Unemployment and mortality and morbidity - epidemiological studies

The aim of this thesis is to examine the associations between unemployment and mortality and morbidity and what roles pre-existing risk factors, such as psychiatric diagnoses, alcohol disorders, behavioural risk factors, sickness absence and socioeconomic factors, might have in these associations. The studies were based on two populations: the Swedish conscription cohort 1969/70, and the Stockholm population 1990/91. The Swedish conscription cohort 1969/70 contained 49,321 men, born in 1949–51, who during mandatory conscription examination went through psychological assessment and screening for mental disorder, and were surveyed for information on social background and alcohol and drug use. Information from registers on mortality from 1971–2006 and morbidity 1973–2006, and mid-life labour market information 1990–94, was linked to the cohort. The Stockholm population 1990/91 consisted of all 24–58 year-olds in Stockholm Sweden during these years, 386,885 men and 384,183 women. Registered labour market information 1990–1994 and morbidity 1993–94 were linked to this cohort. Data were entered into Cox proportional hazard regression models and logistic regression models. In study I, psychiatric diagnosis at age 18 screening, before or at an early stage of labour market entry, was found to be associated with increased risk of suicide and suicide attempt in middle age. In studies II and IV, poor health and risk factors for poor health, measured between ages 10 and 42, were found to be more prevalent among persons who became unemployed in middle age than among those who remained employed. In studies II and IV, it was also found that those who became unemployed had increased risk of mortality – from all-cause mortality, from natural causes including cardiovascular disease, and from external causes (both suicide and causes other than suicide). They also had an increased risk of hospitalisation from alcohol-related causes. The increased risks of the unemployed were to a large extent attenuated by controlling for confounders, but remained significant for mortality, violent death, external death other than suicide, and hospitalisation from alcohol-related causes. The strongest confounder in the associations between unemployment and mortality and morbidity was previous sickness absence. In study III, sickness absence in the Stockholm population was found to be a predictor of unemployment in men and in women. In study III, it was also found that unemployment in 1992–93 was associated with a (statistically significantly) increased risk of suicide for men in 1994–95. This elevated risk was strongly attenuated by controlling for sickness absence before unemployment. The conclusion is that unemployment is associated with an increased risk of mortality and alcohol-related hospitalisation. The persons in poor health and with risk factors for poor health showed an increased risk of unemployment. After taking into account that the unemployed had poorer health and more risk factors for poor health, the associations between unemployment and mortality and alcohol-related hospitalisation were strongly attenuated. Even after controlling for differences in poor health and risk factors for poor health, there were statistically significantly increased risks of mortality and alcohol-related hospitalisation associated with unemployment

Does depressed persons with non-cardiovascular morbidity have a higher risk of CVD? A population-based cohort study in Sweden

Background: Depression often co-exists with non-cardiovascular morbid conditions. Whether this comorbidity increases the risk of cardiovascular disease has so far not been studied. Thus, the aim of this study was to determine if non-cardiovascular morbidity modifies the effect of depression on future risk of CVD.Methods: Data was derived from the PART study (acronym in Swedish for: Psykisk hälsa, Arbete och RelaTioner: Mental Health, Work and Relationships), a longitudinal cohort study on mental health, work and relations, including 10,443 adults (aged 20-64 years). Depression was assessed using the Major Depression Inventory (MDI) and self-reported data on non-cardiovascular morbidity was assessed in 1998-2000. Outcomes of CVD were assessed using the National Patient Register during 2001-2014.Results: Both depression (HR 1.5 (95% CI, 1.1, 2.0)) and non-cardiovascular morbidity (HR 2.0 (95% CI, 1.8, 2.6)) were associated with an increased future risk of CVD. The combined effect of depression and non-cardiovascular comorbidity on future CVD was HR 2.1 (95%, CI 1.3, 3.4) after adjusting for age, gender and socioeconomic position. Rather similar associations were seen after further adjustment for hypertension, diabetes and unhealthy lifestyle factors.Conclusion: Persons affected by depression in combination with non-cardiovascular morbidity had a higher risk of CVD compared to those without non-cardiovascular morbidity or depression alone

