This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Analytical Epidemiology, Subject name: Social & Preventive Medicine
Which of the following is true about Cohort study? 
Select and explain. 
A. Incidence can be calculated, B. It is from effect to cause, C. It is inexpensive, D. Shorter time than case control
A: Incidence can be calculated
Answer: A: Incidence can be calculated 
Explanation: Ans: A (Incidence can be calculated) Ref: Text book of preventive and social medicine, K Park, 22nd edition. page no 72Explanation:Cohort studyIt is an important study design to measure incidence.It is followed from exposure to outcome (cause to effect), unlike ease control study (effect to cause)It involves follow up of a cohort (group with common character, birth cohort, cohort joining service in particular year etc.)During follow up exposure and outcome is measured at periodic intervals OutcomeContinuousDiscreteNumericalOrdinalDichotomousPolvchO'tomousXominalPolychotomousOrdinalContinuousPearson Correlation & RegressionPearson Correlation & RegressionSpearmanRankcorrelation't' testANOVAANOVADiscrete- do -- d -- do -- do -- do -- do -NumericalOrdinalSpearmanRankcorrelationSpearmanRankcorrelationSpearmanRankcorrelationMann Whitney U testKruskal Wallis testKruskal Wallis testDichotomoust testt testMann Whitney U testChi square for 2x2 tableChi square for r x c tableChi square for linear trend in proportionsPolychotomousOrdinalANOVAANOVAKruskal WallisChi square for r x c tableChi square for r x c tableChi square for r x c tablePolychotomousOrdinalANOVAANOVAKruskal WallisChi square for linear trend in proportions- do -- do -Generally followed for long time, until outcome occursThus, it involves high costMeasures relative risk, attributable risk, population attributable risk as strength of association