Rasch analysis of the International Wellbeing Index in older adults

The Disease Burden Morbidity Assessment in older adults and its association with mortality and other health outcomes

The objective of this study was to assess how disease burden caused by chronic conditions is related to mortality (predictive validity) and other health outcomes (convergent validity). This was studied in 625 community-dwelling adults living in Spain aged 65 years and older. Disease burden was measured with the Disease Burden Morbidity Assessment (DBMA). The association with 5-year mortality was assessed using a Cox model and Kaplan-Meier curves. For convergent validity, mean age, sex ratio, patient-centered outcomes and healthcare utilization were compared for high and low DBMA scores (< 10 vs. ≥ 10). Also, a multivariable linear regression model was used to evaluate the DBMA as a function of these variables. Mean DBMA score in our sample was 7.5. After 5 years, 35 participants had died (5.5%). The Cox model displayed a hazard ratio of 1.07, and the Kaplan-Meier curves showed lower survival for high DBMA scores. Among participants with high DBMA scores, low self-perceived health, disability and female sex were more frequent, and this group showed lower mean scores for quality of life (Personal Wellbeing Index), affect balance (Scale of Positive and Negative Experience) and physical activity (Yale Physical Activity Survey), higher mean age and higher healthcare utilization than persons with low DBMA scores. In the multivariable regression, all variables but age were significantly associated with the DBMA. In conclusion, the DBMA showed satisfactory predictive and convergent validity. In our aging society, it can be applied to better understand and improve care for older persons with multiple chronic conditions.

Rasch Analysis and Construct Validity of the Disease Burden Morbidity Assessment in Older Adults

Purpose of the Study

The Disease Burden Morbidity Assessment (DBMA) is a self-report questionnaire in which participants rate the disease burden caused by a number of medical conditions. This paper studies the measurement properties of the DBMA, using Rasch analysis.

Design and Methods

We used data of 1,400 community-dwelling adults aged 50 years and older participating in the Ageing in Spain Longitudinal Study, Pilot Survey (ELES-PS). Test of fit to the Rasch model, reliability, unidimensionality, response dependency, category structure, scale targeting, and differential item functioning (DIF) were studied in an iterative way. Construct validity of the linear measure provided by the Rasch analysis was subsequently assessed.

Results

To achieve an adequate fit to the Rasch model, all items were rescored by collapsing response categories. Reliability (Person Separation Index) was low. The scale was unidimensional and neither response dependency nor relevant DIF were found. The linear measure had a correlation of -0.48 with physical functioning, -0.47 with perceived health, 0.32 with depression, and -0.24 with quality of life (QoL) and displayed satisfactory known-groups validity by sex and age groups. Relative precision analysis showed that the linear measure discriminated better between age groups than the original raw score, but for sex no difference was found.

Implications

Despite some limitations, support was found for the validity of the DBMA in older adults. Its linear scores may be useful to assess strategies aimed at improving the QoL of patients with multimorbidity. More research is needed in a hospital-based sample.

Disease burden morbidity assessment by self-report: Psychometric properties in older adults in Spain

AIM

To carry out an analysis of the psychometric properties of the Disease Burden Morbidity Assessment (DBMA) according to the assumptions of the Classical Test Theory.

METHODS

A sample of 707 community-dwelling adults aged 65 years and older, living in Spain, completed the DBMA. Psychometric properties of the scale (feasibility, acceptability, scaling assumptions, reliability and construct validity) were analyzed.

RESULTS

The mean DBMA score was 6.8. Feasibility and acceptability were satisfactory, except for large floor effects (>50%), as well as a skewed distribution (1.8). Item-total corrected correlation ranged 0.10-0.49, item homogeneity index was 0.09 and Cronbach's alpha was 0.72. Disease burden correlated strongly with physical functioning (r = -0.56) and perceived health (r = -0.56), and moderately with depression (r = 0.41) and the Personal Wellbeing Index (r = -0.41). Exploratory factor analysis extracted five factors, explaining 44% of the variance.

CONCLUSIONS

The DBMA is an acceptable and valid instrument for measuring disease burden in older adults. Future studies should include Rasch analysis to further assess dimensionality and explore other measurement properties. Geriatr Gerontol 2017; 17: 1102-1108.

Design, measures and sample characteristics of the CadeViMa-Spain survey on quality of life in community-dwelling older adults

BACKGROUND

The survey "Quality of life in older adults-Spain" (CadeViMa-Spain) was designed to obtain information about objective and subjective determinants of Quality of Life (QoL) in old age, from a multidimensional perspective. This paper presents the overall description, methodology, sample characteristics and reliability of the measures used.

METHODS

A cross-sectional survey was carried out in a representative sample of 1106 community-dwelling adults aged 60 years and over in Spain. The sample was obtained by a geodemographically-based proportional multistage stratified sampling. A home-based questionnaire included validated scales and questions about sociodemographic characteristics, global QoL, health, family and social networks, financial means and retirement, leisure and social participation, residential environment, and satisfaction with those issues. Face-to-face semi-structured interviews were conducted. Cronbach's α coefficients were used to assess internal consistency of the scales.

RESULTS

This nationally representative survey furnishes information about global QoL, health-related QoL, resources availability, living conditions, and satisfaction with the assessed aspects, including life domains most valued by this group. In general, community-dwelling older adults reported positive assessments of health, living conditions, and high levels of satisfaction with the different aspects of QoL. The reliability of the measures in this population was good.

CONCLUSIONS

This survey provides comprehensive and useful information, based on the view of older people themselves, with potential to contribute to health and social policies towards promoting active aging. The database is available for in-depth comparisons.