Understanding changes over time in workers' compensation claim rates using time series analytical techniques.

Objective: The objective of this study is to better understand the inter-temporal variation in workers' compensation claim rates using time series analytical techniques not commonly used in the occupational health and safety literature. We focus specifically on the role of unemployment rates in explaining claim rate variations.

Methods: The major components of workers' compensation claim rates are decomposed using data from a Canadian workers' compensation authority for the period 1991-2007.

Observations on surgical demand time series: detection and resolution of holiday variance.

Background: Surgical scheduling is complicated by both naturally occurring and human-induced variability in the demand for surgical services. Surgical demand time series are decomposed into periodic, lagged, and linear trends with frequent occurrences of nonconstant variations in mean and variance. The authors used time series methods to model surgical demand time series in order to improve the scheduling of scarce surgical resources.