Efficacy of automated insulin delivery (AID) systems in type 1 diabetes: protocol of a systematic review and network meta-analysis of outpatient randomised controlled trials.

INTRODUCTION: Automated insulin delivery (AID), also known as artificial pancreas system or 'closed-loop system', represents a novel option for current treatments for type 1 diabetes (T1D). The objective of this systematic review and meta-analysis is to assess the efficacy of AID systems in comparison with current intensified insulin therapy for glycaemic control and patient-reported outcomes in individuals with T1D. METHODS AND ANALYSIS: Studies will be eligible if they are randomised controlled trials (RCTs) in people with T1D of all ages, and if they compare an AID system for self-administration during the day and night period with any other type of insulin therapy for at least 3 weeks. The primary outcome will be time in the glucose target range of 70-180 mg/dL. A systematic review will be conducted in the MEDLINE, Embase, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov registries from their inception dates. Two authors will independently screen all references based on titles and abstracts against the eligibility criteria. For data extraction, standard forms will be developed and tested before extraction. All information will be assessed independently by at least two reviewers. The risk of bias of the included studies will be assessed using the Cochrane Risk of Bias 2 tool. The data synthesis will include a random-effects pairwise and network meta-analysis (NMA) in a frequentist framework. Where applicable and if sufficient RCTs are available, sensitivity analyses will be performed, and heterogeneity and publication bias will be assessed. The certainty of evidence from the NMA will be evaluated following the Grading of Recommendations Assessment, Development, and Evaluation working group guidance. ETHICS AND DISSEMINATION: No ethical approval is needed. The results will be reported to the funder, presented in a peer-reviewed scientific journal and at conferences, and disseminated via press release, social media and public events. PROSPERO REGISTRATION NUMBER: CRD42023395492.

Incidence, prevalence and care of type 1 diabetes in children and adolescents in Germany: Time trends and regional socioeconomic situation.

Background: Trends over time and possible socio-spatial inequalities in the incidence and care of type 1 diabetes mellitus (T1D) in children and adolescents are important parameters for the planning of target-specific treatment structures. Methodology: The incidence and prevalence of type 1 diabetes, diabetic ketoacidosis and severe hypoglycaemia as well as the HbA1c value are presented for under 18-year-olds based on data from the nationwide Diabetes Prospective Follow-up Registry (DPV) and the diabetes registry of North Rhine-Westphalia. Indicators were mapped by sex over time between 2014 and 2020, and stratified by sex, age and regional socioeconomic deprivation for 2020. Results: In 2020, the incidence was 29.2 per 100,000 person-years and the prevalence was 235.5 per 100,000 persons, with the figures being higher in boys than in girls in either case. The median HbA1c value was 7.5%. Ketoacidosis manifested in 3.4% of treated children and adolescents, significantly more often in regions with very high (4.5%) deprivation than in regions with very low deprivation (2.4%). The proportion of severe hypoglycaemia cases was 3.0%. Between 2014 and 2020, the incidence, prevalence and HbA1c levels changed little, while the proportions of ketoacidosis and severe hypoglycaemia decreased. Conclusions: The decrease in acute complications indicates that type 1 diabetes care has improved. Similar to previous studies, the results suggest an inequality in care by regional socioeconomic situation.

Is COVID-19 to Blame? Trends of Incidence and Sex Ratio in Youth-Onset Type 2 Diabetes in Germany.

