Initiation of insulin therapy in elderly patients taking oral antidiabetes drugs.
BACKGROUND
We sought to estimate the rate of initiation of insulin therapy among elderly patients using oral anti-diabetes drugs and to identify the factors associated with this initiation.


METHODS
We conducted a population-based cohort study involving people aged 66 or more years who were newly dispensed an oral antidiabetes drug. Individuals who had received acarbose or a thiazolidinedione were excluded. The rate of insulin initiation was calculated by use of the Kaplan-Meier method. Factors associated with insulin initiation were identified by multivariable Cox regression analyses.


RESULTS
In this cohort of 69,674 new users of oral antidiabetes drugs, insulin was initiated at rate of 9.7 cases per 1000 patient-years. Patients who had initially received an insulin secretagogue (rather than metformin), who were prescribed an oral antidiabetes drug by an endocrinologist or an internist, who received higher initial doses of an oral antidiabetes drug, who received oral corticosteroids, used glucometer strips, or were admitted to hospital in the year before initiation of oral antidiabetes therapy, or who received 16 or more medications were more likely than those without these characteristics to have insulin therapy initiated. In contrast, patients who received thiazides or who used up to 12 medications (v. none) were less likely to have insulin therapy initiated.


CONCLUSIONS
Several factors related to drugs and health services are associated with the initiation of insulin therapy in elderly patients receiving oral antidiabetes drugs. It is unclear whether these factors predict secondary failure of oral antidiabetes drugs or instead reflect better management of type 2 diabetes.
Pérez
Norma
N
Unité de recherche en santé des populations, Centre de recherche du centre hospitalier affilié universitairede Québec, Université Laval, Québec, Que.
Moisan
Jocelyne
J
Sirois
Caroline
C
Poirier
Paul
P
Grégoire
Jean-Pierre
JP
D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D003920:Diabetes Mellitus / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007328:Insulin / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D016016:Proportional Hazards Models; D011792:Quebec; D016896:Treatment Outcome
D007004:Hypoglycemic Agents; D007328:Insulin