Nordic registry data: value, validity and future

Adolescent Psychiatric Inpatient Episodes and Subsequent Labor Market Trajectories

PURPOSE

Adolescents with psychiatric disorders are known to be more often not in education, employment, or training (NEET) in young adulthood than their peers. However, since most of the available evidence is based on cross-sectional measurement of NEET, there is less evidence on the processes underlying these differences in labor market disadvantage. We assessed these processes by examining transitions between NEET and non-NEET states across young adulthood and the differences in these transitions by adolescent psychiatric inpatient treatment.

METHODS

We used longitudinal register data on all individuals born in Finland in 1980-1984 (N = 315,508) to identify psychiatric inpatient episodes between ages 10 and 19 and NEET between ages 20 and 34. We modeled the transitions between NEET and non-NEET states and the impact of psychiatric disorders on these transitions with multistate models.

RESULTS

Individuals who had psychiatric inpatient episodes in adolescence started their labor market careers as NEET twice as often as their peers. They were also more likely to transition into NEET states and less likely to transition out of NEET. In total, individuals with a history of psychiatric episodes spent from 1.8 to 6.9 more years as NEET between the ages 20 and 34 than their peers, depending on sex, baseline NEET, and diagnostic group.

DISCUSSION

Adolescents with severe psychiatric disorders are highly vulnerable in terms of labor market outcomes throughout their early adulthood. Supportive measures are required both at the start of employment trajectories and during later career stages.

Incidence and case ascertainment of treated in-hospital cardiac arrest events in a national quality registry - A comparison of reported and non-reported events

BACKGROUND

Approximately 2500 in-hospital cardiac arrest (IHCA) events are reported annually to the Swedish Registry of Cardiopulmonary Resuscitation (SRCR) with an estimated incidence of 1.7/1000 hospital admissions. The aim of this study was to evaluate the compliance in reporting IHCA events to the SRCR and to compare reported IHCA events with possible non-reported events, and to estimate IHCA incidence.

METHODS

Fifteen diagnose codes, eight Classification of Care Measure codes, and two perioperative complication codes were used to find all treated IHCAs in 2018-2019 at six hospitals of varying sizes and resources. All identified IHCA events were cross-checked against the SRCR using personal identity numbers. All non-reported IHCA events were retrospectively reported and compared with the prospectively reported events.

RESULTS

A total of 3638 hospital medical records were reviewed and 1109 IHCA events in 999 patients were identified, with 254 of the events not found in the SRCR. The case completeness was 77% (range 55-94%). IHCA incidence was 2.9/1000 hospital admissions and 12.4/1000 admissions to intensive care units. The retrospectively reported events were more often found on monitored wards, involved patients who were younger, had less comorbidity, were often found in shockable rhythm and more often achieved sustained spontaneous circulation, compared with in prospectively reported events.

CONCLUSION

IHCA case completeness in the SRCR was 77% and IHCA incidence was 2.9/1000 hospital admissions. The retrospectively reported IHCA events were found in monitored areas where the rapid response team was not alerted, which might have affected regular reporting procedures.

Mortality and neurodevelopmental outcome after invasive group B streptococcal infection in infants

AIM

To assess case fatality rate (CFR), infant mortality, and long-term neurodevelopmental disorders (NDDs) after invasive group B streptococcal (GBS; Streptococcus agalactiae) infection in infants.

METHOD

Children born in Norway between 1996 and 2019 were included. Data on pregnancies/deliveries, GBS infection, NDDs, and causes of death were retrieved from five national registries. The exposure was culture-confirmed invasive GBS infection during infancy. Outcomes were mortality and NDDs, the latter at a mean age of 12 years 10 months.

RESULTS

Among 1 415 625 live-born children, 866 (87%) of 1007 infants diagnosed with GBS infection (prevalence 0.71 per 1000) were included. The CFR was 5.0% (n = 43). GBS infection was associated with higher infant mortality (relative risk 19.41; 95% confidence interval [CI] 14.79-25.36) than the general population. Among survivors, 169 (20.7%) children were diagnosed with any NDD (relative risk 3.49; 95% CI 3.05-3.98). In particular, GBS meningitis was associated with high risks of attention-deficit/hyperactivity disorder, cerebral palsy, epilepsy, hearing impairment, and pervasive and specific developmental disorder.

