This exploratory study is the first step towards a better understanding of independent living and its links to cognitive functioning among adults who have grown with the childhood phenotype of DM1. This study brings some evidence of the large variety of difficulties encountered by this population in performing IADLs. Even more importantly, it highlights their need for support to accomplish these activities which are essential to function in everyday life. In addition, a large proportion of participants showed an intellectual functioning below average which is related to the level of dependency exhibited by the individuals. An evaluation of the IADLs should be recommended in this population, notably for individuals with lower IQs.
Considering that there is currently no published study addressing the ability to accomplish IADLs among adults with childhood phenotype of DM1, no comparison can be made with other data. However, results emerging from this research are in line with the retrospective study of Gagnon et al. (2017), which had raised the presence of participation restrictions among this population in domestic life, education and employment.
First of all, if growing up with DM1 as a child may promote anxiety and social withdrawal in children and even teenagers (11), it is to note that considering the low levels of state anxiety found in participants, anxiety seem not to contribute significantly in the difficulties observed in the accomplishment of the IADLs assessed in the study.
Money management was the activity with the highest proportion of dependent participants (8/11). Achieving money management tasks (paying bills, writing a check, planning a budget) involve a range of complex cognitive abilities (e.g., planning, calculation, working memory, problem solving, etc.). Working memory impairment (12) and, more globally, lower intelligence (9,10) have been previously documented in children with the childhood phenotype of DM1, which might contribute to participants’ lower level of independence in this category. These scores reflect problematic situations often reported by patients during clinical follow-up (i.e., bankruptcy, eviction, not paying rent in time, etc.). Health & safety activities is the category with the highest number of independent participants (6/11). This category assesses the individual’s awareness of personal health status and ability to evaluate health problems, handle medical emergencies, and take safety precautions. One of our hypotheses to explain relatively high scores in this category is that these abilities are developed early in and are reinforced throughout our life (i.e., learning not to talk to strangers, looking both sides before crossing the road, etc.). We suspect that these behaviors become habits that are more easily maintained with time, as opposed to more complex abilities such as money management. Moreover, the fact that participants from the Saguenay-Lac-Saint-Jean region are followed up by a nurse case manager during their lifetime, with whom they have a continuous and close relationship, may contribute to their good knowledge on appropriate behaviors in relation to health and security [33].
Health records showed that, for all IADLs, the percentage of participants who needed help from their family and/or from other external resources ranged from 8/11 to 10/11 (82 to 91%), suggesting that only few participants were able to perform by themselves the IADLs required for independent living. This is in accordance with the previous study of Gagnon et al., which revealed that the majority of individuals with this phenotype performed house-related responsibilities adequately, but with services or help [34].
Considering the total scores of the ILS, 8/11 participants were either dependent or semi-independent, meaning that a high proportion of patients experienced difficulties in their everyday life. Adults living with childhood phenotype of DM1 would thus benefit from interventions to help them maintain their ability to carry out IADLs. Moreover, considering the young age of the present sample and the fact that DM1 is a progressive disease, it is essential that health care providers keep in mind the evolution of those difficulties and their long-term impact on quality of life.
The home management and transportation subscale was associated to the global IQ, as reported in the ILS manual. This tends to support the idea that the ability to accomplish some IADLs may be influenced by intellectual functioning, although intelligence tests did not directly assess the ability of an individual to perform activities of daily living. Surprisingly, the executive performance scores were not correlated with the instrumental activities of the ILS involving executive functions such as money management. The FAB is a short questionnaire assessing different aspects of executive functions that might not be specific enough to evidence the cognitive functions involved in those ILS subscales. As an example, the manual of the ILS revealed that the money management subscale show a moderately high correlation with the arithmetic subtest of the WAIS-R [26], thus providing support that it requires specific cognitive functions that are not assessed in the FAB neither the WASI-II.
In a descriptive manner, patients presenting lower IQs, limit or impaired executive functions abilities showed difficulties in performing IADLs, thus raising the concern of the functional impact of those impairments. Accordingly, when neuropsychological clinical evaluation reveals an IQ in the limit range in a patient with the childhood phenotype of DM1, it should be referenced to an occupational therapist to validate abilities to perform IADLs.
The high rate of apathy observed in the current study (5/11 participants) may directly impact the level of activities performed by the individual and their need of help from relatives. Preserved motivation and self-activation are required to initiate, execute and maintain daily activities such as housekeeping and meal preparation. However, in the present study, apathy was not associated to IADLs accomplishment. Difficulties described in the current study might be underestimated considering that results from the ILS were mostly obtained through scenarios regarding IADLs instead of real-life tasks, therefore not considering tangible apathy and initiative abilities. Future studies should consider a more holistic approach, assessing individuals in their real-life context in order to understand more precisely where and when difficulties emerge.
As suggested by Van Heugten et al., it is imperative that rehabilitation services in DM1 address not only motor but also neuropsychological symptoms, especially in the childhood phenotype [35]. For example, acceptability and feasibility of Stanford Chronic Disease Self-Management Program has been previously assessed with patients with DM1 and presented considerable potential [36]. Moreover, as suggested by authors such as Fujino et al. or Graham et al. [37, 38] and considering the implication of cognitive area on IADLs found in this study, neuropsychological rehabilitation techniques could be useful to compensate for cognitive and behavioral impairments and improve patients’ abilities to perform independently IADLs; it could include, among others, goal management training and problem-solving training. Finally, neuropsychologists have an important role in risk reduction by helping patients and colleagues of the multidisciplinary teams understanding more precisely the problematic of cognitive impairments and helping them to notice how they impact their ability to perform IADLs.
Limits
This study has some limits to be considered. First, this exploratory study was performed with a limited number of participants (n = 11), which restrict its generalization. Although those 11 participants were specifically chosen to be a representative sample of the population to limit bias, they can possibly represent the most active DM1 childhood individuals as they accepted to be part of the study. Also, tests assessing intellectual and executive functioning were purposely brief to avoid time and fatigue burden in participants, because the aim of the study was to assess both the performance in IADLs and cognition. A more comprehensive neuropsychological battery may be contributive in further studies.