Methodology is proposed for the design of sequential methods when data are obtained by gauging articles into groups. Exact expressions are obtained for the operating characteristics and average sampling number of Wald Sequential Probability Ratio Tests (SPRTs), and for the average run length of Cumulative Sum (CUSUM) schemes based on grouped data. Step by step design algorithms are provided to ...

The control chart is a very popular tool of statistical process control. It is used to determine the existence of special cause variation to remove it so that the process may be brought in statistical control. Shewhart-type control charts are sensitive for large disturbances in the process, whereas cumulative sum (CUSUM)–type and exponentially weighted moving average (EWMA)–type control charts ...

Adaptive Cumulative SUM charts (ACUSUM) have been recently proposed for providing an overall good detection over a range of mean shift sizes. The basic idea of the ACUSUM chart is to first adaptively update the reference value based on an Exponentially Weighted Moving Average (EWMA) estimate and then to assign a weight on it using a certain type of weighting function. A linear weighting functio...

A system is described for the maintenance of cumulative haematology records for selected patients using a laboratory minicomputer with limited storage capacity. Records are indexed by the patient's name and location since, as in the majority of hospital laboratories, there is no unique numbering scheme which covers all patients. The computer system imitates the procedures of manual filing, list...

Standard control charts are often based on the assumption that the observations follow a specific parametric distribution, such as the normal. In many applications we do not have enough information to make this assumption and in such situations, development and application of control charts that do not depend on a particular distributional assumption is desirable. Nonparametric or distribution-...

Quality control in medicine is generating more and more interest. Industrial concepts of quality control have been refined and transformed to be useful in healthcare monitoring. Whereas medical practitioners first reaction to this new concept of quality control was negative 'we're treating patients, we're not a part of an industrial process', some dramatic cases of inferior medical performance ...

Barriers to the implementation of the Centers for Disease Control and Prevention (CDC) guidelines for surgical site infection (SSI) surveillance have been described in resource-limited settings. This study aimed to estimate the SSI incidence rate in a Cambodian hospital and to compare different modalities of SSI surveillance. We performed an active prospective study with post-discharge surveill...

OBJECTIVE To evaluate the benefits of radiation education with and without feedback reporting in altering clinician radiation use behaviour in performing coronary angiography (CA). DESIGN A retrospective review of radiation use (fluoroscopy time) in coronary angiograms performed between July 1996 and December 2005 by 10 cardiologists to assess the impact of various interventions aimed at mini...