Application of the ERS/ATS Spirometry Standards and Race-Neutral Equations in the COPDGene Study.

RATIONALE: The European Respiratory Society (ERS) and the American Thoracic Society (ATS) recommend using z-scores, and the ATS has recommended using Global Lung Initiative (GLI)- "Global" race-neutral reference equations for spirometry interpretation. However, these recommendations have been variably implemented and the impact has not been widely assessed, both in clinical and research settings. OBJECTIVES: We evaluated the ERS/ATS airflow obstruction severity classification. METHODS: In the COPDGene Study (n = 10,108), airflow obstruction has been defined as a forced expiratory volume in one second to forced vital capacity (FEV1/FVC) ratio <0.70, with spirometry severity graded from class 1 to 4 based on race-specific percent predicted (pp) FEV1 cut-points as recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD). We compared the GOLD approach, using NHANES III race-specific equations, to the application of GLI-Global equations using the ERS/ATS definition of airflow obstruction as FEV1/FVC ratio < lower limit of normal (LLN) and z-FEV1 cut-points of -1.645, -2.5, and -4 ("zGLI Global"). We tested the four-tier severity scheme for association with COPD outcomes. MEASUREMENTS AND MAIN RESULTS: The lowest agreement between ERS/ATS with zGLI Global and the GOLD classification was observed in individuals with milder disease (56.9% and 42.5% in GOLD 1 and 2) and race was a major determinant of redistribution. After adjustment for relevant covariates, zGLI Global distinguished all-cause mortality risk between normal spirometry and the first grade of COPD (Hazard Ratio 1.23, 95% CI 1.04-1.44, p=0.014), and showed a linear increase in exacerbation rates with increasing disease severity, in comparison to GOLD. CONCLUSIONS: The zGLI Global severity classification outperformed GOLD in the discrimination of survival, exacerbations, and imaging characteristics.

Serum Immunoglobulin G Levels Are Associated with Risk for Exacerbations: An Analysis of SPIROMICS.

RATIONALE: Serum Immunoglobulin G (IgG) deficiency is associated with morbidity in chronic obstructive pulmonary disease (COPD) but it is unclear whether concentrations in the lower end of the normal range still confer risk. OBJECTIVES: To determine if levels above traditional cutoffs for serum IgG deficiency are associated with exacerbations among current and former smokers with or at risk for COPD. MEASUREMENTS AND MAIN RESULTS: Former and current smokers in SPIROMICS (n=1,497) were studied, n=1,026 with and n=471 at risk for COPD. In a subset (n=1,031), IgG subclasses were measured. Associations between total IgG or subclasses and prospective exacerbations were evaluated with multivariable models adjusting for demographics, current smoking, smoking history, FEV1% predicted, inhaled corticosteroids, and serum IgA. RESULTS: The 35th percentile (1225 mg/dL in this cohort) of IgG was the best cutoff by Akaike Information Criterion (AIC). Below this, there was increased exacerbation risk (IRR 1.28, 95% CI 1.08-1.51). Among subclasses, IgG1 and IgG2 below 35th percentile (354 and 105 mg/dL, respectively) were both associated with increased risk of severe exacerbation (IgG1: IRR 1.39, 95% CI 1.06-1.84; IgG2: IRR 1.50, 95% CI 1.14-1.1.97). These associations remained significant when additionally adjusting for history of exacerbations. CONCLUSIONS: Lower serum IgG is prospectively associated with exacerbations in individuals with or at risk for COPD. Among subclasses, lower IgG1 and IgG2 are prospectively associated with severe exacerbations. The optimal IgG cutoff was substantially higher than traditional cutoffs for deficiency, suggesting subtle impairment of humoral immunity may be associated with exacerbations.

Preacinar Arterial Dilation Mediates Outcomes of Quantitative Interstitial Abnormalities in the COPDGene Study.