OBJECTIVE: We investigated the incidence of pediatric type 2 diabetes (T2D) in Germany during 2 years of the coronavirus disease 2019 (COVID-19) pandemic (2020-2021) compared with the control period 2011-2019. RESEARCH DESIGN AND METHODS: Data on T2D in children (aged 6 to <18 years) were obtained from the DPV (German Diabetes Prospective Follow-up) Registry. Poisson regression was used to estimate incidences for 2020 and 2021 based on data from 2011 to 2019, and these were compared with observed incidences in 2020 and 2021 by estimating incidence rate ratios (IRRs) with 95% CIs. RESULTS: Incidence of youth-onset T2D increased from 0.75 per 100,000 patient-years (PYs) in 2011 (95% CI 0.58, 0.93) to 1.25 per 100,000 PYs in 2019 (95% CI 1.02, 1.48), an annual increase of 6.8% (95% CI 4.1, 9.6). In 2020, T2D incidence increased to 1.49 per 100,000 PYs (95% CI 1.23, 1.81), which was not significantly higher than predicted (IRR 1.15; 95% CI 0.90, 1.48). In 2021, the observed incidence was significantly higher than expected (1.95; 95% CI 1.65, 2.31 vs. 1.38; 95% CI 1.13, 1.69 per 100,000 PYs; IRR 1.41; 95% CI 1.12, 1.77). Although there was no significant increase in incidence in girls in 2021, the observed incidence in boys (2.16; 95% CI 1.73, 2.70 per 100,000 PYs) significantly exceeded the predicted rate (IRR 1.55; 95% CI 1.14, 2.12), leading to a reversal of the sex ratio of pediatric T2D incidence. CONCLUSIONS: In Germany, incidence of pediatric T2D increased significantly in 2021. Adolescent boys were more affected by this increase, resulting in a reversal of the sex ratio of youth-onset T2D.

Common procedures and conditions leading to inpatient hospital admissions in adults with and without diabetes from 2015 to 2019 in Germany : A comparison of frequency, length of hospital stay and complications.

OBJECTIVE: To evaluate common surgical procedures and admission causes in inpatient cases with diabetes in Germany between 2015 and 2019 and compare them to inpatient cases without diabetes. METHODS: Based on the German diagnosis-related groups (G-DRG) statistics, regression models stratified by age groups and gender were used to calculate hospital admissions/100,000 individuals, hospital days as well as the proportion of complications and mortality in inpatient cases ≥ 40 years with or without a documented diagnosis of diabetes (type 1 or type 2). RESULTS: A total of 14,222,326 (21%) of all inpatient cases aged ≥ 40 years had a diagnosis of diabetes. More middle-aged females with vs. without diabetes/100,000 individuals [95% CI] were observed, most pronounced in cases aged 40-< 50 years with myocardial infarction (305 [293-319] vs. 36 [36-37], p < 0.001). Higher proportions of complications and longer hospital stays were found for all procedures and morbidities in cases with diabetes. CONCLUSION: Earlier hospitalizations, longer hospital stays and more complications in inpatient cases with diabetes together with the predicted future increase in diabetes prevalence depict huge challenges for the German healthcare system. There is an urgent need for developing strategies to adequately care for patients with diabetes in hospital.

Comparison of diabetes distress and depression screening results of emerging adults with type 1 diabetes onset at different ages: findings from the German early-onset T1D study and the German Diabetes Study (GDS).

BACKGROUND: Diabetes distress is increasingly considered one of the most important psychosocial issues in the care of people with type 1 diabetes (T1D). We analyse whether diabetes distress and depression screening results of emerging adults are associated with the age at T1D onset. METHODS: Data were taken from two cohort studies conducted at the German Diabetes Center, Düsseldorf, Germany. The 18-30-year-old participants had an age at onset either before the age of 5 years (childhood-onset long-term T1D study group, N = 749) or during adulthood (adult-onset short-term T1D study group from the German Diabetes Study (GDS), N = 163). Diabetes distress and depression screening were analysed by means of the 20-item Problem Areas in Diabetes (PAID-20) scale and the nine-item depression module from the Patient Health Questionnaire (PHQ-9). The average causal effect of age at onset was estimated by a doubly robust causal inference method. RESULTS: The PAID-20 total scores were increased in the adult-onset study group [potential outcome mean (POM) 32.1 (95% confidence interval 28.0; 36.1) points] compared to the childhood-onset study group [POM 21.0 (19.6; 22.4) points, difference 11.1 (6.9; 15.3) points, p<0.001] adjusted for age, sex and haemoglobin A1c (HbA1c) levels. Moreover, more participants in the adult-onset group [POM 34.5 (24.9; 44.2) %] than in the childhood-onset group [POM 16.3 (13.3; 19.2) %] screened positive for diabetes distress [adjusted difference 18.3 (8.3; 28.2) %, p<0.001]. The PHQ-9 total score [difference 0.3 (-1.1; 1.7) points, p=0.660] and the proportion of participants with a positive screening result for depression [difference 0.0 (-12.7; 12.8) %, p=0.994] did not differ between the groups in the adjusted analyses. CONCLUSIONS: Emerging adults with short-term type 1 diabetes screened positive for diabetes distress more often than adults with type 1 diabetes onset during early childhood when age, sex and HbA1c values were considered confounding factors. Accounting for age at onset or the duration of diabetes may help explain the heterogeneity in the data when psychological factors are examined.

