First Evidence on the Validity of the Complexity Index Derived from the Resident Assessment Instrument for Home Care in Home Care Patients

Objectives

Recently, a Complexity Index (CI), based on the multidimensional complexity model and derived from the Resident Assessment Instrument for Home Care (interRAI HC) was proposed as a decision-support tool to help frontline health care professionals in their clinical evaluation to identify and analyze complex situations. This study aims to test the CI: (1) concurrent validity with another measure of complexity (ie, the COMID), (2) convergent validity with related constructs assessed by interRAI HC scales (eg, depression), (3) divergent validity (comparison between CI-COMID and scales-COMID correlations), and (4) predictive validity on coordination meetings.

Design

A cross-sectional observational design was used for a secondary analysis of interRAI HC and COMID data collected in routine home care nursing practice (July-December 2021).

Setting and Participants

Participants were community-dwelling adults receiving home care, with full interRAI HC and COMID assessments (N = 3533).

Methods

Correlational analyses were conducted to test the concurrent validity of the CI (with the COMID) and the convergent and divergent validity of the CI (with interRAI HC_Switzerland scales, eg, Depression Rating Scale, Method for Assigning Priority Levels, and a Frailty Index). A receiver operating characteristic (ROC) analysis was conducted to test the discriminative ability of CI on specific professional team coordination meetings.

Results

Results showed that the CI correlated positively and strongly with the COMID (ρ = 0.691, P < .001, concurrent validity), positively with all the tested scales (P < .001, convergent validity), whereas the CI-COMID correlation was higher than the interRAI HC scales–COMID correlations (divergent validity). The ROC analysis showed the CI had a high area under the curve (AUC = 0.719, predictive validity).

Conclusions and Implications

The CI demonstrates good validity properties with a strong correlation with the COMID and a high predictive value for coordination meeting. It is distinct from the other interRAI HC scales and has its place among them to support the clinical analysis of complex situations.