Stratification of functional decline among community-dwelling COPD diagnosed older adults: the journey from independent to dependent-living environment (JIDE) score

Abstract

In New Zealand 77% of people aged over 65 dwell in the community. Ageing is associated with development of chronic health conditions such as Chronic Obstructive Pulmonary Disease (COPD). COPD exacerbates functional decline -- reduction in ability to perform self-care activities of daily living (ADL), putting them at higher risk of requiring residential care. A search of the international literature reveals that while there is research into COPD and associated functional decline, and general literature on functional decline and entry to residential care, there is no research that establishes the relationship between all three: COPD, functional decline and entry to residential care. While functional decline may be exacerbated by COPD, and functional decline in an elderly person leads to higher risk of entry to aged residential care, the inter-relationship between COPD, functional decline and entry to aged residential care is unknown.

The aim of this study was to address this ‘gap’ by first, assessing the independent impact of functional decline on transition to aged residential care (ARC) for community-dwelling older adults with COPD after adjustment for all other potential confounding variables, based on interRAI home care assessment data, and second, on the basis of the identified risk factors, develop a risk stratification score (Journey from Independent to Dependent-living Environment: JIDE). The data for this study were obtained from 10, 377 community-dwelling New Zealand residents 65 years and above who were diagnosed with COPD, and assessed between 1st July 2012 and 26th January, 2016.

Likelihood of entry to aged residential care facilities for the COPD cohort of individuals were modelled using a multivariable logistic regression. The regression coefficients from the explanatory model were then used to develop the JIDE score. The score discrimination was assessed using the receiver operating characteristic (ROC) curve in which the AUC value was 0.64 indicting a moderate predictive strength. The findings of the study suggest for the COPD cohort, functional decline in activities of daily living was an independent risk factor for entry to ARC (OR: 1.30 , 95% CI: 1.14-1.49). Other variables that were independently associated with risk of entry to ARC included: higher levels of cognitive impairment (OR:1.28 , 95% CI: 1.21-1.35), loneliness (OR:1.29 , 95% CI: 1.12-1.49), a history of falls (OR: 1.36, 95% CI:1.20- 1.54), being a Māori (OR: 0.39, 95% CI:0.30-0.50), being a Pasifika (OR: 0.16, 95% CI:0.08- 0.27) and lower frequency of pain (OR: 0.89, 95% CI:0.84-0.94). The JIDE composite score was used to categorise community-dwelling older adults into four risk levels: low, mild, moderate and high. The high group (OR: 3.54, 95% CI: 2.71-4.66) had almost four times as much risk of entering residential as the low group (OR: 1.0).

Underlying chronic conditions such as COPD impacts ADL performance levels. When ADL performance level declines, community-dwelling older adults with COPD have a potentially higher risk of moving into ARC. The JIDE score shows the severity of the risk an elderly with COPD is exposed to. Supportive health strategy, service delivery and care plans can be incorporated as part of a comprehensive clinical assessment.