Clinical decision support system

Clinical (or Diagnostic) Decision Support Systems (CDSS) are interactive computer programs that directly assist physicians and other health professionals with decision making tasks. These fall under the class of Decision support systems within medical informatics.

Why do we need such systems at all? If diagnosis becomes the job of the computer program, what will the doctors do? Such questions overlook the key term support - i.e., they are intended to support the clinician, rather than replace them. Computers are not error or fatigue prone like human beings!

In medical diagnosis, there is scope for ambiguity in the inputs, such as the history (patient’s description of the diseased condition), physical examinations (especially in cases of uncooperative or less intelligent patients), and laboratory tests (faulty methods or equipment). Moreover, in treatment, there are the chance of drug reactions and specific allergies, and also of patients' non-compliance of the therapy due to cost or time or adverse reactions. All these factors may not be taken into account by a busy clinician attending hundreds of patients daily.

In all these areas, computers can help the clinician to reach an accurate diagnosis faster. Another new branch of medicine pharmacogenomics is the product of breeding between information technology and biology, leading to individualized treatment.

The basic components of a CDSS include a dynamic (medical) knowledge base and an inference mechanism (usually a set of rules derived from the experts and from the data provided by evidence-based medicine). It may be based on Expert systems or artificial neural networks or both (Connectionist expert systems) - all of which can be loosely termed as Artificial intelligence &endash; AI &endash; techniques.

CDSS may be linked to Electronic health records, for decision making and can also be used for assisting the practice of Evidence-based medicine or EBM in a more structured way. However these systems are not meant to replace physicians, but rather to empower them to make better and more rational decisions.

The role of even an apparently simple search by Google in pointing towards a better diagnosis has been emphasized in a recent publication [1].

Other uses

CDSS offer a powerful medical informatics tool that can be usefully applied to EBM practice. Other applications of informatics that are in ubiquitous in clinical practice nowadays are the use of resources like the Internet and PubMed to look up published medical information, journals and even patient related informational sites or support groups.

Methods of Decision Support

Various tools applied for Artificial intelligence have been used as decision support systems and data mining.

Rule-based expert systems

Here predefined rules in the form of {if-else if-then} guide the decision making. Rules may also be obtained by various forms of decision trees (e.g., Iterative Dichotomizer or ID variants) or Bayesian networks. The early models for building a Knowledge Base and utilizing it for decision-making, were:

1. Logical or deductive: branching logic (e.g., ID3 or iterative dichotomizer 3); e.g., MYCIN, NEOMYCIN [Sotos 1990]
2. Probabilistic: Bayesian e.g., de Dombal [1995] and
3. Hybrid: heuristic reasoning e.g., QMR (Quick Medical Reference), DXplain, ILIAD

A new system is ISABEL.

The critical difficulty in constructing expert systems for medical decision support has been in recruiting experts with domain knowledge to train the system. Training expert systems is time-consuming, and has only produced useable results in narrowly-scoped projects.

Artificial Neural Networks

ANNs (also referred to as connectionist architectures, parallel distributed processing, and neuromorphic systems), are information-processing paradigm inspired by the way the densely interconnected, massively parallel structure of the mammalian brain processes information. ANNs are collections of mathematical models that emulate some of the observed properties of biological nervous systems and draw on the analogies of adaptive biological learning. ANN can perform supervised or unsupervised machine learning, depending on the categorical information maps available at the time of rule inferencing.

Connectionist expert systems

Here the "inferencing" methods of the ANNs can be backtracked and "rules generation" is possible. This might actually lead to the enhancement and enrichment of the medical knowledge base itself. This system architecture corresponds to the concept of "unsupervised" machine learning, where the algorithm looks for patterns in data without being instructed about the actual categories of information. This is also known as data mining

Rule-based CDSS

These are the ones that are mostly found in the commercially available clinical informatics applications. Alerts for allergies and possible drug interactions, prompts for drug doses corrected for weight, height, sex, age and underlying clinical condition are the ones that are most commonly touted as CDSS. Arden Syntax was designed and developed for this very purpose. However, due to some issues related to its acceptance and standardization, it has not really been able to deliver on its immense promise. However, use of Evidence-based medicine (EBM) and Outcomes Analysis (OA) coupled with Bayesian Belief Networks (BBN) can allow for a highly accurate diagnostic tool and treatment planner to be made available in the hands of the healthcare providers.