Rationale: Quantitative interstitial abnormalities (QIAs) are a computed tomography (CT) measure of early parenchymal lung disease associated with worse clinical outcomes, including exercise capacity and symptoms. The presence of pulmonary vasculopathy in QIAs and its role in the QIA-outcome relationship is unknown. Objectives: To quantify radiographic pulmonary vasculopathy in QIAs and determine whether this vasculopathy mediates the QIA-outcome relationship. Methods: Ever-smokers with QIAs, outcomes, and pulmonary vascular mediator data were identified from the Genetic Epidemiology of COPD (COPDGene) study cohort. CT-based vascular mediators were right ventricle-to-left ventricle ratio, pulmonary artery-to-aorta ratio, and preacinar intraparenchymal arterial dilation (pulmonary artery volume, 5-20 mm2 in cross-sectional area, normalized to total arterial volume). Outcomes were 6-minute walk distance and a modified Medical Council Research Council Dyspnea Scale score of 2 or higher. Adjusted causal mediation analyses were used to determine whether the pulmonary vasculature mediated the QIA effect on outcomes. Associations of preacinar arterial dilation with select plasma biomarkers of pulmonary vascular dysfunction were examined. Measurements and Main Results: Among 8,200 participants, QIA burden correlated positively with vascular damage measures, including preacinar arterial dilation. Preacinar arterial dilation mediated 79.6% of the detrimental impact of QIA on 6-minute walk distance (56.2-100%; P < 0.001). Pulmonary artery-to-aorta ratio was a weak mediator, and right ventricle-to-left ventricle ratio was a suppressor. Similar results were observed in the relationship between QIA and modified Medical Council Research Council dyspnea score. Preacinar arterial dilation correlated with increased pulmonary vascular dysfunction biomarker levels, including angiopoietin-2 and N-terminal brain natriuretic peptide. Conclusions: Parenchymal QIAs deleteriously impact outcomes primarily through pulmonary vasculopathy. Preacinar arterial dilation may be a novel marker of pulmonary vasculopathy in QIAs.

Early Evidence of Chronic Obstructive Pulmonary Disease Obscured by Race-Specific Prediction Equations.

Rationale: The identification of early chronic obstructive pulmonary disease (COPD) is essential to appropriately counsel patients regarding smoking cessation, provide symptomatic treatment, and eventually develop disease-modifying treatments. Disease severity in COPD is defined using race-specific spirometry equations. These may disadvantage non-White individuals in diagnosis and care. Objectives: Determine the impact of race-specific equations on African American (AA) versus non-Hispanic White individuals. Methods: Cross-sectional analyses of the COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease) cohort were conducted, comparing non-Hispanic White (n = 6,766) and AA (n = 3,366) participants for COPD manifestations. Measurements and Main Results: Spirometric classifications using race-specific, multiethnic, and "race-reversed" prediction equations (NHANES [National Health and Nutrition Examination Survey] and Global Lung Function Initiative "Other" and "Global") were compared, as were respiratory symptoms, 6-minute-walk distance, computed tomography imaging, respiratory exacerbations, and St. George's Respiratory Questionnaire. Application of different prediction equations to the cohort resulted in different classifications by stage, with NHANES and Global Lung Function Initiative race-specific equations being minimally different, but race-reversed equations moving AA participants to more severe stages and especially between the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 0 and preserved ratio impaired spirometry groups. Classification using the established NHANES race-specific equations demonstrated that for each of GOLD stages 1-4, AA participants were younger, had fewer pack-years and more current smoking, but had more exacerbations, shorter 6-minute-walk distance, greater dyspnea, and worse BODE (body mass index, airway obstruction, dyspnea, and exercise capacity) scores and St. George's Respiratory Questionnaire scores. Differences were greatest in GOLD stages 1 and 2. Race-reversed equations reclassified 774 AA participants (43%) from GOLD stage 0 to preserved ratio impaired spirometry. Conclusions: Race-specific equations underestimated disease severity among AA participants. These effects were particularly evident in early disease and may result in late detection of COPD.

FEV1Q: a race-neutral approach to assessing lung function.

