Evidence mapPaperPMID 41915692Full record

ArticleJournal of medical Internet research2026

Designing a Carbohydrate Counting App for Young Adults With Type 1 Diabetes: Usability Testing Interview Study.

Asmaa Housni, Aidan Shulkin, Alexandra Katz, Giuliana Giannini, Amélie Roy-Fleming, Meranda Nakhla, Courtney South, Anne-Sophie Brazeau

Abstract read
In one paragraph

Article in Journal of medical Internet research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Asmaa HousniSchool of Human Nutrition, McGill University, 21,111 Lakeshore drive, Montreal, QC, H9V 1X9, Canada, 1 514-398-7848.ORCID http://orcid.org/0000-0002-6007-9641
Aidan ShulkinFaculté de médecine, Université de Montréal, Montreal, QC, Canada.ORCID http://orcid.org/0009-0000-1525-0350
Alexandra KatzInternal Medicine, McGill University, Montreal, QC, Canada.ORCID http://orcid.org/0000-0002-7137-6393
Giuliana GianniniSchool of Human Nutrition, McGill University, 21,111 Lakeshore drive, Montreal, QC, H9V 1X9, Canada, 1 514-398-7848.ORCID http://orcid.org/0009-0004-6434-5742
Amélie Roy-FlemingSchool of Human Nutrition, McGill University, 21,111 Lakeshore drive, Montreal, QC, H9V 1X9, Canada, 1 514-398-7848.ORCID http://orcid.org/0000-0001-9696-5592
Meranda NakhlaDivision of Endocrinology, Montreal Children's Hospital, Montreal, QC, Canada.ORCID http://orcid.org/0000-0001-5833-5303
Courtney SouthSchool of Human Nutrition, McGill University, 21,111 Lakeshore drive, Montreal, QC, H9V 1X9, Canada, 1 514-398-7848.ORCID http://orcid.org/0000-0001-8969-283X
Anne-Sophie BrazeauSchool of Human Nutrition, McGill University, 21,111 Lakeshore drive, Montreal, QC, H9V 1X9, Canada, 1 514-398-7848.ORCID http://orcid.org/0000-0002-2699-2920

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Carbohydrate counting (CC) assists people with type 1 diabetes (T1D) adjust mealtime insulin doses; however, it is often burdensome. Mobile apps can simplify this process by automating carbohydrate estimation and insulin calculations, yet no comprehensive solution currently combines photo-based carbohydrate recognition with an integrated bolus calculator. Objective: This study aimed to identify user-informed design principles from usability testing interviews to optimize a novel app supporting young adults with T1D in CC and insulin dosing. Methods: We conducted 4 iterative rounds of usability testing interviews, each with 3 to 5 participants, using a think-aloud protocol to evaluate how easily and effectively users interacted with the app and to identify areas for improvement. Interviews were analyzed qualitatively to derive main design principles, and findings from each round informed the refinement of the app prior to subsequent testing. Results: A total of 18 participants completed the usability testing (median age of 23, IQR 19-24 y and diabetes duration of 9, IQR 6-12 y; n=12, 66.7% young women). Thematic analysis highlighted that a person-centered design that prioritizes the lived experiences of youth with T1D was essential to position the app as a self-management support system, beyond a clinical tool. Personalization was central, including customizable treatment profiles, tailored dashboard metrics, esthetic preferences, and artificial intelligence-driven recommendations based on personal trends. Early usability barriers revealed the need for intuitive navigation, streamlined multistep processes, and clear guidance for data entry and interpretation. Participants valued culturally inclusive content and familiar terminology to enhance accessibility and engagement. Users perceived strong potential for the app to centralize diabetes management tasks, integrate contextual factors (eg, exercise, diet, and timing of insulin) with glucose data, generate sharable reports to facilitate patient-practitioner communication, and strengthen self-efficacy through personalized trend analysis. Concerns about over-reliance on automation underscored the necessity of transparent data verification and user override options to maintain trust in insulin dosing decisions. Conclusions: Iterative usability testing highlighted the importance of balancing automation with user control, personalization, and contextual understanding of personal trends, as key design principles to enhance engagement and the apps' relevance as a self-management tool. Incorporating these features into a CC and insulin-dosing app could improve self-efficacy in youth living with T1D.

Indexed as

Diabetes Mellitus, Type 1Dietary CarbohydratesMobile ApplicationsAdultFemaleHumansInsulinInterviews as TopicMaleUser-Computer InterfaceYoung AdultDietary CarbohydratesInsulincarbohydrate countingmobile appstype 1 diabetesusability testingyouth

Identifiers

PMID41915692
PMCPMC13037768

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.