Changes in cardiovascular risk factors among children and young adults with type 1 diabetes during the COVID-19 pandemic compared to previous years-Results from the German DPV registry.

BACKGROUND: The diverse stages of the COVID-19 pandemic led to several social circumstances that influenced daily life and health behavior. PURPOSE: To evaluate changes in cardiovascular risk factors and physical activity among children and young adults with type 1 diabetes (T1D) during the COVID-19 pandemic in Germany compared to previous years. METHODS: A total of 32 785 individuals aged 6-21 years at baseline with T1D from the German diabetes patient follow-up (DPV) registry contributed data on 101 484 person-years between 2016 and 2021. The first treatment year of each individual within this period was considered as baseline. Based on trends from 2016 to 2019, we estimated differences in body mass index-SD score (BMI-SDS), blood pressure (BP-SDS), and lipid levels (non-high-density lipoprotein [non-HDL]) between observed and predicted estimates for the years 2020 and 2021 using linear regression analysis standardized for age, diabetes duration, sex, and migratory background. The proportion doing organized sports and smoking cigarettes was analyzed using multivariable logistic regression models. RESULTS: BMI-SDS increased constantly from 2016 to 2021 without a significant increase above expected values for 2020/2021. Systolic BP-SDS (difference observed vs. expected with 95% confidence interval, 2020: 0.10 [0.07-0.14], 2021: 0.17 [0.14-0.20]) and non-HDL (2020: 2.7 [1.3-4.1] mg/dl, 2021: 4.1 [2.7-5.5] mg/dl) were significantly increased (all p < .001) in both pandemic years. The proportion of subjects participating in organized sports was reduced from over 70% in prepandemic years to 35%-65% in diverse stages/waves of the COVID-19 pandemic. The percentage smoking cigarettes did not change. CONCLUSIONS: We describe an increase in BP and atherogenic lipid levels coinciding with a reduction in physical activity but no acceleration of the prepandemic increases in BMI-SDS among young people with T1D during the COVID-19 pandemic.

Spatiotemporal association between COVID-19 incidence and type 1 diabetes incidence among children and adolescents: a register-based ecological study in Germany.

Objective: Studies have shown an increased incidence of pediatric type 1 diabetes during the COVID-19 pandemic, but the detailed role of SARS-CoV-2 infection in the incidence increase in type 1 diabetes remains unclear. We investigated the spatiotemporal association of pediatric type 1 diabetes and COVID-19 incidence at the district level in Germany. Methods: For the period from March 2020 to June 2022, nationwide data on incident type 1 diabetes among children and adolescents aged <20 years and daily documented COVID-19 infections in the total population were obtained from the German Diabetes Prospective Follow-up Registry and the Robert Koch Institute, respectively. Data were aggregated at district level and seven time periods related to COVID-19 pandemic waves. Spatiotemporal associations between indirectly standardized incidence rates of type 1 diabetes and COVID-19 were analyzed by Spearman correlation and Bayesian spatiotemporal conditional autoregressive Poisson models. Results: Standardized incidence ratios of type 1 diabetes and COVID-19 in the pandemic period were not significantly correlated across districts and time periods. A doubling of the COVID-19 incidence rate was not associated with a significant increase in the incidence rate of type 1 diabetes (relative risk 1.006, 95% CI 0.987; 1.019). Conclusion: Our findings based on data from the pandemic period indirectly indicate that a causal relationship between SARS-COV-2 infection and type 1 diabetes among children and adolescents is unlikely.