INTERPRETATION

The burden of invasive GBS infection during infancy is considerable and continues to affect children beyond infancy. These findings emphasize the need for new preventive strategies for disease reduction, and the need for survivors to be directly included into early detection pathways to access early intervention if required.

WHAT THIS PAPER ADDS

The burden of invasive group B streptococcal (GBS) infection in Norway is considerable. Of GBS infection survivors, 20.7% were diagnosed with neurodevelopmental disorders (NDDs) at mean age 12 years 10 months. Infants with GBS meningitis were more often diagnosed with NDDs. Absolute risks associated with GBS infections were highest for pervasive and specific developmental disorder, cerebral palsy, and attention-deficit/hyperactivity disorder.

Validation of the Swedish Quality Register for Ear Surgery - SwedEar

BACKGROUND

The Swedish Quality Register for Ear Surgery (SwedEar) is a national register monitoring surgical procedures and outcomes of ear surgery to facilitate quality improvement. The value of the register is dependent on the quality of its data. SwedEar has never been validated regarding data quality or missing entries. Therefor, the purpose of this study was to assess coverage, completeness and response rate in the register and validate the physicians' reported data accuracy.

METHODS

In this validation study, the completeness, response rate and missing registrations were analysed. Data in SwedEar were compared with the yearly collected statistics of otosurgical procedures in The Swedish Otosurgical Society and the comparison of rates between groups was calculated with Fisher's exact test. Validation of registered data accuracy was performed on every 20th registered case during a five-year period. Data were reabstracted from medical records and compared with the original registration. Interrater agreement, reliability measures, Cohen's kappa, Gwet's AC1 and positive predictive value were calculated.

RESULTS

SwedEar has a coverage of 100%. The completeness of registered cases was 84% and the response rate was 74%. The validation of data accuracy assessed 13 530 variables, including audiograms. Less than 3% of incorrect or missing variables were identified. For most of the pre- and postoperative variables the Kappa and Gwet´s AC1 results show an almost perfect agreement (> 0.80). For audiogram data the ICC shows an excellent reliability (> 0.9) for all but one value.

CONCLUSION

This validation shows that SwedEar has excellent coverage, high completeness, and that the data in the register have almost perfect reliability. The data are suitable for both clinical and research purposes. Further efforts to improve completeness are warranted.

The application of spatial measures to analyse health service accessibility in Australia: a systematic review and recommendations for future practice

BACKGROUND

Australia's inequitable distribution of health services is well documented. Spatial access relates to the geographic limitations affecting the availability and accessibility of healthcare practitioners and services. Issues associated with spatial access are often influenced by Australia's vast landmass, challenging environments, uneven population concentration, and sparsely distributed populations in rural and remote areas. Measuring access contributes to a broader understanding of the performance of health systems, particularly in rural/remote areas. This systematic review synthesises the evidence identifying what spatial measures and geographic classifications are used and how they are applied in the Australian peer-reviewed literature.

METHODS

A systematic search of peer-reviewed literature published between 2002 and 2022 was undertaken using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Search terms were derived from three major topics, including: [1] Australian population; [2] spatial analysis of health service accessibility; and [3] objective physical access measures.

RESULTS

Database searches retrieved 1,381 unique records. Records were screened for eligibility, resulting in 82 articles for inclusion. Most articles analysed access to primary health services (n = 50; 61%), followed by specialist care (n = 17; 21%), hospital services (n = 12; 15%), and health promotion and prevention (n = 3; 4%). The geographic scope of the 82 articles included national (n = 33; 40%), state (n = 27; 33%), metropolitan (n = 18; 22%), and specified regional / rural /remote area (n = 4; 5%). Most articles used distance-based physical access measures, including travel time (n = 30; 37%) and travel distance along a road network (n = 21; 26%), and Euclidean distance (n = 24; 29%).

CONCLUSION

This review is the first comprehensive systematic review to synthesise the evidence on how spatial measures have been applied to measure health service accessibility in the Australian context over the past two decades. Objective and transparent access measures that are fit for purpose are imperative to address persistent health inequities and inform equitable resource distribution and evidence-based policymaking.

Validity of chronic disease diagnoses in Icelandic healthcare registries

AIMS

To evaluate the validity of recorded chronic disease diagnoses in Icelandic healthcare registries.

