|Enhanced low-density lipoprotein cholesterol reduction and cost-effectiveness by low-dose colestipol plus lovastatin combination therapy
|Schrott H G, Stein E A, Dujovne C A, Davidson M H, Goris G B, Oliphant T H, Phillips J C, Shawaryn G G
This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.
Use of low-dose combination of drug regimens of colestipol and lovastatin in reducing low-density lipoprotein (LDL) cholesterol levels.
Economic study type
Patients with moderate hypercholesterolemia.
Not explicitly stated. The economic study was conducted in the USA.
Dates to which data relate
Dates for the effectiveness data were not stated. 1994 prices were used.
Source of effectiveness data
Link between effectiveness and cost data
Costing was undertaken retrospectively on the same patient sample as that used in the effectiveness study.
96 patients with moderate hypercholesterolemia were randomly assigned to 4 different double-blind treatment regimens. Randomization to the 12-week drug treatment occurred after 6 weeks of low fat and low cholesterol diet, leaving 94 patients: 24 to the placebo group, 23 to the colestipol 5 g and lovastatin 20 mg/day group (C5+L20), 23 to the colestipol 10 g and lovastatin 20 mg/day group (C10+L20) and 24 to the lovastatin 40 mg/day group (L40). 3 patients did not complete the full 18 week study. The sample size was not determined by a power calculation.
The study was a randomized double-blind, parallel-design, placebo-controlled design.
Analysis of effectiveness
The analysis of the clinical study was based on intention to treat. The primary health outcomes used in the analysis were: total cholesterol, LDL cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, apolipoprotein A-I, apolipoprotein B, lipoprotein A-I, and lipoprotein levels.
The C10+L20 group achieved the greatest reduction in total cholesterol (-32%) and LDL cholesterol (-48%) levels from baseline. This combination also achieved significantly greater reductions in LDL cholesterol levels than the C5+L20 and L40 groups (p<0.01). Whereas mean total apolipoprotein A-I levels increased with all treatments (p<0.05), lipoprotein particles A-I were significantly increased in the C10+L20 group (p<0.01) only.
The combination of low-dose lovastatin (20 mg/day) with low-dose colestipol (5 or 10 g/day) produces LDL cholesterol reductions equal to or greater than higher doses of lovastatin (40 mg/day). Side effects reported by more than 2 subjects in any group during treatment were: headache, chest pain, common cold, constipation, abdominal discomfort, nausea and joint pain. Complaints of constipation more frequent in the colestipol groups.
Measure of benefits used in the economic analysis
The benefit measure was the percentage LDL cholesterol reduction.
Direct health service costs were considered namely drug costs. Quantities and costs were not reported separately.1994 prices were used.
Estimated benefits used in the economic analysis
The C10+L20 group achieved the greatest reduction in total cholesterol (-32%) and LDL cholesterol (-48%) levels from baseline. This combination also exhibited significantly greater reductions in LDl cholesterol levels than C5+L20 and L40 groups.
The annual cost was $803 for C5+L20, $1018 for C10+L20 and $1047 for L40.
Synthesis of costs and benefits
The annual cost ($)/percent LDL cholesterol lowering during treatment was: $21.13 for C5+L20, $21.21 for C10+L20 and $27.56 for L40.
Low-dose combination therapy, especially with C10+L20, offered significant advantages over larger dose lovastatin treatment in terms of both LDL cholesterol reduction and cost efficiency.
This was a good study both in terms of design and economic analysis. The choice of comparators was sensible and explicitly stated. Clinical evidence was based on a randomised, double blind trial with statistically significant results. Costing, however, included only drug costs. A more elaborate cost analysis including statistical tests could have been useful.
Source of funding
Supported by a grant from Upjohn Laboratories, The Upjohn Company, Kalamazoo, Michigan.
Schrott H G, Stein E A, Dujovne C A, Davidson M H, Goris G B, Oliphant T H, Phillips J C, Shawaryn G G. Enhanced low-density lipoprotein cholesterol reduction and cost-effectiveness by low-dose colestipol plus lovastatin combination therapy. American Journal of Cardiology 1995; 75(1): 34-39
Subject indexing assigned by NLM
Apolipoproteins /blood; Cholesterol, LDL /blood; Colestipol /administration & Cost-Benefit Analysis; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Hypercholesterolemia /blood /drug therapy /economics; Lipids /blood; Lipoproteins /blood; Lovastatin /administration & Male; Middle Aged; dosage /therapeutic use; dosage /therapeutic use
Date bibliographic record published
Date abstract record published