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.

Health care utilization among individuals who die by suicide as compared to the general population: a population-based register study in Sweden.

BACKGROUND: Globally, 700 000 people die every year by suicide. Health care consultation patterns the period before suicide could be one potential way to identify people at risk for suicide. Therefore, this study examines health care patterns up to one year prior to the suicide by age, sex and prior diagnoses and specifically investigates if and how this differs from the general population of Skåne, Sweden. METHODS: This cohort study includes all individuals, aged 15 and older, that died by suicide in Region Skåne, Sweden from 2004 to 2015 (n = 1653). The individuals were identified through the Cause of death register and then linked to the Skåne healthcare register. Health care data was analyzed as proportions consulting different types of health care the month and year preceding the suicide, we also investigated the impact of age, sex and the occurrence of prior psychiatric and pain diagnoses. Additionally, we compared the proportion of consulting care among the suicide victims and the general population of Skåne. RESULTS: In the month before their death, 53% of the suicide victims had any health care consultation, compared with 20% in the general population of Skåne, a given month (p < 0.0001). The corresponding figures for the year prior to suicide was 86% among those who died by suicide, compared to 69% in the general population of Skåne, a given year (p < 0.0001). Women, and those having a documented history of psychiatric diagnosis were more likely to have health care consultations in the month and year preceding suicide (p < 0.001), compared to men and suicide victims without a history of psychiatric disease. Older adults that died by suicide, were less likely to consult psychiatric care compared to the younger suicide victims (p < 0.001). CONCLUSION: A majority of the suicide victims consulted health care in the near time before death and the proportion of seeking health care was significantly higher than in the general population of Skåne and higher among female suicide victims as compared to males. Alternative preventive screening measures should be considered for individuals consulting health care, especially for older people and individuals outside the psychiatric care.

Pheochromocytoma in Denmark during 1977-2016: validating diagnosis codes and creating a national cohort using patterns of health registrations.

BACKGROUND: Pheochromocytoma and catecholamine-secreting paraganglioma (PPGL) are rare but potentially life-threatening tumors. We aimed to validate diagnosis codes for PPGL in the Danish National Patient Registry, the Danish National Pathology Registry, and the Danish Registry of Causes of Death and to create a national cohort of incident PPGL patients by linking these three registries. PATIENTS AND METHODS: We obtained data from the three abovementioned registries for all individuals registered with pheochromocytoma or catecholamine hypersecretion in Denmark during 1977-2016 (average population 5.30 million). We then reviewed health records for all individuals living in the North Denmark Region and Central Denmark Region (average population 1.75 million) to validate the diagnosis of PPGL. We tested a number of algorithms for accurately identifying true cases of PPGL to maximize positive predictive values (PPVs) and completeness. The best algorithm was subsequently validated in an external sample. RESULTS: We identified 2626 individuals with a PPGL diagnosis code in Denmark, including 787 (30.0%) in the North Denmark Region and Central Denmark Region. In this subsample, we retrieved the health records of 771/787 (98.0%) individuals and confirmed 198 incident PPGL patients (25.3%). The PPV of PPGL diagnosis codes was 21.7% in the Danish National Patient Registry, 50.0% in the Danish Registry of Causes of Death, and 79.5% in the Danish National Pathology Registry. By combining patterns of registrations in the three registries, we could increase the PPV to 93.1% (95% confidence interval [CI]: 88.5-96.3) and completeness to 88.9% (95% CI: 83.7-92.9), thus creating a national PPGL cohort of 588 patients. PPV for the optimal algorithm was 95.3% (95% CI: 88.5-98.7) in the external validation sample. CONCLUSION: Diagnosis codes for pheochromocytoma had low PPV in several individual health registries. However, with a combination of registries we were able to identify a near-complete national cohort of PPGL patients in Denmark, as a valuable source for epidemiological research.

Differing Procedures for Recording Mortality Statistics in Scandinavia.

