Day and night glycaemic control with a bionic pancreas versus conventional insulin pump therapy in preadolescent children with type 1 diabetes: a randomised crossover trial.

BACKGROUND: The safety and efficacy of continuous, multiday, automated glycaemic management has not been tested in outpatient studies of preadolescent children with type 1 diabetes. We aimed to compare the safety and efficacy of a bihormonal bionic pancreas versus conventional insulin pump therapy in this population of patients in an outpatient setting. METHODS: In this randomised, open-label, crossover study, we enrolled preadolescent children (aged 6-11 years) with type 1 diabetes (diagnosed for ≥1 year) who were on insulin pump therapy, from two diabetes camps in the USA. With the use of sealed envelopes, participants were randomly assigned in blocks of two to either 5 days with the bionic pancreas or conventional insulin pump therapy (control) as the first intervention, followed by a 3 day washout period and then 5 days with the other intervention. Study allocation was not masked. The autonomously adaptive algorithm of the bionic pancreas received data from a continuous glucose monitoring (CGM) device to control subcutaneous delivery of insulin and glucagon. Conventional insulin pump therapy was administered by the camp physicians and other clinical staff in accordance with their established protocols; participants also wore a CGM device during the control period. The coprimary outcomes, analysed by intention to treat, were mean CGM-measured glucose concentration and the proportion of time with a CGM-measured glucose concentration below 3·3 mmol/L, on days 2-5. This study is registered with ClinicalTrials.gov, number NCT02105324. FINDINGS: Between July 20, and Aug 19, 2014, 19 children with a mean age of 9·8 years (SD 1·6) participated in and completed the study. The bionic pancreas period was associated with a lower mean CGM-measured glucose concentration on days 2-5 than was the control period (7·6 mmol/L [SD 0·6] vs 9·3 mmol/L [1·7]; p=0·00037) and a lower proportion of time with a CGM-measured glucose concentration below 3·3 mmol/L on days 2-5 (1·2% [SD 1·1] vs 2·8% [1·2]; p<0·0001). The median number of carbohydrate interventions given per participant for hypoglycaemia on days 1-5 (ie, glucose <3·9 mmol/L) was lower during the bionic pancreas period than during the control period (three [range 0-8] vs five [0-14]; p=0·037). No episodes of severe hypoglycaemia were recorded. Medium-to-large concentrations of ketones (range 0·6-3·6 mmol/dL) were reported on seven occasions in five participants during the control period and on no occasion during the bionic pancreas period (p=0·063). INTERPRETATION: The improved mean glycaemia and reduced hypoglycaemia with the bionic pancreas relative to insulin pump therapy in preadolescent children with type 1 diabetes in a diabetes camp setting is a promising finding. Studies of a longer duration during which children use the bionic pancreas during their normal routines at home and school should be done to investigate the potential for use of the bionic pancreas in real-world settings. FUNDING: The Leona M and Harry B Helmsley Charitable Trust and the US National Institute of Diabetes and Digestive and Kidney Diseases.

Obtaining surrogate consent for a minimal-risk research study in the intensive care unit setting.

BACKGROUND: Obtaining surrogate consent for clinical research studies conducted in the intensive care unit (ICU) setting is logistically challenging. PURPOSE: To determine whether differences in proportions consenting to trial enrollment existed among patients eligible to consent directly versus those requiring surrogate decision makers in a minimal-risk study to evaluate the accuracy of continuous glucose monitoring in the ICU setting. METHODS: Low initial enrollment rates prompted a detailed tracking of the screening and consent process. We analyzed the subset of eligible patients identified during a single year to document whether they were approached about trial enrollment, whether they consented or declined, the reasons for declining, and the method of consent (self or surrogate). The proportion of participants who consented and the reasons for declining were compared for self-consenting and surrogate-consenting participants. RESULTS: Of the 3041 patients screened, one-third (n = 982) were eligible; 119 of the 982 were approached regarding enrollment. Absence of a surrogate accounted for the majority of eligible patients (726; 84%) not approached. The most common reasons for refusal in the self versus surrogate groups included feeling overwhelmed (13% vs 24%), fear of discomfort (22% vs 12%), and fear of risk (7% vs 4%). Of the 57 eligible patients capable of consenting directly, 11 (19%) enrolled versus 12 (19%) of the 62 who required surrogate consent. When recruitment hours were expanded to include evening time, more eligible patients or their surrogates could be approached than during the day-shift hours alone. Consent was obtained for a larger proportion of potential participants with a history of diabetes (40%) than for those without a history of diabetes (14%). LIMITATIONS: The findings are from a subset of the entire study sample; data were available only for participants who could be approached, who may have differed from those who could not be approached. CONCLUSIONS: Surrogate and self-consent rates were similar. Surrogate unavailability was a major barrier to enrollment; overlap of staffing with usual visiting hours should be considered when planning trials in the ICU.