Racial differences in long-term self-monitoring practice among newly drug-treated diabetes patients in an HMO

Abstract

Background: One approach to improving outcomes for minority diabetics may be through better self-care. However, minority patients may encounter barriers to better self-care even within settings where variations in quality of care and insurance are minimized.

Objective: The objective of the study was to evaluate racial differences in long-term glucose self-monitoring and adherence rates in an HMO using evidence-based guidelines for self-monitoring.

Design: Retrospective cohort study using 10 years (1/1/1993-12/31/2002) of electronic medical record data was used.

Patients: Patients were 1,732 insured adult diabetics of black or white race newly initiated on hypoglycemic therapy in a large multi-specialty care group practice.

Measurements: Outcomes include incidence and prevalence of glucose self-monitoring, intensity of use, and rate of adherence to national recommended standards.

Results: We found no evidence of racial differences in adjusted initiation rates of glucose self-monitoring among insulin-treated patients, but found lower rates of initiation among black patients living in low-income areas. Intensity of glucose self-monitoring remained lower among blacks than whites throughout follow-up [IRR for insulin = 0.41 (0.27-0.62); IRR for oral hypoglycemic = 0.75 (0.63, 0.90)], with both groups monitoring well below recommended standards. Among insulin-treated patients, <1% of blacks and <10% of whites were self-monitoring 3 times per day; 36% of whites and 10% of blacks were self-monitoring at least once per day.

Conclusions: Adherence to glucose self-monitoring standards was low, particularly among blacks, and racial differences in self-monitoring persisted within a health system providing equal access to services for diabetes patients. Early and continued emphasis on adherence among black diabetics may be necessary to reduce racial differences in long-term glucose self-monitoring.

Figure 1

Race differences in time from first diabetes medication until first SMBG stratified by oral-hypoglycemic- and insulin-treated patients. Year 1 represents start of drug therapy for each newly diagnosed diabetes patient. Patient assignment to drug treatment group based on drug use in the 12 months of first drug therapy.

Figure 2

Race differences in prevalence of self-monitoring from first SMBG. Year 1 represents start of SMBG for each initiator of SMBG. Analytical sample is restricted to patients with >12 follow-up months.

Figure 3

Race differences in long-term intensity of SMBG since first SMBG. Year 1 represents start of SMBG for each initiator of SMBG. Patient assignment to drug therapy group based on drug use in 12 months of first drug therapy. ADA target of SMBG use per year is approximately 365 strips for oral-hypoglycemic-treated patients and 1,100 strips for insulin-treated patients.

Figure 4

Race differences in rates of insulin-treated patients adherent to recommended standards of SMBG (N = 271). Year 1 represents start of SMBG for each initiator of SMBG. The ADA-recommended standard of SMBG is 3 or more times per day.