Evidence-Based Reproductive Medicine

[[author photo]]Medical practice is more satisfying when clinicians can be confident that their actions and advice are based on the best evidence. Of course, clinical decisions also require doctors to make use of experience and common sense. There is plenty of scope for the use of both evidence and judgment: the average reproductive medicine consultation involves discussions about etiology and prognosis, decisions about diagnosis and therapy, and counseling about costs and side effects. On each point, the principles of evidence-based medicine provide a guide to the quality of the relevant medical care research. Inevitably, however, the application of this evidence must be tailored to the circumstances and needs of individual patients.

Evidence-based medicine is the judicious and conscientious use of current best evidence from medical care research for making medical decisions.[1] The process of finding the best available evidence, rating the quality of the published information, and applying the results in practice is far from novel. Good clinicians have always followed similar steps. What is new, however, is the well-tested set of principles that help to: (1) assess the quality of the evidence; (2) determine the importance of the reported results; and (3) decide whether the valid, important evidence is relevant to patients. In an ideal world, clinicians would have access to the latest medical care research on every important clinical question, but factors such as limited time and the high volume of published evidence stand in the way. Evidence-based medicine helps clinicians to focus on the most valid research literature that will make clinical practice more effective.[2]

In this issue of Seminars in Reproductive Medicine, the authors address medical care problems that arise in the course of a typical clinical practice. Each paper addresses a different clinical question so that this issue can serve as a handbook for getting and using the best evidence, and also as an update on the best evidence pertaining to the clinical examples. The issue is organized to follow the sequence of medical care: for each patient, when the relevant information has been gathered, the clinician formulates a diagnosis, makes a forecast about the prognosis, and considers a treatment plan. The specific treatment choices depend on whether the benefits outweigh any harm that the treatment might cause and on judgments about cost. For readers who wish to go beyond evaluating and interpreting studies, four papers specifically describe how to do good studies about diagnosis, prognosis, treatment, and causation. Also, two papers address the evaluation of cost-effectiveness studies and systematic reviews, and in each of these there is a description of the corresponding methodology.

To orient readers to the resources that are available, the issue begins with James Liu presenting a guide to formulating the question and searching for evidence; the reproductive medicine question arises from a premenopausal woman with hyperandrogenic anovulation who has atypical endometrial hyperplasia. Evers et al then outline how to evaluate a diagnostic test, taking as an example the hysterosalpingogram for tubal patency. Mol and colleagues address the important methodological characteristics of diagnostic studies and further define the unique contributions of cohort studies and randomized controlled trials. Having arrived at a diagnosis, the clinician needs to know the most likely prognosis because that determines whether and when treatment might be needed. Groll and Fritz explore the evaluation of prognosis studies, illustrated by the question of cardiovascular prognosis for women with polycystic ovary syndrome. Eijkemans et al then describe the characteristics of good prognostic studies based on their well-known analyses of the prognosis for women receiving treatment for anovulation. Evaluation of treatment evidence is described by Van Steirteghem and Collins, who provide an appraisal of a randomized trial involving in vitro fertilization compared with intracytoplasmic sperm injection for infertile couples with no male factor. Hughes shows why randomized controlled trials are important and outlines the characteristics of a high-quality trial. No treatment, however, is free from side effects, some of which cause harm; Kashyap and Davis address the evaluation of causation studies with a critical appraisal of whether fertility medications cause ovarian cancer. Daya then goes into the features that one should consider in designing a study to investigate a question about whether a treatment or other exposure causes harm.

Evidence that the benefits of a treatment outweigh the risks does not prove, however, that the treatment is worthwhile, or cost-effective. Van Voorhuis describes the characteristics of a good economic analysis and shows how to determine whether or not the findings are useful in medical practice. Clinicians who conscientiously seek the best current evidence often find that the results are variable and there may even be a lack of agreement among good studies. Schlesselman and Collins conclude the issue with an outline of the methods of systematic review and meta-analysis, and they show how these techniques can help to resolve the conflict caused by diverse study results.

Evidence-based reproductive medicine cannot replace sound clinical judgment, but it can provide access to the research evidence that is needed to implement good judgment. The methods are not complex or obscure. In the future, whether you call it evidence-based medicine, clinical science, or clinical epidemiology, some straightforward stepwise assessment of the burgeoning medical care literature is bound to become a standard operating procedure in the practice of reproductive medicine.

REFERENCES

• 1 Sackett D L, Rosenberg W MC, Gray J AM, Haynes R B, Richardson W S. Evidence based medicine: what it is and what it isn't.  BMJ . 1996;  312 56-57
• 2 Oxman A D, Sackett D L, Guyatt G H. Users' guide to the medical literature I: how to get started.  JAMA . 1993;  270 2093-2095