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

Abstract

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.

Highlight box.

Key findings

• Improvement in Short Form 6-Dimension index (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.

What is known and what is new?

• 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 are unclear.

• Our study showed that higher average steps in week 2 are significantly correlated with higher week 2 SF-6D utility scores. Higher calorie expenditure in week 1 is 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.

What is the implication, and what should change now?

• This study shows that actigraphy provides a feasible and informative method to objectively measure physical activity in patients with MPEs following thoracentesis. This is the largest dataset of patients with effusions in whom actigraphy was implemented for monitoring after undergoing thoracentesis. Further studies are needed to define optimal thresholds and timing for clinical decision-making based on activity data.

Introduction

Malignant pleural effusions (MPEs) contribute to significant symptom burden and impact 15% of all cancer patients during their clinical course (1). With over 150,000 MPEs diagnosed each year in the United States, that result in over 125,000 hospitalizations (2,3), the burden to the overall healthcare system is significant (4).

Although some patients may be asymptomatic initially, the majority will eventually develop dyspnea or other respiratory symptoms that significantly impact their quality of life (QOL) (5). Breathlessness and other symptoms caused by MPEs can significantly limit a patient’s functional capacity and activity level, and this decline in their performance status may in turn limit their systemic treatment options (6). Therefore, focusing on improving these symptoms is of the utmost importance in the management of MPEs. Fortunately, there are several options available for palliation of MPEs (1,7,8).

However, the activity level in patients with MPEs remains largely unknown, particularly in those who have undergone an intervention for symptom palliation. Given that patients with MPEs are known to have a poor prognosis with high symptom burden, and undergo repeated invasive procedures (9), objective data regarding activity levels in this patient population is needed.

Actigraphy devices, worn like a wristwatch, can objectively measure physical activity and sedentary behavior in patients with MPEs (10) and may be able to better characterize small, yet meaningful, changes in activity levels not detected when using more subjective assessment tools. These devices, and other digital activity trackers, are increasingly used to measure activity in patients with cancer (11).

The aim of our study was to obtain preliminary data on the role of actigraphy in the objective evaluation of physical activity in patients with MPEs. The primary objective was to evaluate the association between quality of life [Short Form 6-Dimension index (SF-6D) utility], Borg scale, and physical activity recorded by the ActiGraph at weeks 1 and 2 post-thoracentesis. We present this article in accordance with the STROBE reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2311/rc).

Methods

Study population

This was a prospective, observational, single-center study to evaluate physical activity in patients with symptomatic MPEs using actigraphy. All patients aged 18 years or older who presented to MD Anderson Cancer Center with symptomatic MPE and were to undergo thoracentesis in the ambulatory setting were considered for inclusion. Patients were recruited from July 2022 through June 2023.

Patients with a symptomatic, moderate-to-large, free flowing (non-septated) pleural effusion were considered for inclusion in this study. Effusion size was determined according to chest imaging (chest radiography, computed tomography, or ultrasonography). A moderate-to-large effusion on traditional chest radiography was an effusion filling 1/3^rd or more of the hemithorax. With computed tomography, an effusion was considered moderate-to-large if the maximum anterior-posterior depth of the effusion was 1/3^rd or more of the anterior-posterior dimension on the axial image superior to the hemidiaphragm. This included atelectatic lung surrounded by effusion. By ultrasonography, a moderate-to-large effusion spanned at least 3 interspaces and had a depth of 3 cm or greater in at least 1 intercostal space. Thoracic ultrasonography was performed with the patient in a seated, upright position.

Patients were excluded if they were unable to provide informed consent, could not walk (even with assistance) at the time of recruitment, could not return for a 2-week follow-up, were unwilling to wear an activity monitor for the duration of the study, or had the presence of more than minimal septations and/or loculations (defined as ≥3) on bedside pre-procedure ultrasonography.

Ethics approval declaration or human ethics approval declaration for human studies

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of MD Anderson Cancer Center (No. PA 2020-0090). All adult participants provided written informed consent to participate in this study.

