Predicting COPD Exacerbations With Remote Patient Monitoring

While telemedicine and remote patient monitoring (RPM) have potential for proactive management of patients with chronic obstructive pulmonary disease (COPD) at risk of exacerbation, data is lacking on how symptoms and physiological measures vary prior to flare-ups.

However, new study findings are offering insight into the time leading up to exacerbations, revealing that including factors like forced vital capacity (FVC) and forced expiratory volume in 1 second (FEC₁) in RPM could be leveraged to guide measures for reducing healthcare utilization among these patients.

The small study monitored 17 patients with moderate to severe COPD using RPM over a collective 7 years, capturing daily symptom scores, treatment adherence, self-reported activity levels, daily spirometry, inspiratory capacity, and oxygenation (SpO2). Analyzing these measures, the researchers were able to identify which could be used to predict exacerbations through Anthonisen and other criteria.

The concordance analysis found that FVC (decrease below the 7-day rolling average minus 1.645 SD) (κ=0.747, P < .001) and increased use of inhaled short-acting bronchodilators (κ=0.611, P < .001) had the largest correlation with self-reported healthcare utilization events. FEV₁ (decrease > 1.645 SD below the 7-day rolling average) (κ=0.475, P < .001) and SpO2 (κ=0.474, P < .001) also had a correlation, albeit not as strong.

“Exacerbation defined by self-reported healthcare utilization were best predicted by falls in FVS and FEV₁ below the 95% confidence interval derived from SPC,” explained the researchers. “However, a fall in FVC was a more reliable predictor with stronger concordance (κ=0.747 versus κ=0.475). This observation concurs with other opinions that FEV₁ alone has predictive value for onset of exacerbations, and that due to the heterogeneity of the disease, a broader range of parameters should be measured.”

Throughout the study, the researchers observed that:

• There were 18 days when FEV₁ fell below the 1-sided 95% confidence interval
• There were 15 days when FVC fell below the 1-sided 95% confidence interval
• There were 173 days when SpO2 dropped below 90% and 6 days when SpR2 dropped more than 4% below the 7-day average

The researchers also observed the predictive impact of peak expiratory flow on exacerbations, with their findings supporting the notion that the measure is not reliable in patients with COPD because of its variability, as well as the possibility of pressure-dependent airway collapse in the presence of emphysema.

“Another interesting finding in our study was the absence of concordance between symptomatic and physiological measures and patient reporting of antibiotic or systemic corticosteroid treatment,” wrote the researchers. “The reasons for this disparity are not clear, but one possibility is that patients provided with antibiotics or systemic corticosteroids for discretionary use might not know when they are best clinically indicated unless they are provided with strict criteria.”

Reference

Cooper CB, Sirichana W, Arnold MT, et al. Remote patient monitoring for the detection of COPD exacerbations. Int J Chron Obstruct Pulmon Dis. Published online April 4, 2020. doi:10.2147/COPD.S256907.