Liquid-based cytology can improve efficiency of cervical smear readers: evidence from timing surveys in two NHS cytology laboratories.

OBJECTIVE

Cervical screening programmes in England and Wales were advised by the National Institute for Clinical Excellence in 2003 to adopt liquid-based cytology (LBC) in place of conventional Papanicolaou (Pap) cytology to facilitate laboratory efficiency. Pilot evaluations in England and Scotland monitored daily or weekly workloads of smear readers and concluded that LBC could increase hourly throughput rates. This study, instead, used timing surveys to determine screening rates.

METHODS

Two National Health Service cytology laboratories in Manchester and Stockport were partially converted to the LBC ThinPrep process for a cervical screening trial. Three 1-week timing surveys were conducted over 7 months. The surveys covered all LBC-trained staff. The first survey in Manchester also covered staff undertaking conventional Pap screening. The smear readers used timers to record time taken for examining and reporting each slide.

RESULTS

In Manchester, in the first survey, nearly 1 minute per slide was saved by the LBC method during primary microscopy. In both laboratories, the mean microscopy time for primary screening of LBC slides was reduced by almost 1 minute between the first and second surveys. There was no difference between the second and third surveys. Microscopy by cytopathologists was also 1 minute per slide quicker with LBC than conventional Pap. The LBC inadequate rates for both laboratories were <2.0%. Organizational factors impacted on the hourly LBC primary screening rates in the laboratories, the rate for Stockport being higher than the rates in the pilot evaluations.

CONCLUSIONS

The timing surveys confirm that the LBC ThinPrep technology can improve laboratory efficiency. However, decision-makers should also consider the overall costs and benefits of introducing the technology in screening programmes, including the capital investment and workforce implications.