| 1. |
- Berg, Noora, et al.
(författare)
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Risk factors in adolescence as predictors of trajectories of somatic symptoms over 27 years
- 2022
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Ingår i: European Journal of Public Health. - : Oxford University Press (OUP). - 1101-1262 .- 1464-360X. ; 32:5, s. 696-702
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Tidskriftsartikel (refereegranskat)abstract
- Background: Somatic symptoms among adolescents are common, yet little is known about long-term trajectories of somatic symptoms and the factors in adolescence that shape them. We examined individual, family and schoolbased factors at age 16 as predictors of trajectories of somatic symptoms over 27 years. Methods: Participants from the Northern Swedish Cohort (n ¼ 1001) responded to questions about individual factors (e.g. health behaviours), family factors (e.g. contact with parents, social and material adversity) and school satisfaction at age 16; as well as 10 somatic symptoms at ages 16, 18, 21, 30 and 43. Teacher assessments at age 16 included overall ability at school and peer relations. Age 16 predictors of somatic symptom trajectory group membership were analysed using multinomial logistic regression. Results: Poor contact with mother and poor school satisfaction were significant predictors of adverse symptom trajectories among both men and women. Low birth weight and low parental academic involvement were contributing factors for women, while smoking and social adversity were more relevant factors for men. Conclusions: Our findings emphasize the importance of a holistic approach that considers the unique contributions of individual, family and school-based factors in the development of trajectories of somatic symptoms from adolescence to middle age.
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| 2. |
- Berg, Noora, et al.
(författare)
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The relevance of macroeconomic conditions on concurrent and subsequent alcohol use : results from two Northern Swedish cohorts
- 2020
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Ingår i: Addiction Research and Theory. - : Taylor & Francis. - 1606-6359 .- 1476-7392. ; 28:6, s. 501-509
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Tidskriftsartikel (refereegranskat)abstract
- ackground: The aim of this study is to examine the relevance of macroeconomic conditions (boom vs. recession) and own labor market status on alcohol use in youth and midlife.Method: Two Northern Swedish cohorts, born in either 1965 (boom at age 21 years) or 1973 (recession at age 21 years), included all pupils attending the last grade of compulsory school in Luleå, in 1981 (n = 990) or 1989 (n = 686), respectively. Questionnaires were completed at ages 21 and 43/39 years. Alcohol use was measured as volume of consumption (cl/year) and heavy episodic drinking (HED).Results: Women aged 21 years during the boom (Cohort65) consumed less alcohol and were less likely to be heavy episodic drinkers at age 21 years compared to those who were exposed to recession at the same age (Cohort73). In men there were no such cohort differences. Women, and to some extent men, in Cohort65 increased their consumption at midlife, whereas this decreased for those in Cohort73. HED decreased in both cohorts, but the decrease was steeper in the recession cohort. Analyses stratified by labor market status revealed between-cohort differences in consumption among women who were either employed or students at baseline; but not for men. Alcohol use for those unemployed did not differ between the cohorts.Conclusions: In our study, comparing two cohorts that experienced either macroeconomic boom (1986) or recession (1994) at age 21 years in Sweden, the association between individual alcohol use and concurrent unemployment in youth was not affected by macroeconomic conditions.
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| 3. |
- Hao, Chengcheng, 1986-
(författare)
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Explicit Influence Analysis in Crossover Models
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation develops influence diagnostics for crossover models. Mixed linear models and generalised mixed linear models are utilised to investigate continuous and count data from crossover studies, respectively.For both types of models, changes in the maximum likelihood estimates of parameters, particularly in the estimated treatment effect, due to minor perturbations of the observed data, are assessed. The novelty of this dissertation lies in the analytical derivation of influence diagnostics using decompositions of the perturbed mixed models. Consequently, the suggested influence diagnostics, referred to as the delta-beta and variance-ratio influences, provide new findings about how the constructed residuals affect the estimation in terms of different parameters of interest.The delta-beta and variance-ratio influence in three different crossover models are studied in Chapters 5-6, respectively. Chapter 5 analyses the influence of subjects in a two-period continuous crossover model. Possible problems with observation-level perturbations in crossover models are discussed. Chapter 6 extends the approach to higher-order crossover models. Furthermore, not only the individual delta-beta and variance-ratio influences of a subject are derived, but also the joint influences of two subjects from different sequences. Chapters 5-6 show that the delta-beta and variance-ratio influences of a particular parameter are decided by the special linear combination of the constructed residuals. In Chapter 7, explicit delta-beta influence on the estimated treatment effect in the two-period count crossover model is derived. The influence is related to the Pearson residuals of the subject. Graphical tools are developed to visualise information of influence concerning crossover models for both continuous and count data. Illustrative examples are provided in each chapter.
