PhD defence E.M. (Elfi) Verheul

Below is a brief summary of the dissertation:

The pressure for greater transparency in healthcare outcomes is increasing. Hospitals are increasingly being compared on treatment results. Patients and policymakers are calling for more complete information, not only about the quality of care and differences between hospitals, but also about patients’ quality of life after treatment. At the same time, healthcare systems are moving towards more personalised care. This thesis shows that the responsible use of healthcare outcomes depends on the correct application of robust methodology, and that prediction models based on outcome data can support better decision-making for individual patients.
The first part of the thesis shows that comparisons between hospitals are not always reliable. Quality indicators often focus on short-term outcomes, while a uniform methodological approach is lacking. As a result, comparisons may be unfair or misleading. This thesis develops practical methods to make hospital comparisons more fair and reliable, including improved statistical adjustments for differences between patient populations and the use of multi-year data in hospital-level feedback to reduce the influence of random variation.
In addition, the second part of the thesis demonstrates the importance of personalised cancer care. Existing prediction models (Breast PREDICT) for survival in breast cancer were successfully validated in Dutch, Slovenian, and Swedish patients. New models were also developed to predict how quality of life develops after breast cancer surgery, supporting more realistic expectations during recovery.
Overall, this thesis shows that better use of outcome data, including both clinical outcomes and quality of life, can contribute to improving the quality of cancer care.