Prevalence of type 1 and type 2 diabetes in children and adolescents in Germany from 2002 to 2020: A study based on electronic health record data from the DPV registry.

BACKGROUND: To provide estimates of the nationwide prevalence of type 1 diabetes (T1D) and type 2 diabetes (T2D) in individuals younger than 20 years of age in Germany from 2002 to 2020 and to identify trends. METHODS: Data were obtained from the electronic health record "Diabetes Prospective Follow-up Registry (DPV)" specific to diabetes care. Prevalence was estimated based on prevalent cases at the end of each year for the years 2002, 2008, 2014, and 2020 per 100 000 persons assuming a Poisson distribution and directly age- and/or sex-standardized to the population in 2020. Individuals younger than 20 years of age with a clinical diagnosis of T1D or 10-19-year-olds with T2D were eligible for inclusion in the study. RESULTS: The standardized T1D prevalence per 100 000 persons was 138.9 (95% CI: 137.1; 140.6) in 2002 and 245.6 (243.1; 248.0) in 2020. The standardized T2D prevalence per 100 000 persons was 3.4 (3.1; 3.8) in 2002 and 10.8 (10.1; 11.5) in 2020. The annual percent change (APC) in prevalence declined over the three periods 2002-2008/2008-2014/2014-2020 (T1D: 6.3% [3.6%; 9.0%]/3.1% [0.7%; 5.5%]/0.5% [-1.7%; 2.85], T2D: 12.3% [5.3%; 20.8%]/4.7% [-0.6%; 10.3%]/3.0% [-1.8%; 8.0%]). From 2014 to 2020, the highest APCs were observed among 15-19-year-olds (T1D: 2.5% [1.3%; 3.6%], T2D: 3.4% [-0.5%; 7.5%]). CONCLUSIONS: The increase in diabetes prevalence has slowed, but medical care should be prepared for an increase in adolescents with diabetes.

Type 1 diabetes incidence in children and adolescents during the COVID-19 pandemic in Germany.

AIMS/HYPOTHESIS: The aim of this study was to analyze the incidence of type 1 diabetes in children and adolescents (<20 years of age) during the COVID-19 pandemic (3/2020 to 12/2021) in Germany. METHODS: The present study was based on the IQVIA longitudinal prescription database (LRx), All persons (age ≤ 20 years) with new insulin prescriptions from 2016 to 2021 (index date) were selected and stratified by age group. Weekly (age-specific) data were used to forecast the prescription incidence for the pandemic period based on pre-pandemic data and to explore the relationship between weekly reported age-specific COVID-19 incidences and type 1 diabetes incidence and rate ratios of observed vs. predicted diabetes incidence respectively. RESULTS: During the pre-pandemic period, there was a stable higher insulin prescription incidence during the winter period and a lower insulin prescription incidence during summer. During the pandemic period, there was less seasonal variation in incidence related to the finding that the observed incidence during summer in 2002 and 2021 was 44 % and 65 %, higher, respectively, than the expected incidence based on pre-pandemic year. We did not find any cross-correlations between the COVID-19 incidence and the type 1 diabetes incidence for any age group. Likewise, there were no cross-correlations between the COVID-19 incidence and the incidence rate ratios of observed incidences to predicted incidences. CONCLUSIONS/INTERPRETATION: During the COVID-19 pandemic, there was less seasonal variation in the incidence of type 1 diabetes (defined by new insulin prescriptions), with higher observed than expected incidences during summer. We found no evidence that the increase in type 1 diabetes incidence during the COVID-19 pandemic relates to direct effects of COVID-19 pandemic.

