Elements of Clinical Study Design, Biostatistics & Research

Study designs in medical research fall mainly into three categories: Observational studies, Interventional studies & meta-analyses. Further, each type of study comprises of subtypes. Each study design with its subtypes, and applicability of a specific study design, along with advantages & limitations, are discussed in this chapter.

The scales of measurement could be numerical, nominal or ordinal. The measurement of data requires measurement of its central tendency and discussion. Such data can be presented, depending on its type & nature, in the form of tables & figures. The different types of descriptive statistics & the suitable form of presentation are discussed in this chapter. 

Probability could be objective or subjective. Byestherom is a formula to calculate conditional Probability. The sample methods of random sampling are simple random sampling, systematic random sampling, Stratified random sampling, and cluster random sampling. Use of hypothesis testing, if used as inferential statistics, definite steps are required to be followed. Using confidence intervals as inferential statistics provide more useful information in clinical research. This chapter incorporates a discussion on these aspects. 

In the language of statistics, research is a planned & systemic method of data collection, analysis, & drawing conclusions. In this chapter, a demonstration of the relationship between numerical, nominal & ordinal data & calculation of other statistical techniques applicable in critical research, is described in a nutshell.

The clinical trial could either be an Explanatory Trial/ Randomised Control Trial (RCT) or Correlational Trial/ Pragmatic Trial. For developing new molecules as a drug, RCTs require human studies conducted in 4 phases called Phase I to phase IV of clinical trials. Pragmatic Trials are Correlational Trials. As such RCT & Pragmatic Trials are not dichotomous, there is a continuum. A PRECIS has been developed to assess the said trials. The reverse pharmacology approach is recommended to generate scientific evidence to make herbal drugs more efficacious & safe. These aspects are elaborated on in this chapter. 

A survey is one of the most common methods in health sciences research. As in this case, choosing a suitable study design depends on the research question, so also survey research questions also decide methods. The decision of application of scale of measurement depends on the nature of the observations, which could be numerical, nominal, or ordinal. If research develops his/her new survey instrument (survey questionnaire), its validity & reliability requires other important treatments. This forms the subject of discussion in this chapter.

Reading research papers/literature should be done through reviewing. It should not be not skimming. Biases in a study seriously affect the conclusion of the study adversely. While writing research reports, discrepancies in text, tables, and figures may reflect after-thought data treatment by the researchers: these and other aspects during the planning of research projects and report writing. Precautions required are the very purpose of this chapter.