The American Journal of Managed Care January 2010
Physician Utilization by Insurance Type Among Youth With Type 2 Diabetes
Physician utilization during the year before the first indication of type 2 diabetes did not differ between Medicaid-covered and privately insured youth.
Objective: To evaluate the relationship between insurance type (Medicaid vs private insurance) and access to physician care for youth with type 2 diabetes mellitus by quantifying whether these youth saw a physician during the year before their first diabetes documentation.
Study Design: Retrospective cohort study.
Methods: Youth with Medicaid or private insurance aged 5 to 19 years with type 2 diabetes were identified by an electronic medical record review. The first indication of type 2 diabetes defined the index date. Youth with type 1 diabetes and female patients with polycystic ovaries were excluded. Descriptive statistics evaluated differences in office visits before the index date between patients with the 2 insurance types. Multivariate logistic regression analysis evaluated the likelihood of having an office visit during the year before the index date among youth with Medicaid versus private insurance, controlling for youth characteristics.
Results: Of 2496 included youth, 400 (16.0%) had Medicaid coverage. More than 60% were female, the mean age was 14.5 years, and 68.8% were obese. On average, youth had 1.9 office visits during the year before the index date. Medicaid-covered youth were not significantly less likely to have had an office visit (odds ratio, 0.77; P = .09) or fewer total office visits (incident rate ratio, 1.13; P = .16) during the year before the index date.
Conclusions: The likelihood of youth with type 2 diabetes and a source of physician care having a physician office visit during the year before the index date did not differ between patients with Medicaid versus private insurance. This suggests that the amount of physician care before diagnosis of type 2 diabetes does not differ for Medicaid-covered youth if they can establish a source of care. Additional research is investigating whether physician access before diagnosis is associated with access to diabetes-related care after diagnosis.
(Am J Manag Care. 2010;16(1):55-64)
This study addressed whether physician utilization disparities persist between privately insured youth and Medicaid-covered youth if the latter can overcome initial access barriers.
- When Medicaid-covered youth are able to establish a source of care, utilization of physician services during the year before their first indication of type 2 diabetes is not less than that among privately insured youth.
- Managed Medicaid plans could help to reduce physician access disparities by ensuring adequate network coverage, which may equalize opportunities for screening and preventive care for diabetes and other conditions.
Effective weight and exercise management in overweight and obese individuals can help to delay or prevent the onset of type 2 diabetes in those progressing toward diabetes.8,9 Therefore, access to physician care could facilitate risk assessment, leading to preventive care in youth who show signs of developing type 2 diabetes, as well as create opportunities for early diagnosis and treatment. Thus, barriers to physician care could contribute to prevention, diagnosis, treatment, and outcomes disparities for patients with access issues.
Health insurance status is a factor known to be associated with physician access for individuals of all ages and across many disease states, with access disparities most notable between patients with versus without insurance.10 In the United States, 88% of youth have health insurance, with more than 25% covered by Medicaid or other public programs.11 However, youth with Medicaid coverage are less likely to use physician services in the course of a year and are less likely to receive needed healthcare services than youth with private insurance,12 possibly because of related socioeconomic factors such as issues with transportation or inability to identify a provider with service hours that accommodate working parents. It is unknown whether physician utilization disparities continue to exist if Medicaid-covered youth can overcome initial access barriers.
There are long-term health benefits in preventing type 2 diabetes and in early diagnosis and treatment, but it is unknown if reduced access to care before the diagnosis of type 2 diabetes influences the quality of care through factors such as treatment disparities and poor outcomes. Before establishing the implications of access to care, this article first answers the question of whether physician utilization differences exist for Medicaidcovered youth with type 2 diabetes relative to those with private insurance. This study investigates this baseline question by evaluating whether utilization of physician services differs in the year before the first indication of type 2 diabetes (index date). It also considers youth who have initiated a source of physician care as documented in an ambulatory care–based electronic medical record (EMR) and includes young patients who were able to overcome basic access barriers. Ongoing research is investigating the larger question of whether physician access disparities translate into differences in the utilization of diabetes-related care for youth, which begins to broach the issue of quality of care.
A retrospective cohort study identified physician office visits for youth aged 5 to 19 years with Medicaid or private insurance in the year before the index date. The time frame examined was from January 1996 through December 2007.
The data source for this study was the General Electric Healthcare Centricity EMR (GE EMR) research database.13 The GE EMR contains longitudinal ambulatory electronic health data for 8 million patients from January 1996 through December 2007. Patient-level data includes but is not limited to demographic information, vital signs, office visits, laboratory test results, medication histories and prescription orders, and diagnoses.
The research database has been derived from data contributed by more than 6000 ambulatory care–based practitioners in 35 states who use the GE EMR. Approximately two-thirds of these clinicians practice primary care. Data are centrally collected and undergo a quality control process to remove or correct invalid data. The database is deidentified and is compliant with the Health Information Portability and Accountability Act.
