Prevalence of baseline serum glucose and lipid testing in users of second-generation antipsychotic drugs: a retrospective, population-based study of Medicaid claims data.

OBJECTIVE: Increased risk of diabetes and dyslipidemia is associated with major mental illness and antipsychotic drug use. This study aimed to determine the prevalence of serum glucose and lipid monitoring in public mental health clients initiating second-generation antipsychotic (SGA) drugs.
METHOD: This retrospective cohort study using Medicaid claims data from California, Oregon, Tennessee, and Utah evaluated 55,436 enrollees with a prescription claim for an SGA drug between January 1, 1998, and December 31, 2003. Serum glucose and lipid testing were identified using Current Procedural Terminology (CPT) procedure codes. Baseline was defined as 14 days before through 28 days after the date of the first SGA prescription. Multivariate logistic regression identified patient characteristics associated with testing. Generalized estimating equations evaluated changes associated with SGA drug initiation compared to background rates of testing.
RESULTS: On average, < 20% of individuals initiating SGA drug therapy received baseline glucose testing, and < 10% received baseline lipid testing. Baseline glucose and lipid testing increased modestly with SGA initiation (glucose: 7%-11% increase; lipids: 2%-3% increase; p < .001). Preexisting diabetes and dyslipidemia were associated with a 2- to 3-fold greater likelihood of baseline glucose and lipid testing. The likelihood of glucose testing increased 2-fold between 1998 and 2003 and was 46% more likely in patients with schizophrenia. Enrollees from Oregon, Tennessee, and Utah were 50% to 90% less likely to receive baseline glucose or lipid testing than enrollees from California.
CONCLUSIONS: Glucose and lipid screening is underutilized in patients initiating SGA drug therapy. Psychiatrists can play an important role to ensure metabolic risk is adequately assessed.