BACKGROUND: Forced expiratory volume in 1 s quotient (FEV1Q) is a simple approach to spirometry interpretation that compares measured lung function to a lower boundary. This study evaluated how well FEV1Q predicts survival compared with current interpretation methods and whether race impacts FEV1Q. METHODS: White and Black adults with complete spirometry and mortality data from the National Health and Nutrition Examination Survey (NHANES) III and the United Network for Organ Sharing (UNOS) database for lung transplant referrals were included. FEV1Q was calculated as FEV1 divided by 0.4 L for females or 0.5 L for males. Cumulative distributions of FEV1 were compared across races. Cox proportional hazards models tested mortality risk from FEV1Q adjusting for age, sex, height, smoking, income and among UNOS individuals, referral diagnosis. Harrell's C-statistics were compared between absolute FEV1, FEV1Q, FEV1/height2, FEV1 z-scores and FEV1 % predicted. Analyses were stratified by race. RESULTS: Among 7182 individuals from NHANES III and 7149 from UNOS, 1907 (27%) and 991 (14%), respectively, were Black. The lower boundary FEV1 values did not differ between Black and White individuals in either population (FEV1 first percentile difference ≤0.01 L; p>0.05). Decreasing FEV1Q was associated with increasing hazard ratio (HR) for mortality (NHANES III HR 1.33 (95% CI 1.28-1.39) and UNOS HR 1.18 (95% CI 1.12-1.23)). The associations were not confounded nor modified by race. Discriminative power was highest for FEV1Q compared with alternative FEV1 approaches in both Black and White individuals. CONCLUSIONS: FEV1Q is an intuitive and simple race-neutral approach to interpreting FEV1 that predicts survival better than current alternative methods.

Indoor Air Pollution and Impaired Cardiac Autonomic Function in Chronic Obstructive Pulmonary Disease.

Rationale: Indoor air pollution represents a modifiable risk factor for respiratory morbidity in chronic obstructive pulmonary disease (COPD). The effects of indoor air pollution, as well as the impact of interventions to improve indoor air quality, on cardiovascular morbidity in COPD remain unknown. Objectives: To determine the association between indoor particulate matter (PM) and heart rate variability (HRV), a measure of cardiac autonomic function tied to cardiovascular morbidity and mortality, as well as the impact of household air purifiers on HRV. Methods: Former smokers with moderate-severe COPD were recruited from a 6-month randomized controlled trial of a portable air cleaner intervention to undergo paired assessment of both in-home PM and HRV using 24-hour Holter monitoring at up to five time points. Primary outcomes were HRV measures tied to cardiovascular morbidity (standard deviation of normal-to-normal intervals [SDNN] and root mean square of successive differences between normal-to-normal intervals [RMSSD]). Measurements and Results: Eighty-five participants contributed 317 HRV measurements. A twofold increase in household PM ⩽2.5 µm in aerodynamic diameter was associated with decreases in SDNN (ß, -2.98% [95% confidence interval (CI), -5.12 to -0.78]) and RMSSD (ß, -4.57% [95% CI, -10.1 to -1.60]). The greatest effects were observed with ultrafine particles (<100 nm) (RMSSD; ß, -16.4% [95% CI, -22.3 to -10.1]) and among obese participants. Participants randomized to the active air cleaner saw improvements in RMSSD (ß, 25.2% [95% CI, 2.99 to 52.1]), but not SDNN (ß, 2.65% [95% CI, -10.8 to 18.1]), compared with the placebo group. Conclusions: This is the first U.S. study to describe the association between household PM and cardiac autonomic function among individuals with COPD, as well as the potential cardiovascular health benefits of household air cleaners.

Improved Survival for Patients with Systemic Sclerosis-associated Pulmonary Arterial Hypertension: The Johns Hopkins Registry.

Rationale: To date, it remains unclear whether recent changes in the management of patients with systemic sclerosis-associated pulmonary hypertension (SSc-PH) have improved survival. Objectives: To describe a cohort of patients with SSc-PH and compare their characteristics and survival between the last two decades. Methods: Patients with SSc-PH prospectively enrolled in the Johns Hopkins Pulmonary Hypertension Center Registry were grouped into two cohorts based on the date of diagnostic right heart catheterization: cohort A included patients whose disease was diagnosed between 1999 and 2010, and cohort B included those whose disease was diagnosed between 2010 and 2021. Patients' characteristics were compared between the two cohorts. Measurements and Main Results: Of 504 patients with SSc-PH distributed almost equally between the two cohorts, 308 (61%) had World Symposium on Pulmonary Hypertension group 1, 43 (9%) had group 2, and 151 (30%) had group 3 disease. Patients with group 1 disease in cohort B had significantly better clinical and hemodynamic characteristics at diagnosis, were more likely to receive upfront combination pulmonary arterial hypertension therapy, and had a nearly 4-year increase in median transplant-free survival in univariable analysis than those in cohort A (P < 0.01). Improved transplant-free survival was still observed after adjusting for patients' baseline characteristics. In contrast, for group 2 or 3 patients with SSc-PH, there were no differences in baseline clinical, hemodynamic, or survival characteristics between the two cohorts. Conclusions: This is the largest single-center study that compares clinical characteristics of patients with SSc-PH between the last two decades. Transplant-free survival has improved significantly for those with group 1 disease over the last decade, possibly secondary to earlier detection and better therapeutic management. Conversely, those with group 2 or 3 disease continue to have dismal prognosis.