METHODS

Eight different chronic diseases from multiple sub-specialties of medicine were validated with respect to accuracy, but not to timeliness. For each disease, 30 patients with a recorded diagnosis and 30 patients without the same diagnosis were randomly selected from >80,000 participants in the iStopMM trial, which includes 54% of the Icelandic population born before 1976. Each case was validated by chart review by physicians using predefined criteria.

RESULTS

The overall accuracy of the chronic disease diagnoses was 96% (95% CI 94-97%), ranging from 92 to 98% for individual diseases. After weighting for disease prevalence, the accuracy was estimated to be 98.5%. The overall positive predictive value (PPV) of chronic disease diagnosis was 93% (95% CI 89-96%) and the overall negative predictive value (NPV) was 99% (95% CI 96-100%). There were disease-specific differences in validity, most notably multiple sclerosis, where the PPV was 83%. Other disorders had PPVs between 93 and 97%. The NPV of most disorders was 100%, except for hypertension and heart failure, where it was 97 and 93%, respectively. Those who had the registered chronic disease had objective findings of disease in 96% of cases.

CONCLUSIONS

When determining the presence of chronic disease, diagnosis data from the Icelandic healthcare registries has a high PPV, NPV and accuracy. Furthermore, most diagnoses can be confirmed by objective findings such as imaging or blood testing. These findings can inform the interpretation of studies using diagnostic data from the Icelandic healthcare registries.

Temporal changes in demographic and injury characteristics of traumatic spinal cord injuries in Nordic countries - a systematic review with meta-analysis

STUDY DESIGN

Systematic review with meta-analysis.

OBJECTIVES

To explore temporal changes in incidence rates, demographic and injury characteristics of incident traumatic spinal cord injury (TSCI) in Nordic countries.

METHODS

Peer-reviewed publications and periodic reports about epidemiology of TSCI in the Nordic countries (Denmark, Finland, Iceland, Norway, Sweden) are identified, reviewed and included in the meta-analysis. Data are stratified into 20-year intervals to allow for chronological comparisons. Pooled estimates are derived using random effects meta-analysis.

RESULTS

Twenty-three data sources are included presenting a total of 5416 cases. The pooled incidence rate for 2001-2020 is 15.4 cases/million/year compared to 17.6 and 18.3 cases/million/year during the two previous 20-year intervals. The proportion of cases with TSCI in the 15-29 age-group decreases from 50% (1961-1980) to 20% (2001-2020), while it increases from 9% to 35% in 60+ age-group. Transportation-related injuries decrease from 44% (1961-1980) to 27% (2001-2020). Conversely, fall-related injuries increase from 32% (1961-1980) to 46% (2001-2020). The proportion of individuals with incomplete tetraplegia increases from 31% (1961-1980) to 43% (2001-2020), while complete paraplegia decreases from 25% to 16%.

CONCLUSION

The characteristics of TSCI in the Nordic countries have changed drastically over the last six decades, in line with clinical experiences, and limited research evidence from other countries. These changes indicate the need for adapting research focus, prevention strategies, design and provision of care, rehabilitation and community services towards older individuals, fall-related injuries, and incomplete injuries in Nordic countries and other settings internationally where such changes occur.

Contribution of an extensive medication-based comorbidity index (Rx-Risk) in explaining the excess mortality after hip fracture in older Norwegians: a NOREPOS cohort study

OBJECTIVES

Patients with hip fracture are typically characterised by extensive comorbidities and excess mortality. Methods that account for a wide range of comorbidities are needed when attempting to identify causal associations in registry-based studies. We aimed to study the association between the prescription-based Rx-Risk Comorbidity Index (abbreviated Rx-Risk) and mortality by history of hip fracture, and to quantify the contribution of Rx-Risk in explaining the excess mortality after hip fracture.

SETTING

In this prospective study, we used nationwide registry data from outpatient care. Rx-Risk was based on filled prescriptions recorded in the Norwegian Prescription Database. Medications were mapped to 46 comorbidity categories by Anatomical Therapeutic Chemical code. Information on hip fractures during 1994-2013 was available from the Norwegian Epidemiologic Osteoporosis Studies hip fracture database, and year of death was obtained from Statistics Norway. We estimated 1-year mortality risk (January through December 2014) according to Rx-Risk score based on dispensed prescriptions in 2013, history of hip fracture, age and sex using Poisson regression.