The study was based on a subset of GE EMR youth 19 years or younger on their first day of activity in the database. In summary, youth were included from this subset if they had indications of type 2 diabetes in the GE EMR, were aged 5 to 19 years on the date when type 2 diabetes was first documented in the database (defined as the index date), had at least 1 additional interaction with the GE EMR physician that occurred at least 90 days after the index date, and had Medicaid or private insurance. Youth with type 1 diabetes and female patients with polycystic ovaries were excluded.
More specifically, youth were identified as having type 2 diabetes if they met at least 1 of the following indicators: (1) two consecutive fasting blood glucose levels of at least 126 mg/dL (to convert glucose level to millimoles per liter, multiply by 0.0555), (2) two documented International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes for type 2 diabetes (250.X0 and 250. X2), (3) a prescription order or medication list entry for an oral antidiabetic drug, or (4) a prescription order or medication list entry for insulin with at least 1 ICD-9-CM diagnosis code for type 2 diabetes.
An index date was assigned to each patient and was the earliest date when a patient met 1 of the diagnosis criteria for type 2 diabetes. Once the index date was established, the sample was limited to youth aged 5 to 19 years on the first date when type 2 diabetes was documented in the GE EMR. This age range was used to capture the onset of puberty, which is associated with the development of type 2 diabetes.14-16 Exclusion of patients younger than 5 years, an approach used by other studies17,18 of type 2 diabetes in children, was incorporated because type 2 diabetes diagnoses among children in this age group are rare.19,20
Subjects were included if they continued to have interaction with the GE EMR physician after the first indication of type 2 diabetes, with the last interaction at least 90 days after the index date. This postindex date GE EMR activity was required to ensure that at least a minimal amount of followup care or monitoring occurred after the first GE EMR documentation of diabetes and that the interaction represented the opportunity for youth to establish a usual source of care as opposed to a 1-time visit. It could be argued that this inclusion criterion was unnecessary for the present analyses. However, this step helps to ensure that insurance type is isolated from other barriers to access. Furthermore, we are evaluating access to diabetes-related care after diagnosis in this cohort, and a minimal amount of continuity of care was deemed necessary for the additional analyses.
By this design, all youth had at least 2 interactions with the GE EMR physician. These interactions included office visits but may have been telephone consultations, prescription orders or refills, or other activities performed by the physician or practice that led to clinical entry in the GE EMR. No minimum number of office visits was required for study inclusion. Similarly, no minimum preindex date activity period was required because the study outcome was the occurrence of physician activity during the year before the index date. Requiring GE EMR activity before the first diagnosis of type 2 diabetes could have decreased the study’s sensitivity in identifying youth who had received no care in the year before the index date.
Finally, the study population included patients with Medicaid or private insurance, thereby excluding patients whose insurance type was listed as unknown, private pay, or Medicare. There were too few patients listed as having no insurance (self-pay) or Medicare in the GE EMR to support statistical analyses; therefore, these youth were not included. Conversely, there were too many patients with unknown insurance to make valid inferences about the associations between unknown insurance status and office visits.
Patients were excluded if they had a diagnosis of type 1 diabetes in the GE EMR at any time. This step helped to ensure that youth identified by fasting blood glucose levels did not have type 1 diabetes or that youth with type 1 diabetes initially diagnosed as having type 2 diabetes were not included. In addition, female patients without an ICD-9-CM diagnosis code for type 2 diabetes but with a prescription order for an oral antidiabetic agent and with a diagnosis of polycystic ovaries (code 256.4) were excluded. Oral antidiabetic agents are used off-label to treat this condition21-23 and could have led to the inclusion of young female patients who did not have type 2 diabetes. This study did not identify or exclude young female patients with gestational diabetes; however, few female patients in this study had an indication of being pregnant on or before the index date.
In this study, the dependent variable was the documentation of an office visit during the year before the index date, captured as a dichotomous variable. The number of office visits in the year before the index date was also identified for those with an office visit, captured as a continuous variable, with the value set to zero if no office visits were identified that year. There is no evidence that annual office visits alter the likelihood of at-risk youth developing or being diagnosed as having type 2 diabetes relative to those with less frequent or more frequent office visits. However, studies24-26 of healthcare access among youth have evaluated whether patients had seen a physician in the previous year. To be consistent and to allow for indirect comparisons between studies, the occurrence of office visits during the 1-year period before diagnoses in the GE EMR was evaluated.
The primary independent variable was insurance type, which was categorized as Medicaid or private insurance. Insurance type in the GE EMR is recorded as of the last update; insurance type is not documented for each date when healthcare services were delivered. Therefore, the insurance type or status on record may not be the same as the insurance type on the date when type 2 diabetes was diagnosed. Details beyond Medicaid or commercial coverage are not included in the GE EMR database. Therefore, the GE EMR does not indicate whether commercial patients have employer-sponsored or individual coverage. Similarly, the database does not distinguish between Medicaid fee-for-service or managed Medicaid. It was assumed for this study that all youth with Medicaid, regardless of funding mechanism, were coded as having Medicaid and that those with managed Medicaid were not listed as having commercial insurance.