Study procedure

Patients were recruited from clinic at the time of their evaluation for thoracentesis. Before the thoracentesis, patients completed self-administered SF-6D and Borg scale questionnaires and underwent a 6-minute walk test, as per standard of care. The SF-6D and Borg scale questionnaires were administered again 1 week later, either via telephone or the Research Electronic Data Capture email system, and then self-administered in the clinic at the patient’s 2-week follow-up. For patients who did not develop recurrence, the Borg scale and SF-6D questionnaires were collected from the patients at 1, 2, and 3 months. If patients did not come to the clinic for follow-up, the Borg scale and SF-6D were sent via the Research Electronic Data Capture email system.

Patients underwent thoracentesis as per standard of care. Once the procedure was completed, participants were given an ActiGraph GT9X Link to monitor their ambulatory physical activity and instructed to always wear it on their wrist. The ActiGraph GT9X displays were disabled, and patients were not able to view their data on the wearable device to avoid changes in behavior related to study participation.

Patients had a follow-up appointment 2 weeks after thoracentesis and every 4 weeks thereafter, as per standard of care. Patients were contacted by phone if the ActiGraph GT9X device was found to have not been worn for an extended period. Patient participation in the study ended in the event of recurrence of fluid, need for repeat intervention, or death. Follow-up for those without recurrence ended at 3 months. Please see study schema in supporting information Figure S1.

Actigraphy data

The ActiGraph (ActiGraph GT9X Link; Pensacola, FL, USA) contains a piezo-electric sensor detecting acceleration of the body (parts) in the three axes: vertical (Y-axis), horizontal right-left (X-axis), and horizontal front-back (Z-axis). The detected movement is translated in a digital count. The device captures raw acceleration data, which is then processed through proprietary algorithms. The raw data is downloaded in 1-second epochs.

Physical activity as measured by actigraphy includes a measure of step counts, energy expenditure (number of calories burned), and activity intensity [duration of moderate-to-vigorous physical activity (MVPA)] (12). In addition, triaxial movement measures physical activity across three orthogonal planes: vertical (Y-axis), horizontal right-left (X-axis), and horizontal front-back (Z-axis). This multi-axis collection allows for a thorough assessment of physical activity (13). The duration of triaxial movement measurement refers to the total time during which the ActiGraph GT9X records physical activity data across the three axes (14).

Step counts, energy expenditure (number of calories burned), and activity intensity (duration of MVPA) were recorded. The duration of triaxial movement measurements was recorded as well.

All actigraphy data were aggregated into daily epochs, and epochs with at least 10 hours of monitor wear-time were included. For reliable estimates of physical activity, a previous study suggests a minimum wear-time of 4 days with at least 6 hours of data per day (15). During study planning and preliminary analyses, we evaluated wear-time normalization approaches by the wear time. However, we decided to retain absolute activity measures as the primary outcome, provided that a strict minimum wear-time criteria was met. Specifically, only days with at least 10 hours of valid wear-time were included, and day 0 was excluded to minimize procedural and immediate post-thoracentesis effects, as this was the day the patients received the device.

The primary objective is to evaluate the association between quality of life, as measured by the SF-6D at week 1 and week 2, and physical activity recorded by the ActiGraph. Additionally, the objective includes assessing the association between a validated dyspnea scale (modified Borg) at week 1 and week 2, and physical activity from the ActiGraph.

Statistical analysis

Continuous variables were summarized by the mean, median, standard deviation, range, and quartiles. Categorical variables were summarized with frequency tables. With 30 patients, we calculated 80% power to detect a minimum correlation of 0.49 between two variables, assuming a 2-sided test.

Participants had daily measurements of physical activity by actigraphy starting immediately post thoracentesis. We established separate trajectories for week 1 and week 2 to monitor variations in step counts, energy expenditure (number of calories burned), and activity intensity (duration of MVPA), as well as the triaxial movement and duration of triaxial movement.

