Comprehensive clinical assessment of home-based older persons within New Zealand: an epidemiological profile of a national cross-section

Objective: Since 2012, all community care recipients in New Zealand have undergone a standardised needs assessment using the Home Care International Residential Assessment Instrument (interRAI-HC). This study describes the national interRAI-HC population, assesses its data quality and evaluates its ability to be matched. Methods: The interRAI-HC instrument elicits information on 236 questions over 20 domains; conducted by 1,800+ trained health professionals. Assessments between 1 July 2012 and 30 June 2014 are reported here. Stratified by age, demographic characteristics were compared to 2013 Census estimates and selected health profiles described. Deterministic matching to the Ministry of Health's mortality database was undertaken. Results: Overall, 51,232 interRAI-HC assessments were conducted, with 47,714 (93.1%) research consent from 47,236 unique individuals; including 2,675 Maori and 1,609 Pacific people. Apart from height and weight, data validity and reliability were high. A 99.8% match to mortality data was achieved. Conclusions: The interRAI-HC research database is large and ethnically diverse, with high consent rates. Its generally good psychometric properties and ability to be matched enhances its research utility. Implications: This national database provides a remarkable opportunity for researchers to better understand older persons' health and health care, so as to better sustain older people in their own homes.