Evidence on effectiveness

A literature search was carried out for this briefing. The most relevant or best available published evidence relating to the clinical effectiveness of the technology has been summarised below. Further information about how the evidence for this briefing was selected, and full summaries of the included studies, are available on request by contacting medtech@nice.org.uk.

This briefing summarises 2 published studies and 1 published letter, all of which report outcomes from a UK feasibility study involving the same cohort of up to 57 users of GDm‑Health (table 2).

Table 2 Summary of evidence

Mackillop et al. (2014)

Study size, design and location

Cohort study, n=57. Hospital-based maternity diabetes clinic, UK. Pilot for Mackillop et al. (2016).

Intervention and comparator(s)

Intervention: GDm‑Health

Comparator: none

Key outcomes

In the service development phase, mean weeks of usage was 12.9.

16,534 blood glucose readings were submitted.

The overall percentage of blood glucose readings with additional information was 98.3% labelled as a meal, and 15.7% with free text comments.

A total of 466 text messages were sent to patients from the website, resulting in 26 medication adjustments.

Strengths and limitations

Beta testing was done in 7 patients and additional functionality was added to the system before testing in a larger patient group. There was high usage and excellent compliance with the system. However, the study used a small sample size, and there was a risk of bias in the sample because patients could choose to use the app. There was also no comparator group. The work was funded by the National Institute of Health Research Biomedical Research Centre Programme.

Hirst et al. (2015)

Study size, design and location

User satisfaction survey, n=52. Maternity diabetes clinic, UK.

Intervention and comparator(s)

Intervention: GDm‑Health

Comparator: none

Key outcomes

Patients reported a high degree of satisfaction with GDm‑Health, particularly if they lived far from the hospital or had other commitments. Patients were highly satisfied with system reliability: any problems uploading data were because of poor local network connections rather than with GDm‑Health.

Strengths and limitations

This was a validated questionnaire with high completion rates. However, there was a small sample size, possible risk bias in the sample because patients could choose to use the app, and it used only 1 tool to measure satisfaction. It was also non-comparative. The work was funded by the National Institute of Health Research Biomedical Research Centre Programme.

Hirst et al. (2016)

Study size, design and location

Cohort study, n=49. Maternity diabetes clinic, UK.

Intervention and comparator(s)

Intervention: GDm‑Health

Comparator: none

Key outcomes

Proportion of births that were large for gestational age, accuracy of blood glucose readings and ability to identify readings with respect to meals were facilitated by GDm‑Health.

Compared with normal-for-gestational-age babies, large-for-gestational-age babies had higher mean and 2-hour postprandial readings. The odds of delivering a large-for-gestational-age baby increased around 5 times for every 1 standard deviation increase in mean blood glucose and mean postprandial blood glucose (but not fasting blood glucose).

Strengths and limitations

This was not a full publication (letter), had only a small sample size, it was non-comparative, and outcomes did not focus on the effectiveness of GDm‑Health. There was also possible risk bias in the sample because patients could choose to use the app.

The work was funded by the National Institute of Health Research Biomedical Research Centre Programme.

Overall assessment of the evidence

  • The evidence base for GDm‑Health is still developing and consists mainly of product development and evaluation studies on a small cohort of patient volunteers.

  • All studies are non-comparative and were done in a small cluster of centres by the team currently developing the app.

  • The evidence suggests that GDm‑Health is a reliable and user-friendly method of remote blood glucose monitoring, and that it improves communication between healthcare professionals and people with gestational diabetes.

  • There is a high degree of patient compliance and satisfaction with using the system (Mackillop et al. 2014, Hirst et al. 2015).

  • An ongoing randomised trial comparing GDm‑Health with standard care has completed data collection, and publication of results will add to the current body of evidence particularly in relation to improving clinical outcomes (Mackillop et al. 2016).

Recently completed and ongoing studies

One recent, ongoing or in-development trial on the use of GDm‑Health was identified in the preparation of this briefing.