Factors associated with antibiotic prescribing in a managed care setting: an exploratory investigation

This multi-site, cross-sectional, observational study sought to identify attitudinal and social normative factors associated with the prescribing of oral antibiotics to ambulatory patients in a managed care setting. Participants were 25 physicians specializing in internal medicine, family practice or pediatrics from five ambulatory care clinics within a large, fully integrated health care system in a major midwestern U.S. city. The main outcome measure was number of prescriptions per physician written in the fourth quarter of 1994 for each of seven selected antibiotics. Correlational and multiple regression analyses revealed that behavioral intentions were significantly associated (P < 0.05) with both attitudes and subjective norms. However, physicians' attitudes, subjective norms and intentions were not predictive of actual antibiotic prescribing behavior. Prescribing behavior may have been a function of patient-specific rather than general beliefs about antibiotics. Methodological limitations related to the sample size and the sparseness of the utilization data may also have prevented a significant effect of intentions on behavior from being detected. Alternatively, in managed care settings, it is hypothesized that prescribing behavior may have been influenced more by non-psychological factors, such as management systems, formularies and therapeutic substitution programs, than they were by internal, psychological factors such as attitudes, subjective norms and intentions. Managed care is altering the role of the physician as an autonomous decision-maker. In response, models of prescribing must either incorporate variables such as perceived behavioral control to aid in the prediction of non-volitional behavior, model the decision-making of non-physician managers, or forego psychological models in favor of structural or system-level models of drug utilization.

Efficacy of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors in the treatment of patients with hypercholesterolemia: a meta-analysis of clinical trials

Recent studies have documented the long-term impact of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors on mortality and morbidity related to coronary heart disease, establishing the link between lowering cholesterol levels and reducing cardiac events. Our study was a comparative literature review and meta-analysis of the efficacy of four HMG-CoA reductase inhibitors-fluvastatin, lovastatin, pravastatin, and simvastatin-used in the treatment of patients with hypercholesterolemia. The data sources for our meta-analysis of the efficacy of these cholesterol-lowering agents were 52 randomized, double-masked clinical trials with at least 25 patients per treatment arm. The results showed all four agents to be effective in reducing blood cholesterol levels. We computed summary efficacy estimates for all published dose strengths for the four agents. Fluvastatin 20 mg/d reduced low-density lipoprotein cholesterol (LDL-C) levels by 21.0% and total cholesterol (total-C) levels by 16.4%; fluvastatin 40 mg/d reduced these levels by 23.1% and 17.7%, respectively. Lovastatin 20 mg/d reduced LDL-C levels by 24.9% and total-C levels by 17.7%; lovastatin 80 mg/d reduced these levels by 39.8% and 29.2%, respectively. Pravastatin 10 mg/d reduced LDL-C levels by 19.3% and total-C levels by 14.0%; pravastatin 80 mg/d reduced these levels by 37.7% and 28.7%, respectively. Simvastatin 2.5 mg/d reduced LDL-C levels by 22.9% and total-C levels by 15.7%; simvastatin 40 mg/d reduced these levels by 40.7% and 29.7%, respectively. The results of our meta-analysis can be used in conjunction with treatment objectives and comparative cost-effectiveness data for these agents to decide appropriate therapeutic alternatives for individual patients.