To our knowledge, this is the first detailed nationwide disability prevalence survey of ischaemic stroke patients at 1 year after onset in Korea. The study showed that the prevalence of disability based on the WHODAS 2.0 is 62.6%, almost double that of hemiplegia (33.8%), one of the most common neurological sequelae 1 year after stroke. The prevalence of severe disability (WHODAS 2.0, 50–100%) was higher in participation in society (16.8%) and getting around (11.8%) than in the other domains. The breakdown by domain also showed that prevalence decreased with severity. It also demonstrated that each domain of disability increases with various associated factors. In particular, age, recurrent stroke, moderate-to-severe mRS, hemiplegia, and dysarthria are generally related to different domains of disability, and low MGL- motivation is the only modifiable factor determining the significant association between all six domains of disability after adjustment.
Concerning personal background, age was associated with disability as in previous studies using WHODAS 2.0 [20,21,22]. This study indicated that older participants were more likely to have a greater disability in understanding and communicating, getting around, self-care, and life activities. Disability tends to increase with age. Older adults are more vulnerable to age-related comorbidities related to physical health problems [23]. However, even though the adjusted odds of being in a higher category in each domain except self-care was higher (aOR of 1.13 ~ 1.42) for females than males, these sex-related differences in WHODAS 2.0 disability measurements were not significant. A Korean study previously reported that older male stroke patients seem to be more vulnerable to self-care because of the Korean tradition of the passive domestic role of males [21]. The Framingham study reported that females with ischaemic stroke are not functionally more disabled than males [23].
A prior study considered participation in society as the most problematic and important because this domain involves the use of complex skills and navigation in daily life [22]. Participation in society is particularly limited by almost all the variables, such as living without a spouse, recurrent stroke, moderate to severe mRS, hemiplegia, dysarthria, trouble seeing, cognitive problems, general weakness, and low MGL- motivation. However, among the seven variables of neurological sequelae, both life activities and getting along with people are associated only with hemiplegia and dysarthria. This indicates that participation in society is not only about getting along with people but also about daily life.
Each neurological sequela was associated with different domains of WHODAS 2.0. For example, hemiplegia is associated with five domains: understanding and communicating, dysarthria with understanding and communicating, getting along with people, life activities, and participation in society, trouble seeing with understanding and communicating and participation in society, and general weakness with getting around and participation in society. Therefore, it is necessary to consider customised support, for example, a home visit to hemiplegic patients, which requires comprehensive services, or a going out companion to general weakness, which requires simpler services. It would be reasonable to manage these supports according to periodically assessed HRQoL.
It is of interest and importance that low MGL-motivation was significantly associated with all six domains of disability after adjustment (aOR of 2.59 ~ 3.83). Therefore, it would be worthwhile to improve the level of this modifiable variable. Medication adherence is usually defined as the proportion of days covered (PDC), the percentage of medication actually taken at the prescribed doses [24], at 1 year after stroke. The Epidemiologic Research Council of the Korean Stroke Society reported a much lower adherence compared to a previous study from the US [25] (75% vs. 91% for lipid-lowering drugs, 74% vs. 91% for antidiabetic drugs, and 82% vs. 92% for antihypertensive drugs) [3]. Moreover, unlike MGL-knowledge, MGL- motivation is associated with adherence to lifestyle modifications for risk reduction [26]. Such evidence implies that there is substantial room for improvement in the HRQoL of stroke survivors. It is necessary for stroke survivors to provide interventions to improve MGL- motivation using specific methods, such as tailored education, computer-based education, and mobile phone reminders.
This study had several limitations. Our participants are regarded as persons of higher socioeconomic status in the Korean context; the affluent likely have regular outpatient follow-ups at a particular university hospital. Thus, it is possible that overall, participants demonstrated mild deficits as well as a better level of adherence to their medication compared with stroke survivors in the general population. There is also a possibility of selection bias by excluding stroke survivors 1 year after the event due to difficulties in the interview, even though we tried to ensure that stroke survivors were eligible for the study. However, although this study included only ischaemic stroke, generalisation to haemorrhagic stroke is also possible.
In addition, the WHODAS 2.0 mainly covers the activities and participation domains of the ICF, so there has been a need to address bodily impairments and environmental factors [9]. However, this study chose several factors related to bodily impairments such as hemiplegia, dysarthria, and facial palsy. In future studies, environmental factors such as physical, attitudinal, and social barriers can be considered as other factors to determine disability better.
Finally, cognition problems and general weakness were under-reported and under-screened. In general, in Korea, these problems have not necessarily been assessed during outpatient clinics after 1 year of stroke. As neurologists have regarded these problems as non-specific symptoms which might have many possible causes for stroke survivors, they have started to pay special attention to the severity and cause only when patients mention these two complaints. For that reason, in this study as well, the frequency of these problems could be known by asking an open question what kind of discomfort you are currently experiencing due to the complications of stroke.