Use of the Spirometric "Fixed-Ratio" Underdiagnoses COPD in African-Americans in a Longitudinal Cohort Study.

BACKGROUND: COPD diagnosis is tightly linked to the fixed-ratio spirometry criteria of FEV1/FVC < 0.7. African-Americans are less often diagnosed with COPD. OBJECTIVE: Compare COPD diagnosis by fixed-ratio with findings and outcomes by race. DESIGN: Genetic Epidemiology of COPD (COPDGene) (2007-present), cross-sectional comparing non-Hispanic white (NHW) and African-American (AA) participants for COPD diagnosis, manifestations, and outcomes. SETTING: Multicenter, longitudinal US cohort study. PARTICIPANTS: Current or former smokers with ≥ 10-pack-year smoking history enrolled at 21 clinical centers including over-sampling of participants with known COPD and AA. Exclusions were pre-existing non-COPD lung disease, except for a history of asthma. MEASUREMENTS: Subject diagnosis by conventional criteria. Mortality, imaging, respiratory symptoms, function, and socioeconomic characteristics, including area deprivation index (ADI). Matched analysis (age, sex, and smoking status) of AA vs. NHW within participants without diagnosed COPD (GOLD 0; FEV1 ≥ 80% predicted and FEV1/FVC ≥ 0.7). RESULTS: Using the fixed ratio, 70% of AA (n = 3366) were classified as non-COPD, versus 49% of NHW (n = 6766). AA smokers were younger (55 vs. 62 years), more often current smoking (80% vs. 39%), with fewer pack-years but similar 12-year mortality. Density distribution plots for FEV1 and FVC raw spirometry values showed disproportionate reductions in FVC relative to FEV1 in AA that systematically led to higher ratios. The matched analysis demonstrated GOLD 0 AA had greater symptoms, worse DLCO, spirometry, BODE scores (1.03 vs 0.54, p < 0.0001), and greater deprivation than NHW. LIMITATIONS: Lack of an alternative diagnostic metric for comparison. CONCLUSIONS: The fixed-ratio spirometric criteria for COPD underdiagnosed potential COPD in AA participants when compared to broader diagnostic criteria. Disproportionate reductions in FVC relative to FEV1 leading to higher FEV1/FVC were identified in these participants and associated with deprivation. Broader diagnostic criteria for COPD are needed to identify the disease across all populations.

Population reference equations for handheld peak expiratory flow in older U.S. adults.

BACKGROUND: Peak expiratory flow (PEF) is a simple, inexpensive measure of respiratory effort and is a valuable predictor of health outcomes in older adults. Yet, there is a lack of epidemiological data validating PEF prediction equations among older adult populations, especially those ≥80 years. The National Health and Aging Trends Study (NHATS) is a large, nationally representative sample of U.S. adults ages ≥65 years that offers a unique opportunity to develop PEF population reference equations. METHODS: Using a healthy subsample from the NHATS 2011 cohort (N = 1740; 68.9 % female; mean [SD] age = 77.0 [7.9] years), sex-specific reference equations were generated for PEF, measured via a handheld flow meter, using height and age as predictors. Reference equations for both sexes were validated against the NHATS 2015 cohort by testing measured vs. predicted PEF values. Additionally, new reference equations were compared to spirometry PEF reference equations from the National Health and Nutrition Examination Survey (NHANES). RESULTS: After applying NHATS 2011 reference equations to the NHATS 2015 cohort, measured vs. predicted PEF values were not significantly different (Ps > 0.05). The NHANES equations tended to slightly overestimate handheld PEF measurements in the NHATS 2015 cohort by an average of 29.3 L/min and 10.1 L/min in males and females, respectively. CONCLUSIONS: Results demonstrate the comparability of PEF reference equations from a handheld meter to spirometry reference equations in older adults. New reference equations can be applied to a traditionally undersampled population with an easily obtained and low-cost measure.

