Strength of Evidence; Empirically Supported Treatments

The Evidence Pyramid for Treatment Effectiveness Questions

Clinical Trials – Phases of Development Phase I: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects. Phase II: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety. Phase III: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely. Phase IV: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.

Strength of Evidence Strength of research design: SR of homogeneous studies at the highest level; combines individual studies using a summary metric RCT strongest single research design capable of demonstrating causation Other key dimensions Consistency of evidence Specificity Dose-response Biological or psychological plausability Common sense

RCT Example - NRT

RCT Example – Buproprion v. Placebo

Case Series and Case Reports A group or series of case reports involving patients who were given similar treatment. Reports of case series usually contain detailed information about the individual patients. This includes demographic information (for example, age, gender, ethnic origin) and information on diagnosis, treatment, response to treatment, and follow-up after treatment.

Cohort Studies Definition ||Advantages ||Disadvantages  A Cohort Study is a study in which subjects who presently have a certain condition and/or receive a particular treatment are followed over time and compared with another group who are not affected by the condition under investigation. For research purposes, a cohort is any group of individuals who are linked in some way or who have experienced the same significant life event within a given period. There are many kinds of cohorts, including birth (for example, all those who born between 1970 and 1975) disease, education, employment, family formation, etc. Any study in which there are measures of some characteristic of one or more cohorts at two or more points in time is cohort analysis. In some cases, cohort studies are preferred to randomized experimental design. For instance, since a randomized controlled study to test the effect of smoking on health would be unethical, a reasonable alternative would be a study that identifies two groups, a group of people who smoke and a group of people who do not, and follows them forward through time to see what health problems they develop. In general, Cohort analysis attempts to identify cohorts effects: Are changes in the dependent variable (health problems in this example) due to aging, or are they present because the sample members belongs to the same cohort (smoking vs. non smoking)? In other words, cohort studies are about the life histories of sections of populations and the individuals who comprise them. They can tell us what circumstances in early life are associated with the population's characteristics in later life - what encourages the development in particular directions and what appears to impede it. We can study such developmental changes across any stage of life in any life domain: education, employment, housing, family formation, citizenship and health

The main advantages of case control studies are:   They can be done quickly. By asking patients about their past history, researchers can quickly discover effects that otherwise would take many years to show themselves. Researchers don't need special methods, control groups, etc. They just take the people who show up at their institution with a particular condition and ask them a few questions. The first study to suggest a new medical conclusion will often be a case control study, perhaps designed to check on a hypothesis suggested by a case series. If possible, researchers will generally try to confirm the results with a randomized controlled trial or a cohort study.

Empirically Supported Treatments in Psychology Let’s take a look at the Division 12 website: http://www.apa.org/divisions/div12/homepage.html

Historical Aspects of EST TASK FORCE ON PROMOTION AND DISSEMINATION OF PSYCHOLOGICAL PROCEDURES A Report Adopted by the Division 12 Board - October 1993 Categories of support: I: supported by at least two RCT’s showing superiority to a palcebo or other bonafide treatment II: supported by at least one RCT showing superiority to a placebo or other bonafide treatment, or some other reasonably well-controlled situation III: heterogeneous with low levels of evidence Current state of website: http://www.apa.org/divisions/div12/est/chamble2.pdf Criticisms of EST

EST Criticisms EST’s used inappropriately in managed care Malpractice for failure to follow guidelines Practice restriction/restraint of trade EST data is flawed RCTism Rejects qualitative approach Favors CBT Manualization restricts generalization Limits application to specific cases Not the way it happens in real life Limited effectiveness data (as opposed to efficacy)