Rationale

Telemonitoring of lung function and symptoms might help to identify exacerbations to prevent hospitalizations. We investigated the acceptance and usability of telemonitoring in COPD patients.

Methods

In this prospective multicentre study we used home-based spirometry, accelerometry, a smartphone-based disease-control interface (DCI) for symptoms: CAT questionnaire, need for rescue inhaler. We evaluated individual changes of FEV1 beyond day-to-day variability, steps, change in CAT score, rescue inhaler use for 12 months follow-up after exacerbation 

Results

43 patients (n=43; mean age, 65±7 years; mean FEV1%, 42± 14) were enrolled. Adherence to home-based spirometry, DCI and accelerometry was 247, 252 and 58 days, respectively. We found a good agreement between in-clinic and home-based spirometry (Bland?Altman: mean difference 111 ml; 95% limits of agreement: ?506 to 782 ml). In patients with exacerbation during follow-up (n=17), home-based spirometry revealed a mean decline of 152 ml in FEV1 vs. stable FEV1 (+22 ml) in those without exacerbation, (p=0.056). Changes in home-based FEV1 showed a stronger correlation with time to first exacerbation and number of exacerbations (correlation coefficients 0.38 and -0.25) than in-clinic based-FEV1. There was a good correlation between both components of DCI (R=0.36, p=0.044). Clinically relevant changes in FEV1 and DCI could be observed 5 days right before and during exacerbations. 

Conclusion

In adherent COPD patients home-based telemonitoring provides plausible and reliable changes of symptoms and lung function that might allow an early intervention.