Why don't diabetes patients achieve recommended risk factor targets? Poor adherence versus lack of treatment...

Despite the availability of effective hypertension, hyperlipidemia, and hyperglycemia therapies, target levels of systolic blood pressure (SBP), LDL-cholesterol (LDL-c), and hemoglobin A1c control are often not achieved.

To examine the relative importance of patient medication nonadherence versus clinician lack of therapy intensification in explaining above target cardiovascular disease (CVD) risk factor levels.

Cross-sectional assessment.

In 2005, 161,697 Kaiser Permanente Northern California adult diabetes patients were included in the study.

"Above target" was defined as most recent A1c >/=7.0% for hyperglycemia, LDL-c >/=100 mg/dL for hyperlipidemia, and SBP >/=130 mmHg for hypertension. Poor adherence was defined as medication gaps for >/=20% of days covered for all medications for each condition separately. Treatment intensification was defined as an increase in the number of drug classes, increased dosage of a class, or a switch to a different class within the 3 months before or after notation of above target levels.

Poor adherence was found in 20-23% of patients across the 3 conditions. No evidence of poor adherence with no treatment intensification was found in 30% of hyperglycemia patients, 47% of hyperlipidemia patients, and 36% of hypertension patients. Poor adherence or lack of therapy intensification was evident in 53-68% of patients above target levels across conditions.

Both nonadherence and lack of treatment intensification occur frequently in patients above target for CVD risk factor levels; however, lack of therapy intensification was somewhat more common. Quality improvement efforts should focus on these modifiable barriers to CVD risk factor control.