Point-of-care mobile digital microscopy and deep learning for the detection of soil-transmitted helminths and Schistosoma haematobium

Background: Microscopy remains the gold standard in the diagnosis of neglected tropical diseases. As resource limited, rural areas often lack laboratory equipment and trained personnel, new diagnostic techniques are needed. Low-cost, point-of-care imaging devices show potential in the diagnosis of these diseases. Novel, digital image analysis algorithms can be utilized to automate sample analysis. Objective: Evaluation of the imaging performance of a miniature digital microscopy scanner for the diagnosis of soil-transmitted helminths and Schistosoma haematobium, and training of a deep learning-based image analysis algorithm for automated detection of soil-transmitted helminths in the captured images. Methods: A total of 13 iodine-stained stool samples containing Ascaris lumbricoides, Trichuris trichiura and hookworm eggs and 4 urine samples containing Schistosoma haematobium were digitized using a reference whole slide-scanner and the mobile microscopy scanner. Parasites in the images were identified by visual examination and by analysis with a deep learning-based image analysis algorithm in the stool samples. Results were compared between the digital and visual analysis of the images showing helminth eggs. Results: Parasite identification by visual analysis of digital slides captured with the mobile microscope was feasible for all analyzed parasites. Although the spatial resolution of the reference slide-scanner is higher, the resolution of the mobile microscope is sufficient for reliable identification and classification of all parasites studied. Digital image analysis of stool sample images captured with the mobile microscope showed high sensitivity for detection of all helminths studied (range of sensitivity = 83.3-100%) in the test set (n = 217) of manually labeled helminth eggs. Conclusions: In this proof-of-concept study, the imaging performance of a mobile, digital microscope was sufficient for visual detection of soil-transmitted helminths and Schistosoma haematobium. Furthermore, we show that deep learning-based image analysis can be utilized for the automated detection and classification of helminths in the captured images.Peer reviewe

Long-term stability in obsessive thoughts and compulsive behavior in the general population: a longitudinal study in Sweden

OBJECTIVE: Obsessive thoughts and compulsive behavior and their related disorder Obsessive-Compulsive Disorder (OCD) commonly occur in the general population. Clinical populations indicate a high level of stability, although there are few longitudinal studies in the general population. The recommended drug treatments are SSRIs/TCAs. However, there are few long-term follow up studies. The goal of this study was to 1) examine the occurrence and stability of obsessions, compulsions, and OCD in a longitudinal population-based survey, 2) investigate the use of SSRI and TCA and the potential effect on symptoms. METHODS: A ten-year longitudinal general population in Stockholm was used (2000 and 2010, n = 5650) Obsessional washing, checking, intrusive unpleasant thoughts and the level of suffering due to these symptoms were measured by self-report. Information on use of SSRIs and TCAs by these individuals was obtained from registers. Stability was examined using contingency tables and multinomial logistic regression. RESULTS: At baseline, 2.1, 11.7 and 11.9% reported obsessional washing, checking and intrusive thoughts. A total of 5% reported considerable suffering from these (i.e. OCD). Based on psychiatric interview only 0.4% had OCD. Ten years later a quarter of OCD cases were still classified as having OCD, one quarter reported any obsessive or compulsive symptom and half were classified as symptom-free. Treatment receipt was low and controlling for medication did not change the stability. CONCLUSION: Obsessive thoughts and compulsive behavior are common and stable. While this group is potentially undertreated, there is no indication that those treated display a different pattern of recovery

