RESUMEN
Background: Current inventory theory is based on simulated data and unrealistic formulae. Inventory replenishment processes are therefore commonly disrupted, and out-of-stock (OOS) events are unnecessarily frequent. Objective: OOS events at a large-volume, long-term care pharmacy in North Carolina were compared among 4 sequentially applied methods of inventory control: (a) a manual system without Six Sigma protocol, (b) a manual system with Six Sigma protocol, (c) a computer-assisted system with Six Sigma protocol, and (d) an automated system with Six Sigma protocol. Methods: Daily OOS rates were recorded for 11 weeks during the implementation of each method. Between-group comparisons were performed, and time-series analyses were conducted during each implementation to determine the significance of the change in OOS rates over the evaluation period. Results: In terms of the 2 manual systems, OOS rates were lower for the system to which a Six Sigma protocol was applied. In terms of the 3 Six Sigma systems, ranked differences were significant. The computer-assisted system had a lower OOS rate than did the automated system, and the automated system had a lower OOS rate than did the manual Six Sigma system. OOS rates were significantly reduced over an 11-week period for the computer-assisted and the automated systems. Conclusions: Six Sigma was found to be an effective process improvement strategy in the selected pharmacy setting. The study was the first inventory analysis performed with OOS events used as an empirical measure, in contrast to the simulated data used in prior studies.
RESUMEN
Pilot error has caused the majority of helicopter emergency medical services (HEMS) accidents in the United States for almost 2 decades. Pilot fatigue may have contributed to some of these accidents. This nonexperimental quantitative study investigated the relationships between fatigue reported by on-duty HEMS pilots (the criterion variable) and consecutive HEMS pilot day shifts, consecutive HEMS pilot night shifts, age, and experience as an HEMS pilot (the predictor variables). Surveys completed by 395 on-duty HEMS pilots in the US were examined to quantify respondent fatigue with the Brief Fatigue Inventory (BFI). This study found some evidence of a statistically significant positive relationship between HEMS pilot night shift respondent BFI scores and experience as an HEMS pilot, while controlling for consecutive HEMS pilot night shifts and age. A 1-way analysis of variance suggested that the effect of experience as an HEMS pilot on HEMS pilot night shift respondent BFI scores was statistically significant. Multivariate regression analysis suggested that experience as an HEMS pilot predicted HEMS pilot night shift respondent BFI scores. Additional quantitative research is recommended to confirm the results of this study and to investigate relationships between fatigue experienced by HEMS pilots and other variables that were not considered in this investigation. Qualitative research to identify and document fatigue management strategies that are used by experience HEMS pilots is also recommended.