Hospitalisation rate and mortality among people with and without diabetes during the COVID-19 pandemic year 2020.

Most studies reported reduced health care use among people with diabetes during the COVID-19 pandemic. This may be due to restricted medical services or people avoiding health care services because they fear being infected with COVID-19 in health care facilities. The aim of our study was to analyse hospitalisation and mortality in people with and without diabetes in Germany during the COVID-19 pandemic year 2020 compared to 2017-2019. The data were sourced from a German statutory health insurance company covering 3.2 million people. We estimated age-sex standardised rates of mortality, all-cause hospitalisation, hospitalisation due to coronary heart disease (CHD), acute myocardial infarction (AMI), stroke, diabetic foot syndrome (DFS), and major and minor amputations in people with and without diabetes. We predicted rates for 2020 using Poisson regression based on results from 2017-2019 and compared these with the observed rates.In people with diabetes, the hospitalisation rate for major amputation was significantly increased, while all-cause hospitalisation rate and hospitalisation due to CHD, AMI and DFS were significantly decreased compared to the previous period. Moreover, we found a significantly increased mortality and hospitalisation rate for minor amputation in people without diabetes while all-cause hospitalisation and hospitalisation due to CHD and AMI was significantly lower during the COVID-19 pandemic year 2020.We observed changes in health care utilisation and outcomes during the COVID-19 pandemic compared to previous years in people with and without diabetes. Concerning diabetes care, the increase of hospitalisations due to amputation in people with diabetes with a simultaneous reduction in DFS needs special attention.

Comorbidities in Recent-Onset Adult Type 1 Diabetes: A Comparison of German Cohorts.

Aims: Restrictive exclusion criteria from different study populations may limit the generalizability of the observations. By comparing two differently designed German cohorts, we assessed the prevalence of cardiovascular risk factors and diabetes-related complications in recent-onset adult type 1 diabetes. Methods: This study evaluated 1511 persons with type 1 diabetes of the prospective diabetes follow-up registry (DPV) and 268 volunteers of the prospective observational German Diabetes Study (GDS) with a known diabetes duration <1 year. Participants had similar age (36 years), sex distribution (41% female) and BMI (26 kg/m2) in both cohorts. Results: The average HbA1c was 6.4 ± 0.8% in the GDS and 7.0 ± 1.1% in the DPV. Prevalence of hypertension (24%) was similar, while more DPV participants had dyslipidemia and lipid-lowering medication than GDS participants (77% vs. 41% and 7% vs. 2%, respectively; p<0.05). Prevalence of retinopathy and nephropathy was higher in DPV compared to GDS participants (10% vs. 3% and 18% vs. 7%, respectively; p<0.001). Conclusions: Diabetic nephropathy and retinopathy are the most frequent complications in type 1 diabetes, affecting up to every 10th patient within the first year after diagnosis, underlining the need for more stringent risk factor management already at the time of diagnosis of type 1 diabetes.

Frequency of Ketoacidosis at Diagnosis of Pediatric Type 1 Diabetes Associated With Socioeconomic Deprivation and Urbanization: Results From the German Multicenter DPV Registry.