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| 4. |
- Lallukka, Tea, et al.
(författare)
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Co-occurrence of depressive, anxiety, and somatic symptoms : trajectories from adolescence to midlife using group-based joint trajectory analysis
- 2019
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Ingår i: BMC Psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Background: Co-occurrence of mental and somatic symptoms is common, and recent longitudinal studies have identified single trajectories of these symptoms, but it is poorly known whether the symptom trajectories can also co-occur and change across the lifespan. We aimed to examine co-occurring symptoms and their joint trajectories from adolescence to midlife.Methods: Longitudinal data were derived from Northern Sweden, where 506 girls and 577 boys aged 16years participated at baseline in 1981 (99.7% of those initially invited), and have been followed up in four waves until the age of 43. Survey data were collected about depressive, anxiety, and somatic symptoms. Potential joint development of this three-component symptom set was examined with multiple response trajectory analysis, a method that has not been previously used to study co-occurrence of these symptoms.Results: We identified a five trajectory solution as the best: very low (19%), low (31%), high (22%), late sharply increasing (16%) and a very high increasing (12%). In the late sharply increasing and very high increasing groups the scores tended to increase with age, while in the other groups the levels were more stable. Overall, the results indicated that depressive, anxiety, and somatic symptoms co-exist from adolescence to midlife.Conclusions: The multiple response trajectory analysis confirmed high stability in the co-occurrence of depressive, anxiety, and somatic symptoms from adolescence to midlife. Clinicians should consider these findings to detect symptoms in their earliest phase in order to prevent the development of co-occurring high levels of symptoms.
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| 5. |
- Leino-Arjas, Päivi, et al.
(författare)
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Trajectories of musculoskeletal pain from adolescence to middle age : the role of early depressive symptoms, a 27-year follow-up of the Northern Swedish Cohort
- 2018
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Ingår i: Pain. - : LIPPINCOTT WILLIAMS & WILKINS. - 0304-3959 .- 1872-6623. ; 159:1, s. 67-74
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Tidskriftsartikel (refereegranskat)abstract
- Depression and musculoskeletal pain are associated, but long-term follow-up studies are rare. We aimed to examine the relationship of early depressive symptoms with developmental patterns of musculoskeletal pain from adolescence to middle age. Adolescents ending compulsory school (age 16) in Lulea, Northern Sweden, in 1981 (n = 1083) were studied and followed up in 1986, 1995, and 2008 (age 43) for musculoskeletal pain. Attrition was very low. Indicators for any and severe pain were based on pain in the neck-shoulders, low back, and the extremities. Latent class growth analyses were performed on 563 men and 503 women. Associations of a depressive symptoms score (DSS, range 0.0-2.0) at age 16 with pain trajectory membership were assessed by logistic and multinomial regression, adjusting for parental socioeconomic status, social adversities, smoking, exercise, body mass index, and alcohol consumption at age 16. For any pain, 3 trajectories emerged: high-stable (women 71%, men 61%), moderate (11%, 17%), and low-increasing (18%, 22%). With the low-increasing trajectory as reference, for each 0.1-point increase in the DSS, the odds ratio of belonging to the high-stable trajectory was 1.25 (95% confidence interval 1.11-1.41) in women and 1.23 (1.10-1.37) in men. For severe pain, 2 trajectories were found: moderate-increasing (women 19%, men 9%) and low-stable. For each 0.1-point increase in the DSS, the odds ratio of membership in the moderate-increasing trajectory was 1.14 (1.04-1.25) in women and 1.17 (1.04-1.31) in men in the fully adjusted model. Thus, depressive symptoms at baseline are strongly associated with pain trajectory membership.
