Can mobile-health applications contribute to long-term increase in physical activity after medical rehabilitation?–A pilot-study

Due to the positive effects of rehabilitation declining over time, the aim of this study was to investigate the long-term physical activity level (PAL) following inpatient rehabilitation in relation to the use of a smartphone-based after-care program. 202 patients (mean Body Mass Index (BMI): 30,8 kg/m2; 61% female) with chronic diseases (e.g., diabetes mellitus, obesity, chronic low back pain, depression) were recruited between 08/2020 and 08/2021 in this single-arm observational study. All patients underwent a 3-week inpatient rehabilitation program. PAL (in total activity minutes/week) was measured with a validated (online) questionnaire (Freiburger Questionnaire on PA) after 3, 6, 9, and 12 months. App usage (online time, completion of a course) was recorded automatically and used to evaluate the app user behavior (adherence). A variety of socio-economic factors (age, sex, education level, income etc.) were collected to identify possible barriers of app use. Except for sex, no significant difference was observed for socio-economic factors regarding app usage behavior. Median PAL significantly increased after rehabilitation in the total cohort from 360 min/week (before rehabilitation) to 460 min/week 6 months after rehabilitation, then declined to 420 min/week 9 months after rehabilitation before falling below baseline level after 12 months. There was no significant difference in PAL between app users (45%, 91/202) and non-users (55%, 111/202), although app users tended to retain higher activity levels after 3 and 6 months, respectively. Overall, our study emphasizes the effectiveness of a 3-week rehabilitation program on PAL and the acceptance and usability of a smartphone-based after-care program in this patient group. The adherence to this 3-months after-care app program was acceptable (30%), with modest evidence supporting the effectiveness of app use to sustain PAL in the short term.Author summary: Increasing PAL is an important goal of medical rehabilitation in a variety of chronic diseases. This goal is often achieved by inpatient rehabilitation programs but is difficult to implement in everyday life and therefore mostly utilized for short periods of time. In this prospective study, we included 202 patients and followed them over a 12-month period. We recommended patients to use a 3-month smartphone app program at home following a 3-week inpatient rehabilitation, to support them in their transition to everyday life conditions. Use of this smartphone app was recorded automatically and used to evaluate the app usage behavior. Besides sex, we did not find significant differences in socio-economic factors between app users and non-users. In addition, there was no significant difference in PAL (measured by a questionnaire). However, app users tended to be more active after 3 and 6 months respectively, which could indicate an additional short-term benefit of the app program after rehabilitation.