Assessment of Functioning and Disability Based on WHODAS 2.0 and Related Factors Among People Aged 80 and Over Hospitalized in a Geriatric Ward in Southeastern Poland

Introduction

Current statistics suggest that by 2030, every sixth person in the world will be at least 60 years old. However, the fastest increase will be observed in the proportion of people in the oldest age groups within populations. The global population aged 60 and over is expected to double from 1 billion in 2020 to 2.1 billion in 2050. The number of people aged 80 and over will triple over the same period, reaching 426 million in 2050 [1]. A similar demographic trend is also occurring in Poland. In 2023, people aged 80 and over constituted 16.2% of the older population in Poland; by 2060, this proportion is expected to increase by 7.5% [2].

As the number of people in the oldest age groups increases, so do the prevalences of diseases and health problems, which greatly contribute to the increased incidence of disability and dependence in everyday functioning in this population. According to data from a nationwide survey of older people in Poland (PolSenior2), 28.1% of men and 47.1% of women aged 80 to 84 report limited independence requiring assistance from others. These proportions substantially increase with age, exceeding 70% in men and 84% in women aged 90 and over [3]. With increasing age and the presence of multiple co-occurring chronic diseases, the frequency of hospitalization also considerably rises [4]. Hospitalization is strongly associated with changes in functional status, both during and after the hospital stay. The hospital care process itself – including polypharmacy and the associated risk of iatrogenic effects, prolonged bed rest, and general weakness resulting from impaired health status – may hinder a return to pre-hospitalization levels of functional independence. A patient’s clinical condition upon admission to the ward, particularly the presence of major geriatric syndromes and prior hospitalization within the preceding 12 months, is also considered a factor that may determine the decline in functional independence during hospitalization [5]. de Almeida Tavares et al reported that most hospitalized older adults demonstrate impaired functional capacity relative to their pre-hospitalization status, along with an increased level of dependency at 3 months after discharge [6]. These changes often lead to the need for home care services or placement in a nursing home [7]. Therefore, assessments of older patients during hospitalization in terms of functional status and level of disability, as well as factors associated with these outcomes, are essential. Such assessments enable the identification of risk factors for disability in this population and facilitate the definition of targeted therapeutic goals to be achieved during hospitalization, serving as a preventive measure against disability onset. They also provide relevant data for planning post-discharge care and therapeutic services [8].

Accordingly, assessments of older patients should incorporate tools based on the biopsychosocial model, thereby enabling comprehensive evaluation of disability and functioning while considering social relationships, participation, and environmental influences. One such tool is the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), developed by the World Health Organization (WHO), which is based on the International Classification of Functioning, Disability and Health framework [9].

WHODAS 2.0 has been widely used in studies of various populations, including older adults, confirming its reliability and utility [10–12]. In the Polish population, this tool has also been used to assess functioning and disability, including in studies of older adults (aged 60–80 years) living in the community [13], those in institutional care [14], and individuals over 50 years of age who have undergone hip or knee osteoarthritis procedures [15].

A search of the literature revealed that the WHODAS 2.0 questionnaire has not yet been used to comprehensively assess the level of functioning and disability among hospitalized individuals in the oldest age group (80 and over) in Poland. Given the increasing proportion of this age group in the Polish population, as well as challenges associated with hospitalization in this population, the present study aimed to evaluate the level of functioning and disability using WHODAS 2.0 and related factors, including sociodemographic variables, health parameters, and variables determining functional status in adults aged 80 and over hospitalized in a geriatric ward in southeastern Poland.

Based on the study aim, the following research questions were established:

Material and Methods

STUDY DESIGN AND SETTING:

This cross-sectional study was conducted between January 2019 and March 2020 among patients hospitalized in the geriatric ward of the Hospital in Przeworsk (southeastern Poland). Prior to initiation, the study received approval from the Bioethics Committee of the University of Rzeszów (Resolution No. 2/12/2018). In accordance with the Declaration of Helsinki, all participants were informed about the purpose and procedures of the study and provided written informed consent.

The study was designed in accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines [16].

PARTICIPANTS:

The study included older adults admitted to the geriatric ward of the hospital in Przeworsk. Inclusion criteria were: (a) age 80 years and over; (b) no cognitive impairment (Abbreviated Mental Test Score >6 points); and (c) functional status enabling the performance of gait, muscle strength, and balance tests (Katz Activities of Daily Living Scale ≥3). Exclusion criteria were: (a) presence of serious systemic diseases or infections preventing the planned assessments; (b) severe visual impairment preventing performance of functional tests; (c) severe hearing impairment preventing understanding of instructions and questions, as well as provision of reliable responses; and (d) lack of informed consent to participate in the study.