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| 6. |
- Ngaruye, Innocent
(författare)
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Contributions to Small Area Estimation : Using Random Effects Growth Curve Model
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation considers Small Area Estimation with a main focus on estimation and prediction for repeated measures data. The demand of small area statistics is for both cross-sectional and repeated measures data. For instance, small area estimates for repeated measures data may be useful for public policy makers for different purposes such as funds allocation, new educational or health programs, etc, where decision makers might be interested in the trend of estimates for a specic characteristic of interest for a given category of the target population as a basis of their planning.It has been shown that the multivariate approach for model-based methods in small area estimation may achieve substantial improvement over the usual univariate approach. In this work, we consider repeated surveys taken on the same subjects at different time points. The population from which a sample has been drawn is partitioned into several non-overlapping subpopulations and within all subpopulations there is the same number of group units. The aim is to propose a model that borrows strength across small areas and over time with a particular interest of growth profiles over time. The model accounts for repeated surveys, group individuals and random effects variations.Firstly, a multivariate linear model for repeated measures data is formulated under small area estimation settings. The estimation of model parameters is discussed within a likelihood based approach, the prediction of random effects and the prediction of small area means across timepoints, per group units and for all time points are obtained. In particular, as an application of the proposed model, an empirical study is conducted to produce district level estimates of beans in Rwanda during agricultural seasons 2014 which comprise two varieties, bush beans and climbing beans.Secondly, the thesis develops the properties of the proposed estimators and discusses the computation of their first and second moments. Through a method based on parametric bootstrap, these moments are used to estimate the mean-squared errors for the predicted small area means. Finally, a particular case of incomplete multivariate repeated measures data that follow a monotonic sample pattern for small area estimation is studied. By using a conditional likelihood based approach, the estimators of model parameters are derived. The prediction of random effects and predicted small area means are also produced.
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| 7. |
- Nummi, Tapio, et al.
(författare)
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Trajectories of a set of ten functional somatic symptoms from adolescence to middle age
- 2017
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Ingår i: Archives of Public Health. - : Springer Science and Business Media LLC. - 0778-7367 .- 2049-3258. ; 75
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Tidskriftsartikel (refereegranskat)abstract
- Background: Functional somatic symptoms (FSS), or symptoms without a clear medical explanation are a considerable challenge for health care systems. There is no general consensus as to which symptoms should be regarded functional. Few longitudinal studies on the development of FSS exist and these have mainly been based on the assumption that the factorial structure of a FSS scores variable remains invariant over time. When the analysis covers longer periods of the life course, this may be challenged. The aim of our study was to investigate how ten functional somatic symptoms (FSS) evolve when individuals are ageing. Methods: The data of the Northern Swedish Cohort (n = 1001) from questionnaire surveys at ages 16, 18, 21, 30 and 42, were analysed. Participation rates remained very high over the five surveys. The list of symptoms included backache, breathlessness, dizziness, fatigue, headache or migraine, nausea, overstrain, palpitations, sleeplessness and stomach ache. We used multivariate trajectory analysis (TA) with logistic broken-stick regression models to describe sub-groups in the data. In multivariate TA the joint development of the set of item variables can be investigated. There is no need to construct a special FSS summary score variable. Results: Four well separated trajectories were identified. In two groups, healing symptoms (25.4% of the sample) and low symptom load (32.2% of the sample), the symptom level stayed relatively low in adulthood. In the third group of high symptom load (17.2%) the probability of having symptoms was high for all FSS variables. In the fourth group of increasing symptoms (25.3%) the level of symptoms was first intermediate, but increased markedly with age. Conclusions: Instead of a single FSS score we were able to assign each individual to one of four trajectories described jointly by 10 separate symptoms. The profile of development, but not the probability level, was rather similar over the symptoms within the trajectories, with few exceptions. The results provide better understanding of the longitudinal development of the symptoms from the adolescence to the middle age.
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| 8. |
- Rajaleid, Kristiina, et al.
