Does a Lipid Clinic Increase Compliance With National Cholesterol Education Program Treatment Guidelines? Report of a Case-Matched Controlled Study.

ABSTRACT: Despite a national effort to promote measurement of cholesterol levels in adults, previous studies have shown that poor control is the norm. We sought to determine the effects of implementation of a structured lipid treatment program. Forty-one clinic-managed patients were matched with similar control patients. Clinic patients had more risk factors overall and therefore lower low-density lipoprotein (LDL) goals. They had significantly greater LDL reduction after the 6-month visit, resulting in a lower final LDL level. The percentage of patients reaching the LDL goal recommended by the National Cholesterol Education Program (NCEP) was the primary endpoint of the study. The NCEP guidelines were followed more frequently within the clinic, and significantly more clinic patients were treated to NCEP LDL goal than control patients. When indicated medication was more frequently used and titrated in clinic patients. This study shows the efficacy of an organized lipid treatment clinic in management of dyslip idemia.

THE National Cholesterol Education Program (NCEP) Adult Treatment Panel [1] promulgated guidelines to help health care practitioners treat patients with lipid disorders. Guidelines identify LDL cholesterol concentrations as a major cardiovascular risk predictor and specify treatment goals based on LDL levels. However, data from the National Health and Nutrition Examination Survey (NHANES III) [2] revealed that 57% of adults older than age 20 and having two or more risk factors were not at LDL target level and 85% of patients with coronary artery disease (CAD) were not at target level. A study in the veterans' population showed that only 36.2% of patients with two or more risk factors and taking medication for primary prevention met their LDL goal, and only 35.4% of patients with CAD met their LDL goal. [3] A risk-based capitated study, which reviewed care of patients in a southern Florida health maintenance organization, revealed that only 13.6% of patients who qualified for drug therapy (according to NCEP AT P-II) had ever been treated with cholesterol-lowering drugs. [4]

Many facilities have developed specialized clinics in attempts to improve the rate of NCEP goal attainment. The Naval Hospital in Jacksonville developed a Lipid Disorders Clinic in 1997, using recommendations of the NCEP treatment panel as the basis for treatment. The purpose of the clinic was to optimize the care for patients with dyslipidemia by providing appropriate monitoring, education, and follow-up.

LIPID CLINIC PROCEDURES

The lipid clinic operates two half days per week in the internal medicine clinic module and is staffed by a clinical pharmacist. An internal medicine department physician provides medical supervision of the clinic. Patients were eligible to be enrolled in the clinic by any health care provider within the facility. The pharmacist scheduled all new appointments for the clinic and ordered appropriate laboratory studies before the first visit. At the first clinic visit, each patient was interviewed by the clinical pharmacist for baseline information. An LDL goal was determined and recorded in the clinic chart. All patients were offered a formal dietary consultation with a registered dietitian, and the American Heart Association Step 1 or 2 diet was prescribed for 3 to 6 months. Drug therapy may have been initiated concurrently in accordance with the NCEP recommended guidelines. Counseling for smoking cessation and alcohol consumption was also provided when appropriate, and enrollment in a formal smoking cessation program was encouraged. Liver function tests were monitored by the clinic if indicated by drug therapy. Thyroid function was also assessed if indicated. Any patient who missed a follow-up appointment was called and rescheduled. Patients were evaluated by the clinic every 3 months until NCEP goal was met. Compliance with diet and drug therapy was assessed and discussed at each follow-up visit. After reaching LDL goal at two consecutive measurements, visits were decreased to semiannually.

METHODS

This retrospective, case-matched study was designed to compare patients managed in our formal lipid clinic (clinic patients) and patients managed elsewhere in our system (control), with the primary endpoint being NCEP LDL goal attainment. Study sample size was calculated to detect a 20% difference with 80% power and 95% confidence. We reviewed 41 consecutive clinic patients.

Clinic patients were randomly selected and matched retrospectively to facility patients for whom cholesterol determinations were ordered. Patients were matched according to baseline LDL value (+/- 10%), sex, and age.

