Question

In this study conducted in nine countries, we assigned 11,093 patients with acute stroke (85% of the strokes were ischemic) to receive care in either a lying-flat position or a sitting-up position with the head elevated to at least 30 degrees, according to the assignment of the hospital to which they were admitted; the designated position was initiated soon after hospital admission and was maintained for 24 hours. The primary outcome was degree of disability at 90 days, as assessed with the use of the modified Rankin scale (scores range from 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death).

1. What is the design of this study? Provide detailed explanation.

Answer 1

Answer:

study design---

• experimental/ interventional analytical study design
• international multi centric pragmatic open therapeutic interventional trial---- related to head positioning and observed degree of disability in acute stroke patients.

Detailed explanation:

Types of study design

There are two main types of the study designs in clinical research

1.experimental study/Interventional study

Studies which are based on an experiment or an intervention being performed in the group that is being studied are called experimental or interventional studies.The study where there  has been an intervention planned and the researcher is not just observing the allocated subjects,these are experimental studies.Often randomization is used for allotment of the intervention to the study subjects.Blinding is used in some studies in order to decrease the bias and error of the study.These studies are generally analytical and  based on PICO model which includes question to be answered.

P-Population with the identified problem [ Acute stroke patient here]

I- intervention[ lying down position versus sitting up position here]

C- comparison to another interventional group or control[ the two interventional groups are compared against each other here---Quasiexperimental]

O-- outcome[ outcome studied in terms of degree of disability related to positioning ]

2.observational studies/ non experimental studies

These are based on observation of a particular group of findings/ observations in an identified group of people in order to study the disease.These include case series, cross-sectional studies, case report studies which form the descriptive observational studies and case control and cohort studies which form the analytic observational studies.

Descriptive studies versus analytical studies

Descriptive studies are associated with disease description and associated characteristics description as seen in observational studies like case series and case reports and do not involve statistical calculations while the analytical studies involve statistical calculation as to the statistical significance of the occurrence of different outcomes by doing statistical data analysis. Case control,cohort study and experimental studies are essentially analytical in nature

Discussion:

In the above study, an intervention has been planned for the acute stroke patients of different hospitals in different countries of the world with respect to lying down position or sitting up position with at least 30 degree of elevation. Here intervention has been performed and not merely an observation.The study answers the question as to which intervention in the stroke patients with respect to positioning decreases the disability at 90 days from the occurrence of the stroke. It identifies the acute stroke patients as the population, two different positionings as the intervention with comparison of the disability at 90 days as the outcome in relation to the different positionings in the patient.So,the above study is an example of an Experimental interventional study.design .As the results of the different interventions in the two groups are analyzed with respect to the difference in the outcomes measured using the Rankin scale, it is an example of analytical study

Further, the study design is of an international ,multi centric, pragmatic, open, therapeutic, interventional trial [ clinical trial study].

Rationale and explanation:

1.The study comprises an intervention of two different positioning on acute stroke patients. So it is an experimental or interventional study.There is no real control group[control group--true experiment] hence it is quasiexperimental study.

2. This study comprises clinical study done in a hospital setting and hence is a clinical trial study design which is based on the therapeutic intervention of positioning in order to decrease the disability. Hence it is therapeutic intervention trial study

3. As the study involves multiple countries across the world and is done in different hospitals/centres worldwise,it is a multi centric international trial study.

4.The study is based on the real life situation of acute stroke causing disability and is aimed at understanding the effect of the positioning of the patient whether lying down or sitting up with a minimum head elevation of about 30 degrees affecting the degree of disability of the patient at a 90 day period.. Since it is based on real life situations, it is a pragmatic study.

5. In this study, there is no blinding of the research participants and the patient. Both are aware of the intervention that is being given to the patient and hence this is an open trial study.

6. It is not mentioned in the given case study details as to how the assignment of the hospitals was done to the intervention.In general randomization is used for experimental studies.

If the assignment of the hospitals for the study had been randomized[ as randomization is generally used for experimental studies], this study design would be cluster randomized study design as it involves the randomization of the people belonging to a cluster[ particular hospital/ a particular group] for the study rather than individual randomization.

Conclusion:

As the above given study has patients of acute stroke with two different interventions in order to study the results of the same on the disability at 90 day period, the study design is that of an experimental or interventional analytical study.To add to the details,further the study design is of an international ,multi centric, pragmatic ,open, therapeutic interventional trial.