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Epidemiology Designs for Clinical Trials

Dr. Nancy Agnes, Head,

Technical Operations, Pubrica

sales@pubrica.com

Keywords:

Investigational New Drug Application,

post-marketing observation, cross-sectional

studies, human preliminaries, anticancer

medications

I. INTRODUCTION

Choosing the best accessible preventive and

therapeutic measures to evade disability and

passing is a significant objective as far as

wellbeing might be concerned specialists.

To accomplish this objective, we need to

perform considers that decide the estimation

of these actions. Epidemiology research

alludes to examining ailment, infections, and

causative reasons in population;

epidemiology fills in as the highest quality

level of population health appraisal.

Accessory, cross-sectional, and case-control

considers are out and out demonstrated as

observational investigations. Consistently

these studies are the fundamental

commonsense strategy for thinking about

various issues. A clinical preliminary's vital

place is exploring the distinction of the

patient gatherings caused exclusively by the

treatment strategies that are applied.

II. CLINICAL TRIAL STUDY DESIGN

Our goal in clinical research is to design a

study that will enable us to draw a true and

significant scientific conclusion using

statistical methods that can be applied in a

“real world” environment. Before deciding

on a research design, one must first define

the study's goals and objectives, as well as

choose a target population that is

representative of the population being

studied. The findings of a research study can

either enhance health care or cause damage

to patients inadvertently. As a result, a well-

designed clinical research study with a

strong foundation of comprehensive

methodology and adherence to ethical

standards is required.

From an epidemiological perspective,

there are two most important types of

clinical study designs, Observational

study design and Experimental study

design.

Observational studies are hypothesis‐

generating studies, and they can be again

divided into descriptive studies and

analytic studies.

Descriptive observational studies

describe the exposure and/or the

outcome, while analytic observational

studies assess the relationship between

the exposure and the outcome.

Hypothesis research studies, on the other

hand, are experimental studies. It entails

a procedure for determining whether

there is a connection between the

exposure and the outcome.

Each study design is distinct, and so it

would be critical to choose a design that

would most properly answer the

Copyright © 2021 pubrica. All rights reserved 2

question and provide the most useful

information. We will be reviewing each

study design in detail.

III. OBSERVATIONAL STUDY DESIGNS

Cohort Study design

Patients in cohort studies are initially

divided into two classes based on their

contact status. The Cohorts are followed

over time to see who in the exposed and

non-exposed classes develops the disease.

Retrospective or prospective cohort studies

are both possible. In contrast to a case-

control study, which starts with diseased and

non-diseased patients, a cohort study starts

with exposed and unexposed patients,

allowing for direct calculation of incidence.

A cohort study's impact is calculated using

relative risk. Recall bias is very minimal in

cohort studies, and many results can be

studied at the same time. Cohort studies

have the drawback of being more

susceptible to selection bias. Cohort research

can be very costly and time-consuming

when researching rare diseases and results

with long follow-up periods.

Case-Control Studies

Contrasted with the cohort and cross-

sectional studies, case-control considers are

generally retrospective. Case-control

contemplates easy to arrange and

reflectively contrast two gatherings with

discovering the indicators of a result. Grant

appraisal of the impact of indicators on the

result utilizing the count of a chances

proportion.

Cross-Sectional Studies

Cross-sectional studies are retrospective and

include a snapshot of the research subjects'

characteristics at a specific point in time.

Cross-sectional studies, unlike cohort

studies, do not require a follow-up period

and are thus relatively easy to perform. The

weakest of the observational designs, cross-

sectional research design, cannot include

cause-effect relationships. The exposure

status and result of interest information are

obtained in a single moment in time, often

through surveys. This method is often used

to define the prevalence of a disease in a

population.

Copyright © 2021 pubrica. All rights reserved 3

Ecological Studies

Data at the person level is inaccessible, or

large-scale comparisons are needed to

investigate the population-level impact of

exposures on a disease condition. Ecological

studies are used. As a consequence,

ecological research findings are only valid at

the community level. In ecological studies,

the types of measures used are aggregates of

individual-level data. As a result, these

studies are prone to a form of confounding

known as an ecological fallacy, which arises

when associations found in group data are

presumed to hold for individuals. In public

health science, ecological experiments are

commonly used.

IV. EXPERIMENTAL STUDY DESIGNS

Randomized Clinical Trials

The gold standard in clinical research design

is randomized clinical trials, also known as

randomized control trials (RCT). In an RCT,

the participants are randomly assigned to

one of two groups: control or experimental.

Randomization eliminates confounding and

reduces selection bias in RCTs. This allows

the researcher to establish identical

experimental and control groups, allowing

them to isolate the intervention's influence.

The experimental group is exposed

to/treated with a drug that may involve the

cause, prevention, or treatment of a disease.

The groups are then followed in the future to

see who develops the desired outcome.

RCTs are costly, and researchers who use

this study often encounter problems with

randomization integrity due to refusals,

dropouts, crossovers, and non-compliance.

V. CONCLUSION

There are numerous potential wellsprings of

errors that can bring about distortions of

study results. These bends are an issue,

particularly when the disease transmission

specialist assesses the relationship between a

risk factor and a medical condition. Whether

a risk factor or a defensive factor goes

undetected, or typical conduct or condition

is misidentified as a risk or defensive factor,

the ramifications may bring genuine

ramifications for general society. A

mistakenly recognized danger component

may cause superfluous dread among people,

or perhaps an unnecessary redirection of the

restricted investigation reserves. Disease

transmission specialists leading

observational examinations (cohort, go-

sectional, and specifically case-control

should be aware of predispositions' ability

and apply extra consideration to eliminate or

cut their result. As a translator of reports,

we, the overall population, must be aware of

the suitable predispositions in such reviews

after we outline their decisions as

recommended by the mass communications.

Contact Pubrica for any clinical product

development services.

REFERENCES

1. Chidambaram, A. G., & Josephson, M. (2019).

Clinical research study designs: The

essentials. Pediatric Investigation, 3(4), 245-252.

2. Puljak, L., Makaric, Z. L., Buljan, I., & Pieper, D.

(2020). What is a meta-epidemiological study?

Analysis of published literature indicated

heterogeneous study designs and definitions. Journal

of comparative effectiveness research, 9(7), 497-508.

3. https://www.researchgate.net/publication/312546983_

Epidemiology_Concepts_for_Clinical_Trials/link/5bc

af5b392851cae21b49c18/download

4. Rezigalla, A. A. (2020). Observational study designs:

Synopsis for selecting an appropriate study

design. Cureus, 12(1).