Frequency of instrumental activities of daily living is associated with objectively measured physical activity in stable patients with cardiovascular disease
Authors: Kariya H , Yamaoka-Tojo M , Hamazaki N , Komatsu T , Miyagi S , Kitasato L , Maekawa E , Kobayashi S , Shibuya M , Ichikawa T , Takahashi M , Nozaki K , Kamiya K , Matsunaga A , Ako J 
Published: November 2023

Abstract

Introduction
Implementation of instrumental activities of daily living (IADL) has the necessary items for independent living in community-dwelling, which is reported as a relevant factor for better prognosis in patients with cardiovascular disease (CVD). Physical activity (PA) is well-known to have benefits in reducing the risk of all-cause mortality and CVD. Although IADL and PA are similar behaviors and crucial intervention targets to prevent the recurrences of CVD in patients who participate in phase III cardiac rehabilitation, these interrelations remain unclear.

Purpose
This study aimed to evaluate the association between IADL frequency and objectively measured PA, including step counts and time of vigorous activity, in stable patients with CVD. Additionally, we examined whether detailed types of IADL frequency were associated with PA.

Methods
This was a single-center cross-sectional observational study. We included patients with CVD who received outpatient care with stable condition for at least six months. Participants completed Frenchay Activities Index (FAI) questionnaire as an assessment of IADL frequency. The FAI contains 15 items, classified as housework and leisure activity. We used accelerometers to measure the objective number of steps and minutes of moderate to high-intensity physical activities for two weeks and calculated their averages per day as indicators of PA levels. The associations of FAI total score and 15 FAI sub-items with physical activities (the number of steps and minutes of moderate to high-intensity physical activities per day) were analyzed using a multivariate linear regression model.

Results
Studied patients consisted of 1126 stable patients with CVD (mean age, 72.6 ± 10.0 years; 848 males). After adjusting for clinical confounding factors, high FAI total score was significantly associated with higher levels of physical activities (the number of steps per day: unstandardized coefficient [В] for FAI increase of 1 point = 78.1 [95% confidence interval {CI}, 54.9–101.4], Figure 1-A; the minute of moderate to high-intensity PA per day: В = 0.184 [95%CI, 0.063–0.304], Figure 1-B). In the sub-items of FAI, four items of housework activities (washing up, light housework, heavy housework, and local shopping) and six items of leisure activity (walking outside for &gt; 15 minutes, actively pursuing hobbies, driving a car or bus travel, gardening, reading books and gainful work) were also positively associated with the number of steps per day. Conversely, only two items of leisure activity (walking outside and actively pursuing hobbies) were associated with moderate to high-intensity PA per day (Figure 2).

Conclusions
The frequency of IADL has a positive association with objectively measured PA, suggesting that IADL might be useful behavior to administrate PA in stable patients with CVD. Moreover, leisure activity in IADL is especially relevant to vigorous PA in these patients.Figure 1Figure 2