Study design and methodology

Source Bosworth HB, et al. The take control of your blood pressure study study design and methodology, Contemporary Clinical Trials 28 33 7 (2007). 

Phase IV clinical trials and prospective observational cohort studies have been criticised as no more than promotional devices used by aggressive pharmaceutical companies. The fact that misuse has sometimes happened should not be allowed to obscure the greatly more important needs of safety evaluation and the further development of new and improved therapies. A set of guidelines has been published in the United Kingdom which are specifically intended to provide the high standards of study design and methodology necessary for observational cohort studies. It is to be hoped that similar procedures will be adopted internationally. 

The previous chapter discussed the (currently) relatively loosely defined statistical approaches to safety data collected in clinical trials. In contrast, there are widely accepted statistical methods for demonstrating efficacy in clinical trials. As has been noted several times in this book, if the study design and methodology have been appropriate and have led to the collection of optimum quality data, the statistical analysis and interpretation of efficacy data are relatively straightforward. The clinical (biological) interpretation of efficacy data is typically not quite as clear-cut, but there are widely accepted methodologies that are very useful in this realm too. Of particular importance here is the expert judgment of the clinicians who will review the statistical results with the statisticians and the rest of the study team. 

Senn KM, McGuinness BM, Buck Louis GM, Vena JE, Anderson S, Rogers BT (2005) Longitudinal study of babies born to mothers enrolled in a preconception prospective pregnancy study Study design and methodology, New York State angler cohort study. Environ Res, 97(2) 163-169. 

Evaluates the literature with regard to study design and methodology, statistical analysis, and significance of reported data so that appropriate assessments and conclusions may be applied to the solution of drug therapy problems. 

When the clinical research team has decided on their research question, and the appropriate study design and methodology to acquire optimum quality data with which to answer this question, all this information needs to be documented. The clinical study protocol is the document that is written for this purpose. Chow and Chang (2007, p 1) noted that the study protocol is "the most important document in clinical trials, since it ensures the quality and integrity of the clinical investigation in terms of its planning, execution, conduct, and the analysis of the data."... 

Conventional applications of IDMS in quantitative elemental analysis usually involve the use of a single isotopically enriched tracer/spike. This is different in metabolic studies. The use of two or more tracers of the same element in parallel permits the use of more refined study designs and methodologies, as discussed later. When two isotopic labels X and Y are used in parallel [9], the tracer to tracee ratio for label Y in the sample can be calculated using... 

Scott Research Laboratories, Inc. 1969 Atmospheric Reaction Studies in the Los Angeles Basin. Vol. 1. Program Design and Methodology. Data Summary and Discussion. Fmal Report. Plumsteadville, Pa. Scott Research Laboratories, Inc., 1970. 1113 pp.l... 

Future development efforts in field study design and data management should 1) develop methodologies for choosing sampler location, sampling schedule, and sampling devices 2) measure the collection efficiency of available samplers as a function of particle size, windspeed and wind direction 3) create a series of "typical" design scenarios which can be specified for different aerosol study objectives 4) develop standardized data bases from which ambient and source information can be recovered. 

Janicak PG, Javaid Jl, Davis JM. Neuroleptic plasma levels methodological issues, study design, and clinical applicability. In Marder SR, Davis JM, Janicak PG, eds. Clinical use of neuroleptic plasma levels. Washington, DC American Psychiatric Press, 1993 17-44. 

This book, which focuses on biological considerations in clinical trials, is written very much in this spirit. While study design, experimental methodology, and statistical analysis are central characters in our discussions of new drug development, their importance lies in their role in the development of drugs that influence a patient s biology for the better. 

The premise of inferential statistics is that, if data are carefully collected in a study that employs the appropriate design and methodology, analysis of these data... 

There are two components to evidence-based medicine and two related sets of responsibilities. The first component is clinical research. Clinical research is a scientific endeavor that provides evidence concerning potential therapeutic interventions. This book has focused on one particular therapeutic intervention, drug therapy. Once clinical trials have been conducted, the evidence obtained is published in clinical communications in journals. Everyone involved in clinical research has the responsibility to provide the best possible evidence in this manner. As noted throughout the book, this includes all aspects of clinical research study design, experimental methodology and clinical operations, analysis and interpretation, and also accurate and complete representation of study findings in clinical communications as discussed in Section 13.6. 

Improving precision as much as possible is also a highly desirable attribute in a study design, and statistical methodology aims to improve precision in several ways, including reducing error variance. Better measurements will yield data that provide a more precise answer, e.g., narrower confidence intervals around the treatment effect obtained in a trial. 

If forced to summarize the purposes of study design, experimental methodology, and statistical analysis in one sentence each, the following might be suitable ... 

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