# Heterogenous long-term health and social outcomes of type 1 diabetes: a full population 30-year observational cohort study

## TL;DR

This study examines how type 1 diabetes affects long-term health and social outcomes in Finland, finding that outcomes vary based on social and economic factors.

## Contribution

The study uses a full population cohort and causal forests to reveal heterogeneous effects of T1D across multiple domains.

## Key findings

- T1D individuals had higher rates of antidepressant use, being unpartnered, and lower income compared to controls.
- Outcomes varied by subgroup, with women and those from low socioeconomic backgrounds being particularly affected.
- Educational attainment was not significantly impacted by T1D.

## Abstract

Type 1 diabetes (T1D) is known to have adverse long-term health and social outcomes, but the modifying factors are largely unknown. We investigate to what extent T1D outcomes are modified by area-, household-, and individual-level social and economic characteristics in Finland. National registers from 1987 to 2020 were used to identify all 3048 children with T1D diagnosed at ages 7-17 years and matched controls (n = 78 883). Using causal forests, we estimated the average association between T1D and adult health, social, and economic outcomes at ages 28-30 years, and the modifying roles of more than 30 covariates. Individuals with T1D were more likely to be deceased (2.3% vs 0.9% in the control group), to use antidepressants (17% vs 13%), and to be unpartnered (36% vs 32%), and had more months of unemployment (1.18 vs 1.02) and lower annual income (25 697 euros vs 27 453 euros), but not significantly lower educational attainment (10.8% vs 10.3% with only basic education). Type 1 diabetes had a heterogenous association with all outcomes except mortality and income, but no specific population subgroup was vulnerable across all outcomes. However, women with T1D had particularly high rates of antidepressant use, and individuals from low socioeconomic families were more likely to be unpartnered.