Revision of quality indicators for cervical cancer and trend analysis of existing indicators in Japan

Cervical cancer rates in Japan (16.0/100,000) exceed the global average rate (11.3/100,000, according to the High/Very-High Human Development Index in 2020). This necessitates the evaluation of care quality and the quality indicators (QIs) for cervical cancer that were developed in 2013 to serve this purpose. This study updated these indicators using current evidence and consensus while longitudinally examining trends in practice patterns.

The revision involved reviewing existing QIs and patterns of care indicators and incorporating new indicators using the modified Delphi method. Adherence to these indicators was assessed using a linked hospital-based cancer registry-based diagnostic procedure combination database covering approximately 70% of patients with cancer in Japan. The longitudinal trends of the existing indicators were evaluated using the linear probability model.

Seven new indicators were added to the existing twelve. Two of the new indicators mainly focused on early-stage surgical intervention, while one focused on advanced-stage bevacizumab combination therapy, with adherence rates of 81.7%, 0.8%, and 45.9%. Longitudinal analyses revealed significant improvements with the use of cisplatin in concurrent chemoradiotherapy for advanced-stage cervical cancer (+1%/year), oral anticancer agents as maintenance therapy after primary treatment for early-stage cervical cancer (-0.8%/year), and hysterectomy for adenocarcinoma in situ in patients above 44 years old (-2%/year).

The QIs for cervical cancer in Japan have been revised based on 2022 evidence. The existing and new indicators should be continually evaluated to correspond to the latest knowledge. This will facilitate the standardization and promotion of bottom-up improvements in cervical cancer care.