Practical feasibility of outcomes research in oncology: lessons learned in assessing drug use and cost-effectiveness in The Netherlands

Objective: To investigate the practical feasibility to develop evidence on drug use and cost-effectiveness in oncology practice.

Patients and methods: Feasibility was examined using three Dutch case studies. Each case study investigated the degree of appropriate drug use and its incremental cost-effectiveness. Detailed data were retrospectively collected from hospital records. In total, 391, 316 and 139 patients with stage III colon cancer, metastatic colorectal cancer and multiple myeloma were included in 19, 29 and 42 hospitals, respectively.

Results: The methods used in the case studies were feasible to develop evidence on some aspects of drug use including types of treatments used, dosages, dose modifications and healthcare costs. Aspects such as baseline patient characteristics, reasons to start or stop a treatment and treatment effects were less feasible because of missing values. Despite difficulties to correct for confounding by indication, it was possible to estimate incremental cost-effectiveness by synthesising evidence in two of the three case studies.

Conclusion: It is possible to generate evidence about drug use and cost-effectiveness in oncology practice to facilitate informed decision-making by both payers and physicians. This can improve quality of care and enhance the efficient allocation of resources. However, the optimal approach differs between drugs and their indications. Generating high-quality evidence requires active interdisciplinary collaboration. Patient registries can facilitate data collection but cannot resolve all issues. In most circumstances it is inevitable to use data-synthesis to obtain valid incremental cost-effectiveness estimates, but for some indications it will not be feasible to derive a valid and precise estimate.