OBJECTIVE: To investigate whether socioeconomic deprivation and urbanization are associated with the frequency of diabetic ketoacidosis (DKA) at diagnosis of pediatric type 1 diabetes. RESEARCH DESIGN AND METHODS: Children and adolescents aged ≤18 years, living in Germany, with newly diagnosed type 1 diabetes documented between 2016 and 2019 in the Diabetes Prospective Follow-up Registry (DPV; Diabetes-Patienten-Verlaufsdokumentation), were assigned to a quintile of regional socioeconomic deprivation (German Index of Socioeconomic Deprivation) and to a degree of urbanization (Eurostat) by using their residence postal code. With multiple logistic regression models, we investigated whether the frequency of DKA at diagnosis was associated with socioeconomic deprivation or urbanization and whether associations differed by age-group, sex, or migration status. RESULTS: In 10,598 children and adolescents with newly diagnosed type 1 diabetes, the frequency of DKA was lowest in the least deprived regions (Q1: 20.6% [95% CI 19.0-22.4], and increased with growing socioeconomic deprivation to 26.9% [25.0-28.8] in the most deprived regions [Q5]; P for trend <0.001). In rural areas, the frequency of DKA at diagnosis was significantly higher than in towns and suburbs (intermediate areas) or in cities (27.6% [95% CI 26.0-29.3] vs. 22.7% [21.4-24.0], P < 0.001, or vs. 24.3% [22.9-25.7], P = 0.007, respectively). The results did not significantly differ by age-group, sex, or migration background or after additional adjustment for socioeconomic deprivation or urbanization. CONCLUSIONS: This study provides evidence that prevention of DKA at diagnosis by means of awareness campaigns and screening for presymptomatic type 1 diabetes should particularly target socioeconomically disadvantaged regions and rural areas.

Impact of applying a diabetes risk score in primary care on change in physical activity: a pragmatic cluster randomised trial.

AIM: There is little evidence of the impact of diabetes risk scores on individual diabetes risk factors, motivation for behaviour changes and mental health. The aim of this study was to investigate the effect of applying a noninvasive diabetes risk score in primary care as component of routine health checks on physical activity and secondary outcomes. METHODS: Cluster randomised trial, in which primary care physicians (PCPs), randomised (1:1) by minimisation, enrolled participants with statutory health insurance without known diabetes, ≥ 35 years of age with a body mass index ≥ 27.0 kg/m2. The German Diabetes Risk Score was applied as add-on to the standard routine health check, conducted in the controls. Primary outcome was the difference in participants' physical activity (International Physical Activity Questionnaire) after 12 months. Secondary outcomes included body mass index, perceived health, anxiety, depression, and motivation for lifestyle change. Analysis was by intention-to-treat principle using mixed models. RESULTS: 36 PCPs were randomised; remaining 30 PCPs (intervention: n = 16; control: n = 14) recruited 315 participants (intervention: n = 153; controls: n = 162). A slight increase in physical activity was observed in the intervention group with an adjusted mean change of 388 (95% confidence interval: - 235; 1011) metabolic equivalents minutes per week. There were no relevant changes in secondary outcomes. CONCLUSIONS: The application of a noninvasive diabetes risk score alone is not effective in promoting physical activity in primary care. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT03234322, registration date: July 31, 2017).

Glycated hemoglobin at diagnosis of type 1 diabetes and at follow-up in children and adolescents during the COVID-19 pandemic in Germany.

BACKGROUND: This study investigated the diagnostic delay and the subsequent quality of care during the Covid-19 pandemic among children with new-onset type 1 diabetes. METHODS: We compared the HbA1c levels of 3111 children at diagnosis of type 1 diabetes and of 2825 children at a median follow-up of 4.7 months (interquartile range, 4.1-5.4) together with their daily insulin requirement during the Covid-19 pandemic with the two previous years via multivariable linear regression, using data from the German Diabetes Registry DPV. RESULTS: During the Covid-19 pandemic, HbA1c levels were higher at diagnosis of type 1 diabetes (mean estimated difference, 0.33% [95% confidence interval, 0.23-0.43], p < 0.001), but not at follow-up (mean estimated difference, 0.02% [-0.02-0.07]). Children with diabetes onset during the Covid-19 pandemic had a significantly higher daily insulin requirement after initiation of therapy (mean estimated difference, 0.08 U/kg [0.06-0.10], p < 0.001). Both the increase in HbA1c and daily insulin requirement were evident only after the first wave of the pandemic. CONCLUSIONS: This increase in HbA1c at diagnosis of type 1 diabetes during the Covid-19 pandemic may indicate a delay in seeking medical care due to the pandemic. However, this did not affect short-term glycemic control. The increased insulin requirement at follow-up could suggest a more rapid autoimmune progression during the pandemic.

