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Screening for cardiovascular risk: cost-benefit considerations in a comparison of total cholesterol measurements and two compound blood lipid indices |
Berg J E |
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Record Status 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. Health technology Using compound lipid indices versus total cholesterol measurement alone to assess cardiovascular risk in order to increase the number of true positive, and reduce the number of false positive cases.
Economic study type Cost-effectiveness analysis.
Study population All healthy 40 years old adults with cholesterol level equal or greater than 6 mmol
Setting Occupational health service. The economic study was carried out in Norway.
Dates to which data relate Effectiveness data related to the period 1991 to 1993. 1992 cost and resource data were used.
Source of effectiveness data The effectiveness data were based on a review of previously completed studies (Berg and Hostmark, 1993; Stampfer et al 1991; Kuyl et al. 1992; Hostmark et al, 1991)
Link between effectiveness and cost data The costing was undertaken retrospectively on the same patient sample.
Outcomes assessed in the review The outcomes assessed were the sensitivity and specificity of the screening tests, and the avoidance of false positive and false negative cases.
Study designs and other criteria for inclusion in the review Sources searched to identify primary studies Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data Number of primary studies included Four primary studies were included in the review. Two of them were unspecified prospective studies, one was a case control study, and one was an unspecified study.
Methods of combining primary studies Two of the primary studies measured the same outcome, but the combination of results was not stated. The rest of the primary studies were not combined as they measured different health outcomes.
Investigation of differences between primary studies Two studies measured the relationship between cholesterol and lipoprotein concentration and cardiovascular mortality. One measured the relationship between compound indices and atherosclerosis and the other measured the sensitivity and specificity of different screening methods.
Results of the review According to total cholesterol to high-density lipoprotein cholesterol (TC:HDLC) ratios,19.9% of women and 29.9% of men will be allocated to advice or treatment which they do not required. The corresponding figures for atherogenic index were 10.4% of women and 15.2% of men. By screening the population of 200,000 people, the number of both false positive and false negative cases would be reduced by using the compound indices compared to using total cholesterol measurement alone.
Measure of benefits used in the economic analysis Outcomes measured were the sensitivity and specificity of the screening tests, and the avoidance of false positive and false negative cases.
Direct costs Some quantities and costs were analysed separately. Direct drug costs, costs of screening and doctors' visit costs were included. 1992 costs were used.
Indirect Costs Some quantities and costs were analysed separately. Loss of production and abstention from former consumption were measured.
Sensitivity analysis No sensitivity analysis was performed.
Estimated benefits used in the economic analysis According to TC:HDLC ratios 19.9% of women and 29.9% of men who were identified as positive cases according to the cholesterol test result alone would be allocated to advice or treatment that they did not need. The corresponding figures for atherogenic index were 10.4% of women and 15.2% of men. The false negative cases according to TC:HDLC ratios were 15.1% of women and 12.2% of men, while in the atherogenic index they were 22.9% of women and 18.5% of men.
Using the TC:HDLC ratios, 19,900 false positive women and 29,200 false positive men would be inappropriately advised to restrict their lifestyle, from the 100,000 women and 100,000 men eligible for screening. Using the atherogenic index 10,400 men and 15,200 women would be inappropriately advised to restrict their lifestyle. Using the TC:HDLC ratios 15,100 false negative women and 12,200 false negative men would not be appropriately advised to restrict their lifestyle. Using the atherogenic index 18,500 men and 22,900 women men would not be appropriately advised to restrict their lifestyle.
Cost results Using the TC:HDLC ratios the total cost of false positive cases (49,100 patients) was 437,431,900 Nkr. Using the atherogenic index 25,600 false positive cases cost 228,070,400 Nkr. The net cost of screening 200,000 people was 7,600,000 Nkr for the TC:HDLC test, and 47,600,000 Nkr for the atherogenic index test. The value of extending screening to those 200,000 people would be 7,862,400 Nkr using the TC:HDLC ratio and 11,923,200 Nkr using the atherogenic index.
Synthesis of costs and benefits The total gain of screening 200,000 people using the TC:HDLC ratio would be 437,694,300 Nkr, and using the atherogenic index would be 192,393,600 Nkr. Using compound lipid indices in the screening for cardiovascular diseases was the dominant strategy, the TC:HDLC ratio being particularly dominant.
Authors' conclusions Using compound lipid indices in the screening for cardiovascular diseases was the dominant strategy.
CRD Commentary A justification was given for the comparator used. More details on the derivation and the justification of effectiveness data could have been useful. It is difficult to judge the quality of cost data since no details of the sources were reported. Cost data related to a Norwegian setting and may not be applicable to other countries. A sensitivity analysis of costs could therefore have strengthened the validity and generalisability of the study.
Bibliographic details Berg J E. Screening for cardiovascular risk: cost-benefit considerations in a comparison of total cholesterol measurements and two compound blood lipid indices. Journal of Cardiovascular Risk 1995; 2(5): 441-447 Indexing Status Subject indexing assigned by NLM MeSH Adult; Aged; Apolipoproteins A /blood; Apolipoproteins B /blood; Cardiovascular Diseases /economics /prevention & Cholesterol /blood; Cholesterol, HDL /blood; Cholesterol, LDL /blood; Cost-Benefit Analysis; False Positive Reactions; Female; Health Education /economics; Humans; Hypercholesterolemia /economics /prevention & Lipids /blood; Male; Mass Screening /economics; Middle Aged; Norway; Occupational Health Services /economics; control; control AccessionNumber 21996001696 Date bibliographic record published 31/01/1998 Date abstract record published 31/01/1998 |
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