SAMPLE SIZE:

The sample size was determined based on statistical data concerning the number of people aged 80 and over in the hospital catchment area [17], as well as data regarding the average hospitalization rate in geriatric wards in the region [18]. Considering a population of 3383 individuals aged 80 and over and a hospitalization rate of 88.03 per 100 000 inhabitants, it was estimated that 1060 individuals in this age group were hospitalized in the region during the study period. This estimate was used for sample size calculation. The Online Sample Size Calculator (https://www.calculator.net/sample-size-calculator.html) was used, assuming a 5% margin of error and 95% confidence level, resulting in a minimum required sample size of 282 participants.

VARIABLES:

The following variables were included in the study: (a) level of disability assessed using WHODAS 2.0; and (b) contextual factors potentially related to disability during hospitalization (eg, sociodemographic factors, health status parameters, and functional status parameters).

WHODAS 2.0: WHODAS 2.0 is a standardized tool developed by the WHO to measure health, functioning, and disability across cultures and populations. It is based on the framework of the International Classification of Functioning, Disability and Health. This study utilized the 36-item version of the questionnaire, translated and validated for use in the Polish population [13]. WHODAS 2.0 assesses functioning and disability over the 30 days preceding the evaluation across 6 domains: (1) Cognition – understanding and communicating; (2) Mobility – moving and getting around; (3) Self-care – hygiene, dressing, eating, and being alone; (4) Getting along – interacting with other people; (5) Life activities – domestic responsibilities (5.1) and work and school (5.2); and (6) Participation – engagement in community activities. Due to the characteristics of the study population, domain 5.2 (work and school) was not assessed. Responses are recorded on a 5-point scale: 0 – no problem (0–4%); 1 – mild problem (5–24%); 2 – moderate problem (25–49%); 3 – severe problem (50–95%); and 4 – complete problem (96–100%) [19].

SOCIODEMOGRAPHIC VARIABLES AND HEALTH STATUS MEASUREMENT:

A proprietary questionnaire was used to collect basic sociodemographic data, including age, sex, place of residence, education level, and marital status. Data regarding environmental factors were also collected, including subjective assessment of housing conditions in relation to functional needs, support received in daily functioning, history of falls in the previous year, and physical activity. Based on medical record review, information was obtained concerning the number of comorbidities and medications. Both chronically used medications and those prescribed upon admission to the geriatric ward were included.

ASSESSMENT OF PARTICIPANTS’ BODY MASS INDEX (BMI): Measurements were performed using a medical scale with a height gauge. Participants were asked to remove their shoes and stand on the scale, looking straight ahead with their arms at their sides [20]. BMI was calculated based on the obtained height and weight. Classification followed the standards proposed by the Committee on Diet and Health, according to which a healthy body weight in individuals over 65 years corresponds to a BMI of 24 to 29 kg/m2, underweight to below 24 kg/m2, and overweight to above 29 kg/m2 [21].

BERG BALANCE SCALE (BBS): This scale was used to assess participants’ static and dynamic balance. It consists of 14 tasks performed in standing and sitting positions, including activities such as reaching, turning, and picking up objects from the floor. Each task is scored on a 4-point scale, with a maximum total score of 56. Higher scores indicate better balance [22,23].

TIMED UP AND GO TEST: This test was used to assess mobility and fall risk. Participants were instructed to sit in a chair with a backrest (seat height approximately 46 cm) with their feet flat on the floor. The test involved standing up, walking 3 m at a comfortable pace on a flat surface, turning 180 degrees, returning to the chair, and sitting down. The total time to complete the task was recorded in seconds [24]. This simple and inexpensive test is widely used in clinical practice. It is also recommended as a screening tool for fall risk in the geriatric population [25].

10-METER WALK TEST (10MWT): This test was conducted to assess gait. It was performed along a level corridor over a designated 10-m distance, with an additional 2 m at both the start and end to allow for acceleration and deceleration. Participants began in a standing position. The outcome measure was the time required to walk the 10-m distance [26,27].

