JMIR Publications

ABSTRACT

Background:

Adherence in digital therapies remains a critical challenge. Despite increasing adoption of certified digital health applications (DiGAs), real-world data on strategies to improve long-term engagement is limited. Simple, scalable interventions such as SMS reminders and telephone follow-ups may offer potential solutions, but evidence for their effectiveness in digital ED therapy is sparse.

Objective:

This study aimed to systematically evaluate whether low-threshold digital support strategies — namely SMS-based reminders and structured telephone calls — can improve therapy adherence and patient-centered outcomes among users of a certified DiGA for erectile dysfunction.

Methods:

A total of 470 men with physician-diagnosed ED were quasi-randomly assigned to one of three groups: a control group (no additional support), an SMS group (text reminders after inactivity), and a call group (structured telephone contact following inactivity). The primary endpoint was the number of active training weeks during a 12-week therapy period. Secondary endpoints included Clinical Global Impression Improvement (CGI-I), changes in IIEF-5 (International Index of Erectile Functioning) scores, therapy continuation intent, and actual therapy continuation (conversion).

Results:

Patients completed a mean of 6.34 (SD = 4.44) active weeks. The SMS group showed significantly greater adherence than the control group (mean = 6.80 vs. 5.79 weeks, p = .049, Cohen’s d = -0.223). No significant mean differences were observed between control and call groups (p = .110), but a trend towards reduced variance suggests greater behavioral consistency. The call group showed a significantly higher intent to continue therapy (49% vs. 38%, p = .035), although conversion rates did not differ significantly. Group differences in CGI-I and IIEF improvements were not statistically significant, likely reflecting the impact of lower response rates.

Conclusions:

Low-threshold digital interventions can effectively enhance adherence and motivation in digital ED therapies. While text message reminders are a cost-effective way to increase activity, telephone contacts are suitable for promoting longer-term adherence to therapy. These findings can contribute to the optimization of digital care models for patients.