Novel tool measures parent’s perceptions of obesity impact on child’s life quality

A parent-proxy, obesity-specific health-related quality of life (HRQoL) measure, Sizing Them Up (STU), demonstrates acceptable internal consistency, test-retest reliability, construct validity, and convergent validity in adolescents undergoing weight management treatment in Singapore, reports a study.

Factors significantly associated with STU scores include race, parental education level, and parental marital status.

“Knowing the demographic variables associated with STU can enable clinicians to identify adolescents whose HRQoL are disproportionately affected by obesity,” the researchers said.

Ninety-one adolescents aged 11‒17 years and their parents from KK Women’s and Children’s Hospital in Singapore were recruited in this study between June 2022 and January 2023. Upon recruitment, parents completed the STU and the generic Pediatric Quality of Life Inventory (PedsQL). They repeated STU at least 2 weeks later.

Majority of the participants (65 percent) were male, with a mean age of 13.6 years and mean BMI of 32.3 kg/m². [Proc Singap Healthc 2024;doi:10.1177/20101058241289617]

STU showed a robust internal consistency (overall Cronback’s α, 0.85) and moderate test-retest reliability (intraclass correlation coefficients, 0.30‒0.70). STU scores were strongly associated with BMI and equivalent domains of PedsQL, indicating moderate-to-strong construct and convergent validity, respectively.

Notably, Indian ethnicity, lower parental education levels, and solo parenthood significantly predicted poorer STU scores.

Racial difference

These findings support previous studies showing racial differences in parents’ reporting of their child’s HRQoL. [Obesity 2008;16:2624-2633; Ethn Dis 2014;24:321-327]

“However, unlike our findings of differences in scores between Indian and Chinese parents, a past local study showed that parents of Malay adolescents with obesity in the community scored their child more poorly on the PedsQL than their Chinese counterparts independent of BMI,” according to the researchers. [Qual Life Res 2010;19:167-176]

In the current study, 62 percent of participants were Chinese, 23 percent Malays, 10 percent Indians, and 5 percent other races. This racial breakdown differed from the ethnic composition of the population in Singapore (74 percent Chinese, 13.5 percent Malays, 9 percent Indians, 3.4 percent other races). [https://www.singstat.gov.sg/-/media/files/publications/population/population2023.ashx]

Overall, “[o]ur study demonstrated that STU has strong overall internal consistency, moderate test-retest reliability, good construct validity when correlated with the adolescents’ BMI, as well as strong convergent validity with PedsQL,” the researchers said.

Specifically, the test-retest reliability was relatively lower in the school behaviour scale, which was consistent in the STU validation in Taiwan. [Int J Clin Health Psychol 2018;18:81-89]

One potential reason for the lower reliability of the school behaviour scale was that test-retest intervals crossed into the school examination and holiday period for some respondents. This could have influenced parental perceptions of school participation.

“Further qualitative studies will be required to explain the relatively lower test-retest reliability and guide interpretations of the school behaviour scale,” the researchers said.

“All in all, our findings suggest that STU is a valid and reliable parent-proxy HRQoL tool which can potentially be applied in Singapore to quantify parents’ impression of the psychosocial complications of obesity in their child,” they added.