The SF-6D health index contains 6 questions regarding the quality of life (physical functioning, role limitations, social functioning, pain, mental health, and vitality), each with four to six possible answers. An algorithm was used to convert the raw results into a health utility score that ranges from 0.3 (worst possible score for someone alive) to 1.0 (fully functioning with no problems). The modified Borg dyspnea scale measures troubles with breathing. Scores range from 0 (no exertion) to 10 (maximum exertion). Thus, higher scores are better for the SF-6D and worse for the Borg scale.

We used univariable linear regression models to examine the association between the SF-6D utility score and Borg scale at week 1, week 2, and changes from week 1 to week 2 with physical activity recorded by the ActiGraph. For each model, the average and slope of the actigraphy measurements over each week were included as independent variables. The scales of MVPA, calories, steps, and triaxial movements were adjusted by 100, 1,000, 1,0000, and 1,000,000, respectively, to match the scale of the Borg and SF-6D indices. Estimates are presented as MVPA, calories, etc. per point in utility score or Borg scale. Thus, for MVPA, for example, an estimate of 0.1 for the association with SF-6D utility score would be interpreted as a 0.1×100=10-point increase in MVPA being associated with a 1-unit increase in SF-6D utility score on average.

Results

There was a total of 34 patients included in our study. Table 1 summarizes the baseline patient characteristics in this study. Actigraphy proved to be an effective way to objectively monitor activity levels (mean wear-time was 17.7 hours daily). Figure 1A-1D represents the changes in steps, calories, and MVPA over time recorded by actigraphy.

Table 1. Baseline characteristics.

Variable	Value
Age (years)
Mean ± SD	61.29±16.25
Median	63.5
Min–Max	23–84
Amount of fluid drained (mL)
Mean ± SD	1,168.38±540.53
Median	1,025
Min–Max	400–2,300
Cholesterol BF (mg/dL)
Mean ± SD	74.18±27.07
Median	69
Min–Max	33–124
LDH BF (U/L)
Mean ± SD	226.45±210.9
Median	156
Min–Max	119.5–1,078
Protein BF (gm/dL)
Mean ± SD	4.04±0.78
Median	4.2
Min–Max	2.10–5.40
Triglycerides BF (mg/dL)
Mean ± SD	40.90±38.66
Median	29
Min–Max	13–209
Gender, n (%)
Male	18 (52.9)
Race, n (%)
White	24 (70.6)
African American	3 (8.8)
Hispanic	3 (8.8)
Other	4 (11.8)
History of COPD, n (%)
Yes	4 (11.8)
History of heart disease, n (%)
Yes	12 (35.3)
ECOG, n (%)
0	1 (2.9)
1	18 (52.9)
2	10 (29.4)
3	5 (14.7)
Size of the effusion on chest X-ray, n (%)
Blunting of costophrenic angle, but at least part of diaphragm is still visible	3 (8.8)
Effusion greater than 1, and up to the inferior border of the vascular pedicle	14 (41.2)
Effusion greater than 2, and up to the top of the cardiac silhouette	13 (38.2)
Effusion greater than 3, and up to the top of the aortic arch	3 (8.8)
Effusion greater than aortic arch	1 (2.9)
Pleural fluid cytology, malignant, n (%)
Yes	19 (55.9)
Type of malignancy, n (%)
Lung cancer	12 (35.3)
Solid non-lung	17 (50.0)
Liquid malignancy	5 (14.7)

BF, body fluid; COPD, chronic obstructive pulmonary disease; ECOG, Eastern Cooperative Oncology Group; LDH, lactate dehydrogenase; SD, standard deviation.

Figure 1.

Post-thoracentesis evaluation of actigraphy variables over time in days. (A) Number of steps over time in days; (B) calories burnt over time in days; (C) MVPA over time in days; (D) triaxial movement over time in days. MVPA, moderate-to-vigorous physical activity.

