Progressive Decline in Daily and Social Activities: A 9-year Longitudinal Study of Participation in Myotonic Dystrophy Type 1

Objective: To describe and compare changes in participation over a 9-year period in women and men with myotonic dystrophy type 1 (DM1). To compare participation restrictions with available reference values from a typical aging population living in the community.

Design: Descriptive longitudinal design comparing data from baseline (2002) with data from follow-up (2011).

Setting: Neuromuscular clinic and participant's home.

Participants: Adults with DM1 participated in the follow-up study (N=115).

Interventions: Not applicable.

Main outcome measure: The Assessment of Life Habits measured participation in 10 domains of daily and social activities. The minimal clinically important difference is 0.5 on a 10-point scale for participation accomplishment level.

Results: A total of 62% of participants were women, and the mean age was 52.3±10.3 years. A decline (P<.01) was observed with increasing difficulty and assistance required in global participation (mean ± SD, -0.5±0.9), social activities subscore (-0.6±1.2), nutrition (-0.7±1.4), fitness (-1.0±1.6), personal care (-0.7±1.2), mobility (-0.5±1.9), community life (-0.8±1.9), and recreation (-1.5±3.0). More life areas are disrupted over time: 8 domains were below reference values from a population aged 55-64 years at follow-up compared with 2 domains at baseline. Satisfaction with participation remains high and stable over time.

Conclusion: As disease duration increases, global participation and more daily and social domains were restricted with increasing difficulty and assistance required. Adults with DM1 showed not only age-associated but disease-specific changes in participation. Description over time of participation could improve clinical assessment and guide interdisciplinary management of DM1, leading to higher rehabilitation success. Further investigation of the factors influencing changes in participation is required to support disease management and services planning.