An observational study of the effectiveness of practice guideline implementation strategies examined according to physicians' cognitive styles.

Background: Reviews of guideline implementation recommend matching strategies to the specific setting, but provide little specific guidance about how to do so. We hypothesized that the highest level of guideline-concordant care would be achieved where implementation strategies fit well with physicians' cognitive styles.

Methods: We conducted an observational study of the implementation of guidelines for hypertension management among patients with diabetes at 43 Veterans' Health Administration medical center primary care clinics. Clinic leaders provided information about all implementation strategies employed at their sites. Guidelines implementation strategies were classified as education, motivation/incentive, or barrier reduction using a pre-specified system. Physician's cognitive styles were measured on three scales: evidence vs. experience as the basis of knowledge, sensitivity to pragmatic concerns, and conformity to local practices. Doctors' decisions were designated guideline-concordant if the patient's blood pressure was within goal range, or if the blood pressure was out of range and a dose change or medication change was initiated, or if the patient was already using medications from three classes.

Results: The final sample included 163 physicians and 1,174 patients. All of the participating sites used one or more educational approaches to implement the guidelines. Over 90% of the sites also provided group or individual feedback on physician performance on the guidelines, and over 75% implemented some type of reminder system. A minority of sites used monetary incentives, penalties, or barrier reduction. The only type of intervention that was associated with increased guideline-concordant care in a logistic model was barrier reduction (p < 0.02). The interaction between physicians' conformity scale scores and the effect of barrier reduction was significant (p < 0.05); physicians ranking lower on the conformity scale responded more to barrier reduction.

Conclusion: Guidelines implementation strategies that were designed to reduce physician time pressure and task complexity were the only ones that improved performance. Education may have been necessary but was clearly not sufficient, and more was not better. Incentives had no discernible effect. Measurable physician characteristics strongly affected response to implementation strategies.