Development and validation of risk of CPS decline (RCD): a new prediction tool for worsening cognitive performance among home care clients in Canada

Abstract

Background: To develop and validate a prediction tool, or nomogram, for the risk of a decline in cognitive performance based on the interRAI Cognitive Performance Scale (CPS).

Methods: Retrospective, population-based, cohort study using Canadian Resident Assessment Instrument for Home Care (RAI-HC) data, collected between 2010 and 2018. Eligible home care clients, aged 18+, with at least two assessments were selected randomly for model derivation (75%) and validation (25%). All clients had a CPS score of zero (intact) or one (borderline intact) on intake into the home care program, out of a possible score of six. All individuals had to remain as home care recipients for the six months observation window in order to be included in the analysis. The primary outcome was any degree of worsening (i.e., increase) on the CPS score within six months. Using the derivation cohort, we developed a multivariable logistic regression model to predict the risk of a deterioration in the CPS score. Model performance was assessed on the validation cohort using discrimination and calibration plots.

Results: We identified 39,292 eligible home care clients, with a median age of 79.0 years, 62.3% were female, 38.8% were married and 38.6% lived alone. On average, 30.3% experienced a worsening on the CPS score within the six-month window (i.e., a change from 0 or 1 to 2, 3, 4, 5, or 6). The final model had good discrimination (c-statistic of 0.65), with excellent calibration.

Conclusions: The model accurately predicted the risk of deterioration on the CPS score over six months among home care clients. This type of predictive model may provide useful information to support decisions for home care clinicians who use interRAI data internationally.

Plain Language Summary

It is important to sort out who has early signs of cognitive impairment such as memory trouble or problems with making decisions. It is important since some people with early signs of cognitive decline will get worse and develop dementia. We set out to create and test a new tool to predict a person’s risk of getting worse in terms of their cognitive functioning. We focused on people who were getting home care across Canada. Each person’s cognitive performance was measured by a trained assessor using a standard measure, called the Cognitive Performance Scale. We followed about 40,000 people who had no trouble based on the Cognitive Performance Scale score, or who had only mild issues. They were followed for up to six months to see if their cognitive performance changed or not. The group we followed were 79 years of age on average, about 60% were female, and around 40% of people were married. After six months, we saw that about 30% of them got worse on the Cognitive Performance Scale score. This was the same for men and for women. A number of statistics were used to see how well this new prediction tool was working. We found that it worked quite well to predict who would get worse over six months. The group who had the highest risk of getting worse included people who were older, who had Parkinson’s disease, who had experienced a stroke, were lonely, or who had recently fallen. This type of prediction tool can help health care professionals working in home care. They have to make important choices about the type of care that the person should receive to best meet their needs. This new tool can guide them as they make these vital decisions.