Research Activities, January 2014
Population factors explain most between-State disparities in rates of gestational diabetes
Gestational diabetes mellitus (GDM) rates, adjusted for age and race, varied twofold among a sample of 23 States—from 3.47 cases per 100 deliveries in Utah to 7.15 cases per 100 deliveries in Rhode Island, according to a new study.
Diabetes is one of the most common complications of pregnancy in the United States, with the incidence varying between the country's various racial and ethnic groups. However, since much health care planning and program implementation takes place at the State level, AHRQ researcher Anne Elixhauser, Ph.D., and coinvestigators wanted to obtain information on GDM prevalence by State in a wider variety of population subgroups. They analyzed data from AHRQ's Healthcare Cost and Utilization Project 2008 State Inpatient Databases on GDM rates among women in different racial/ethnic groups, between distinct 5-year age groups (for the range 15–44 years old), between quartiles of State median household income (by patient Zip Code), by type of hospital (number of beds, ownership type, rural versus urban), and by type of insurance.
Based on approximately 1.8 million deliveries in the 23 States during 2008, mean age-adjusted GDM rates were higher for Asians and Hispanics (8.14 and 7.02 cases per 100 deliveries, respectively) than for whites and blacks (4.40 and 5.30 cases per 100 deliveries, respectively). Overall, the individual-, hospital-, and State-level characteristics accounted for 86.1 percent of the between-State variability in GDM rates, with individual-level characteristics accounting for 35.3 percent of the variability (14.7 percent by age group, 11.8 percent by race or ethnicity, and 5.9 percent by type of insurance). State-level characteristics accounted for another 33.2 percent of the variability, primarily due to the variability in prevalence of obese women (27.4 percent of between-State variability). In contrast, hospital-level characteristics accounted for only 17.6 percent of the variability.
More details are in "Variation in prevalence of gestational diabetes mellitus among hospital discharges for obstetric delivery across 23 states in the United States," by Barbara H. Bardenheier, Ph.D., M.P.H., M.A., Dr. Elixhauser, Giuseppina Imperatore, M.D., Ph.D., and others in the May 2013 Diabetes Care 36(5), pp. 1209-1214.