Proficiency testing in immunohaematology in Ontario, Canada, 1977-1979

Abstract

An analysis of the results of a compulsory proficiency testing programme in immunohaematology is presented. Error rates have been calculated for the determination of ABO and Rh(D) groups, the direct antiglobulin test and antibody detection according to defined criteria. The introduction of proficiency testing has been associated with alterations in error rates for some determinations. An educational programme introduced for laboratories with poor performance has proved effective in improving their results in the proficiency testing programme.

A system for proficiency testing in immunohaematology

“…Since LPTP began, there has been a change in the pattern of practice, and in the number and type of errors made in LPTP immunohaematology surveys (Pinkerton et al 1979(Pinkerton et al , 1981. For example, all laboratories now undertake both forward and reverse grouping in ABO typing, the use of appropriate controls in Rh typing is more extensive, and all participating laboratories now include screening for alloand auto-antibodies in their practice.…”

“…Those differences from reference results considered to be 'not an error' are retrievable from the computer file and are not subsequently coded as errors in the summary of laboratory's performance file. Those differences regarded as errors are classified as 'major' or 'lesser', as defined elsewhere (Carstairs et ai, 1976, Pinkerton et al 1981, and are entered on the summary of laboratory's performance file.…”

“…A summary of the measures taken in the event of poor performance is also given. The results of this mandatory programme of proficiency testing are described in detail elsewhere (Carstairs et al 1976, Pinkerton et al 1979, 1981.…”

The UK National External Quality Assessment Scheme in Blood Group Serology. ABO and D grouping and antibody screening 1982-1983

“…In view of the lack of benefit of Du testing to blood recipients or to pregnant women and of the possible adverse consequences of misgrouping D-negative patients as Du or D-positive, it is recommended that Du testing be abandoned in these groups of patients. The surveys of antibody screening demonstrated lack of, standardisation and error rates similar to those previously reported in the UK for compatibility testing.Evidence has been obtained in external quality assessment schemes that errors may occur even in uncomplicated ABO and D grouping (Pinkerton et al 1979, Pinkerton et al 1981, Walker et al 1982, Walker et al 1983). In the Ontario scheme error rates for uncomplicated ABO and D grouping fell in the first few years of the scheme and since then have remained unchanged for some 5 years.…”

“…Evidence has been obtained in external quality assessment schemes that errors may occur even in uncomplicated ABO and D grouping (Pinkerton et al 1979, Pinkerton et al 1981, Walker et al 1982, Walker et al 1983). In the Ontario scheme error rates for uncomplicated ABO and D grouping fell in the first few years of the scheme and since then have remained unchanged for some 5 years.…”