(författare)
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Social adversities in adolescence predict unfavourable trajectories of internalized mental health symptoms until middle age : results from the Northern Swedish Cohort
- 2016
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Ingår i: European Journal of Public Health. - : Oxford University Press (OUP). - 1101-1262 .- 1464-360X. ; 26:1, s. 23-29
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Experiencing adversities during upbringing has short-term and long-term effects on mental health. This study aims to explore how social adversities in adolescence predict trajectories of internalized mental health symptoms (IMHS), from adolescence and onward until middle age.METHODS: Based on 1040 individuals from the Northern Swedish Cohort Study, a community-based cohort with 27 years of follow-up. We applied latent class growth analysis to extract trajectories of IMHS between ages 16 and 43. Multinomial logistic regression was used to study the association of social adversities (residential mobility, residential crowding, parental loss, unemployment of a parent, physical illness of a parent, mental illness or alcohol problems of a parent) in adolescence with IMHS trajectories.RESULTS: Five trajectory classes were identified: 'very low stable' (26% of the sample), 'low stable' (58%), 'moderate stable' (5%), 'increasing' (8%) and 'high decreasing' (3%). Both in men and women, reporting social adversities at the age of 16 increased the risk of belonging to the classes with less favourable development of IMHS. Reporting adversities was positively associated with the initial level of the IMHS trajectories. Thus it seems that the influence of adversities is more pronounced during the early years of follow-up and is attenuated over time.CONCLUSION: Experiencing social adversities in adolescence increases the risk of entering unfavourable developmental trajectories of mental health until middle age.
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| 9. |
- Virtanen, Pekka, et al.
(författare)
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Mental health in adolescence as determinant of alcohol consumption trajectories in the Northern Swedish Cohort
- 2015
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Ingår i: International Journal of Public Health. - : Springer Science and Business Media LLC. - 1661-8556 .- 1661-8564. ; 60:3, s. 335-342
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Tidskriftsartikel (refereegranskat)abstract
- The study aimed to analyze whether poor mental health in adolescence predicts heavy alcohol consumption over the long term. Alcohol consumption in the population cohort (n = 1010) was surveyed at the ages of 16, 18, 21, 30 and 42. Utilizing latent class growth analysis, six consumption trajectories ranging from 'Late Onset Low' to 'Early Onset High' were defined and analyzed with respect to internalization (depressiveness and anxiousness) and externalization (truancy and vandalism) at age 16. Poor mental health predicted the Early Onset High trajectory (risk ratios in relation to the compliant trajectory 3.59 for anxiousness, 2.85 for depressiveness, 5.69 for truancy and 7.75 for externalized vandalism). Moreover, significant associations were found for the Early Onset Moderate and Early Onset Low trajectories. This is the first study to show an association between internalized mental health problems in adolescence and lifelong heavy drinking. The study also confirmed a strong association between externalized behavior and heavy drinking, indicating a need of preventive measures in this group. Nevertheless, the analyses demonstrated that most teenagers with mental health problems continue along a reasonable drinking trajectory.
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| 10. |
- Virtanen, Pekka, et al.
(författare)
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Psychosocial conditions during school-age as determinants of long-term labour market attachment : a study of the Northern Swedish Cohort from the 1980s to the 2020s
- 2024
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Ingår i: BMC Public Health. - : BioMed Central (BMC). - 1471-2458. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: This study, conducted on a Swedish population cohort, explores how internalized (depressive and functional somatic) and externalized (smoking, drinking, truancy, vandalism, delinquency) mental health symptoms, as well as close interpersonal relations (family climate and school connectedness) reported during adolescence, influence the work-life course up to late midlife.Methods: We examined repeated measurements of labour market status from age 16 to 56 using sequence analyses. We identified five different labour market attachment (LMA16-56) trajectories, namely ‘strong,’ ‘early intermediate,’ ‘early weak,’ ‘late weak,’ and ‘constantly weak.’ Multinomial logistic regressions were employed to relate each of the nine determinants to the identified trajectories.Results: When compared to the risk of ‘strong’ LMA16-56, adversity in all conditions, except for vandalism, entailed a higher risk of the ‘constantly weak’ trajectory. Moreover, all conditions, except for functional somatic symptoms, entailed a higher risk of the ‘late weak’ LMA16-56. The risk of the ‘early intermediate’ LMA16-56 was non-significant across all the conditions.Conclusions: This study contributes to existing knowledge through its novel exploration of labour market attachment and the revelation of the significance of proximal interpersonal relationships in attachment outcomes. Additionally, the study reaffirms the importance of externalizing behaviour, while suggesting that internalized symptoms in adolescence might have a less influential, though not negligible, role. These results underscore the importance of addressing acting out behaviour and nurturing human relationships during compulsory basic education, when the entire age group is still within reach. This approach aims not only to reduce frictions in the school-to-work transition but also to prevent midlife labour market attachment problems that may arise with delayed intervention.
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