Priming insulin pens is recommended to remove air from needles to ensure full dose administration. Little is known regarding how often or how much patients prime during home use or its relation to glucose control. We evaluated patterns of pen priming in patients with type 1 diabetes using NovoPens for insulin administration. Patients were trained on use of pens including how and why to prime for doses. Two sites taught a 2 unit prime, site 3 until insulin seen. Pens were synced to a study phone via a near field communicator and marked as prime or injection. Records were assessed for prime frequency and amount. For this interim analysis, 16,135 pen records from 25 patients were analyzed. The percent of injections with a prime was 80% overall but ranged from 2-99%. Prime amount varied and did not correlate to HbA1C. For patients who primed until insulin seen, 74% of the primes did not necessitate 2 or more units. Prime frequency was defined as low if <25%, variable if 25-75% or consistent if >75%. The frequencies were not evenly distributed; instead patients would prime the majority of the time or infrequently. Percentage of missed prime did not correlate with HbA1C, but seemed to correlate with male gender and younger age. Missed prime of insulin pens is fairly common, but the frequency is variable. Insulin pens which track doses offer important data regarding appropriate use. This information provides insight for education and treatment.

 Gender HbA1c at enrollment Age (yrs) Diabetes duration (yrs) No prime (%injections) <2 units primes (%injections) ≥2 units primes (%injections) 
Low primers (<25%) 3 men 7.9% 23 90% 5% 5% 
Variable (25-75%) 3 men 6.4% 24 10 35% 22% 43% 
Consistent (>75%) 6 men 13 women 7.6% 36 20 6% 29% 65% 
Overall 12 men 13 women 7.5% (range 5.3-9.3%) 33 (range 17-57) 17 (range 2-44) Overall: 20%. Sites teaching 2 units: 19%. Site teaching until insulin seen: 21%. Overall: 25%. Sites teaching 2 units: 7%. Site teaching until insulin seen: 62%. Overall: 55%. Sites teaching 2 units: 74%. Site teaching until insulin seen: 17%. 
 Gender HbA1c at enrollment Age (yrs) Diabetes duration (yrs) No prime (%injections) <2 units primes (%injections) ≥2 units primes (%injections) 
Low primers (<25%) 3 men 7.9% 23 90% 5% 5% 
Variable (25-75%) 3 men 6.4% 24 10 35% 22% 43% 
Consistent (>75%) 6 men 13 women 7.6% 36 20 6% 29% 65% 
Overall 12 men 13 women 7.5% (range 5.3-9.3%) 33 (range 17-57) 17 (range 2-44) Overall: 20%. Sites teaching 2 units: 19%. Site teaching until insulin seen: 21%. Overall: 25%. Sites teaching 2 units: 7%. Site teaching until insulin seen: 62%. Overall: 55%. Sites teaching 2 units: 74%. Site teaching until insulin seen: 17%. 

Disclosure

G. O'Malley: None. S.J. Ogyaadu: None. D.W. Lam: None. L.M. Norlander: None. J. Robic: None. C.M. Levister: None. S. Anderson: Research Support; Self; Medtronic. Consultant; Self; Senseonics. L. Hsu: None. S.E. Loebner: None. L. Ekhlaspour: None. M.D. Breton: Stock/Shareholder; Self; TypeZero Technologies, Inc.. Speaker's Bureau; Self; Ascensia Diabetes Care. Consultant; Self; Sanofi. Speaker's Bureau; Self; Roche Diabetes Care Health and Digital Solutions. Research Support; Self; Dexcom, Inc., Ascensia Diabetes Care, Senseonics. B.A. Buckingham: Advisory Panel; Self; Novo Nordisk Inc., ConvaTec Inc.. Research Support; Self; Medtronic, Insulet Corporation, Dexcom, Inc., Tandem Diabetes Care, Inc.. Consultant; Self; Tandem Diabetes Care, Inc., Becton, Dickinson and Company. C.J. Levy: Advisory Panel; Self; Medtronic MiniMed, Inc.. Research Support; Self; Lexicon Pharmaceuticals, Inc., Dexcom, Inc..

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