A risk‐adjusted exponentially weighted moving average control chart for detection of the scale parameter in surgical quality monitoring

Abstract Risk‐adjusted control charts have been widely used in monitoring surgical quality detecting risks of performance. Most the previous approaches focus on shifts location parameter as well existence scale parameter, which cannot get full measure under different levels. Ignoring magnitude methods detect variations mortality that is measured by and required to reflect improvement. The method interest This paper uses a new weighted h‐likelihood obtain score test for from logistic model. Then an exponentially moving average chart can be constructed monitor changes variance risks, could practical programs. Simulation results indicate proposed approach performs more efficiently than existing various magnitudes parameters top pre‐set threshold stability. In addition, application real data Surgical Outcome Monitoring Improvement Program Hong Kong shows improvement deterioration hospital's outcomes.