Diabetes Alert Dogs (DADs): An assessment of accuracy and implications

Abstract

Aims To test the accuracy of Diabetes Alert Dogs (DADs) by comparing recorded alerts to continuous glucose monitoring (CGM) device readings during waking and sleeping hours. Methods 14 individuals (7 adults with type 1 diabetes and 7 youth with type 1 diabetes/parents) who owned DADs for ≥ 6 mos wore masked CGM devices over a several-week period while recording DAD alerts electronically and in paper diaries. Results During waking hours, sensitivity scores across participants were 35.9% for low BG events and 26.2% for high BG events. DAD accuracy was highly variable with 3/14 individual dogs performing statistically higher than chance. Sensitivity scores were lower during sleep hours of the person with diabetes (22.2% for low BG events and 8.4% for high BG events). DAD accuracy during sleeping hours was also highly variable, with 1/11 individual dogs performing statistically better than chance. Rate of change analyses indicated that DADs were responding to absolute BG level, rather than rapid shifts in glucose levels. Conclusions In this study the majority of DADs did not demonstrate accurate detection of low and high BG events. However, performance varied greatly across DADs and additional studies are needed to examine factors contributing to this variability. Additionally, more research is needed to investigate the significant gap between the positive experiences and clinical outcomes reported by DAD owners and the mixed research findings on DAD accuracy.

Dogs demonstrate the existence of an epileptic seizure odour in humans

“…Nevertheless, in real-life conditions, diabetes dogs appeared to show a poor reliability: 26.2 to 59.2% in sensitivity 33,34 ; 36% sensitivity and the PPV of 12% only due to inappropriate alerts 35 with a large variability across dogs.…”

An Owner-Independent Investigation of Diabetes Alert Dog Performance

“…Many dogs are trained to respond to their individual owner's target glucose range (32), so testing their accuracy using these ranges may give a fairer assessment of efficacy, whilst considering extreme glucose levels gives an indication of their value at preventing severe episodes and requiring paramedic call outs. Gonder-Frederick et al (31) saw no substantive differences in accuracy to “extreme” glucose levels as compared to the standard definitions of hypo- and hyperglycaemia, however, no previous study has assessed accuracy levels to owners' individual target ranges and extreme glucose levels.…”

“…Two recent experimental studies overcame the issue of potentially missing false negatives by utilizing Continuous Glucose Monitoring Systems (CGMS) (30, 31). CGMS are owner-independent as they automatically record interstitial fluid glucose levels via a sensor inserted under the skin, which facilitates a more accurate measure of DAD sensitivity since all OOR episodes are recorded.…”

“…Hence, of the reported 88% “incorrect” alerts, it is unknown what proportion were actually events where the dog was alerting to hyperglycaemia. Gonder-Frederick et al (31) collected CGMS data, blood test readings, and owner reports of DAD alerts from 14 participants over 6 weeks, and similarly found substantial variation in performance between dogs, with only three out of 14 dogs performing statistically above chance level. The cause of this variability is as yet unexplored.…”

“…Whether a dog's alert is considered “correct” will depend on the glucose values used to determine hypo- and hyperglycaemia. Both Los et al (30) and Gonder-Frederick et al (31) used the clinical definition of glycaemic states (≤ 3.9 mmol/L: hypoglycaemia and ≥10.0 mmol/L: hyperglycaemia) whilst Gonder-Frederick et al (31) also considered “more extreme” hypoglycaemic (≤ 3.0 mmol/L) and hyperglycaemic states (≥13.9–16.7 mmol/L). Many dogs are trained to respond to their individual owner's target glucose range (32), so testing their accuracy using these ranges may give a fairer assessment of efficacy, whilst considering extreme glucose levels gives an indication of their value at preventing severe episodes and requiring paramedic call outs.…”