Longitudinal Changes in Peak Expiratory Flow Predict Risk for Incident Dementia.

BACKGROUND: Impaired respiratory function, measured via peak expiratory flow (PEF), has been associated with increased dementia risk. However, much of the current literature uses cross-sectional measures of PEF, whereas longitudinal relationships between changes in respiratory function and dementia risk are underexplored. METHODS: Using 10 years of data (2011-2021) from 2,439 adults ages 65 and older in the National Health and Aging Trends Study (NHATS), we examined whether 5-year changes in PEF (2011-2016) were associated with risk for incident dementia over the subsequent 5-year period (2017-2021). PEF slopes for each participant were estimated using linear mixed-effects models and then grouped into quartiles: rapid, moderate, mild, and no declines. Discrete-time Cox proportional hazards models were used to estimate the risk for incident dementia by PEF slope category, while controlling for several health and sociodemographic characteristics. RESULTS: After excluding dementia cases during the exposure window (2011-2016), we identified 338 cases of incident dementia (13.9%) between 2017-2021. Rapid PEF declines between 2011-2016 were associated with 85% higher risk for incident dementia between 2017-2021 compared to those with no declines in PEF (HR=1.85; 95% CI [1.24, 2.76]). Results were robust to several sensitivity analyses. CONCLUSIONS: These findings demonstrate that declines in PEF may precede declines in cognition, suggesting that respiratory function may be an important dementia risk factor in older adults. Additionally, these findings highlight the utility of measuring PEF via a peak flow meter, which is a simple and inexpensive measure of respiratory function.

Diffusing Capacity as a Predictor of Hospitalizations in a Clinical Cohort of Chronic Obstructive Pulmonary Disease.

Rationale: Chronic obstructive pulmonary disease (COPD) hospitalizations are a major burden on patients. Diffusing capacity of the lung for carbon monoxide (DlCO) is a potential predictor that has not been studied in large cohorts. Objectives: This study used electronic health record data to evaluate whether clinically obtained DlCO predicts COPD hospitalizations. Methods: We performed time-to-event analyses of individuals with COPD and DlCO measurements from the Johns Hopkins COPD Precision Medicine Center of Excellence. Cox proportional hazard methods were used to model time from DlCO measurement to first COPD hospitalization and composite first hospitalization or death, adjusting for age, sex, race, body mass index, smoking status, forced expiratory volume in 1 second (FEV1), history of prior COPD hospitalization, and comorbidities. To identify the utility of including DlCO in risk models, area under the receiver operating curve (AUC) values were calculated for models with and without DlCO. Results were externally validated in a separate analogous cohort. Results: Of 2,793 participants, 368 (13%) had a COPD hospitalization within 3 years. In adjusted analyses, for every 10% decrease in DlCO% predicted, risk of COPD hospitalization increased by 10% (hazard ratio, 1.1; 95% confidence interval, 1.1-1.2; P < 0.001). Similar associations were observed for COPD hospitalizations or death. The model including demographics, comorbidities, FEV1, DlCO, and prior COPD hospitalizations performed well, with an AUC of 0.85 and an AUC of 0.84 in an external validation cohort. Conclusions: Diffusing capacity is a strong predictor of COPD hospitalizations in a clinical cohort of individuals with COPD, independent of airflow obstruction and prior hospitalizations. These findings support incorporation of DlCO in risk assessment of patients with COPD.

Estimating rate of lung function change using clinical spirometry data.

RATIONALE: In chronic obstructive pulmonary disease (COPD), accurately estimating lung function from electronic health record (EHR) data would be beneficial but requires addressing complexities in clinically obtained testing. This study compared analytic methods for estimating rate of forced expiratory volume in one second (FEV1) change from EHR data. METHODS: We estimated rate of FEV1 change in patients with COPD from a single centre who had ≥3 outpatient tests spanning at least 1 year. Estimates were calculated as both an absolute mL/year and a relative %/year using non-regressive (Total Change, Average Change) and regressive (Quantile, RANSAC, Huber) methods. We compared distributions of the estimates across methods focusing on extreme values. Univariate zero-inflated negative binomial regressions tested associations between estimates and all-cause or COPD hospitalisations. Results were validated in an external cohort. RESULTS: Among 1417 participants, median rate of change was approximately -30 mL/year or -2%/year. Non-regressive methods frequently generated erroneous estimates due to outlier first measurements or short intervals between tests. Average change yielded the most extreme estimates (minimum=-3761 mL/year), while regressive methods, and Huber specifically, minimised extreme estimates. Huber, Total Change and Quantile FEV1 slope estimates were associated with all-cause hospitalisations (Huber incidence rate ratio 0.98, 95% CI 0.97 to 0.99, p<0.001). Huber estimates were also associated with smoking status, comorbidities and prior hospitalisations. Similar results were identified in an external validation cohort. CONCLUSIONS: Using EHR data to estimate FEV1 rate of change is clinically applicable but sensitive to challenges intrinsic to clinically obtained data. While no analytic method will fully overcome these complexities, we identified Huber regression as useful in defining an individual's lung function change using EHR data.

