The role of clinical uncertainty in treatment decisions for diabetic patients with uncontrolled blood pressure.

BACKGROUND

Factors underlying failure to intensify therapy in response to elevated blood pressure have not been systematically studied.

OBJECTIVE

To examine the process of care for diabetic patients with elevated triage blood pressure (> or =140/90 mm Hg) during routine primary care visits to assess whether a treatment change occurred and to what degree specific patient and provider factors correlated with the likelihood of treatment change.

DESIGN

Prospective cohort study.

SETTING

9 Veterans Affairs facilities in 3 midwestern states.

PARTICIPANTS

1169 diabetic patients with scheduled visits to 92 primary care providers from February 2005 to March 2006.

MEASUREMENTS

Proportion of patients who had a change in a blood pressure treatment (medication intensification or planned follow-up within 4 weeks). Predicted probability of treatment change was calculated from a multilevel logistic model that included variables assessing clinical uncertainty, competing demands and prioritization, and medication-related factors (controlling for blood pressure).

RESULTS

Overall, 573 (49%) patients had a blood pressure treatment change at the visit. The following factors made treatment change less likely: repeated blood pressure by provider recorded as less than 140/90 mm Hg versus 140/90 mm Hg or greater or no recorded repeated blood pressure (13% vs. 61%; P < 0.001); home blood pressure reported by patients as less than 140/90 mm Hg versus 140/90 mm Hg or greater or no recorded home blood pressure (18% vs. 52%; P < 0.001); provider systolic blood pressure goal greater than 130 mm Hg versus 130 mm Hg or less (33% vs. 52%; P = 0.002); discussion of conditions unrelated to hypertension and diabetes versus no discussion (44% vs. 55%; P = 0.008); and discussion of medication issues versus no discussion (23% vs. 52%; P < 0.001).

LIMITATION

Providers knew that the study pertained to diabetes and hypertension, and treatment change was assessed for 1 visit per patient.

CONCLUSION

Approximately 50% of diabetic patients presenting with a substantially elevated triage blood pressure received treatment change at the visit. Clinical uncertainty about the true blood pressure value was a prominent reason that providers did not intensify therapy.