A study of patients not registered in the Swedish Cancer Register but reported to the Swedish Register of Palliative Care 2009 as deceased due to cancer.
The Swedish Cancer Register (SCR), an old and reputable health data register, contributes a large amount of data used in research. The quality of the research using SCR data depends on the completeness and validity of the register. In Sweden, every healthcare provider is obligated to report newly detected cases of cancer to the SCR regardless of the diagnostic basis. This study aimed to clarify whether there is an under-reporting of patients with cancer to the SCR or an over-reporting of cancer as cause of death to the SRPC as all patients do not appear in both registers. In addition, this study looked at the distribution of under-reporting or over-reporting related to age, sex, type of cancer, diagnostic basis, and department responsible for cancer diagnosis. Of the 10 559 patients whose cause of death was cancer as reported to the SRPC (2009), 1394 patients (13.2%) were not registered in the SCR (1958-2009). Medical records from a representative sample of 203 patients were collected and reviewed. The medical records for 193 patients were obtained; of those, 183 (95%) patients should have been reported to the SCR. Among these, radiologic investigation was the most common basis for diagnosis and there was a significant over-representation of cancer of the pancreas, lung, liver, and bile ducts. This study cannot quantify the completeness of the SCR. The findings indicate that 12.5% of patients dying of cancer in palliative care are not reported, that specialized hospital departments diagnose the vast majority of the unreported patients, and that routines for how to report patients to the SCR based on radiological findings should be revised.