Changes in Spirometry Interpretative Strategies: Implications for Classifying COPD and Predicting Exacerbations.

BACKGROUND: Recent guidelines for spirometry interpretation recommend both race-neutral reference equations and use of z score thresholds to define severity of airflow obstruction. RESEARCH QUESTION: How does the transition from race-specific to race-neutral equations impact severity classifications for patients with COPD when using % predicted vs z score thresholds, and do changes in severity correspond to clinical risk? STUDY DESIGN AND METHODS: This retrospective cohort study included Black and White patients with COPD and available spirometry from the Johns Hopkins Health System. Global Lung Function Initiative (GLI) 2012 (race-specific) equations and GLI Global (race-neutral) equations were used to determine FEV1 % predicted and z score values. Patients were classified as having mild, moderate, or severe disease according to % predicted or z score thresholds. Associations between a change in severity classification from race-specific to race-neutral with COPD exacerbations and all-cause hospitalizations were evaluated using logistic regression. RESULTS: This cohort included 13,324 patients, of whom 9,232 patients (69.3%) were White (mean age, 65.7 years) and 4,092 patients (30.7%) were Black (mean age, 61.1 years). More Black than White patients showed a change in severity classification between approaches when using % predicted thresholds (20.2% vs 6.1%; P < .001), but not with z score thresholds (12.6% vs 12.3%; P = .68). An increased severity classification with a race-neutral approach was associated with increased risk of exacerbation when using z score thresholds (OR, 2.34; 95% CI, 1.51-3.63), but not when using % predicted thresholds (OR, 1.08; 95% CI, 0.61-1.93). A decreased severity classification with a race-neutral approach was associated with lower risk of exacerbation with both % predicted (OR, 0.49; 95% CI, 0.28-0.87) and z score (OR 0.67; 95% CI, 0.50-0.90) thresholds. INTERPRETATION: The proportions of Black and White individuals reclassified were similar with z score thresholds, and changes in severity corresponded to clinical risk with z scores. These results support recent recommendations for use of race-neutral equations and z score thresholds for spirometry interpretation.

Impact of automated data flow and reminders on adherence and resource utilization for remotely monitoring physical activity in individuals with stroke or chronic obstructive pulmonary disease.

As rehabilitation advances into the era of digital health, remote monitoring of physical activity via wearable devices has the potential to change how we provide care. However, uncertainties about patient adherence and the significant resource requirements needed create challenges to adoption of remote monitoring into clinical care. Here we aim to determine the impact of a novel digital application to overcome these barriers. The Rehabilitation Remote Monitoring Application (RRMA) automatically extracts data about physical activity collected via a Fitbit device, screens the data for adherence, and contacts the participant if adherence is low. We compare adherence and estimate the resources required (i.e., time and financial) to perform remote monitoring of physical activity with and without the RRMA in two patient groups. Seventy-three individuals with stroke or chronic obstructive pulmonary disease completed 28 days of monitoring physical activity with the RRMA, while 62 individuals completed 28 days with the data flow processes being completed manually. Adherence (i.e., the average percentage of the day that the device was worn) was similar between groups (p=0.85). However, the RRMA saved an estimated 123.8 minutes or $50.24 per participant month when compared to manual processes. These results demonstrate that automated technologies like the RRMA can maintain patient adherence to remote monitoring of physical activity while reducing the time and financial resources needed. Applications like the RRMA can facilitate the adoption of remote monitoring in rehabilitation by reducing barriers related to adherence and resource requirements.