Following thoracentesis, step count analysis showed a slight day-by-day increase in the overall number of steps taken (Figure 1A). A higher number of average steps in week 1 was associated with a marginally better SF-6D utility score at week 1 (0.07, P=0.07), suggesting a trend but not reaching statistical significance (Table 2). A higher average daily number of calories burned in week 1 was significantly associated with as a higher SF-6D utility score at week 1 as well (0.14, P=0.047). In week 2, higher average steps were significantly associated with higher SF-6D utility scores (0.10, P=0.004) (Table 2). None of the actigraphy measurements were significantly associated with the change in SF-6D utility from week 1 to week 2 (Table 3).

Table 2. SF-6D week 1 and week 2 actigraphy—univariate assessment.

Actigraphy	Week 1			Week 2
	Estimate	P value		Estimate	P value
Steps
Average	0.07	0.07		0.10	0.004
Slope	0.09	0.58		0.04	0.81
Calories
Average	0.14	0.047		0.14	0.16
Slope	1.18	0.15		0.33	0.53
MVPA
Average	−0.06	0.61		0.12	0.37
Slope	0.81	0.39		0.41	0.55
Triaxial movement
Average	0.07	0.46		0.10	0.31
Slope	0.67	0.36		−0.03	0.96

MVPA, moderate-to-vigorous physical activity; SF-6D, Short Form 6-Dimension index.

Table 3. SF-6D change from week 1 to week 2 actigraphy—univariate assessment.

Actigraphy item	Estimate	P value
Steps: week 1
Average	0.02	0.66
Slope	−0.08	0.63
Calories: week 1
Average	−0.04	0.57
Slope	−0.55	0.49
MVPA: week 1
Average	0.07	0.52
Slope	−0.24	0.78
Triaxial movement: week 1
Average	0.02	0.80
Slope	−0.30	0.66

MVPA, moderate-to-vigorous physical activity; SF-6D, Short Form 6-Dimension index.

None of the actigraphy measurements were significantly associated with the Borg dyspnea scale at week 1. At week 2, the average triaxial movement was significantly associated with the raw Borg scale (−2.47, P=0.02); higher average triaxial movement was thus associated with lower dyspnea (Table 4). For the change in Borg scale from week 1 to week 2 (week 2–week 1), a negative trend in calories burned, MVPA, and triaxial movement in week 1 were each associated with higher Borg scale changes, and thus worsening dyspnea (Table 5).

Table 4. Borg week 1 actigraphy—univariate assessment.

Actigraphy	Week 1			Week 2
	Estimate	P value		Estimate	P value
Steps
Average	−0.68	0.14		−0.40	0.30
Slope	−0.27	0.89		2.77	0.21
Calories
Average	−0.70	0.41		−1.25	0.31
Slope	−0.06	>0.99		2.27	0.72
MVPA
Average	0.50	0.70		−2.43	0.12
Slope	4.56	0.68		2.42	0.76
Triaxial movement
Average	−0.30	0.77		−2.47	0.02
Slope	−2.17	0.80		2.82	0.57

MVPA, moderate-to-vigorous physical activity.

Table 5. Borg change from week 1 to week 2: week 1 actigraphy—univariate assessment.

Actigraphy item	Estimate	P value
Steps: week 1
Average	0.11	0.86
Slope	−0.17	0.95
Calories: week 1
Average	0.48	0.59
Slope	−32.80	0.002
MVPA: week 1
Average	0.04	0.98
Slope	−38.36	0.003
Triaxial movement: week 1
Average	−0.39	0.72
Slope	−27.14	0.006

MVPA, moderate-to-vigorous physical activity.

Discussion

This study demonstrates that actigraphy can effectively capture changes in physical activity following thoracentesis, revealing distinct patterns across different metrics and their associations with patient-reported outcomes. While step count slightly increased over time, higher average steps in week 2 were significantly linked to better SF-6D utility scores in week 2. Calorie burn, which increased in week 2 compared to week 1, showed a significant positive relationship with SF-6D in week 1 and predicted reduced dyspnea (larger Borg scale reductions) when it rose sharply in week 1. In contrast, both MVPA and triaxial movement declined in week 2 compared to week 1, yet their greater increases in week 1 were also significant predictors of lower perceived exertion by week 2. Notably, none of these activity metrics significantly influenced the SF-6D utility change from week 1 to week 2.

