Secondary failure of glycemic control for patients adding thiazolidinedione or sulfonylurea therapy to a metformin regimen.
OBJECTIVE
To assess glycemic control and secondary failure in patients adding thiazolidinedione or sulfonylurea therapy to a metformin regimen in a managed care setting.


METHODS
Retrospective cohort study using administrative claims data.


METHODS
Participants (mean age, 51.1 years; 55.4% female) were required to have at least 1 prescription claim for a sulfonylurea (n = 300) or a thiazolidinedione (n = 279) between January 1, 2001, and March 31, 2004, as well as metformin use during the prior 6 months and continued metformin use. Secondary failure was measured for patients who initially achieved a glycosylated hemoglobin (A1C) level of less than 7.0% and was defined as a subsequent A1C level of at least 7.0%.


RESULTS
The mean baseline A1C level was 8.2% and was higher for the patients receiving a combination of metformin and sulfonylurea (A1C level, 8.4%) compared with patients receiving a combination of metformin and thiazolidinedione (A1C level, 8.0%) (P < .05). Overall, 77.7% of patients had a baseline A1C level of at least 7.0%. The mean A1C level decreased by 1.2 (to 7.0%), and 65.1% of patients with a baseline A1C level of at least 7.0% reached goal A1C level. Therapy intensification via addition of another antihyperglycemic agent occurred in 60.7% of study patients. Approximately 2 in 5 patients (41.5%) who initially achieved goal A1C level experienced secondary failure; the mean time to failure was 1.3 years.


CONCLUSIONS
Although most patients failing metformin monotherapy reached goal A1C level after addition of a sulfonylurea or a thiazolidinedione, 41.5% of patients observed for up to 4 years who initially attained goal A1C level experienced secondary failure.
Health Economics and Outcomes, i3 Innovus, an Ingenix Company, Eden Prairie, Minn, USA.
Aylin A
AA
Riedel
Herbert
H
Heien
Jenifer
J
Wogen
Craig A
CA
Plauschinat
D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000453:epidemiology; D019468:Disease Management; D004359:Drug Therapy, Combination; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis / Q000187:drug effects; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D008297:Male; D008329:Managed Care Programs; D008687:Metformin / Q000008:administration & dosage* / Q000627:therapeutic use; D008875:Middle Aged; D012189:Retrospective Studies; D013453:Sulfonylurea Compounds / Q000008:administration & dosage* / Q000627:therapeutic use; D045162:Thiazolidinediones / Q000008:administration & dosage* / Q000627:therapeutic use; D017211:Treatment Failure; D014481:United States / Q000453:epidemiology
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D008687:Metformin; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones; C089946:2,4-thiazolidinedione