Search results for "Interrupted time series"
showing 3 items of 3 documents
Effect of a distal weight-bearing implant on visual analog scale scores in 23 transfemoral amputees.
2018
The objective of this interrupted time series clinical trial was to evaluate the effect of a distal weight-bearing implant on well-being in patients with transfemoral amputations using the visual analog scale (VAS). A total of 29 patients from five hospitals with previous transfemoral amputations were surgically implanted with an osseoanchored implant with a distal spacer that allows a direct load on the residuum over the distal surface of the socket. Patients were followed for a 14-month period and assessed presurgically and postsurgically using the VAS. The Wilcoxon test was used to evaluate the differences between variables. VAS mean scores improved significantly after intervention. Sign…
Methodological considerations for interrupted time series analysis in radiation epidemiology: an overview
2021
Interrupted time series analysis (ITSA) is a method that can be applied to evaluate health outcomes in populations exposed to ionizing radiation following major radiological events. Using aggregated time series data, ITSA evaluates whether the time trend of a health indicator shows a change associated with the radiological event. That is, ITSA checks whether there is a statistically significant discrepancy between the projection of a pre-event trend and the data empirically observed after the event. Conducting ITSA requires one to consider specific methodological issues due to unique threats to internal validity that make ITSA prone to bias. We here discuss the strengths and limitations of …
Effectiveness of Safety Warnings in Atypical Antipsychotic Drugs
2009
Studies conducted to obtain drug authorization are often of short duration and based on small sample sizes in selected populations. Policies on drug safety rely on the validity of the methods used to achieve rapid and effective communication of new information. No formal evaluation has ever been made of the Spanish communications system, although indirect data have raised questions about its effectiveness.To evaluate the impact of two safety warnings issued by the Spanish Drug Agency, and of a later prior authorization requirement involving the use of atypical antipsychotic drugs in the elderly.The study was based on a time-series analysis constructed with data corresponding to monthly invo…