Quantifying surgical under-treatment in older adult cancer patients.

This project looking at cohorts of cancer patients diagnosed between 2011-2015 compiled in a dataset by the NICR, and will be linked to the 2011 Census and therefore meets the longitudinal criterion required for a NILS project. The NILS and NICR have the full complement of data required to answer the research question in the census year 2011. The quality of staging, comorbidity, and treatment information in NICR has increased to sufficient levels in the last 10 years. From the NILS dataset, we require the health information on frailty (e.g. Q22, 2011 Census) and comorbidity (Q23, 2011 Census) only available in 2011.

However, the NILS data is uniquely placed to contribute to this study because it is very difficult to capture frailty data (albeit self-report, which has shown good correlation to objective performance status data). In addition, the ability to adjust at an individual level for socio-economic factors and ethnicity is unprecedented.

The primary question is to assess the relationship between age and treatment rates, and requires a combination of necessary variables to adjust for multiple sources of confounding that have been identified in the literature (disease stage at diagnosis, patient frailty, and comorbidity). Detailed information on the cancer, its stage, treatment, and patient comorbidity will be linked in from the NICR register.

A secondary question for the research project is to assess whether surgery improved net survival in the elderly as compared to the younger cancer patient. NILS database will allow net survival to be determined. For this, we will require year of death and month of death of patients plus cause of death.