BBN

It is a mathematical model for using AI (probabilistic) networks for predictive purposes. It is used in the CDSS module as an AI engine to help make probabilistic predictions based upon the observations made by the clinician. These could be used for diagnostics, treatment planning, and even predicting outcomes.

Effectiveness

In internal medicine, a study of four diagnostic support systems diagnosed a collection of tests cases with accuracy ranging from 0.52 to 0.71.

In pedicatrics, a systematic review by the Cochrane Collaboration concluded "there are very limited data from randomised trials on which to assess the effects of clinical rgb(255, 255, 204);">decision rgb(255, 255, 204);">support systems in neonatal care."

Further reading

1. Bergman LG, Fors UG, Computer-aided DSM-IV-diagnostics – acceptance, use and perceived usefulness in relation to users’ learning styles. BMC Med Inform Decis Mak. 2005; 5:1
2. de Dombal FT, Computer-aided diagnosis and medical decision support are not synonymous. Methods Inf Med. 1995; 34: 369-370
3. de Lusignan S, Lakhani M, Chan T, The role of informatics in continuing professional development quality improvement in primary care, J Postgrad Med, 2003, 49: 163 – 165.
4. Garg AX, et al, Effects of computerized clinical decision support systems on practitioner performance and patient outcomes: a systematic review. JAMA. 2005 293:1223-38.
5. Kavitha S, Sarbadhikari SN, Rao Ananth N, Implementation of Decision Tree Classifier Using Classification Algorithm for Some Inborn Errors of Metabolism, Proc. Global Convention and Exposition on Telemedicine and eHealth, New Delhi 17-22 August, 2006.
6. Kunnamo I, et al, 2005, National Decision support database based on computer-readable guidelines and using structured data from electronic patient records http://www.terveysportti.fi/pls/kotisivut/docs/f1917377807/ gin_poster_decision_support_v2.pdf (Accessed July 2006)
7. Lemaire JB, et al, Effectiveness of the Quick Medical Reference as a diagnostic tool, CMAJ • September 21, 1999; 161 (6) http://www.cmaj.ca/cgi/content/full/161/6/725
8. Mendelson D, Carino TV, Evidence-Based Medicine In The United States—De Rigueur Or Dream Deferred? Health Affairs, 2005, 24: 133 – 136. doi: 10.1377/hlthaff.24.1.133
9. Pradhan M, The Crystal Ball - The Future of Informatics and Decision Making, http://www.informatics.adelaide.edu.au/topics/DS/MP-CrystalBallTalk.html 2001 (Accessed July 2006)
10. Sarbadhikari SN, A CDSS for diagnosing amenorrhea www.geocities.com/drsupten 2006
11. Sarbadhikari, SN Automated diagnostic systems. Indian Journal of Medical Informatics, 2004b, 1: 25-28. [Also accessible at http://openmed.nic.in/218/]
12. Sim I, Gorman P, Greenes RA, Haynes RB, Kaplan B, Lehmann H, Tang PC; Clinical decision support systems for the practice of evidence-based medicine, J Am Med Inform Assoc. 2001; 8:527-534.
13. Smith S, The Classification Algorithm http://www.cs.mdx.ac.uk/ staffpages/serengul/The.Classification.algorithm.htm (Accessed July 2006).
14. Sotos G, MYCIN and NEOMYCIN: two approaches to generating explanations in rule-based expert systems. Aviat Space Environ Med. 1990; 61: 950-954.

External links

• OpenClinical maintains an extensive archive of Artificial Intelligence systems in routine clinical use.
• Some useful links
• Prerequisites
• A chapter of a book
• Another book chapter
• A slide show
• A systematic review
• A white paper on the use of CDSS for the practice of EBM
• A recent paper showing that the computerized clinical decision support systems can improve existing antimicrobial management programs
• Improving Outcomes with Clinical Decision Support: An Implementer’s Guide is a new resource designed to help healthcare organizations use clinical decision support (CDS) to measurably improve key healthcare outcomes such as the quality, safety, and cost-effectiveness of care delivery.