Question

STUDY QUESTION: Does use of diet drug fen-phen (fenfluramine-phentermine) cause valvular heart disease?

HINT: Valvular heart disease is most objectively identified by echocardiography. A fairly high percentage of persons with valvular heart disease don’t have a detectable heart murmur and thus, would not be identified by physical examination alone. For this study, valvular heart disease will include mitral and aortic regurgitation. These are graded as absent, trace, mild, moderate, and severe. The Food and Drug Administration (FDA) criterion for significant mitral valve regurgitation is moderate or higher; for aortic regurgitation the criterion is mild or higher.

DESIGN 5: NON-CONCURRENT COHORT STUDY

Briefly describe the layout of a non-concurrent cohort (retrospective cohort) study designed to address the research question. In formulating your description, consider the following points:

1. How will the exposure and the outcome be defined ?Answer the question using the research question and the study design(no-concurrent cohort study)

2. How will the study participants in each group be selected?Answer the question using the research question and the study design(no-concurrent cohort study)

3. How will information on the exposure and the outcome be collected (ascertained)?Answer the question using the research question and the study design(no-concurrent cohort study)

DESIGN 1: ECOLOGIC COMPARISON STUDY

Briefly describe the layout of an ecological comparison study designed to address the study question. In formulating your description, consider the following points:

1. How will exposure and outcome be defined and measured?Answer the question using the research question and the study design(ecological  study)

2. Where might you get information on the exposure and the outcome?Answer the question using the research question and the study design(ecological  study)

Answer 1

Exposure:-

Exposure is defined as the state of being in contact with something or is defined as a condition that can develop from being subject to bad weather.

Major objective of exposure assessment is to estimate the risk caused by the exposure of a chemical contaminant to an individual and ecosystem.

Exposure assessment is the process of estimating or measuring the magnitude, frequency and duration of exposure to an agent, along with the number and characteristics of the population exposed. Ideally, it describes the sources, pathways, routes, and the uncertainties in the assessment.

Outcome:-

outcome measure, endpoint, effect measure or measure of effect is a measure within medical practice or research, (primarily clinical trials) which is used to assess the effect, both positive and negative, of an intervention or treatment.Measures can often be quantified using effect sizes.Outcomes measures can be patient-reported, or gathered through laboratory tests such as blood work, urine samples etc. or through medical examination.Outcomes measures should be relevant to the target of the intervention (be it a single person or a target population).

Depending on the design of a trial, outcome measures can be either primary outcomes, in which case the trial is designed around finding an adequate study size (through proper randomization and power calculation).Secondary or tertiary outcomes are outcome measures which are added after the design of the study is finalized, for example when data has already been collected. A study can have multiple primary outcome measures.

Outcome measures can be divided into clinical endpoints and surrogate endpoints where the former is directly related to what the goal of the intervention, and the latter are indirectly related.