ImportanceContinuous glucose monitoring (CGM) devices have demonstrated efficacy in adults and more recently in youths and older adults with type 1 diabetes. In adults with type 1 diabetes, the use of real-time CGM compared with intermittently scanned CGM was associated with improved glycemic control, but there are limited data available for youths.ObjectiveTo assess real-world data on achievement of time in range clinical targets associated with different treatment modalities in youths with type 1 diabetes.Design, Setting, and ParticipantsThis multinational cohort study included children, adolescents, and young adults younger than 21 years (hereinafter referred to collectively as youths) with type 1 diabetes for a duration of at least 6 months who provided CGM data between January 1, 2016, and December 31, 2021. Participants were enrolled from the international Better Control in Pediatric and Adolescent Diabetes: Working to Create Centers of Reference (SWEET) registry. Data from 21 countries were included. Participants were divided into 4 treatment modalities: intermittently scanned CGM with or without insulin pump use and real-time CGM with or without insulin pump use.ExposuresType 1 diabetes and the use of CGM with or without an insulin pump.Main Outcomes and MeasuresProportion of individuals in each treatment modality group achieving recommended CGM clinical targets.ResultsAmong the 5219 participants (2714 [52.0%] male; median age, 14.4 [IQR, 11.2-17.1] years), median duration of diabetes was 5.2 (IQR, 2.7-8.7) years and median hemoglobin A1c level was 7.4% (IQR, 6.8%-8.0%). Treatment modality was associated with the proportion of individuals achieving recommended clinical targets. Adjusted for sex, age, diabetes duration, and body mass index standard deviation score, the proportion achieving the recommended greater than 70% time in range target was highest with real-time CGM plus insulin pump use (36.2% [95% CI, 33.9%-38.4%]), followed by real-time CGM plus injection use (20.9% [95% CI, 18.0%-24.1%]), intermittently scanned CGM plus injection use (12.5% [95% CI, 10.7%-14.4%]), and intermittently scanned CGM plus insulin pump use (11.3% [95% CI, 9.2%-13.8%]) (P < .001). Similar trends were observed for less than 25% time above (real-time CGM plus insulin pump, 32.5% [95% CI, 30.4%-34.7%]; intermittently scanned CGM plus insulin pump, 12.8% [95% CI, 10.6%-15.4%]; P < .001) and less than 4% time below range target (real-time CGM plus insulin pump, 73.1% [95% CI, 71.1%-75.0%]; intermittently scanned CGM plus insulin pump, 47.6% [95% CI, 44.1%-51.1%]; P < .001). Adjusted time in range was highest among real-time CGM plus insulin pump users (64.7% [95% CI, 62.6%-66.7%]). Treatment modality was associated with the proportion of participants experiencing severe hypoglycemia and diabetic ketoacidosis events.Conclusions and RelevanceIn this multinational cohort study of youths with type 1 diabetes, concurrent use of real-time CGM and an insulin pump was associated with increased probability of achieving recommended clinical targets and time in range target as well as lower probability of severe adverse events compared with other treatment modalities.