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N/A (device / behavioral)CompletedACTRN12622001400752

CLOSE IT: open-source AID without meal announcement vs hybrid closed loop

What this study tests

A randomized trial in 73 adults compared an open-source AID system without meal announcement against the same system with meal announcement after a 12-week run-in. Final time in range was 66% versus 69% (adjusted difference −2.2 percentage points, 95% CI −6.2 to 1.7), within the protocol’s 7-point non-inferiority margin. The protocol still allowed specified rescue correction boluses. The accessible results abstract does not quantify severe hypoglycemia or DKA.

Editorial review: .

Most recent recorded citation date: 2026-02-12. Only explicit date metadata is included; an undated citation may be newer. This does not mean every claim was reviewed on that date.

Trial status, labels and access can change between reviews. How we review the evidence · How to read the evidence

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Evidence at a glance

Who can enter the study?
Adults aged 18–70 with T1D for more than 12 months. Participants could enter using injections or pump therapy and received training and a 12-week hybrid-closed-loop run-in before randomization. The protocol excluded recent severe hypoglycemia or DKA, pregnancy, and other specified conditions. Registered eligibility ↗Enrollment criteria describe who may enter. They do not establish who was analyzed or the denominator for a reported result.
Reported benefit and results
Seventy-three adults were randomized: 36 without meal announcement and 37 continuing hybrid closed loop. Time in range was 69 ± 11% at run-in end and 66 ± 8% at trial end without meal announcement, versus 70 ± 9% and 69 ± 13% with meal announcement. The adjusted difference was −2.2 percentage points (95% CI −6.2 to 1.7). This interval is within the protocol’s 7-point non-inferiority margin, but does not exclude a clinically relevant loss of time in range. Severe hypoglycemia and DKA counts are not reported in the accessible results abstract; the paywalled full results were not verified in this review.Read the result sources and their limitations →
Important harms
Read the reported results, safety discussion and original sources. A separate harms summary is not available; this does not establish safety.
Research access and approval
Study regions: Australia, Other regions. A trial listing does not establish product approval or current recruitment at a particular site. Check the study’s current entry requirements.
What remains uncertain?
Read the full discussion and original sources for study limitations. Planned endpoints and completion dates are not results.

Research status alone does not establish approval, clinical benefit or local availability.

Primary endpoints

  • Percentage of time in target glucose range (70-180 mg/dL; 3.9-10.0 mmol/L) over the final 14 days of the 12-week trial phase, adjusted for the same measure over the final 14 days of run-in

The full picture

What was tested

CLOSE IT compared a locked oref1 algorithm in the Lotus Android app, a Ypsomed pump and Dexcom G6 with and without meal announcement. Participants received training and completed a 12-week hybrid-closed-loop run-in before the 12-week randomized comparison. They did not need prior open-source AID experience to enter.2

The protocol specified NovoRapid in the main trial. Fiasp was studied separately in a subsequent extension. The no-announcement arm still permitted manual correction for symptomatic hyperglycemia or sensor glucose above 15 mmol/L for at least one hour; this was not a protocol banning every manual bolus.2

Results and limits

Of 73 randomized adults, 36 stopped meal announcement and 37 continued it. Final time in range (70–180 mg/dL) was 66 ± 8% versus 69 ± 13%, with an adjusted difference of −2.2 percentage points (95% CI −6.2 to 1.7). The primary measure used the last 14 days of each phase.4

The confidence interval stayed within the protocol’s 7-percentage-point non-inferiority margin. The protocol authors noted that this margin was larger than the 3-point margin recommended in a later consensus statement. This result does not establish equal glycemic performance or superiority without meal announcement.42

The accessible results abstract does not report severe hypoglycemia or DKA counts. Those safety outcomes remain unverified here because the full results article was not accessible. Evidence for this tested configuration does not establish the performance of every current AndroidAPS, Trio or other open-source build.42

Sources

  1. [1]
  2. [2]
    Study protocol for the CLOSE IT trial · Peer-reviewed study · 2024-02-20

    Wilkinson T, et al. CLOSE IT study protocol. BMJ Open (2024);14:e078171. Methods: run-in, trial phase, extension, eligibility and statistical considerations.

  3. [3]
  4. [4]

    Wilkinson T, et al. Glycemic Outcomes During Outpatient Use of Automated Insulin Delivery Without Meal Announcement in Adults with Type 1 Diabetes: Results from the CLOSE IT Randomized Controlled Trial. Diabetes Technology & Therapeutics (online 12 February 2026). https://doi.org/10.1177/15209156261423558