This approach is rarely been used today because it’s very unlikely that any existing product hasn’t been subjected to the Prospective validation process. Therefore, this type of validation is only acceptable for well-established processes and will be inappropriate where there have been recent changes in the composition of product, operating processes, or equipment. Validation of these facilities, processes, and process controls is possible using historical data to provide the necessary documentary evidence that the process is doing what it is believed to do. Retrospective validation is used for facilities, processes, and process controls in operation use that have not undergone a formally documented validation process. In fact, validation of a process by this approach often leads to transfer of the manufacturing process from the development function to production. This approach to validation is normally undertaken whenever the process for a new formula (or within a new facility) must be validated before routine pharmaceutical production commences.

A) Prospective validation (or premarket validation)Ī) Prospective validation (or premarket validation)Įstablishing documented evidence prior to process implementation that a system does what it proposed to do based on preplanned protocols.

The exposure and outcome information in a cohort study are identified retrospectively by using administrative datasets, reviewing patient charts, conducting interviews, etc.The guidelines on general principles of process validation mentions four types of validation: Retrospective Cohort StudyĪ retrospective cohort study allows the investigator to describe a population over time or obtain preliminary measures of association to develop future studies and interventions.

It is very important in a case-control study that the cases be as similar to the controls on all factors except the outcome of interest. Cases and controls are established based on the presence of the condition, and exposure is assessed by looking back over time. In a retrospective case-control study the investigator can quickly estimate the effect of an exposure on outcome status. We’ll discuss two types of retrospective studies: Obtain preliminary measures of association.Quickly estimate the effect of an exposure on an outcome.

Study a rare outcome for which a prospective study is not feasible.In general, the reasons to conduct a retrospective study are to: A retrospective study design allows the investigator to formulate ideas about possible associations and investigate potential relationships, although causal statements usually should not be made.Īn investigator conducting a retrospective study typically utilizes administrative databases, medical records, or interviews with patients who are already known to have a disease or condition. In a retrospective study, the outcome of interest has already occurred at the time the study is initiated.

Types of retrospective studies