Diabetes Care, Vol 16, Issue 11 1470-1478, Copyright © 1993 by American Diabetes Association
A prospective study identifying risk factors for discontinuance of insulin pump therapy
JC Floyd, RG Cornell, SJ Jacober, LE Griffith, MM Funnell, LL Wolf and FM Wolf
Department of Internal Medicine, University of Michigan, Ann Arbor.
OBJECTIVE--To identify characteristics of adult patients at baseline
associated with duration of subsequent, continuous, subcutaneous infusion
of insulin treatment (pump therapy) of type I diabetes. RESEARCH DESIGN AND
METHODS--For 6 wk, patients followed a standardized conventional therapy
and kept a record of insulin dosages, capillary blood glucose
concentrations, and symptomatic hypoglycemia. They were then hospitalized.
Additional baseline data were obtained and pump therapy was started.
Survival analysis was used to determine the relationship between baseline
independent variables or risk factors and duration of pump therapy, which
is the dependent variable. RESULTS--Of the 68 participants, 33 (49%)
terminated pump therapy after an average of 9.9 mo of treatment. Two models
(each P < 0.00005) were developed that exhibited a high degree of
consistency. Of the 6 variables, 5 were common to both models (HbA1,
autonomic neuropathy, mean amplitude of glycemic excursions, frequency of
symptoms of hypoglycemia when blood glucose was < 70 mg/dl, and erythema
at injection sites). The sixth variable in model 1 (insulin dosage) was
replaced in model 2 by a variable, Adult Self-Efficacy for Diabetes, which
was obtained on the 33 more recently enrolled patients; this variable
related to patient perceptions of self-care behaviors. CONCLUSIONS--We
found that, at baseline, the presence of a high concentration of HbA1 and a
low estimation by the patient of their ability to treat the disease portend
failure of insulin pump therapy as evidenced by its discontinuation. This
effect is accentuated when clinical evidence of autonomic neuropathy is
observed. These findings offer guidance in selecting patients with type I
diabetes for insulin pump therapy.