CATIE  Clinical Antipsychotic Trials of Intervention Effectiveness A Multicenter, double-blind, parallel-group, randomized, controlled trial

MRCPsych Paper B SAMPLE SIZE CALCULATION Critical Review Question You are checking the frequency of “the Perceived stress scale among doctors serving at various Government and private hospitals in Faisalabad. (JPMA-2020-02-232)” If you aimed for a specific category of doctors, then that will be your target population. For example juniors, seniors, permanent visiting, etc. Introduction Once we plan a survey or a research experiment, then we have a target population in mind. For example, some surveys cover the entire population of the country like census and political elections. If we take an example for census first, then what sample size do you think would be the correct representative in that case? The obvious answer is 100% of the population of the country, not a single percent less. Examples Now take the example of the political elections, let’s say 50% was the turnout on polls. Would that be an excellent election turn out? Probably not, because half the population of the country d...

  Sampling Stratified & Random  Stratified Sampling Random sampling refers to sampling via which every member of the target population has an equal chance of making it to the sample. Assign numbers and choose random, place names in a box and select.  Random Sampling Stratified sampling is when the demographic characteristics of the target population are reflected in the sample. For example, if there are 1% working females in a target population, then the sample should also have 1% working females.