B and D) (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0188544#sec007" target="_blank">Materials and Methods</a> section). An FMD 2–to–FMD 1 ratio greater than 1 (dotted, horizontal line) indicates that the FMD response was greater at the completion of the sitting period relative to baseline. Box and whisker plots (Panels A and B): x = mean, line = median, dots above boxes are outliers. n = 10 for the control, 2-minute walking every hour, and 10-minute standing every hour conditions; n = 9 for the 2-minute standing every 20 minutes condition. <i>p</i>-value vs. the control condition. * Statistically significant after Bonferroni correction. Bonferroni-corrected cut-off for significance in 3-arm comparison with control was <i>p</i>< 0.0167.</p