BACKGROUND: There may be various reasons for differences in suicide rates between countries and over time within a country. One reason can be different registration practices. AIMS: The purpose of this study was to describe and compare the present procedures for mortality and suicide registration in the three Scandinavian countries and to illustrate potential sources of error in the registration of suicide. METHOD: Information about registration practices and classification procedures was obtained from the cause of death registers in Norway, Sweden, and Denmark. In addition, we received information from experts in the field in each country. RESULTS: Sweden uses event of undetermined intent more frequently than Denmark does, and Denmark more frequently than Norway. There seems to be somewhat more uncertainty among deaths classified as ill-defined and unknown cause of mortality in Norway, compared with the other two countries. Sweden performs more forensic autopsies than Norway, and Norway more than Denmark. In Denmark, in cases of a suspected unnatural manner of death, a thorough external examination of the deceased is performed. CONCLUSION: Differences in the classification of causes of death and in postmortem examinations exist in Scandinavian countries. These differences might influence the suicide statistics in Scandinavia.

Increased incidence of subarachnoid hemorrhage during cold temperatures and influenza epidemics.

OBJECTIVE This study investigated whether the increased incidence of aneurysmal subarachnoid hemorrhage (SAH) in winter is related to temperature or increased incidence of influenza. Such relationships may elucidate the pathogenesis of intracranial aneurysm rupture. METHODS A nationwide sample of 18,714 patients with SAH was linked with weekly temperature and influenza-like illness consultation data. Poisson regression analyses were used to calculate incidence density ratios (IDRs) with corresponding 95% CIs for the association of SAH incidence with temperature and influenza epidemics; IDRs were adjusted for study year (aIDR). In addition, SAH incidence data from 30 European population-based studies were linked with daily temperature data from the European Climate Assessment. RESULTS The aIDR for SAH during influenza epidemics was 1.061 (95% CI 1.022-1.101) in the univariable and 1.030 (95% CI 0.989-1.074) in the multivariable analysis. This association declined gradually during the weeks after epidemics. Per 1°C temperature drop, the aIDR was 1.005 (95% CI 1.003-1.008) in the univariable and 1.004 (95% CI 1.002-1.007) in the multivariable analysis. In the European population-based studies, the IDR was 1.143 (95% CI 1.129-1.157) per 1°C temperature drop. CONCLUSIONS The incidence of SAH is increased during cold temperatures and epidemic influenza. Future studies with individual patient data are needed to investigate causality between temperature or influenza and SAH.

Causes of death among undocumented migrants in Sweden, 1997-2010.

BACKGROUND: Undocumented migrants are one of the most vulnerable groups in Swedish society, where they generally suffer from poor health and limited health care access. Due to their irregular status, such migrants are an under-researched group and are not included in the country's Cause of Death Register (CDR). OBJECTIVE: To determine the causes of death among undocumented migrants in Sweden and to ascertain whether there are patterns in causes of death that differ between residents and undocumented migrants. DESIGN: This is a cross-sectional study of death certificates issued from 1997 to 2010 but never included in the CDR from which we established our study sample of undocumented migrants. As age adjustments could not be performed due to lack of data, comparisons between residents and undocumented migrants were made at specific age intervals, based on the study sample's mean age at death±a half standard deviation. RESULTS: Out of 7,925 individuals surveyed, 860 were classified as likely to have been undocumented migrants. External causes (49.8%) were the most frequent cause of death, followed by circulatory system diseases, and then neoplasms. Undocumented migrants had a statistically significant increased risk of dying from external causes (odds ratio [OR] 3.57, 95% confidence interval [CI]: 2.83-4.52) and circulatory system diseases (OR 2.20, 95% CI: 1.73-2.82) compared to residents, and a lower risk of dying from neoplasms (OR 0.07, 95% CI: 0.04-0.14). CONCLUSIONS: We believe our study is the first to determine national figures on causes of death of undocumented migrants. We found inequity in health as substantial differences in causes of death between undocumented migrants and residents were seen. Legal ambiguities regarding health care provision must be addressed if equity in health is to be achieved in a country otherwise known for its universal health coverage.