Quantitative measurement of quality outcome in malignant glioma patients using an independent living score (ILS): Assessment of a retrospective cohort

Purpose. Although a number of tools have been developed to measure 'quality of life' in patients with malignant glioma, there remains no completely satisfactory technique that incorporates a quality of life measure into survival analysis. We propose that a patient's ability to maintain independent activity offers a way to accomplish this goal. Patients and methods. An independent living score (ILS) is generated by awarding points on a monthly basis based on Karnofsky score and weighing the score based on the particular month of the clinical course. The ILS has a large range for any given survival, and can discriminate important treatment effects to which standard survival analyses are completely insensitive. Using this score and several variations, we were able to retrospectively analyze a patient cohort to assess what correlated with ILS. Results. We found a strong correlation with survival of all the measures tested. Interestingly, we found that patients for whom a total resection was performed and those who were most intensively treated had significantly higher ILS values, suggesting that not only did more aggressive treatment improve survival but that it did not simply increase survival at the expense of the time a patient remained independent. Conclusion. Since the general course for patients with malignant glioma is one of increasing disability and loss of independence, we feel that these measures can serve as a way to distinguish between those therapies that increase survival at the expense of quality of life versus those that do not. Consideration should be given to incorporating these measures into prospective trials.