The extraordinary complex magnetic field of the helium-strong star HD 37776

The early-type chemically peculiar stars often show strong magnetic fields on their surfaces. These magnetic topologies are organized on large scales and are believed to be close to an oblique dipole for most of the stars. In a striking exception to this general trend, the helium-strong star HD 37776 shows an extraordinary double-wave rotational modulation of the longitudinal magnetic field measurements, indicating a topologically complex and, possibly, record strong magnetic field. Here we present a new investigation of the magnetic field structure of HD 37776, using both simple geometrical interpretation of the longitudinal field curve and detailed modeling of the time-resolved circular polarization line profiles with the help of magnetic Doppler imaging technique. We derive a model of the magnetic field structure of HD 37776, which reconciles for the first time all magnetic observations available for this star. We find that the local surface field strength does not exceed ~30 kG, while the overall field topology of HD 37776 is dominated by a non-axisymmetric component and represents by far the most complex magnetic field configuration found among early-type stars.Comment: 9 pages, 8 figures; accepted for publication in The Astrophysical Journa

A novel deep learning-based point-of-care diagnostic method for detecting Plasmodium falciparum with fluorescence digital microscopy

Background Malaria remains a major global health problem with a need for improved field-usable diagnostic tests. We have developed a portable, low-cost digital microscope scanner, capable of both brightfield and fluorescence imaging. Here, we used the instrument to digitize blood smears, and applied deep learning (DL) algorithms to detect Plasmodium falciparum parasites. Methods Thin blood smears (n = 125) were collected from patients with microscopy-confirmed P. falciparum infections in rural Tanzania, prior to and after initiation of artemisinin-based combination therapy. The samples were stained using the 4′,6-diamidino-2-phenylindole fluorogen and digitized using the prototype microscope scanner. Two DL algorithms were trained to detect malaria parasites in the samples, and results compared to the visual assessment of both the digitized samples, and the Giemsa-stained thick smears. Results Detection of P. falciparum parasites in the digitized thin blood smears was possible both by visual assessment and by DL-based analysis with a strong correlation in results (r = 0.99, p <0.01). A moderately strong correlation was observed between the DL-based thin smear analysis and the visual thick smear-analysis (r = 0.74, p <0.01). Low levels of parasites were detected by DL-based analysis on day three following treatment initiation, but a small number of fluorescent signals were detected also in microscopy-negative samples. Conclusion Quantification of P. falciparum parasites in DAPI-stained thin smears is feasible using DL-supported, point-of-care digital microscopy, with a high correlation to visual assessment of samples. Fluorescent signals from artefacts in samples with low infection levels represented the main challenge for the digital analysis, thus highlighting the importance of minimizing sample contaminations. The proposed method could support malaria diagnostics and monitoring of treatment response through automated quantification of parasitaemia and is likely to be applicable also for diagnostics of other Plasmodium species and other infectious diseases.Peer reviewe

A Malaria Diagnostic Tool Based on Computer Vision Screening and Visualization of Plasmodium falciparum Candidate Areas in Digitized Blood Smears

Peer reviewe

Does a history of cannabis use influence onset and course of schizophrenia?

Introduction: While evidence strongly supports a causal effect of cannabis on psychosis, it is less clear whether the symptom pattern, clinical course, and outcomes differ in cases of schizophrenia with and without a background of cannabis use. Methods: Analysis of medical records from a longitudinal follow‐up of Swedish conscripts with data on cannabis use in adolescence and subsequent incidence of schizophrenia. One hundred sixty patients with schizophrenia were assessed using the OPCRIT protocol. Cases were validated for diagnosis schizophrenia according to OPCRIT. Results: Patients with a cannabis history (n = 32), compared to those without (n = 128), had an earlier age at onset, a higher number of hospital admissions and a higher total number of hospital days. There was no significant difference in type of onset and clinical symptom profiles between the groups. Conclusion: Our findings indicate that the disease burden of schizophrenia is greater in individuals who use cannabis during adolescence. Strengthening evidence on causality and teasing out long‐term effects of pre‐illness cannabis use from continued post‐illness has clinical implications for improving schizophrenia outcomes