Rev Bras Oftalmol.2014;73(2):67-68
Definition of population and randomization of sample in clinic surveys
DOI: 10.5935/0034-7280.20140015
The first step for design a scientific study is to raise doubts which at that moment could not be solved with the information available in literature (a gap in knowledge). In clinic surveys, one should expect that the response to that doubt is to contribute to improve medical practice. The following step is to determine what population will be investigated. For example, when evaluating the efficacy of an intraocular lens (IOL) with yellow pigmentation in the prevention of macular degeneration related to age (ARMD), the population to be studied would be made up by patients operated by cataract, who received the implant of that IOL in one or more specific zones in a certain time (1-3) […].