Objective: To determine the effectiveness of a nurse case management model to lower blood lipids in patients with coronary heart disease (CHD).
Design: A randomized controlled trial with follow-up through one year.
Population, Sample, Setting, Years: A total of 228 consecutive, eligible hypercholesterolemic adults with CHD were recruited during hospitalization following coronary revascularization at a large tertiary medical center from January 1998 to December 2000.
Intervention and Outcome Variables: Patients were randomized to receive lipid management, including individualized lifestyle modification and pharmacologic intervention, from a nurse practitioner for one year following discharge in addition to their usual care (NURS) or to usual care enhanced with feedback regarding lipids to their primary provider and /or cardiologist (EUC). Changes in lipids, dietary fat intake, and physical activity level were measured at baseline and one year following revascularization.
Methods: Patients randomized to EUC were followed by their usual primary providers and/or cardiologists. Usual care was enhanced by sending results of full lipid profiles to EUC patients and their physicians. Patients also received recommendations regarding goal levels for lipoproteins and general recommendations for diet and physical activity at baseline and again at the time of follow-ups. Patients randomized to the NURS group received case management from a nurse practitioner for one year following discharge. The nurse practitioner augmented the physician’s cardiac care by providing one outpatient visit 4 to 6 weeks after discharge to initiate a plan for lipid management. The plan included counseling for lifestyle modifications and prescription or adjustment of appropriate lipid-lowering medications. Follow-up telephone calls to the patient reinforced counseling and prescribed appropriate adjustments in medications based on follow-up blood tests. The nurse practitioner initiated or adjusted drug therapy with the use of lipid management algorithms. The results of lipid testing and adjustments of medications were communicated by letter to the primary provider and/or cardiologist on a regular basis. Serum total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C) levels were measured by standardized methods after a 12-hour overnight fast. Low-density lipoprotein cholesterol (LDL-C) was estimated using the Friedewald Equation. Dietary intake was assessed by a standardized food frequency instrument, the Block Health Habits and History Questionnaire. Physical activity was measured by the Physical Activity Questionnaire from the Aerobics Center Longitudinal Study. Outcome data were analyzed using an intention to treat analysis based on all randomized patients, as randomized. To determine the factors that independently predicted LDL-C at one year, a multiple linear regression was used.
Findings: Significantly more patients in the NURS group vs. the EUC group achieved LDL-C levels lower than 2.59 mmol/dL (100mg/dL)(65% vs 32%; p=.001), the target goal for patients with CHD. At one year, 87% of patients in the NURS group and 79% of patients in the EUC group were on lipid-lowering drugs. Favorable changes in lipids were accompanied by significant improvements in dietary and exercise patterns in the NURS group. Compared to patients in the EUC group, those in the NURS group reported a greater reduction in dietary consumption of calories from total fat (p=.0004), saturated fat (p=.0004), and cholesterol (p=.02), as well as a trend for a greater increase in dietary fiber (p=.13), while caloric intake was similar. A significantly higher proportion of patients in the NURS group (40%) reported exercising at a level of 6 MET hours per week compared with patients in the EUC group (26%) (p=.02). In multivariate analysis adjusting for other covariates, being assigned to the NURS group (p <.0001) and being on a lipid-lowering medication (p=.001) were significant independent predictors of LDL-C.
Conclusions: Despite the large body of evidence confirming the effectiveness of lipid lowering for the secondary prevention of CHD events, undertreatment of hyperlipidemia is common; and, those who do receive lipid-lowering medications often fail to attain the recommended goals. Results of this study indicate that control of hypercholesterolemia in patients who have undergone coronary revascularization can be improved by a nurse case management program.
Implications: As the National Cholesterol Education Program Adult Treatment Panel III guidelines have broadened the definition of high-risk populations that warrant aggressive treatment, nurse case management programs may offer key opportunities to enhance appropriate application of new treatment paradigms.
Back to Studies in Health Care Economics and Interventions
Back to The Advancing Nursing Practice Excellence: State of the Science