Sequence symmetry analysis in pharmacovigilance and pharmacoepidemiologic studies.

Sequence symmetry analysis (SSA) is a method for detecting adverse drug events by utilizing computerized claims data. The method has been increasingly used to investigate safety concerns of medications and as a pharmacovigilance tool to identify unsuspected side effects. Validation studies have indicated that SSA has moderate sensitivity and high specificity and has robust performance. In this review we present the conceptual framework of SSA and discuss advantages and potential pitfalls of the method in practice. SSA is based on analyzing the sequences of medications; if one medication (drug B) is more often initiated after another medication (drug A) than before, it may be an indication of an adverse effect of drug A. The main advantage of the method is that it requires a minimal dataset and is computationally efficient. By design, SSA controls time-constant confounders. However, the validity of SSA may be affected by time-varying confounders, as well as by time trends in the occurrence of exposure or outcome events. Trend effects may be adjusted by modeling the expected sequence ratio in the absence of a true association. There is a potential for false positive or negative results and careful consideration should be given to potential sources of bias when interpreting the results of SSA studies.

Case-based assessment in an online nursing pharmacotherapy course.

OBJECTIVE: To implement and evaluate the effectiveness of case-based assessments in an online pharmacotherapy course for nursing students. DESIGN: Four case-based examinations developed in parallel for the midterm and final examinations and designed to address potential barriers to maintaining academic integrity were compared. ASSESSMENT: The use of online, case-based assessments was successful in providing 4 parallel examinations that assessed case-based decision making while maintaining academic integrity and minimizing instructor grading burden. CONCLUSIONS: Using an online, case-based assessment strategy is effective and feasible for evaluating the clinical application knowledge of nursing students enrolled in a pharmacotherapy course.