PARTICIPANTS

All individuals aged 65 years and older who were alive by the end of 2013 and had filled at least one prescription in an outpatient pharmacy in Norway in 2013 (n=735 968).

RESULTS

Mortality increased exponentially with increasing Rx-Risk scores, and it was highest in persons with a history of hip fracture across the major range of Rx-Risk scores. Age- and sex-adjusted mortality risk difference according to history of hip fracture (yes vs no) was 4.4 percentage points (7.8% vs 3.4%). Adjustment for Rx-Risk score further attenuated this risk difference to 3.3 percentage points.

CONCLUSIONS

History of hip fracture and comorbidity assessed by Rx-Risk are independent risk factors for mortality in the community-dwelling older population in Norway. Comorbidity explained a quarter of the excess mortality in persons with a history of hip fracture.

Economic burden of low physical activity and high sedentary behaviour in Finland

BACKGROUND

Low physical activity and high sedentary behaviour are unquestionably relevant for public health while also increasing direct and indirect costs.

METHODS

The authors examined the direct and indirect costs attributable to low physical activity and high sedentary behaviour in Finland in 2017. Costs related to major non-communicable diseases drawn from Finnish registries covered direct costs (outpatient visits, days of inpatient care, medication and institutional eldercare) and indirect costs (sickness-related absences, disability pensions, unemployment benefits, all-cause mortality and losses of income tax revenue). Prevalences of low physical activity and high sedentary behaviour (≥8 hours per 16 waking hours) were based on self-reports among adolescents or accelerometer data among adults and the elderly from three Finnish population studies: FINFIT 2017, Health 2011 and the Cardiovascular Risk in Young Finns Study. Cost calculations used adjusted population attributable fractions (PAF) and regression models. Total annual costs were obtained by multiplying PAF by the total costs of the given disease.

RESULTS

The total costs of low physical activity in Finland in 2017 came to approximately €3.2 billion, of which direct costs accounted for €683 million and indirect ones for €2.5 billion. Costs attributable to high sedentary behaviour totalled roughly €1.5 billion.

CONCLUSION

The findings suggest that low physical activity and high sedentary behaviour levels create substantial societal costs. Therefore, actions intended to increase physical activity and reduce excessive sedentary behaviour throughout life may yield not only better health but also considerable savings to society.

Register-based information on thyroid diseases in Europe: lessons and results from the EUthyroid collaboration

OBJECTIVE

Registers of diagnoses and treatments exist in different forms in the European countries and are potential sources to answer important research questions. Prevalence and incidence of thyroid diseases are highly dependent on iodine intake and, thus, iodine deficiency disease prevention programs. We aimed to collect European register data on thyroid outcomes to compare the rates between countries/regions with different iodine status and prevention programs.

DESIGN

Register-based cross-sectional study.

METHODS

National register data on thyroid diagnoses and treatments were requested from 23 European countries/regions. The provided data were critically assessed for suitability for comparison between countries/regions. Sex- and age-standardized rates were calculated.

RESULTS

Register data on ≥1 thyroid diagnoses or treatments were available from 22 countries/regions. After critical assessment, data on medication, surgery, and cancer were found suitable for comparison between 9, 10, and 13 countries/regions, respectively. Higher rates of antithyroid medication and thyroid surgery for benign disease and lower rates of thyroid hormone therapy were found for countries with iodine insufficiency before approx. 2001, and no relationship was observed with recent iodine intake or prevention programs.

CONCLUSIONS

The collation of register data on thyroid outcomes from European countries is impeded by a high degree of heterogeneity in the availability and quality of data between countries. Nevertheless, a relationship between historic iodine intake and rates of treatments for hyper- and hypothyroid disorders is indicated. This study illustrates both the challenges and the potential for the application of register data of thyroid outcomes across Europe.