RESULTS

A total of 41 matched cases were included in the study Each patient record was reviewed retrospectively for baseline and 6-month visit data. Additional interim visit information was also recorded if available. There was no statistically significant difference between the clinic patients and controls in baseline values of the following: total cholesterol, LDL, HDL, and triglycerides (t test of the mean), as shown in Table 1. Clinic patients required a significantly greater reduction in LDL to reach NCEP goal (P= .0082). In addition, a chi-square analysis of the LDL goal between the clinic and control patients showed that the clinic group had significantly more patients with an LDL goal of 100 mg/dL and fewer with a goal of 160 mg/dL than the facility group (P= .006) (Table 2). This was the result of the significantly greater number of risk factors present in clinic patients versus facility control patients (2.8 and 2.0, respectively; P=.0007). Clinic patients had significantly greater LDL reduction after the 6-month visit (P = .014), resulting in a lower final LDL (114 and 143 mg/dL, respectively; P=.0001).

LDL Goal Attainment

The percentage of patients reaching the NCEP LDL goal was the primary endpoint of the study. Sixty-six percent of the clinic patients attained their NCEP goal, compared with 41% of the control patients. This difference was statistically significant (P = .027) (Table 3). Fourteen clinic patients and 3 control patients had CAD. Of the clinic patients with CAD, 57% attained NCEP goal, compared with 0% of the control patients. However, the small number of patients with CAD limits making any strong conclusion about this class of patients.

NCEP Guidelines

Each patient was assessed to see whether the treatment of hyperlipidemia followed the NCEP guidelines. Significantly more patients in the clinic group were treated according to NCEP guidelines (P = .000, chi-square) (Table 3). The primary criteria by which practitioners were judged to have not followed NCEP guidelines were not initiating drug therapy when indicated and not titrating the dose when the LDL goal was not achieved.

Percent Reduction of LDL

The percent LDL reduction achieved by the clinic health care providers was an average of 26%. Facility providers treating the control patients achieved only an average of 6% reduction in LDL. This difference was statistically significant (P= .019, 2-tailed t test).

Medication Use Patterns

Of patients eligible for pharmacotherapy according to the NCEP guidelines, 26 of 40 clinic patients and 11 of 36 nonclinic patients were treated with medication (P = .003, chi-square). In clinic-managed patients treated with medications, 26 were given HMG Co-A reductase inhibitors (25 patients took atorvastatin, and 1 patient took pravastatin), 3 were given niacin, 1 was given colestipol, and 1 cholestyramine. Among nonclinic patients, 13 were treated with medication (10 with atorvastatin, 1 with pravastatin, 2 with gemfibrozil). Of patients not reaching their LDL goal at the first measurement after treatment initiation, 12 of 15 clinic patients and 3 of 13 nonclinic patients had medications increased in an attempt to achieve goal LDL levels (P= .017, chi-square).

DISCUSSION

Many published trials support the direct relationship between the levels of LDL and the rate of CAD. [2,5-7] Despite publication and dissemination of guidelines and media attention, it has been reported in the literature that 15% to 43% of patients met their NCEP goal. [8]

Barriers to effective treatment are poorly characterized, and we did not investigate these barriers in our study. We postulate that they include provider knowledge deficits, patient disinterest and noncompliance, and expense of treatment.

The LDL goal attainment was 23% to 51% higher in our clinic patients relative to the published literature. The control patients reached NCEP goal at the national average. This is remarkable in light of the fact that the clinic patients had an overall lower and therefore more difficult goal to achieve. We found our lipid treatment clinic to be well received among our medical staff, and the multidisciplinary approach has improved patient satisfaction. We believe that clinic patients likely had improved compliance with medications and life-style change recommendations as well, though these factors were not measured in this study.

CONCLUSION

Our study results suggest that a formally structured lipid clinic has a significant positive impact on the percentage of patients reaching NCEP LDL goal, following NCEP guidelines for initiating and titrating drug therapy, and overall percent reduction in LDL. This has been shown to significantly improve outcomes for patients with and without CAD. Treatment of hyperlipidemia has been correlated with lower CAD event rates. [5,9]

From the Departments of Internal Medicine and Pharmacy, Jacksonville Naval Hospital, Jacksonville, Fla.

