Background <p>Determinants of telemedicine applications use by general practice patients with chronic respiratory diseases are not yet fully known. The aim of this study was twofold: (a) to assess facilitators and barriers for the use of digital home spirometers in primary care, and (b) to evaluate parameters for process quality in implementing guideline-recommended care in daily practice.</p> Methods <p>The study was evaluated using a mixed-methods design. Patients with bronchial asthma or chronic obstructive pulmonary disease were instructed to take daily measurements using a digital home-spirometry device. Primary care physicians regularly controlled spirometry data using a digital monitoring portal. Telephone interviews were conducted with patients and healthcare professionals. Qualitative analysis of the transcripts was based on content analysis. Quantitative data included the assessment of quality indicators in the beginning (t0) and at the end (t1) of each individual’s participation in the study, the Patient Assessment of Chronic Illness Care Short-Version (t0) and reasons for use/non-use of the spirometer (t1). Logistic regression was performed to determine predictors of use according to instructions.</p> Results <p>Altogether, 127 patients participated in the study; the average age was 59 years, 61% (<i>n</i> = 78) of participants were female. 21 telephone interviews with patients and healthcare professionals were conducted. Facilitators included: sense of obligation, habituation, visualization of progression, self-efficacy, physician contacts, remote treatment, and positive aspects of integration into daily practice. Barriers included: understanding of the disease, dyspnea, as well as project and technical requirements. Care providers considered time-consuming procedures and clinical assessability as barriers. At t0 and t1, approximately one third of respondents (33% resp. 36%) stated that they had received disease-specific training, and 57% stated in both cases that they had gotten the annual influenza vaccination. Logistic regression revealed that duration of disease (OR 0.96; CI 95% 0.93; 0.99), a daily measurement being too strenuous (OR 0.165; CI 95% 0.04; 0.076), and the fact that measurements could not be taken while away from home (OR 0.235; CI 95% 0.07; 0.75) to be negative predictors of use according to instructions.</p> Conclusions <p>For the patients in the study, digital applications improved self-efficacy and self-control. However, a better understanding of these applications and additional medical feedback could be helpful for the patients using such digital applications. The evaluation of process quality parameters showed potential for improving rates of disease-related education and influenza vaccination.</p>