Patterns of Care Study quantitative evaluation of the quality of radiotherapy in Japan

Quality assurance (QA) of clinical practice is important for any medical specialty. Programs based on the Patterns of Care Study (PCS) have been developed to compare the quality of radiotherapeutic care at individual institutions, with the national average representing the process and outcome of radiotherapy. The feasibility of these programs was analyzed.

Calculation programs for the national average and standard score were developed to evaluate quantitatively the process and outcome of radiotherapy at individual institutions as well as at the national level. The programs were used to evaluate the quality of radiotherapy for 561 esophageal carcinoma patients surveyed in the Japanese PCS.

As a representative example of QA measurement, the national average for the 5-year survival rate for these patients in the nonsurgery group was 5%. The regional averages for those in academic and nonacademic institutions were 9% and 1%, respectively (P = 0.0142), showing a significant difference between these two institutional strata. The standard score compared with the national average for institution No.105, for example, was 16.3 (P < 0.0001), with the positive value indicating that the outcome at this institution was significantly higher than the national average. The corresponding figure compared with the regional average was -0.3 (P = 0.7391), with the negative value indicating the outcome is not superior to the regional average of academic institutions.

These programs make it possible to compare quantitatively the quality of radiation therapy at individual institutions with the national and regional averages. They should also be useful for nationwide QA projects in radiation oncology as well as in other medical specialities.