Performance of the Toddler and Infant (TANDI) Health-Related Quality of Life Instrument in 3-4-Year-Old Children.

The Toddler and Infant (TANDI) dimensions of Health-Related Quality of Life assess 'age appropriate' behaviour and measurement could be extended to older children. A sample of 203 children 3-4 years of age was recruited, and their caregivers completed the TANDI, Pediatric Quality of Life Inventory (PedsQL) and EQ-5D-Y Proxy. Spearman and Pearson's correlation coefficients, and Kruskal-Wallis H-test were used to explore the feasibility, known-group validity, discriminate validity and concurrent validity of the TANDI. Children with a health condition (n = 142) had a lower ceiling effect (p = 0.010) and more unique health profiles (p < 0.001) than the healthy group (n = 61). The TANDI discriminated between those with and without a health condition. In children with a health condition, the TANDI discriminated between clinician rated severity of the health condition. The TANDI had moderate to strong correlations with similar PedsQL and EQ-5D-Y items and scores. The TANDI is valid for children aged 3-4 years and is recommended for children with a health condition, whereas the PedsQL may be better for healthy children. The TANDI is recommended for studies with young children whereas the EQ-5D-Y Proxy is recommended for a sample including older children or for longitudinal studies with preschoolers. Further work on the TANDI is recommended to establish test-retest reliability and responsiveness.