Is objective mobility data associated with pharmacologic venous thromboembolism (VTE) prophylaxis use among hospitalized older adults?

Background: Clinical practice guidelines state that mobility is supposed to play an important role in determining use and duration of pharmacologic VTE prophylaxis. This study examines whether measured mobility levels relate to pharmacologic VTE prophylaxis use among hospitalized older adults.

Methods: Prospective observational data from a sample of community-dwelling older adults aged ≥ 60 years, admitted to an academic hospital’s general medicine service. Inpatient mobility was objectively measured using ankle-mounted accelerometers from admission until discharge (or ≤ 7 days). Clinical and demographic factors, and pharmacologic VTE prophylaxis use was manually abstracted from the medical record. We performed descriptive statistics for daily mobility parameters (time spent in activity, sedentary time, and step counts) according to VTE risk stratification using a validated stratification tool (Padua Score) and prophylaxis use. Pearson’s correlation was used to determine the correlation of mobility measures with use and duration of VTE prophylaxis.

Results: Among hospitalized older adults in this sample (N=65), 71% (n=46) were low risk for VTE occurrence, yet 62% (n=40) received pharmacological VTE prophylaxis during an average of 57% of their hospital stay (SD 46). Median time in activity was 65 minutes/day (IQR 40, 102; Range 5 – 289 mins/day). Median time spent in sedentary activity (awake but not moving) was 15 hrs/day (IQR 12, 17; Range: 3 – 20 hrs/day). Median total daily steps was 1370 (IQR 852, 2387; Range: 86 – 6134 steps/day). There was significantly greater sedentary time (16 hrs/day) for high risk patients compared to low risk patients (13 hrs/day) (p=0.02), but no differences in activity time or step counts. There were no detectable differences in mobility measures between those receiving and not receiving pharmacological VTE prophylaxis, and no significant correlations between mobility measures and duration of VTE prophylaxis.

Conclusions: Among hospitalized older adults, use and duration of VTE prophylaxis did not differ by higher or lower mobility activity, suggesting that better mobility awareness is needed to guide appropriate pharmacological VTE prophylaxis use.