Prevalence and Factors Associated with Impairment of Instrumental Activities of Daily Living in Older People: A Population Study

Research Article

Gerontol Gerontol Geriatr Res. 2021; 7(1): 1051.

Prevalence and Factors Associated with Impairment of Instrumental Activities of Daily Living in Older People: A Population Study

Nunes DP1*, Castro DC2, Mota JPN3, Moura BM4, Vera I5, Menezes RL6, Pereira LV7 and Pagotto V8

1School of Nursing, Campinas State University, Leader of the Aging and Care Research Group, Brazil

2State Department of Health of the Federal District, Brazil

3School of Nursing of Goias Federal University, Brazil

4Tocantins Federal University, Brazil

5Federal University of Catalão, Researcher and Leader of the Research Group Management, Teaching and Care in Health and Nursing, Brazil

6Faculty of Ceilandia, University of Brasília, Graduate Program in Health Sciences and Technologies, Brazil

7School of Nursing, Goias Federal University, Graduate Program in Nursing, Brazil

8School of Nursing, Goias Federal University, Brazil

*Corresponding author: Nunes DP, R. Tessália Vieira de Camargo, 126-Cidade Universitária, CEP: 13083-887, Campinas, São Paulo, Brazil

Received: April 06, 2021; Accepted: April 26, 2021; Published: May 03, 2021


Objective: To identify the prevalence and factors associated with functional disability for Instrumental Activities of Daily Living (IADL) among older people in a Brazilian capital. Methods: This is a cross-sectional study carried out on 927 older people in the city of Goiânia, Goiás, Brazil. Lawton’s scale was used to assess IADL. Functional disability was characterized as difficulty in performing at least one activity. Multiple logistic regression was employed for the analysis of association. Results: A 58.2% prevalence of disability was identified, and the most compromised activities were doing manual work, doing the laundry, and ironing. There was an association between disability and old age, poor/very poor self-rated health, cerebrovascular accident, widowhood, cognitive impairment, musculoskeletal disorder, and living alone. Conclusions: The prevalence of functional disability for IADL was higher than that of national and international studies. We verified associated factors that can be modified by health promotion initiatives, which are configured as priority areas for interventions.

Keywords: Older people; Aging; Daily activities; Cross-sectional studies; Geriatric nursing


Decreased functional capacity among older adults occurs at a hierarchical level, beginning with Instrumental Activities of Daily Living (IADL), until reaching basic Activities of Daily Living (ADL), related to self-care. IADL are more complex with regard to physical and neuropsychological functioning, are developed in the social environment, and are essential for maintaining autonomy and independence in this group [1-4].

Several studies worldwide use the Lawton’s scale for assessing the performance in IADL [1,5-8]. We highlight the study carried out in the city of São Paulo (SP), Brazil, whose authors assessed the pattern of IADL impairment over a period of 10 years, and identified a prevalence of difficulty accounting for 35.4; 45.8; and 41.0%, respectively, in the years 2000, 2006, and 2010 [2]. The functional worsening of each age group reinforces the need to know the factors associated with dependence among older adults.

Studies carried out in different Brazilian regions have demonstrated several factors related to IADL functional disability in older people, namely: old age, women, widowhood, low education level, low income, nonwhite ethnicity, multimorbidities, cognitive impairment, poor self-rated health, low level of physical activity, former smoker, and depression [9-14]. Considering these aspects, functional decline causes negative repercussions for older people, family members, and healthcare services.

Regarding older adults, the risk of negative events, such as social isolation, hospitalization, and demand for care needs (presence of caregiver), and increases. As for the family, relatives must be reorganized in order to provide care for the dependent older adult and, according to the demand for care, it may generate care burden. Therefore, we verify the need for considering these factors when planning healthcare actions aimed at preserving functional capacity, considering that it contributes to the quality of life of older adults and their family members, providing well-being in old age [11,15].

Thus, in this study we aimed at identifying the prevalence and factors associated with functional disability for Instrumental Activities of Daily Living (IADL) among older people in a Brazilian capital.


