Development, implementation and evaluation of a smartphone application aimed to reduce sedentary time and increase physical activity among Indian sedentary office workers – findings from SMART-STEP trial

Background: Excessive sedentary time (ST) is linked to an increased risk of cardiometabolic diseases. Although various behavioral interventions have emerged to reduce ST, the potential of smartphone (SmPh)-based interventions remains relatively unexplored in workplace settings. This study aimed to explore the development, implementation and acceptability of a SmPh application among Indian desk-based office workers. Methods: One hundred thirty-six office workers were randomised to one of three interventions for six months: (1) SmPh-based ST and physical activity (PA) reminders (SMART); (2) traditional education (TRADE) and (3) usual work group (CONT). A threshold of 70% adherence (equivalent to responding to at least 580 out of 828 assigned prompts) was used to classify participants as ‘compliant’. Of 44 SMART group participants who were assigned to 24 weeks of intervention, nine participants were purposefully selected based on compliance, Moreover, they were interviewed for potential barriers associated with the SmPh application using semi-deductive approach. Results: The SMART STEP application was developed over eight months, during which three versions were created and pilot tested. The cost of application development was reasonable (≈ $1,860). Of 44 participants who received SmPh application-based reminders, 37 completed the two follow-ups at 3rd and 6th month. Mean prompt engagement rates, defined as ‘the percentage of prompts participants actively responded to’, during the 1st, 2nd, 3rd, 4th, 5th, and 6th months were 77% (n = 107), 59% (n = 82), 54% (n = 74), 45% (n = 63), 43% (n = 59), and 31% (n = 43), respectively. Barriers such as workload, lack of movement sensing, and insufficient organizational and peer support were key factors contributing to the decline in long-term engagement among office workers. Conclusion: The SMART-STEP application appears to be an affordable and promising solution for reducing ST and promoting PA among office workers in low-resource settings. However, enhancements such as embedding movement sensing technology, organizational policies and peer education are needed to improve long-term usability and acceptability. Trial registration: Clinical Trial Registry of India (CTRI/2020/03/024138) registered on 20/03/2020.