Patients with advanced cancer are mostly sedentary (10,16), and data show that physical activity reduces fatigue and improves physical functioning and overall QOL, both during and after treatment (17). Performance status scales are used to assess cancer patients’ suitability for various treatments or interventions (18) and are known predictors of survival in patients with MPEs (3,19). The Eastern Cooperative Oncology Group and Karnofsky performance status scales, which quantify the functional abilities of patients to engage in their usual activities of daily living, are the most commonly used measures of performance status in cancer patients (20,21). However, these scales are subjective, broad, and may not detect more subtle changes in activity level. Other scales that measure degree of breathlessness with exertion, such as the Borg dyspnea scale, or that assess QOL metrics, like the SF-6D index, are also widely implemented in cancer patients (22,23) but rely on subjective patient reporting.

Wearable technologies have recently gained prominence in determining activity levels and performance status in patients with advanced cancer, and several studies are now evaluating the utility of such technologies for prognostication in this patient population (24-28). Specifically in patients with MPEs, Jeffrey et al. (10) evaluated the feasibility of utilizing actigraphy to objectively measure physical activity and sedentary behavior (10). Out of 46 patients who received accelerometers, 44 (95.7%) returned the device at study completion and 40 (90.9%) were compliant with the actigraphy protocol (10). The patients averaged 15.3 hours of waking wear-time per day but spent 11.0 hours sedentary; these patients participated in 4.2 hours of light activity and 9.5 minutes of MVPA per day (equivalent to 71.6%, 27.4%, and 1.0% of their waking hours, respectively) (10). In this study, only 5 (10.9%) patients completed 150 minutes or more of MVPA over the 7-day period, and only 15 (34.9%) patients achieved the target of 7,000 or more steps per day (10).

In a study of 145 patients with symptomatic effusions (63% were MPEs, 37% were benign-related), Muruganandan et al. (29) assessed symptoms as well as cardiopulmonary parameters prior to, and after, effusion drainage. Drainage provided significant relief for breathlessness in 73% of patients and resulted in significant improvements in pre- and post-procedure resting and exertional Borg scales, and significant increase in the 6-minute walk distance (29). However, in this analysis, prediction models were not able to accurately predict which patients were likely to be “responders” to pleural fluid drainage (i.e., to report significant improvement in symptoms), and the analysis did not evaluate how long after drainage symptom benefit lasts (29).

As previously mentioned, patients with MPE undergo multiple invasive procedures (9), since roughly 30% of effusions recur within 15 days of drainage (30). Therefore, gaining a better understanding of the efficacy of interventions is imperative. A recent pilot study by Jagan et al. (31) assessed improvement in physical activity in patients who had undergone thoracentesis. A total of 18 patients were enrolled and statistically significant changes were observed for triaxial movement (P=0.005) and calories burned (P=0.028), as both outcomes showed increases through day 7 after thoracentesis followed by decreases back to baseline by day 14 (26). In contrast, no statistically significant changes were observed for step count, sedentary time, or subjective symptoms (29). The authors postulated that the increased movement and caloric expenditure observed were not accompanied by an increase in the number of steps or a decrease in sedentarism because patients primarily had an increase in seated physical activity (29). It was also noted that the sample size in that study may have been too small to identify certain associations.

Like prior studies, our study shows that wearable devices can effectively monitor patients following interventions. Over the 2-week follow-up, the mean ActiGraph GT9X wear-time was 17.7 hours per day. Thoracentesis was associated with improvements in patient-reported symptoms (Borg) and quality of life (SF-6D), alongside changes in activity data. Step count increased over time and was significantly linked to better SF-6D utility scores in week 2, while calorie burn rose in week 2 and improved week 1 SF-6D. Greater week 1 increases in calories, MVPA, and triaxial movement was associated with reduced Borg score by week 2, though MVPA and triaxial movement declined over time. No metrics significantly influenced SF-6D changes from week 1 to week 2. These findings suggest that activity benefits post-thoracentesis may be temporary, particularly for MVPA and triaxial movement, potentially necessitating repeat interventions. This highlights the importance of close follow-up in this population to assess the need for additional procedures, though the optimal timing requires further investigation.

