RANDOMIZED-CONTROLLED TRIAL

Economic Evaluation in Healthcare (Randomized-Controlled Trial)

Economic Evaluation in Healthcare (Randomized-Controlled Trial)

Introduction

Randomized controlled trials (RCT) produce one of the highest levels of robust evidence available to evaluate the efficacy of health care interventions. Unclear or incomplete reporting makes the interpretation of randomised controlled trials difficult, even impossible in some cases, and may jeopardise an otherwise wellplanned and performed trial. “Inadequate reporting of results and outcomes can also have a detrimental effect on the interpretation and application of trial publications and can lead to the clinical use of harmful interventions” (Zelen, 2006, Pp. 174).

The concept of external validity is straightforward. For any assessment, “internal validity” refers to the mechanism of conducting a clinical trial, and the reliability of results on the original setting. A professionally conducted RCT that yields a high level of statistical significance is said to be “internally valid.” However, it is fairly obvious that an intervention rigorously proven to work in one setting may or may not work in another setting. This second criterion—the extent to which results apply outside the original research setting—is known as “external validity.” “External validity may be low because the populations in the original and the new research setting are not really comparable—for example, results of a clinical trial conducted on adults may not apply to children” (Swerissen and Peterson, 2006, Pp. 68). But external validity may also be low because the environment in the new study setting is different in some fundamental way, not accounted for by the researcher, from the original study setting. “Econometric studies that seek to draw conclusions about effectiveness from data that span large geographical areas or highly varied populations thus typically have lower levels of internal validity, but higher levels of external validity” (Brewin and Bradley, 2008, Pp. 685).

So, once again, the fundamental issue is not the purity of the methodology employed (as exciting as such methodological purity is to the technically inclined) but rather the inherent complexity of the world being studied.

“For this precise reason, it turns out that those who most vociferously and naïvely advocate that we apply techniques from public health to economics (a group that does not include Esther Duflo) make a fundamental error” (Streiner & Norman, 2010, Pp. 54). They fail to appreciate the fact that, when it comes to external validity, public health is the exception that proves the rule. Indeed, in aid-led development in general, of the few real historical successes, nearly all are in public health. Outside of public health, few of the large-scale, top-down development programs have in fact succeeded.

Discussion

The reporting of randomized controlled trials has received considerable criticism in recent years and has previously been shown in many cases to be incomplete, biased, and inconsistent with study protocols and effective reporting of findings. The CONSORT (Consolidated Standards of Reporting Trials) statement of 1996, and updated in 2001 and 2010, gives recommendations for reporting randomized controlled trials and is endorsed by the World Association of Medical Editors, the Council of Science Editors, and the International Committee of Medical ...