A Comparison of Methods for Identifying Informal Carers: Self-Declaration Versus a Time Diary

Objectives Two main methods for identifying whether an individual is an informal carer are self-declaration and the use of a time diary. We analysed the level and predictors of agreement between these two methods among co-residential informal carers of adult recipients. Methods We used the 2014/15 UK Time Use Survey, which is a large-scale household survey for those aged 8 years old and over. It contains an individual questionnaire for self-declaration and a time diary for activity-based identification that records all activity in 10-min slots for two 24-h periods. Our analysis: (i) assesses the degree of overlap across approaches; (ii) explores the differences in characteristics between carers identified via one approach relative to non-carers using a bivariate probit estimator; and (iii) shows what factors are associated with being identified by both approaches using two independent probit estimators. Results Out of 6301 individuals, we identified 545 carers (8.6%) by at least one method and only 104 (19.1% of 545 carers) by both methods. We found similar factors predicted caregiving using either method but the magnitudes of the effects of these factors were larger for self-declared carers. Activity-based carers who provided more activities to a dependent adult and spent more time caregiving were more likely to also self-declare. Conclusions Our results show low levels of agreement between the two main methods used to identify informal carers. Any assessment of current caregiving research or future means to collect caregiving information should pay particular attention to the identification method as it may only relate to certain carer groups.