Comparison of data from the Cause of Death Registry and the Norwegian Patient Register

Abstract

Background: The quality of the data in the Cause of Death Registry is crucial to produce reliable statistics on causes of death. The Cancer Registry of Norway uses data from the Norwegian Patient Register to request information from hospitals regarding patients registered with cancer in the patient registry, but not in the cancer registry. We wanted to investigate whether data from the Norwegian Patient Register can also be used to advantage in the Cause of Death Registry.

Material and method: Data from the Cause of Death Registry on deaths that occurred during the period 2009 – 2011 (N = 124,098) were collated with data on contact with somatic hospitals and psychiatric institutions during the last year of life, retrieved from the Norwegian Patient Register. Causes of death were grouped in the same way as in standard statistics on causes of death.

Results: Out of 124,098 deaths, altogether 34.9% occurred in somatic hospitals. A total of 80.9% of all deceased had been admitted to a somatic hospital and/or had attended an outpatient consultation during their last year of life. The proportion with hospital contact was highest for those whose cause of death was cancer. In cases of unknown/unspecified cause of death, more than half also had contact with hospitals, but the majority of these were registered with only outpatient consultations. Altogether 5.4% of all deceased had been admitted to and/or had an outpatient consultation in a psychiatric institution during their last year of life. For those whose cause of death was suicide, this proportion amounted to 41.8%.

Interpretation: In case of incomplete information on the cause of death, data from the Norwegian Patient Register can supply valuable information on where the patient has been treated, thus enabling the Cause of Death Registry to contact the hospitals in question. However, any potential benefit is restricted by the fact that deceased persons with unknown/unspecified causes of death had less frequently been admitted to hospital during their last year of life.