A STATISTICAL APPROACH TO MEASURING THE COMPETENCE OF ANESTHETIC TRAINEES AT PRACTICAL PROCEDURES

Cusum analysis is a statistical technique to distinguish deviations fr om an acceptable failure rate. The progress of anaesthetic trainees le arning four practical procedures (obstetric extradural anaesthesia, sp inal anaesthesia, central venous cannulation and arterial cannulation) was monitored from their first attempt using cusum analysis. Suitable acceptable and unacceptable failure rates for each procedure were cho sen by consultant anaesthetists. For obstetric extradural anaesthesia, four trainees eventually achieved acceptable failure rates (5%) and t he number of attempts required to demonstrate this statistically range d from 29 to 185; three trainees had an unacceptable failure rate (10% ) and five trainees had inconclusive records. For spinal anaesthesia, two trainees achieved an acceptable failure rate (10%) and the number of attempts required to demonstrate this statistically ranged from 39 to 67; two trainees had an unacceptable failure rate (20%) and four tr ainees had inconclusive records. One trainee demonstrated statisticall y an acceptable failure rate in arterial cannulation (20%) after 14 at tempts and four trainees had inconclusive records. Two records of cent ral venous cannulation were inconclusive. Some records showed variable failure rates which were sometimes associated with lack of practice o r a change in technique. Cusum analysis can be used to monitor trainin g in practical procedures and as a continuous audit of quality of clin ical practice.