The terms OOS, OOE and OOT is very important from pharmaceutical Quality Assurance & Regulatory Affairs point of view. These deals with handling of deviating analysis results.
Out-of-Specification (OOS) Results
A result that falls outside established acceptance criteria which have been established in official compendia and/or by company documentation.
Out-of-Expectation (OOE) Results
An atypical, aberrant or anomalous result within a series of results obtained over a short period of time is an OOE result. An OOE result is a result that meets specifications, but is outside the expected variability of the analytical procedure.
Out of Trend (OOT) Results
A time dependent result which falls outside a prediction interval or fails a statistical process control criterion.
A trend is a sequence of temporal procedures, e.g. for the manufacture of different batches of a product. There are two types of trends:
- In one case, no trend is expected, e.g. in production or when analysing process data where everyone expects that they are under statistical control.
- In the other case, a trend is expected. One typical example for that is stability testing where one expects that the content of the API reduces over the storage period, or that the quantity of impurities increases over time.
There is a fundamental difference between these two types of OOT results: indeed, in the second situation the dispersion increases over time.
GMP requires DATA TREND ANALYSIS. This is important for management of the data integrity.
Under GMP, historical data should be preserved. So that in future trends can be recognized and assessed.