1.HTA (=Health Technology Assessment)
2.EBM (= Evidense Based Medicine)
3.HE (=Health Economy)
4.Different perspectives in medical decision making?

HTA/Health Technology Assesment
Equivalent danish acronym: MTV (Medicinsk Teknologi-vurdering)
Short definition: HTA is the “decision support information” necessary for assessing the value of medical technology. The decision support information comprise data generated with different analytical perspectives: Technology(safety and effectiveness) and Health Economy (budget impact and/or e.g. cost-effectiveness). In the Danish HTA definition the organisational perspective and patient perspective are also included in the definition.
Methodology: For specific national methodology guidelines, please consult the websites of the national HTA egencies (se LINKs). One important international methodology guidelines is the “TA101”.

EBM/Evidence Based Medicine
Short definition: EBM implies a quality rating of clinical trials giving rise to a ranking of validity of the derived results or postulates.
Methodology: The gold standard for quality rating is described in the “Cochrane manual” and the resulting Evidence reports is published in the “Cochrane Library”. There are however a series of “evidence reports” using less stringent but satisfactory quality rating methods arising from the national HTA-agencies or from professional medical societies.
A shortened Danish methodology paper is available : “Litteratursøgning og evidensvurdering – en kort vejledning”.
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HE/Health Economy
Short definition: Health Economy is a broad discipline comprising all kinds of economic assessments and perspectives. The most commonly used perspective used in HTA is the “society perspective”. It is adviced to consult a textbook of health Economy to learn the precise definitions and theory behind the different terms.
Methodology: For easy introduction the following short articles can be read:
Assessing quality in decision Analytical modeling, York.
BMJ-article, Economic notes-Economic Evaluation.
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Combined use of Health Economy, EBM and HTA
The history of the combined use of these principles in medical decision making has been summarized in the short article below:

Different perspectives in medical decision making?

We define information used to support clinical decisions as decision support information. Scientific articles have through centuries been an important source to decision support information.
During the latest 2 decades the paradigm of evidence has gradually become the gold standard for quality assessment of clinical scientific publications. The driving force behind this development was an unsatisfactory and very large variation in quality of the design of the underlying studies. Another driving force was also a large de facto variation in the treatment of patients having the same disease from region to region and from doctor to doctor within the same region. (Eddy 1992) (Grimes 1993)
The aim of the paradigm of evidence (Dans et al 1998) (Haynes and Haines, 1998) is a search for the ultimate proof that new treatments are effective and safe compared to conventional treatments.
Today “evidence” is a mantra when decisions are made to introduce new medical technologies. The concept of medical evidence was originally developed to assist the single clinician with the decision processes concerning his own patients (Sackett et al.1996).
Today the application of the paradigm of evidence is more widespread than this (The Scharr institute: This is due to the fact that the paradigm of evidence has also become an integral part of HTA (Health Technology assessment) (Perleth, et al, 2001). The application of the paradigm of evidence is today applied by a broader group of professionals. Publically financed HTA-institutions has been set up in many western countries with the aim of providing independent decision support information for politicians, hospital managers, medicines agencies, administrators, medical experts, professors and clinicians.

One of the earliest places to introduce the paradigm of evidence was the requirement for blinded randomized controlled trials (RCT’s), before market authorizations can be granted to new pharmceutical drugs. This praxis is today defined and regulated in the international ICH- guidelines (ICH, International Committee of Harmonization) with the aim of harmonizing the rules around Registration of new pharmaceutical drugs. (Rockhold 2002)
The focus of the ICH guidelines is to assure that new drugs have a sufficient safety and efficacy. The efficacy is assessed by running a randomized controlled trial with an adequate control group, in order to create the strongest possible evidence for a causal relation between the treatment and the observed efficacy.
A significant threat against strong evidence is the presence of confounders or other sources of bias. This risk is minimized by the exclusion of patients with confounding diseases, treatments or other factors that are potentially able to harm a clear conclusion on the study. In this way a high internal validity is created for the proof of efficacy.
There has been an increasing focus on the fact that narrow patient inclusion criteria does not reflect the patients that occur in clinical practice and this is why data from RCT’s are not ideal for Health Economic calculations and modeling. (Revicki and Frank 1999). This is also why naturalistic data sources are increasingly preferred in many countries for Health Economic calculations. This is done in order to assure that such calculations of e.g. cost effectiveness are done on realistic patient data.
(Guidelines for economic evaluation of pharmaceuticals; Canada, 1997) (Taylor 2001) (The pharmacoeconomic Outlook to 2003).
The idealised requirement of the application of more naturalistic data in Health Economic analysis is therefore a new challenge that goes beyond the design of clinical trials for registration purposes.
(Powe and Griffiths, 1995)

Jørgen Folkersen MD, Dr. Sc.

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Reference List

Guidelines for economic evaluation of pharmaceuticals: Canada. 1997. CCOHTA Publications, Ontario Canada.

The pharmacoeconomic Outlook to 2003. 2003. Reuters, Datamonitor PLC.
Eddy, D. M. "Medicine, money, and mathematics." Bull Am Coll.Surg. 77.6 (1992): 36-49.

Grimes, D. A. "Technology follies. The uncritical acceptance of medical innovation." JAMA 269.23 (1993): 3030-33.

Perleth, M., E. Jakubowski, and R. Busse. "What is 'best practice' in health care? State of the art and perspectives in improving the effectiveness and efficiency of the European health care systems." Health Policy 56.3 (2001): 235-50.

Powe, N. R. and R. I. Griffiths. "The clinical-economic trial: promise, problems, and challenges." Control Clin.Trials 16.6 (1995): 377-94.

Revicki, D. A. and L. Frank. "Pharmacoeconomic evaluation in the real world. Effectiveness versus efficacy studies." Pharmacoeconomics. 15.5 (1999): 423-34.

Rockhold, F. W. "Industry perspectives on ICH guidelines." Stat.Med 21.19 (2002): 2949-57.

Sackett, D. L. et al. "Evidence Based Medicine: what it is and what it isn't." BMJ 312.7023 (1996): 71-72.

Taylor, R. "Using health outcomes data to inform decision-making: government agency perspective." Pharmacoeconomics. 19 Suppl 2 (2001): 33-38.

Background knowledge