Family Structure is Associated with Mental Health and Attention Deficit (Hyperactivity) Disorders in Adolescents with Type 1 Diabetes.

OBJECTIVE: To analyze the cross-sectional associations of family structure with mental health and attention deficit (hyperactivity) disorders (AD(H)D) in 11- to 17-year-old adolescents with early-onset type 1 diabetes participating in one of three baseline surveys as part of an ongoing cohort study. METHODS: Parents (n=1,631) completed the Strengths and Difficulties Questionnaire to screen for their child's mental health and answered questions about their child's diagnosis of AD(H)D. Associations between mental health or AD(H)D and family structure were analyzed using multivariable logistic regression analyses adjusted for various personal and diabetes-related variables. RESULTS: Compared to adolescents living with both parents, adolescents living with one parent and his/her partner had 2.35 (95% confidence interval 1.32; 4.21) higher odds of abnormal screening result and 2.08 (1.09; 3.95) higher odds of a borderline screening result while adolescents living with a single parent had 1.84 (1.07; 3.17)/1.08 (0.53; 2.21) higher odds of abnormal/borderline screening results. The odds ratios for diagnosed attention deficit (hyperactivity) disorder were 2.17 (0.98; 4.84) for adolescents living with one parent and his/her partner and 1.27 (0.54; 3.01) for those living with a single parent vs. both parents. CONCLUSIONS: Our results indicate higher odds of mental health problems and AD(H)D in adolescents with type 1 diabetes who do not live with both parents; this finding was most pronounced in individuals living with one parent and his/her partner vs. both parents. Longitudinal studies are needed to verify our results and elucidate the underlying mechanisms.

Overestimation and underestimation of youths' health-related quality of life are associated with youth and caregiver positive screens for depression: results of a population-based study among youths with longstanding type 1 diabetes.

BACKGROUND: This study aimed to analyze the extent and direction of disagreement between self- and proxy-reported quality of life (QoL) and the factors associated with QoL overestimation and underestimation by caregivers compared with self-reports. METHODS: This study used data from population-based questionnaire surveys conducted in 2012-2013 and 2015-2016 with 11- to 17-year-olds with a duration of type 1 diabetes of 10 years or longer and their caregivers (n = 1058). QoL in youth was assessed via 10-item KIDSCREEN (KIDSCREEN-10) self- and proxy-reported questionnaires. The scores ranged from 0 to 100, with higher scores indicating better QoL. Depression screening was performed via the Center for Epidemiological Studies Depression Scale for Children for youths (CES-DC screen positive: score > 15) and WHO-5 Well-being Index for parents/caregivers (WHO-5 screen positive: score ≤ 50). RESULTS: The mean self- and proxy-reported normalized KIDSCREEN-10 scores were 64.2 (standard deviation [SD] 11.4) and 66.1 (11.5), respectively. More caregivers overestimated (self-reported minus proxy-reported score < - 0.5*SD self-reported score) than underestimated (self-reported minus proxy-reported score > 0.5*SD self-reported score) youths' QoL (37% versus 23%, p < 0.001). Youths who screened positive for depression (18%) were at higher risk of their QoL being overestimated and lower risk of their QoL being underestimated by caregivers than youths who screened negative for depression (RROverestimation 1.30 [95% CI 1.10-1.52], RRUnderestimation 0.27 [0.15-0.50]). Caregivers who screened positive for depression (28%) overestimated the QoL of their children less often and underestimated the QoL of their children more often than caregivers who screened negative for depression (RROverestimation 0.73 [0.60-0.89], RRUnderestimation 1.41 [1.14-1.75]). CONCLUSIONS: Caregivers often over- or underestimated their children's QoL. Positive screens for depression among both youths and caregivers contributed to the observed differences between self- and caregiver-reported QoL.