Question

Natural history of disease and benefits/drawbacks of screening (e.g., diagnoses, lead time bias, actual death, extended survival, etc.)

What is Generalizability (and what assumptions or conditions need to be met)

Compare and contrast Bias (recall, sample, information, interviewer, etc.)

Answer 1

Natural history of disease is the course a disease taken in individual people from its pathological onset until it's eventual resolution through complete recovery or death.it is the major element of descriptive epidemiology

Benefits of screening are

• They aim to detect diseases at an early stage,before any symptoms become noticeable.
• To treat the disease much earlier
• Mortality reduction

Drawbacks

• It gives sometimes false positive results which create unneeded worrying
• Over diagnosis which results in unnecessary treatment
• Costs of screening test

Generalizability can be defined as the extension of research findings and conclusions from a study conducted on a sample population to the population at large.

It should fulfil following points

• Greater representativeness- it increase generalization
• Time effects- it should be same to all sample
• Sample size should large.it provide significant results

Recall bias-it is a systematic error caused by differences in the accuracy or completeness of the recollection retrieved by study participants regarding events or experiences from the past.

Sample bias- it is a bias in which a sample is collected in such a way that some members of the intended population are less likely to be included than others.

Information bias- it refers to bias arising from measurement error

Interviewet bias- a partiality towards a preconceived response based on the structure,phrasing or tenor of questions asked in the interviewing process.