30-SECOND SIT-TO-STAND TEST: This test was conducted to assess lower limb strength in the study cohort. Participants were instructed to sit on a chair approximately 43 cm in height, with their feet flat on the floor and arms crossed over the chest. The chair was placed against a wall to prevent movement during the test. The task involved repeatedly standing up and sitting down (with full contact of the buttocks on the seat) for 30 seconds. The outcome was the number of completed sit-to-stand cycles within 30 seconds [28].

ASSESSMENT OF HAND GRIP STRENGTH: Hand grip strength was measured using a hand dynamometer (JAMAR PLUS+ Digital Hand Dynamometer, Patterson Medical). Measurements were performed with the participant seated on a chair without armrests, feet flat on the floor, arms alongside the body, elbows flexed at 90 degrees, forearms in a neutral position, and wrists in 0 to 30 degrees of extension. Participants were instructed to squeeze the dynamometer with maximal effort and maintain the grip for 6 seconds. The procedure was repeated 3 times, with a 1-minute rest between attempts. The result was expressed in kilograms as the mean of the 3 measurements [29,30].

DATA COLLECTION:

Data were collected once, on the day of admission to the geriatric ward. The study procedure consisted of 3 stages and was coordinated by the attending physician. A 30-minute rest period was provided between stages; the total duration of the procedure, including breaks, was approximately 1.5 hours. The stages were as follows:

STATISTICAL ANALYSIS:

Descriptive statistics included absolute and relative frequencies for qualitative variables and mean±standard deviation (SD) for quantitative variables. The Shapiro-Wilk test was used to assess distribution normality. Because quantitative variables displayed non-normal distributions, Spearman’s rank correlation coefficient (for quantitative variables) and the Mann-Whitney U test (for qualitative variables with 2 categories) were used to evaluate associations with disability levels across domains and overall. A linear regression model was utilized to assess the combined effects of variables on disability. Regression coefficients were presented with confidence intervals and corresponding significance levels. The statistical significance threshold was set at P<0.05.

Data were analyzed using TIBCO Statistica version 13 (TIBCO Software Inc., 2017; Statistica version 13, http://statistica.io).

Results

ANALYSIS OF SOCIODEMOGRAPHIC, FUNCTIONAL, AND HEALTH STATUS VARIABLES IN THE STUDY COHORT:

The analysis included 282 participants who met the inclusion criteria (Figure 1). The study cohort comprised 64.18% women and 35.82% men, with a mean age of 84.80 years. The majority of participants were rural residents (76.60%) and were single, including widowed individuals (65.96%). Most participants had not experienced a fall in the preceding year (56.38%) and reported that their living environment was not adapted to their needs and functional abilities (69.86%); however, most had access to assistance from others at their place of residence (85.11%). Overall, 79.08% of participants reported no engagement in physical activity related to household chores. The mean number of comorbid chronic conditions was 7.51, and the mean number of medications taken was 8.23. The largest proportion of participants were overweight or obese (40.78%), whereas the smallest proportion were underweight (22.70%). The mean BBS score was 36.04 points, and most participants (55.32%) had a high risk of falling. Mean hand grip strengths were 16.42 kg for the left hand and 17.89 kg for the right hand; reduced grip strength was observed in the majority of participants (70.21% for the left hand and 62.41% for the right hand). Similarly, reduced lower limb strength was observed in most participants (70.21%), with a mean result of 6.22 repetitions in the sit-to-stand test. Most participants also demonstrated reduced walking speed (75.53%), with a mean gait speed of 0.53 m/s. In the Timed Up and Go test, the majority of participants displayed an increased risk of falls (52.84%), with a mean test result of 29.09 seconds (Table 1).

ANALYSIS OF DISABILITY LEVEL USING WHODAS 2.0:

The highest mean level of disability in the study cohort was observed in Domain 5 – Life Activities, with an average score of 77.27 points. According to the classification of disability levels, 26.24% of participants had extreme problems and 63.12% had severe problems in this domain. The second highest level of disability was observed in Domain 2 – Mobility, with a mean score of 55.90 points. In this domain, 2.48% of participants reported extreme problems, whereas 63.48% had severe problems. The lowest mean score was found in Domain 1 – Cognition (29.17 points). In this domain, the largest proportion of participants (17.38%) reported no problems (Table 2).

