Objectives: This study compared discussion board involvement between family carers and non-carers in the Understanding Dementia Massive Open Online Course (UD-MOOC).

Methods: A mixed methods observational cohort study of family carers and non-carers was undertaken over the February-April 2020 UD-MOOC. Discussion board engagement was measured as number of posts and replies and examined longitudinally using mixed models. Discussion topics were explored through structural topic models (STM). Subsequently, thematic analysis of STM derived-topic exemplars was conducted to contextualise these discussions.

Results: Family carers were (n = 2320) found to post (p < 0.001) and reply (p= 0.029) significantly more often than non-carers (n = 2392). Of the 32-STM derived-topics, meaningful activities (mean Δ = 0.007, 95% CrI [0.005-0.100]), personal stories of diagnosis (mean Δ = 0.007, 95% CrI [0.005-0.009]), and family history of dementia (mean Δ = 0.006, 95% CrI [0.004-0.008]) were discussed significantly more frequently by family carers compared to non-carers.

Conclusion: These results may reflect underlying motivational differences and circumstantial relevance. Perhaps the greater engagement by family carers is related to a sense of having inadequate relevant offline social resources, where engagement in the UD-MOOC discussion boards may serve as means to share experiences with others.