How to Create Person Level Summary Metrics
The summary variables that will be calculated here include a description of mean total counts per day, mean counts/min per day, and time above specified intensity thresholds. The minutes above thresholds are calculated both in defined bouts and with accumulation of every minute above threshold.
Sample Code
data =pam_day;
by seqn;
where valid_person= 1 and valid_day= 1 ;
var tot_dur_mv tot_dur_mv1
tot_dur_m tot_dur_m1
tot_dur_v tot_dur_v1
tot_dur_s1 tot_dur_l1 tot_dur_ls1 tot_dur_nw1
tot_min_wr tot_cnt_wr;
output out =valid_days
mean (tot_dur_mv tot_dur_mv1
tot_dur_m tot_dur_m1
tot_dur_v tot_dur_v1
tot_dur_s1 tot_dur_l1 tot_dur_ls1 tot_dur_nw1
tot_min_wr tot_cnt_wr)=
allmean_mv allmean_mv1
allmean_m allmean_m1
allmean_v allmean_v1
allmean_sed1
allmean_light1
allmean_lifemod1
allmean_nonwear1
allmean_min_wr
allmean_cnt
sum (tot_min_wr tot_cnt_wr)=all_min_wr all_cnt_wr;
;
Apply Labels to Physical Activity Monitor Data Variables
Variables are given a text description using a LABEL statement. One way to do this is by using a SAS data step, as shown below in the sample code from the “PAXMSTR” program. User-defined labels always should be surrounded by single- or double-quotation marks. Below we show labels for the primary summary metrics we will use in further analyses.
Sample Code
set valid_days;
label
allmean_cnt='Mean total counts per day from all valid days'
allmean_mv='Mean duration (minutes) of moderate and vigorous activity bouts (8 out of 10 minute bouts) per day from all valid days'
;