ANALYSIS OF CORRELATIONS BETWEEN DISABILITY LEVEL ON THE WHODAS 2.0 SCALE AND SOCIODEMOGRAPHIC, FUNCTIONAL, AND HEALTH STATUS VARIABLES:

Analysis of correlations between selected sociodemographic factors and disability levels across WHODAS 2.0 domains revealed a significantly higher level of disability among women in the domains of Mobility (P=0.002), Self-care (P=0.001), Getting along (P=0.033), and Participation (P=0.001), as well as the overall disability score (P=0.003), compared with men. A significantly higher level of disability was also observed among widowed and single individuals in the domains of Self-care (P=0.013), Getting along (P=0.015), and Participation (P=0.010), as well as the overall disability score (P=0.031). Experiencing a fall in the preceding year was associated with a significantly higher level of disability across all WHODAS 2.0 domains. Participants who did not engage in physical activity exhibited higher disability levels in the domains of Self-care (P=0.042), Getting along (P=0.015), and Life Activities (P=0.005), as well as the overall disability score (P=0.038). A higher number of comorbidities was associated with increased disability in the Self-care domain (P=0.047). In the study cohort, higher disability levels across all analyzed domains and in the overall WHODAS 2.0 score were significantly associated with worse performance on the Timed Up and Go test and longer time to complete the 10MWT. Lower disability levels were associated with higher BBS scores, greater hand grip strength in both hands, and greater lower limb strength according to the 30-Second Sit-to-Stand Test (Table 3).

LINEAR REGRESSION ANALYSIS OF FACTORS ASSOCIATED WITH DISABILITY LEVEL:

Factors exhibiting statistically significant associations with disability levels in specific domains were included in the linear regression model. Due to a positive correlation between Timed Up and Go results and the 10MWT, the 10MWT variable was included in the model.

The analysis showed that lack of physical activity at home was associated with a statistically significant increase of 4.507 points in Domain 5 (Life Activities). Participants who had not experienced a fall in the year preceding the study had lower disability levels by 2.643 points in Domain 1 (Cognition), 2.966 points in Domain 3 (Self-care), 2.503 points in Domain 4 (Getting along), and 2.287 points in the overall WHODAS 2.0 score. Additionally, each 1-second increase in time to complete the 10MWT was associated with a statistically significant increase in disability across all analyzed domains and in the overall WHODAS 2.0 score (Table 4).

Discussion

LIMITATIONS:

This study has some important limitations. First, its cross-sectional design limits the analysis to a single time point; therefore, the observed associations only apply to the period of hospitalization in the geriatric ward. Longitudinal studies are needed to evaluate changes in disability over time in relation to the duration of hospitalization and the extent of support received during and after discharge. Second, individuals with advanced cognitive impairment were excluded because disability in this population cannot be assessed using WHODAS 2.0. Consequently, the overall level of disability in the study cohort may have been underestimated. Future studies should consider incorporating objective assessment tools that allow the inclusion of individuals with advanced cognitive impairment.

STRENGTHS AND PRACTICAL IMPLICATIONS:

This study provides important information about the level of disability among the oldest-old individuals undergoing hospitalization and identifies domains that require targeted support to enhance independence during and after hospital stay. Such information is particularly relevant given the specific health profiles and increased risk of hospital-associated disability in this population. The study also addresses a gap in current knowledge because demographic projections indicate a rapid increase in the population aged 80 years and over in Poland, but data concerning disability levels in hospitalized individuals within this group remain limited. Key practical recommendations for clinicians include the routine assessment of mobility and gait speed as an initial step prior to comprehensive geriatric assessment in geriatric wards. This approach may facilitate earlier identification of high-risk individuals and enable timely implementation of targeted interventions to support mobility and reduce the risk of hospital-associated disability.

Conclusions

In the study cohort of individuals aged 80 years and over hospitalized in a geriatric ward, the level of disability was high; the greatest impairment was observed in the domains of Life Activities and Mobility. Significant associations were identified regarding disability levels with selected health status and functional parameters. Longer time to walk 10 m was the strongest factor associated with increased disability, showing significant relationships across all WHODAS 2.0 domains. These findings highlight the need for systematic mobility monitoring in hospitalized older adults, using simple and cost-effective tools such as the 10MWT. They also support the implementation of strategies to promote mobility, both during hospitalization and after discharge. Such strategies may include environmental adaptations to facilitate safe movement and tailored exercise programs. These measures may help to reduce disability, maintain independence in daily functioning, extend life expectancy, and decrease the burden on healthcare and long-term care systems in southeastern Poland.