References

(1.) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in adults. Summary of the second report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol. JAMA 1993; 269:3015-3023

(2.) Hoerger TJ, Bala MV, Bray JW, et al: Treatment patterns and distribution of low-density lipoprotein cholesterol levels in treatment-eligible United States adults. Am J Cardiol 1998; 82:61-65

(3.) Ito MK, Stolley SN, Morreale AP,, et al: Rationale, design, and baseline results of the Pravastatin-to-Simavastatin Conversion Lipid Optimization Program (PSCOP). Am J Health Syst Pharm 1999; 56:1107-1113

(4.) Lai LL, Poblet M, Bello C: Are patients with hyperlipidemia being treated? investigation of cholesterol treatment practices in an HMO primary care setting. South Med J 2000; 93:283-286

(5.) West of Scotland Coronary Prevention Group: WOSCOP identification of high-risk groups and compare with other cardiovascular intervention trials. Lancet 1996; 348:1339-1342

(6.) La Rosa JC, Hunninghake D, Bush D, et al: The cholesterol facts. a summary of the evidence relating dietary fats, serum cholesterol, and coronary heart disease, a joint statement by the American Heart Association and the National Heart, Lung, and Blood Institute, the Task Force on Cholesterol Issues, American Heart Association. Circulation 1990; 81:1721-1733

(7.) Gordon T, Kannel WB, Castelli WP, et al: Lipoproteins, cardiovascular disease, and death: the Framingham Study. Arch Intern Med 1981; 141:1128-1131

(8.) Marcelino JJ, Feingold KR: Inadequate treatment with HMG Co-A reductase inhibitors by health care providers. Am J Med 1996; 100:605-610

(9.) Scandinavian Simvastatin Survival Study Group: Randomized trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4s). Lancet 1994; 344:1383-1389

TABLE 1

Baseline and Final Patient Information


                                           Clinic
                                          Patients

Average age (yrs)                           54
Average No. of risk factors                  2.8
Baseline LDL (mg/dL)                     157 (SD 30)
Final LDL (mg/dL)                        114 (SD 30)
Baseline total cholesterol (mg/dL)       232 (SD 38)
Final total cholesterol (mg/dL)          191 (SD 35)
LDL reduction required at baseline (1%)   13 (SD 16)
LDL reduction achieved (1%)               11 (SD 18)




                                         Facility Patients
                                            (Controls)      P Value

Average age (yrs)                              54              -
Average No. of risk factors                     2.0         P = .0007
Baseline LDL (mg/dL)                         157 (SD 32)    P = 1.0
Final LDL (mg/dL)                            143 (SD 37)    P = .0001
Baseline total cholesterol (mg/dL)           224 (SD 65)    P = .49
Final total cholesterol (mg/dL)              195 (SD 85)    P = .80
LDL reduction required at baseline (1%)        9 (SD 14)    P = .0082
LDL reduction achieved (1%)                  2.3 (SD 15)    P = .019



LDL = Low-density lipoprotein.
TABLE 2

Low-Density Lipoprotein (LDL) Goal


                                       LDL Goal
                             ([less than or equal to]100)

Clinic patients                           13
Facility (control) patients                3



                                 LDL Goal          LDL Goal
                             ([less than]130)  ([less than]160)

Clinic patients                     22                 6
Facility (control) patients         23                15
TABLE 3

NCEP [*] Goal Attainment and NCEP Guidelines


                           Lipid Clinic  Control  P Value

NCEP goal attainment           66%         41%    P = .027
NCEP goal attainment
 (subset of patients with
 coronary artery disease)      57%          0%    ND
Treated according to
 NCEP guidelines               93%         37%    P = .000



(*)National Cholesterol Education Program. [1]

KEY POINTS

* A formally structured lipid clinic has a significant positive impact on the percentage of patients reaching National Cholesterol Education Program (NCEP) low-density lipoprotein (LDL) goals.

* A structured lipid clinic has a positive impact on patients following NCEP guidelines for initiating and titrating drug therapy and overall percent reduction in LDL.

* This type of clinic improved outcomes for patients with and without coronary artery disease (CAD).

* Treatment of hyperlipidemia has been correlated with lower rates of CAD.