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

Abstract

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 (NZ115). 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 52.3AE10.3 years. A decline (P<.01) was observed with increasing difficulty and assistance required in global participation (mean AE SD, À0.5AE0.9), social activities subscore (À0.6AE1.2), nutrition (À0.7AE1.4), fitness (À1.0AE1.6), personal care (À0.7AE1.2), mobility (À0.5AE1.9), community life (À0.8AE1.9), and recreation (À1.5AE3.0). 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.

Predictors of participation restriction over a 9-year period in adults with myotonic dystrophy type 1

“…This study thus aimed to identify personal and environmental predictors of participation restriction over nine years in adults with DM1. This paper extends our previous study describing changes in participation over 9-year [27]. Based on the same participant's sample, predictors were specifically identified for the categories of participation that restriction has been found to clinically significantly increase in a substantial proportion of adult with DM1 in our previous study [27].…”

“…Most parsimonious final models were identified considering the best adjusted R 2 , standardized coefficient, and lower confidence intervals. As they were found to be potentially modifying factors [27,38,46], interaction terms of sex with grip strength was tested in final models when applicable. Linearity, homoscedasticity, and normality assumptions were tested on final models with a graphical review of standardized predicted values on studentized residuals as well as with Kolmogorov-Smirnov's analysis.…”

“…Participants' flowchart. Already published in Raymond et al [27] (reuse permission granted). Abbreviation.…”

“…To limit this bias, participants were encouraged to respond honestly. Finally, predictors for long-term education and employment restriction were not assessed [27] and, acknowledging their importance in adulthood, further studies should consider them.…”

“…As DM1 is a slowly progressive neuromuscular disease, participation restriction gradually increases over time. A clinically significant increase in restriction has been found in a substantial proportion of adult with DM1 globally (34%), in daily and social activities domains (35% and 38%), and in seven categories: nutrition (34%), fitness (55%), personal care (37%), housing (31%), mobility (44%), community life (36%), and recreation (51%) [27]. To optimize the participation of adults with DM1, medical and rehabilitation long-term follow-up is therefore needed [28], in addition to access to community services and inclusive policies [29].…”