Using actigraphy to evaluate physical activity in patients with pleural effusion: a pilot study.

Background: Malignant pleural effusions (MPEs) are common in cancer patients and significantly impair physical activity. Although symptom relief is the primary treatment goal, the extent of activity limitation and the effectiveness of interventions remain unclear. We used actigraphy to assess the impact of thoracentesis on activity level. The primary objective was to evaluate the association between physical activity (via ActiGraph), quality of life [Short Form 6-Dimension index (SF-6D) utility score], and dyspnea (Borg scale) at weeks 1 and 2 following thoracentesis. Methods: We conducted a prospective, observational, single-center study in adults with symptomatic, moderate-to-large MPEs. Results: Participants wore actigraphy devices for a mean of 17.7 hours daily. Higher average steps in week 2 significantly correlated with higher week 2 SF-6D utility scores. Higher calorie expenditure in week 1 significantly correlated with better week 1 SF-6D utility scores. However, no actigraphy metrics significantly affected SF-6D utility score changes from week 1 to week 2. For Borg, higher average triaxial movement in week 2 was modestly associated with lower dyspnea in week 2. Greater week 1 increases (slopes) in calories, moderate-to-vigorous physical activity (MVPA), and triaxial movement significantly predicted larger Borg scale reduction from week 1 to week 2. Conclusions: These findings suggest that improvement in SF-6D utility scores is tied to average activity levels (calories in week 1, steps in week 2), whereas dyspnea improvement by Borg scale over time is more strongly related to early gains in week 1 activity. Triaxial movement was also associated with less dyspnea in week 2.