Development of the Happy Hands Self-Management App for People with Hand Osteoarthritis: Feasibility Study
Authors: Tveter Anne Therese , Varsi Cecilie , Maarnes Marit Kristin , Pedersen Stein Jarle , Christensen Barbara S , Blanck Thale Beate , Nyheim Sissel B , Pelle Tim , Kjeken Ingvild 
Published: October 2024

Background
Patient education, hand exercises, and the use of assistive devices are recommended as first-line treatments for individuals with hand osteoarthritis (OA). However, the quality of care services for this patient group is suboptimal in primary care.

Objective
The overarching goal was to develop and evaluate feasibility of an app-based self-management intervention for people with hand OA. This feasibility study aims to assess self-reported usability and satisfaction, change in outcomes and quality-of-care, exercise adherence and patients’ experiences using the app.

Methods
The development and feasibility testing followed the first 2 phases of the Medical Research Council framework for the development and evaluation of complex interventions and were conducted in close collaboration with patient research partners (PRPs). A 3-month pre-post mixed methods design was used to evaluate feasibility. Men and women over 40 years of age diagnosed with painful, symptomatic hand OA were recruited. Usability was assessed using the System Usability Scale (0-100), while satisfaction, usefulness, pain, and stiffness were evaluated using a numeric rating scale (NRS score from 0 to 10). The activity performance of the hand was measured using the Measure of Activity Performance of the Hand (MAP-Hand) (1-4), grip strength was assessed with a Jamar dynamometer (kg), and self-reported quality of care was evaluated using the Osteoarthritis Quality Indicator questionnaire (0-100). Participants were deemed adherent if they completed at least 2 exercise sessions per week for a minimum of 8 weeks. Focus groups were conducted to explore participants’ experiences using the app. Changes were analyzed using a paired sample t test (mean change and 95% CI), with the significance level set at P<.05.

Results
The first version of the Happy Hands app was developed based on the needs and requirements of the PRPs, evidence-based treatment recommendations, and the experiences of individuals living with hand OA. The app was designed to guide participants through a series of informational videos, exercise videos, questionnaires, quizzes, and customized feedback over a 3-month period. The feasibility study included 71 participants (mean age 64 years, SD 8; n=61, 86%, women), of whom 57 (80%) completed the assessment after 3 months. Usability (mean 91.5 points, SD 9.2 points), usefulness (median 8, IQR 7-10), and satisfaction (median 8, IQR 7-10) were high. Significant improvements were observed in self-reported quality of care (36.4 points, 95% CI 29.7-43.1, P<.001), grip strength (right: 2.9 kg, 95% CI 1.7-4.1; left: 3.2 kg, 95% CI 1.9-4.6, P<.001), activity performance (0.18 points, 95% CI 0.11-0.25, P<.001), pain (1.7 points, 95% CI 1.2-2.2, P<.001), and stiffness (1.9 points, 95% CI 1.3-2.4, P=.001) after 3 months. Of the 71 participants, 53 (75%) were adherent to the exercise program. The focus groups supported these results and led to the implementation of several enhancements in the second version of the app.

Conclusions
The app-based self-management intervention was deemed highly usable and useful by patients. The results further indicated that the intervention may improve quality of care, grip strength, activity performance, pain, and stiffness. However, definitive conclusions need to be confirmed in a powered randomized controlled trial.

Trial Registration
NCT05150171