Cohort profile: The Youth and Mental Health Study (YAMHS) - a longitudinal study of the period from adolescence to adulthood

The aim of this article is to provide a detailed description of the Youth and Mental Health Study (YAMHS),a population-based, representative (cluster sampling), prospective cohort study that was conducted to investigate risk and resilience factors for mental health conditions, specifically depressive symptoms and disorders, from adolescence to adulthood. The baseline data were collected in 1998 (T1) in two counties in central Norway from 2464 adolescents (response rate 88.3%, mean age 13.7 years). The first follow-up was conducted in 1999 (T2) (n = 2432, response rate of 87.1%, mean age 14.9 years). A subgroup of individuals was assessed at T2 (n = 345) with clinical interviews, and this subgroup was reassessed in 2005 (T3) (n = 265, 70.1%, 20 years). The last follow-up (of participants assessed at T1 and T2) was conducted in 2012 (T4) (n = 1266, 51.9%, 27.2 years). Demographics, depressive symptoms, general psychopathology, suicidal ideation and attempts and psychological and somatic factors were recorded. Among adolescents of both sexes, psychosocial variables were correlated with and predicted depressive symptom severity. The strongest predictors were sex (female), the levels of depressive symptoms the preceding year, and the total number of stressful events. The association between stressful life events and depressive symptoms was moderated by physical activity, while the relationship between stressful events and coping style was mediated by depressive symptoms. The rate of use of specialised mental health services among the depressed was low. The lifetime prevalence of depressive disorders was 23% at 15 years, and the most common disorder was minor depression. Adolescents who attempted suicide were more often victims of violence and less resilient than were non-suicide attempters. The existing longitudinal data from the cohort will be further analysed. Follow-up data will be obtained from existing national registries by links created with individual identification numbers.

Causal modelling of variation in clinical practice and long-term outcomes of ADHD using Norwegian registry data: the ADHD controversy project

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is among the most common mental disorders in children and adolescents, and it is a strong risk factor for several adverse psychosocial outcomes over the lifespan. There are large between-country and within-country variations in diagnosis and medication rates. Due to ethical and practical considerations, a few studies have examined the effects of receiving a diagnosis, and there is a lack of research on effects of medication on long-term outcomes.Our project has four aims organised in four work packages: (WP1) To examine the prognosis of ADHD (with and without medication) compared with patients with other psychiatric diagnoses, patients in contact with public sector child and adolescent psychiatric outpatient clinics (without diagnosis) and the general population; (WP2) Examine within-country variation in ADHD diagnoses and medication rates by clinics' catchment area; and(WP3) Identify causal effects of being diagnosed with ADHD and (WP4) ADHD medication on long-term outcomes.

METHOD AND ANALYSIS

Our project links several nationwide Norwegian registries. The patient sample is all persons aged 5-18 years that were in contact with public sector child and adolescent psychiatric outpatient clinics in 2009-2011. Our comparative analysis of prognosis will be based on survival analysis and mixed-effects models. Our analysis of variation will apply mixed-effects models and generalised linear models. We have two identification strategies for the effect of being diagnosed with ADHD and of receiving medication on long-term outcomes. Both strategies rely on using preference-based instrumental variables, which in our project are based on provider preferences for ADHD diagnosis and medication.

ETHICS AND DISSEMINATION

The project is approved by the Regional Ethics Committee, Norway (REC number 2017/2150/REC south-east D). All papers will be published in open-access journals and results will be presented in national and international conferences.

TRIAL REGISTRATION NUMBERS

ISRCTN11573246 and ISRCTN11891971.

The illusion of universality: The use of Nordic population registers in studies of migration, employment and health

Aims: Nordic register material is often considered to be a gold standard for studies of social epidemiology and population health, but it comes with certain limitations. This short communication aims to draw attention to lacking coverage as a potentially growing problem of Nordic register material. Methods: The article is based on a short review of previous studies and commentaries on the strengths and limitations of Nordic register data with a particular focus on studies of employment and migration. Results: In times of institutional and demographic change in the Nordic countries, the assumption of universal register coverage can be challenged. Precarious and informal employment arrangements, important social determinants of health, provide a good illustration of the problem. Work that is carried out in the semi-legal margins of the labour market, sometimes by a ‘hidden population’ of non-resident, short-term labour immigrants, will not be covered by the registers. Researchers may therefore run the risk of misrepresenting reality if they maintain the belief that population registers cover the entire population. Conclusions: The Nordic registers are an extraordinary resource for public health researchers, but continuous quality control and assessment of validity and completeness will be crucial to maintain relevance in a transitioning society.