Biometrical Letters vol. 47(1), 2010, pp. 69-81


Show full-size cover
CONTROL CHARTS AND CHRONIC RESPIRATORY PATIENTS

Florbela Correia1, Pedro Oliveira2

1Instituto Politécnico de Viana do Castelo, Escola Superior de Ciências Empresariais,
Av. Miguel Dantas, 4930-678 Valença, Portugal, e-mail: florbelacorreia@esce.ipvc.pt
2Universidade do Minho, Departamento de Produção e Sistemas, Campus de Azurém,
4800-058 Guimaraes, Portugal, e-mail: pno@dps.uminho.pt


Statistical Process Control has been the focus of many researchers who have tried to expand its applicability to different areas, from industry to health. The main objective of the present work is to use Statistical Process Techniques in the control and follow-up of respiratory patients, since in clinical practice it has been observed that the variation between patients is much larger than the variation shown by a single patient. Therefore we tried to compare, under the same experimental conditions, the most cited control charts for control of the mean of independent data. The charts compared in this study are the Shewhart and EWMA charts and the modified MA. The measure used to compare the performance of the different charts was the Average Run Length. Noteworthy is the performance of the modified MA chart, which is much more robust with respect to false alarms, and also much simpler to implement than the EWMA chart. Lastly, we constructed control charts that might provide insights in medical decision-making.


Control charts, Average Run Length, False Alarms, Statistical Process Control, Shewhart Chart, Exponential Moving Average chart, Moving Average Chart, Chronic Respiratory Patients