Programmatic assessments of the clinical effectiveness of gynecologic liquid-based cytology

Evaluation of cellular adequacy in endometrial liquid-based cytology

OBJECTIVE

This study evaluated cellular adequacy in endometrial liquid-based cytology (LBC) specimens.

METHODS

In total, 1267 cases were obtained and the rate of unsatisfactory specimen and diagnostic accuracy for malignancy were assessed. If ≥10 cellular clusters composed of ≤30 endometrial cells were found per specimen, then the sample was provisionally considered adequate.

RESULTS

The unsatisfactory rate (with fewer than 10 clusters) was 15.4%. Diagnostic accuracy in specimens with ≥10 clusters was significantly higher (90.5% vs 36.4%) than that in specimens with fewer than10 clusters. Moreover, the unsatisfactory rate in patients aged ≥60 years was significantly higher (33.8% vs 13.2%) than that in patients younger than 60 years. Although the unsatisfactory rate was decreased, significant differences were not found between cases with fewer than five clusters (22.6%) and fewer than 10 clusters (33.8%) in patients aged ≥60 years. Diagnostic accuracy in cases with five or more clusters was significantly higher (90.3% vs 0%) than that in cases with fewer than five clusters.

CONCLUSIONS

We propose that ≥10 clusters with ≥30 endometrial cells per cluster could be used as a specimen adequacy criterion for endometrial LBC. If ≥10 clusters cannot be found in patients aged ≥60 years, then the use of the alternative criterion of five or more clusters may yield satisfactory specimen adequacy.

An alternative cost effectiveness analysis of ThinPrep in the Australian setting

OBJECTIVE

To assess the clinical and economic impacts of the use of liquid based cytology (LBC) in the Australian average risk population from the perspective of the public health care budget.

BACKGROUND

Concerns over the evaluation of medical technologies in Australia, which are assessed by the Medicare Services Advisory Committee (MSAC), have been raised recently. We report on the evaluation of LBC, which although being widely adopted in other parts of the world, has, despite substantial uptake in the private sector in Australia, been rejected for public funding by MSAC.

METHODS

We used the health economic model developed by MSAC, but populated the model with the best available international data, sourced from a published review article. The economic model considered the clinical benefits and the costs arising from a biennial cervical screening programme. Net costs divided by life years saved is the cost per life year saved and this is reported as the incremental cost effectiveness.

RESULTS

Populating the MSAC model with data on test performance showed that one type of LBC (ThinPrep) 'dominates' the conventional Pap smear in the screening of average risk women in the Australian setting.

CONCLUSION

The health economic model created by MSAC predicts that ThinPrep dominates the conventional Pap as a screening test for cervical cancer. An additional 2240 high-grade lesions could be detected, resulting in 480 life years gained and delivering an expected saving to the health care system of $5,536,000 per annum if liquid based cytology replaced the conventional Pap.