Garbage codes in the Norwegian Cause of Death Registry 1996-2019.

BACKGROUND: Reliable statistics on the underlying cause of death are essential for monitoring the health in a population. When there is insufficient information to identify the true underlying cause of death, the death will be classified using less informative codes, garbage codes. If many deaths are assigned a garbage code, the information value of the cause-of-death statistics is reduced. The aim of this study was to analyse the use of garbage codes in the Norwegian Cause of Death Registry (NCoDR). METHODS: Data from NCoDR on all deaths among Norwegian residents in the years 1996-2019 were used to describe the occurrence of garbage codes. We used logistic regression analyses to identify determinants for the use of garbage codes. Possible explanatory factors were year of death, sex, age of death, place of death and whether an autopsy was performed. RESULTS: A total of 29.0% (290,469/1,000,128) of the deaths were coded with a garbage code; 14.1% (140,804/1,000,128) with a major and 15.0% (149,665/1,000,128) with a minor garbage code. The five most common major garbage codes overall were ICD-10 codes I50 (heart failure), R96 (sudden death), R54 (senility), X59 (exposure to unspecified factor), and A41 (other sepsis). The most prevalent minor garbage codes were I64 (unspecified stroke), J18 (unspecified pneumonia), C80 (malignant neoplasm with unknown primary site), E14 (unspecified diabetes mellitus), and I69 (sequelae of cerebrovascular disease). The most important determinants for the use of garbage codes were the age of the deceased (OR 17.4 for age ≥ 90 vs age < 1) and death outside hospital (OR 2.08 for unknown place of death vs hospital). CONCLUSION: Over a 24-year period, garbage codes were used in 29.0% of all deaths. The most important determinants of a death to be assigned a garbage code were advanced age and place of death outside hospital. Knowledge of the national epidemiological situation, as well as the rules and guidelines for mortality coding, is essential for understanding the prevalence and distribution of garbage codes, in order to rely on vital statistics.

The quality of medical autopsy reports. / Kvaliteten på medisinske obduksjonsrapporter.

BACKGROUND: Medical autopsies are rarely made subject to quality assurance. We have investigated the quality of autopsy reports in Norway and assessed the impact of errors on the cause of death statistics. MATERIAL AND METHOD: Every fifth medical autopsy report for adults (> 2 years) in 2014 was reviewed. The significance of the autopsy result for the registration of cause of death was studied by comparing the death certificate issued by the clinician with the coding in the Cause of Death Registry after the autopsy. RESULTS: A total of 389 autopsy reports from 15 departments of pathology were reviewed. The autopsy request, as well as the death certificate and the codes for the cause of death from the Cause of Death Registry were available for 339 and 360 cases respectively. Ninety-five requests had specified clinical questions, but were commented on by the pathologist in 33 cases. Obesity was rarely reported as a finding, even in cases of pathological deviations from a normal weight. A post-mortem virus examination or toxicology had been performed in 1 and 28 autopsies respectively. The average turnaround time for autopsies without and with a neuropathological examination was 99 and 138 days respectively. Errors in reporting the cause of death or inadequate reporting were evident in 69 cases (18 %), most frequently for deaths from cardiovascular diseases. The autopsy result led to a change to the cause of death in the Cause of Death Registry in 206 out of 360 (57 %) cases for which coding data were available. Errors in the formulation of the autopsy result resulted in erroneous coding of the cause of death in 22 out of 47 (47 %) of cases with errors. INTERPRETATION: The proportion of autopsy reports with errors in the formulation of the cause of death was unexpectedly high and may have consequences for the cause of death statistics. Long turnaround times for autopsies complicate communication with the clinician about the findings.

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

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.