Joanne Blair: What is the most effective way to deliver subcutaneous insulin—pumps or injections?

The SCIPI study was developed between 2007 and 2010, a period of soul searching among British paediatric diabetes healthcare professionals. Glycaemic control was poorer in the United Kingdom than in other European countries and in North America, where insulin pumps were used more frequently. Observational and anecdotal data, and a small number of randomised controlled trials suggested a link between superior glycaemic control and insulin pump use, offering clinicians the prospect of improving patient outcomes through enhanced insulin pump use. [1] Soon recommendations for insulin pump therapy were published by NICE and pump therapy was adopted widely to routine clinical practice.

However, to the SCIPI investigators’ knowledge, there were no robust data to support the widespread introduction of costly insulin pump therapy. Published data from clinical studies were subject to considerable bias. It was also unclear whether it was the mode of insulin delivery that made the difference, or the other elements of the insulin pump package such as enhanced education, intensification of blood glucose monitoring and insulin dose titration, and increased healthcare professional support.

To address these gaps in the evidence base we performed the SCIPI study.

During the lifetime of the study, a number of new observations were reported in the insulin pump literature, including a clear association between deprivation, ethnicity, and insulin pump use. The most deprived patients and those from ethnic minority groups were less likely to be treated with insulin pump therapy than those from more affluent families or white children. This observation was reported across multiple countries and healthcare settings. [2-6] A dose dependent effect of deprivation on glycaemic control was also reported, with the most deprived patients having the poorest glycaemic control. [6,7] Poorer glycaemic control was also reported in those from ethnic minority groups. [5,6]

The SCIPI study found that paediatric patients treated in the NHS setting during the first year of diagnosis did not experience better outcomes than those treated with multiple daily injections, however treatment was more expensive. We therefore concluded that, in this treatment paradigm, insulin pump therapy is not cost effective.

Advances in insulin pump technology, a qualitative approach to the assessment of quality of life, or observation over a longer period of time, may reveal benefits to insulin pump therapy that were not evident in the SCIPI trial. It may also be that patients with greater experience in the management of diabetes could use insulin pump therapy to greater effect than newly diagnosed patients. Alternatively, it may be that important areas of bias inherent in observational studies and previous clinical trials were addressed in the design of the SCIPI trial, which randomised treatment allocation and ensured equitable education in the management of diabetes and healthcare professional support across treatment arms. This may account, in part, for the reasons why we did not demonstrate superiority of insulin pump therapy.

Our study is modest, lasting only for one year, and our challenge is now to map the trajectories of study participants over the first ten years of treatment, to determine whether the critical first year of treatment has influenced their longer term outcomes.

However, we would suggest that the findings of the SCIPI study raise much broader questions about the adoption of expensive therapies to a resource limited healthcare setting, ahead of robust data reporting benefit. Our health economics evaluation led us to speculate on the practice of selective distribution of expensive insulin pump therapy to more advantaged patients, possibly diverting healthcare expenditure away from the most vulnerable, even in healthcare settings with universal funding. The SCIPI data suggest that the universal use of insulin pump therapy as a means of addressing the inequalities in outcomes in children with diabetes are unlikely to be successful.

Joanne Blair is a consultant endocrinologist and honorary professor, clinical lead in the clinical research division, Alder Hey Children’s NHS Foundation Trust.

Competing interests: See research paper

References:

  1. Blair JC, Peak M, Gregory JW What is the best way to deliver subcutaneous insulin to infants, children, and young people with type 1 diabetes mellitus? BMJ. 2011 Sep 2;343:d5221. doi: 10.1136/bmj.d5221
  2. Shulman R, Stukel TA, Miller FA, Newman A, Daneman D, Guttmann A Insulin pump use and discontinuation in children and teens: a population-based cohort study in Ontario, Canada. Pediatr Diabetes. 2017 Feb;18(1):33-44. doi: 10.1111/pedi.12353. Epub 2016 Jan 8.
  3. Lin MH1, Connor CG, Ruedy KJ, et al. Pediatric Diabetes Consortium Race, socioeconomic status, and treatment center are associated with insulin pump therapy in youth in the first year following diagnosis of type 1 diabetes. Diabetes Technol Ther. 2013 Nov;15(11):929-34. doi: 10.1089/dia.2013.0132. Epub 2013 Jul 19.
  4. McKergow E, Parkin L, Barson DJ, et al. Demographic and regional disparities in insulin pump utilization in a setting of universal funding: a New Zealand nationwide study. Acta Diabetologica 2016:1-9
  5. Willi SM, Miller KM, DiMeglio LA, et al.  T1D Exchange Clinic Network. Racial-ethnic disparities in management and outcomes among children with type 1 diabetes. Pediatrics. 2015 Mar;135(3):424-34. doi: 10.1542/peds.2014-1774.
  6. Khanolkar AR, Amin R, Taylor‐Robinson D, et al. Young people with Type 1 diabetes of non‐white ethnicity and lower socio‐economic status have poorer glycaemic control in England and Wales. Diabet Med. 2016;33:1508-1515
  7. National Paediatric Diabetes Audit. 2015-16 report 1: care processes and outcomes. https://www.rcpch.ac.uk/system/files/protected/page/Complete%20NPDA%202015-16%20report%20FINAL.pdf