The Unseen Costs of Hypoglycemia in Diabetes

Liam Davenport

March 24, 2015

LONDON — The prevalence of hypoglycemic episodes among patients with diabetes is higher than previously thought and is associated with increased length of hospital stay and higher costs, attendees at a recent UK diabetes conference heard.

These episodes more than double the length of hospital stay and increase the risk of in-hospital mortality, increasing hospital costs by almost a quarter, doctors told a session at the Diabetes UK Professional Conference, held on March 11–13. But educational measures can reduce the number of severe episodes, they explained.

The session was chaired by David Russell-Jones, MD, from the Royal Surrey County Hospital, Guildford, United Kingdom.

Summarizing the session for Medscape Medical News, he said: "What was quite novel here is that hypoglycemia in patients in hospitals is actually much more common...than one would expect from the randomized clinical-trial data." He added: "It leads to a greater length of stay and a huge health cost, and this is something that needs to be addressed."

Dr Russell-Jones explained that while that the cost of hypoglycemia is not "high on the worry list of many managers," the case for prioritizing hypoglycemic episodes is clear.

"Once people are admitted, the costs spiral out of control, and that should give us an opportunity to make very robust business cases to try to prevent this," he observed.

The well-attended session was divided into presentations that looked at the prevalence and incidence of hypoglycemic episodes in various settings and their consequences, as well as ways in which severe episodes could be prevented.

Hypoglycemia: More Common Than Thought

Two presentations from a research team led by Kamlesh Khunti, MD, PhD, from the Diabetes Research Centre, University of Leicester, United Kingdom, concluded that the prevalence of hypoglycemic episodes reported in clinical trials is likely to be an underestimate, and the findings highlight the need for educational interventions and individualized therapies, they said.

The first examined the prevalence and incidence of hypoglycemia among type 2 diabetes patients on oral therapies and insulin and involved a systematic search of the Medline, Embase, and Cochrane databases for relevant trials published to February 2014, yielding 46 studies, with a total of 532,542 patients.

The researchers showed that the prevalence of mild/moderate hypoglycemia was 44%, while that of severe hypoglycemia was 6%. The respective incidence of mild/moderate and severe hypoglycemia was 19 and 0.8 episodes per person-year.

The highest prevalence and incidence of hypoglycemia was among patients taking insulin, at 50% and 23 events per person-year, respectively, for mild/moderate episodes and 21% and one event per person-year, respectively, for severe episodes.

Dr Khunti also presented data from the Hypoglycemia Assessment Tool (HAT), a noninterventional, multicenter, 6-month retrospective and 1-month prospective study of hypoglycemic events in 24 countries.

Patients with type 1 or type 2 diabetes aged 18 years and older completed a self-assessment questionnaire to document the number of severe and nonsevere hypoglycemic events over the past 6 months and filled in 4-week patient diaries of hypoglycemic events.

In all, 83.4% of type 1 patients and 50.8% of type 2 reported experiencing one or more hypoglycemic events in the 4 weeks before baseline, at a rate of 51.5 and 16.5 events per patient-year, respectively. However, incidence rates were higher in the 4 weeks after baseline, at 73.3 events per person-year for type 1 patients and 19.3 events per person-year for type 2 patients.

Dr Kunti concluded that the findings suggest that hypoglycemia is underreported in self-assessment questionnaires.

Inpatient Hypoglycemia Leads to Worse Outcomes

Another talk during the session looked at frequency of hypoglycemia in a large acute teaching hospital in the United Kingdom.

Charlotte Hammond and Georgina Keogh, medical students at the Leeds Teaching Hospitals NHS Trust, presented their pilot study of inpatient capillary blood glucose (CBG) values, which are taken via glucometers present on every ward and automatically downloaded to an electronic database.

Over the course of 1 month, 339 (4.15%) of 8165 CBG readings in 244 diabetes inpatients were less than 4.0 mmol/L. The researchers calculated that 39.0% of diabetes patients experienced one or more hypoglycemic episodes, at a mean of 2.7 episodes per patient.

Patients who experienced a hypoglycemic episode tended to be older than other patients, had significantly worse renal function, were more likely to have type 1 diabetes, and were more likely to be receiving hypoglycemic agents.

The students also found that patients with a hypoglycemic episode had a significantly longer length of hospital stay than diabetes patients without such an episode, at 26.8 days vs 20.21 days (P = .04).

Furthermore, 1-year mortality following discharge was significantly higher among patients who had a hypoglycemic episode than nonhypoglycemic patients, at 36.7% vs 22.2% (P = .03).

Analysis of patient demographics may help identify at-risk patients, they concluded.

The Real Cost of Hypoglycemic Episodes

In another presentation, Marc Evans, MD, a consultant diabetologist at Llandough Hospital and the University Hospital of Wales, Cardiff, reported a retrospective, matched-cohort study on all UK insulin-treated diabetes inpatients who experienced a severe hypoglycemia event over a 10-year period.

Using data from the UK Clinical Practice Research Datalink database, Dr Evans and colleagues paired 1079 patients with type 1 or type 2 diabetes patients who experienced an inpatient hypoglycemic episode with the same number of patients who did not have an episode, matching them by age, primary diagnosis, and diabetes type.

Patients with hypoglycemic episodes had a significantly longer mean length of hospital stay than unaffected patients, at 11.91 days vs 4.80 days ( P < .0001), and were significantly more likely to die in the hospital, at an odds ratio of 1.439 (P < .0195).

Among patients who had a hypoglycemic episode, increased age was associated with an increased risk of all-cause mortality, at an odds ratio of 1.026 ( P < .0001).

The average cost of hospital admission was also higher for patients who experienced a hypoglycemic episode, at £2235 per patient admission vs £1591 for those who did not. Multivariate analysis indicated that the cost for patients with an episode was 38.7% higher than for patients without an episode ( P < .0001).

Patient Education May Reduce Severe Hypoglycemia

Finally, Ester Yeoh, MD, from the Diabetes Centre, King's College Hospital, London, United Kingdom, presented the results of a systematic review and meta-analysis of educational interventions to restore impaired awareness of hypoglycemia in type 1 diabetes patients, involving a total of 22 studies.

Structured education programs in insulin self-management were found to reduce rates of severe hypoglycemia and improve hypoglycemia awareness and glycemic control, she reported.

In particular, group-based psychoeducational programs, such as the Dose Adjustment for Normal Eating-Hypoglycemia Awareness Restoration Training (DAFNE-HART), appeared to improve hypoglycemia awareness and reduce severe hypoglycemia rates by up to 45% in patients with impaired hypoglycemia awareness.

Diabetes UK Professional Conference. March 11–13, 2015; London, UK. Abstracts A63–A68, presented March 13, 2015.


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