EDITORIAL

EVIDENCE BASED MEDICINE IN PSYCHIATRY

Dr. S. SHAJI

Evidence Based Medicine has been proposed as a new paradigm of practicing  medicine. By definition it is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients (Sackett et al; 1996) Evidence based medicine integrates research evidence, clinicians expertise and patient preferences to guide decision making.

The process of evidence based medicine practice involves the following five stages :

1. Defining a clinically relevant question.

2. Searching for the best evidence

3. Appraising the quality of evidence.

4. Applying the evidence to clinical practice.

5. Evaluating the process.

The basic question in Evidence Based Medicine is, How the evidence is produced and how it is applied. Good evidence is evidence that is based upon rebuts study design ie., the evidences that comes from randomized controlled trials, systematic reviews and meta-analysis. The evidences should be relevant to your individual patient. It can be obtained rapidly enough to be of use to the physician and the individual patients.

EBM asserts the primacy of randomized controlled trials for demonstrating efficacy and in some cases the use of meta analysis or systematic reviews conducted according to the pre-specified criteria.

There are many factors which make EBM approach difficult in psychiatry, which include perceived limitations in the methodology of randomized controlled trials and systematic reviews, gaps in evidence base, problems in interpreting available evidence and the neglect of the individual patient's uniqueness.

Systematic reviews and meta analysis are retrospective observational studies intermediate in design between primary research and traditional narrative reviews. The units of observation are the results obtained from other studies, hence the reviewer has many constraints that can lead to biases and subsequent errors (Tharyan 2004). There are a number of biases which can effect the validity of systematic reviews. Sampling biases can occur due to publication bias. Publication bias refers to the tendency for studies that report statistically significant results to be published. Unpublished studies are likely to have negative results as well as smaller sample size. Reliance only on the results of published trials produces over estimates of treatment effects and leads to erroneous conclusion that could prove detrimental to patient care.

Four sources of biases are relevant in assessing the quality of trials which include selection bias, performance bias, attrition bias and detection bias. The accuracy and inter-observer validity of data extraction from trials is a potential source of bias in meta-analysis. Biases in analysing and interpreting results can be another source of error.

Psychiatric was one of the first medical specialties to use the tools of Evidence Based Medicine and as many treatment decisions in psychiatry are evidence based as in general medicine. Psychiatry is a branch of medicine with its own unique characteristics. The practice psychological medicine involves difficult decisions about diagnosis, treatment and assessing prognosis. If we look at the various stages in the process of evidence based medical practice, it is evident that there can be problems related to each stages.

One of the main apprehensions about EBM is that it may be used by health care providers and managers as a tool to dictate medical practice and it may adversely affect physician's autonomy. The potential for abuse remains a challenge for all evidence based practice. Despite improving evidence base for practice it is still suspectable to compromise and misrepresentation due to unexamined and undeclared bias. Unless the potential for abuse is recognized and checked, EBM in psychiatry is in danger of being discredited at the hands of some of its own proponents. There is a need for more rigorous pursuit of evidence based psychiatry, including more systematic declaration of bias in all research, whether qualitative or quantitative in design.

Though we can point out many imitations regarding the practice of EBM in Mental health there can be consensus about many of its positive aspects. EBM can be utilised as a tool to overcome the problems faced by clinicians in their day to day clinical practice. Today only 4% of health care decisions are based on sound evidence, 45% on strong consensus among physicians and in 51% neither (Segars & Rouse). By providing clinicians a set of skills which allow them to base clinical decisions on the best available, Most up to date evidence based medicine, evidence based medicine also aims to be a method of self directed, career-long learning (Geddes & Harrison, 1997).

References

Geddes, J.R. & Harrison, P.J. (1997) Closing the gap between Research and practice. British Journal of Psychiatry, 171, 220-225.

Sackett, D.L., Rosenberg, W.H., Gray, J.A., Haynes, R.B. & Richardson W.S.(1996) Evidence Based Medicine: What it is and  what it isn't. British Medical Journal, 317,71-72.

Segars, M. & Rouse, D.J. (1998). Evidence Based Medicine. Journal of Clinical Obstetrics and Gynecology, 41, 233

Tharyan, P. (1998). The relevance of Meta-analysis, Systematic reviews and the Cochran Collaboration to Clinical Psychiatry, Indian Journal of Psychiatry Vol.40, 2, 135-147.