This is a population-based study with a cross-sectional design, which is part of the research entitled Situação de Saúde da população idosa do município de Goiânia (GO) (Health status of older people living in the city of Goiânia (GO), Brazil). Individuals aged 60 years or older, living in the urban area of Goiânia, state of Goiás, Brazil, and who lived in the household visited for the survey were considered eligible for the study.

The number of older people (60 years and over) residing in Goiânia, in 2007, corresponded to 7% of the population of the municipality (1,249,645 inhabitants). Sample size was calculated based on a 95% confidence interval, a 5% significance level, 30% expected frequency for health conditions assessed in the matrix project, 5% absolute precision, Design Effect (DEFF) of 1.8, and an increase of 11% for possible losses. The representative sample of the population of older adults living in the urban area of Goiânia consisted in 934 older people.

In this study, 7 individuals were excluded because they did not completely answer all the items of the IADL instrument. It was investigated whether the sample of the project was sufficient for functional disability, totaling 927 older people. Hence, the estimation was carried out by using the OpenEpi® software, version 2.3.1 (2010) for cross-sectional study with sample by clusters, considering the average frequency of physical mobility in older people residing in Goiânia of approximately 26% 16, absolute precision of 2.6%, and 1.8 DEFF. A sample of 842 individuals was estimated for a power of 80%, in order to certify that the sample of the project was representative for the outcome under study.

Interviewers were properly trained in the application of the consent form, data collection, and clarification of doubts on the part of the study individuals and their families. Data were collected between December 2009 and April 2010.

Functional disability for IADL consisted in the dependent variable of this study. The Lawton-Brody [8] instrument adapted by the Brazilian Ministry of Health [17] was chosen for the study for being widely used in national and international studies and the Brazilian Ministry of Health recommends its use for evaluating the functionality for instrumental activities of older people in primary care. Partial or total dependence on at least one evaluated activity, as reported by the older adults, was considered as IADL disability.

Independent variables were grouped into: socioeconomic and demographic characteristics (sex, age, marital status, education level, income, living alone); health conditions (self-rated health, hypertension, diabetes, chronic obstructive pulmonary disease, Cerebrovascular Accident (CVA), musculoskeletal disorder, osteoporosis, cancer, acute myocardial infarction, visual impairment, hearing impairment, pain, falls, hospitalization, and cognitive impairment), and lifestyle habits (smoking habit, physical activity, and alcohol consumption).

Cognitive impairment was assessed by the Mini-Mental State Exam. The score was stratified according to education levels. The cutoff point for cognitive impairment was considered as follows: <19 points for illiterates; <23 points for elementary school; <24 points for high school; and <28 points for higher education [18].

The research was approved by the Research Ethics Committee of Universidade Federal de Goiás under protocol No. 050/2009, and complied with Resolution 466/12 of the National Health Council on research involving human beings [19].

Data were entered into the Excel for Windows® 2003-2007 program and analyzed using the Stata® software version 14.0. For analyzing the association between IADL disability and independent variables, the Chi-Square or Fisher’s exact tests were used, with a 5% significance level. Multiple logistic regression analysis was used to identify factors associated with functional disability. The Hosmer-Lemeshow test was performed to verify the goodness of fit of the model [20]. The area under the ROC curve was also calculated to verify the prediction of the final model.


Among the 927 older people, most of them were women (62.8%), aged between 60 and 69 years (48.3%), married (49.7%), with elementary school (47.5%), with income lower than or equal to one minimum wage (42.5%), and lived with other people (87.3%).

The prevalence of functional disability for IADL was 58.2%, and the most compromised activities were: doing manual work (42.4%), doing the laundry and ironing (40.7%), housekeeping (35.3%), using public mode of transportation (28.0%), shopping (24.7%), preparing meals (18.6%), handling finances (17.0%), using the telephone (16.9%), and taking medications correctly (14.5%).

When stratifying IADL by age and sex, we observed differences in relation to sex in the age group of 60 and 69 years for preparing meals and doing manual work. In the age group of 70 to 79 years, we observed differences related to using modes of transportation, preparing meals, and doing manual work. For long-lived older adults (aged over 80 years), we found associations regarding the use of modes of transportation, shopping, and doing manual work (Table 1).