The Zimbabwe External Quality Assessment Scheme (ZEQAS) in clinical chemistry: results of the pilot programme

A pilot programme for assessing laboratory performance in clinical chemistry laboratories in Zimbabwe is described (ZEQAS). Twenty four laboratories providing patient care services participated. Eight lyphilised bovine sera were distributed over one year. Consensus values and the spread of interlaboratory agreement were calculated for each of 12 analytes and compared with results previously obtained in a large mature national EQA scheme in the UK (UK NEQAS). For all analytes except phosphate, the mean consensus value obtained in ZEQAS was between 94 and 108 pc of the UK target, although the spread of results in ZEQAS was generally two to threefold greater for individual analytes than in UK NEQAS. It is concluded the ZEQAS consensus values for the analytes surveyed provide a valid target against which individual laboratory performance can be assessed. The wide spread of results from individual laboratories suggests there is considerable scope for improving interlaboratory agreement. This is being addressed by the continuing programme, with increased interaction and production of local specimens.