The association of socioeconomic status and response to pediatric health behavior and lifestyle obesity treatment in Germany and Sweden: A multiyear, two-cohort observational study.

backgroundWhether socioeconomic status (SES) influences obesity treatment response among children remains unclear. This study aimed to examine the association between SES and response to health behavior and lifestyle pediatric obesity treatment over 3 years in two European countries. METHODS AND

findingsIn this two-cohort study, data were obtained from the Swedish Childhood Obesity Treatment Register (BORIS) and the German/Austrian/Swiss Adiposity Patients Register (APV). SES was divided into quintiles, using individual-level indicators as a composite index in Sweden and an area-level index in Germany. Treatment response was assessed as change in body mass index standard deviation score (BMI SDS) using linear mixed-effects models, obesity remission using Cox regression, and treatment discontinuation within six months using mixed-effects logistic regression. Analyses were stratified by country and adjusted for sex, baseline obesity class, age group, and migration background. Among 45,804 children with obesity who received health behavior and lifestyle obesity treatment, 31,293 (18,588 in Sweden and 12,705 in Germany) received at least six months of treatment. In both countries, higher baseline BMI SDS was associated with lower SES, <0.001. Associations between SES and change in BMI SDS differed between countries. In Sweden, SES was not associated with change in BMI SDS over time (p = 0.143). In Germany, higher SES was associated with greater reductions in BMI SDS (p < 0.001), with the largest decreases observed in the highest SES quintile after 2 years of treatment, -0.36 (95% CI [-0.38, -0.34]), sustained at 3 years (-0.34, 95% CI [-0.38, -0.29]). The difference in BMI SDS reduction between the highest and the lowest SES was greatest after 2 years, -0.12 (95% CI [-0.13, -0.12]) than after 3 years, -0.05 (95% CI [-0.07, -0.03]). Obesity remission showed a socioeconomic gradient in both countries, with higher adjusted probabilities in the highest versus lowest SES quintile (Sweden: 0.49 versus 0.37; Germany: 0.53 versus 0.45), corresponding to rate ratios of 1.63 (95% CI [1.44, 1.86]; p < 0.001) and 1.35 (95% CI [1.22, 1.50]; p < 0.001), respectively. Treatment discontinuation also differed by country. In Germany, higher SES compared to the lowest SES was associated with lower odds of discontinuation,OR of 0.82 (95% CI [0.74, 0.90]; p < 0.001), whereas no association was observed in Sweden. Residual confounding due to unavailable clinical and familial characteristics could not be ruled out.

conclusionsSES was associated with pediatric obesity treatment outcomes, but patterns differed between countries. While socioeconomic gradients in remission were observed in both settings, inequalities in BMI SDS reduction and treatment discontinuation were evident only in Germany, pointing to potential roles of both measurement differences and contextual factors.