Overall, these findings highlight that SF-6D utility is driven by average activity levels (calories in week 1, steps in week 2), while Borg improvements over time depend on week 1 activity increases, with triaxial movement also reducing week 2 dyspnea. However, the lack of association with changes in SF-6D utility scores between weeks indicates that other factors may drive short-term shifts in overall well-being, though re-accumulation of pleural fluid and need for a definitive intervention in most patients by week 2 may show that the improvement post thoracentesis is short lived. These insights highlight the value of actigraphy in objectively monitoring recovery and its complex interplay with subjective health measures, warranting further investigation into optimizing activity levels for patient benefit after thoracentesis.

Objective measurement of activity levels post-thoracentesis, combined with subjective symptom reports (Borg, SF-6D), may help identify patients who could benefit from repeat interventions for MPEs. For instance, patients with MPEs showing sustained or increasing step counts may maintain better quality of life (SF-6D), as higher week 2 steps significantly improved SF-6D health utility scores, though step trends showed weak, non-significant ties to increased dyspnea. Conversely, patients with declining triaxial movement, which decreased in week 2, may indicate effusion re-accumulation and increased dyspnea, as higher week 2 triaxial movement reduced Borg scores, yet its impact on SF-6D remained non-significant. Greater week 1 activity increases (e.g., calories, MVPA, triaxial movement) predicted significant Borg reductions by week 2, suggesting intervention benefits persist for exertion but not consistently for quality of life. These trends support a potential role for remote monitoring, as digital activity tracking could signal the need for re-evaluation before severe symptoms emerge, though further study is needed to confirm timing and efficacy.

There are limitations to this study. First, the battery of the ActiGraph used in this analysis runs out after 14 days, so monitoring patients for longer durations with this wearable device was not possible. It is possible that some of the activity parameters measured did not meet statistical significance due to duration of follow-up rather than a true lack of association.

Second, the sample size is small, and the study’s power is inherently fixed, limiting more detailed evaluations. Follow-up analysis with a larger sample size and longer follow-up times, as well as a multicenter study, would be valuable for validating these preliminary findings and refining thresholds for intervention. Lastly, our study was conducted in a single, tertiary, academic center, and the results may not be generalizable to community settings, where follow-up can be particularly challenging due to factors such as limited support, transportation barriers, and other obstacles that hinder patient participation, which are issues that are commonly observed in similar studies.

Conclusions

Actigraphy provides a feasible and informative method to objectively measure physical activity in patients with MPEs following thoracentesis. Actigraphy could be potentially advantageous when there is discordance between objectively measured patient activity levels following thoracentesis and subjective patient reports of symptom improvement. This may allow for the identification of patients who could benefit from repeated interventions for their effusions. For example, when monitoring patients with MPEs, those who begin to show a decline in the number of steps taken per day may be more likely to have an increased Borg scale score and a decreased SF-6D score, and therefore, may warrant earlier re-evaluation for repeat drainage. Alternatively, patients who show decreasing levels of triaxial movement on ActiGraph monitoring may indeed have re-accumulation of their effusions but may not necessarily require repeat intervention as they are less likely to have symptom improvement. Although prior studies have utilized wearable devices to examine improvements in physical activity amongst patients who undergo thoracentesis, these have included only a small number of patients. To our knowledge, this study is the largest dataset of patients with effusions in whom actigraphy was implemented for monitoring after thoracentesis. Further studies are needed to define optimal thresholds and timing for clinical decision-making based on activity data.

Supplementary

The article’s supplementary files as

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of MD Anderson Cancer Center (No. PA 2020-0090). All adult participants provided written informed consent to participate in this study.

Data Sharing Statement

Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2311/dss

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DOI: 10.21037/jtd-2025-aw-2311