An app promoting weight gain prevention via healthy behaviours amongst young women with a family history of breast cancer: acceptability and usability assessment

Background
Breast cancer is the most frequent female malignancy in the UK. Around 20% of cases are linked to weight gain, excess weight and health behaviours. We designed a weight gain prevention, health behaviour intervention for young women at increased risk.

Methodology
Single arm observational study over two months testing acceptability and usability of the intervention: online group welcome event, app, and private Facebook group. Females 18-35 years at moderate or high risk of breast cancer (>17% lifetime risk) were recruited via invite letters and social media posts. The app included behaviour change techniques and education content. Online questionnaires were completed at baseline, one and two months. We also assessed feasibility of study procedures.

Results
Both recruitment methods were successful. Thirty-five women were recruited, 26% via social media posts. Median age was 33 (IQR 28.2-34.5) years, the majority (94.1%) were of White ethnicity. Thirty-four participants were included in the analyses, of which 94% downloaded the app. Median self-monitoring logs per participant during the study period was 10.0 (IQR 4.8-28.8). App quality mean (SD) score was 3.7 (0.6) at one and two months (scale: 1-5). Eighty-nine percent rated the app at average or above at one month and 75.0% at two months. Nineteen women (55.9%) joined the Facebook group and there were 61 comments and 83 reactions and votes from participants during the study period.

Conclusions
This first iteration of the app and intervention was well received and is suitable to progress to the next stage of refining and further testing