What is the minimum number of patients for quality control of lung cancer management in Norway

Introduction There are few data available on the optimal number of lung cancer patients needed to generate and compare estimates of quality between units managing lung cancer. The number of lung cancer patients per management unit varies considerably in Norway, where there are 42 hospitals that treated between 1 and 454 lung cancer patients in 2011. Aims To estimate the differences in quality indicators that are of sufficient importance to change a pulmonary physician's lung cancer management program, and to estimate the size of the patient samples necessary to detect such differences. Method Twenty-six physicians were asked about the relative differences from a national average of quality indicators that would change their own lung cancer management program. Sample sizes were calculated to give valid estimates of quality of a management unit based on prevalence of quality indicators and minimally important differences (MID). Results The average MID in quality indicators that would cause a change in management varied from 18% to 24% among 26 chest physicians, depending on the indicator. Conclusions To generate precise estimates for quality control of lung cancer care in Norway, the number of management units must be reduced. Given the present willingness of chest physicians to change their procedures for management of lung cancer according to the results of quality control indicators, we recommend a maximum of 10 units with a minimum of 200 incident lung cancer patients per year for each management center.