Northern Finland Birth Cohort Research Articles

The relation of temporomandibular disorders with oral health-related quality of life in the Northern Finland Birth Cohort 1966

ABSTRACT Objective This study aimed to evaluate the association between temporomandibular disorders (TMD) and oral health-related quality of life (OHRQoL) in an adult population. Methods The data included 1,768 adults 46 years of age in the Northern Finland Birth Cohort 1966 (NFBC1966) study. The symptoms, signs and diagnoses of TMD were assessed using a modified protocol of the Diagnostic Criteria for TMD (DC/TMD) and validated questionnaires. OHRQoL was measured using the Oral Health Impact Profile (OHIP-14). Associations of TMD and OHRQoL were evaluated with χ2 -test and Fisher’s exact test. Results In females, pain-related TMD signs and diagnoses associated significantly with prevalence of OHIP total and all dimensions, whereas in joint-related TMD, psychological dimensions showed the strongest association. Males with pain- or joint-related TMD, the most impaired dimension was physical pain. Conclusion Pain-related TMD seems to associate more strongly with lower OHRQoL than joint-related TMD especially in females.

Associations between pain-related temporomandibular disorders and dental anxiety at 46 years of age in the Northern Finland Birth Cohort 1966

Objectives The aims were (1) to study the association between dental anxiety (DA) and temporomandibular disorders (TMDs) and whether subgroups formed differ in psychological symptoms and pain sensitivity in the Northern Finland Birth Cohort 1966 and (2) to confirm the factor structure of the Hopkins Symptom Checklist-25 assessing psychological symptoms. Materials and methods Data were acquired using questionnaires and clinical examinations at age 46 years (n = 1889). Dental anxiety was assessed with Modified Dental Anxiety Scale (MDAS). Pain-related TMD (myalgia, arthralgia) were assessed according to modified diagnostic criteria for temporomandibular disorders. Pressure pain threshold and tolerance were measured with an algometer. Explanatory factor analysis revealed three factors, named ‘depression’, ‘anxiety’ and ‘distress’. Results Those with high DA and myalgia and/or arthralgia reported higher depression (mean = 1.52), anxiety (mean = 1.61) and distress (mean = 2.06) scores, and lower pressure pain threshold (mean = 496 kPa) and tolerance (mean = 741 kPa) values than those with only DA (1.22; 1.56; 1.84; 613; 875), TMD (1.21; 1.39; 1.83; 600; 908) or neither (1.12; 1.29; 1.58; 707; 1006), respectively. Conclusions Patients with DA and/or myalgia/arthralgia have similar profiles regarding pain sensitivity and psychological symptoms, the burden being highest among those with DA and a TMD diagnosis.

Low testosterone at age 31 associates with maternal obesity and higher body mass index from childhood until age 46: A birth cohort study.

Low testosterone (T) levels in men associate with increased risks of obesity, type 2 diabetes, metabolic syndrome, and cardiovascular diseases. However, most studies are cross-sectional with follow-up-time<10 years, and data on early growth are limited. To compare prenatal factors and body mass index (BMI) development from birth to age 46 in relation to low T at age 31. Men with low T (T<12.1nmol/L, n=132) and men with normal T at age 31 (n=2561) were derived from the Northern Finland Birth Cohort 1966. Prenatal factors, longitudinal weight and height data from birth to age 14, and cross-sectional weight and height data at ages 31 and 46, and waist-hip-ratio (WHR) and T levels at age 31 were analyzed. Longitudinal modeling and timing of adiposity rebound (AR, second BMI rise at age 5-7 years) were calculated from fitted BMI curves. Results were adjusted for mother's pre-pregnancy BMI and smoking status, birth weight for gestational age, alcohol consumption, education level, smoking status, and WHR at age31. Neither gestational age nor birth weight was associated with low T at age 31; however, maternal obesity during gestation was more prevalent among men with low T (9.8%vs. 3.5%, adjusted aOR: 2.43 [1.19-4.98]). Men with low T had earlier AR (5.28vs. 5.82, aOR: 0.73 [0.56-0.94]) and higher BMI (p<0.001) from AR onward until age 46. Men with both early AR and low T had the highest BMI from AR onward. In men, maternal obesity and early weight gain associate with lower T levels at age 31, independently of adulthood abdominal obesity. Given the well-known health risks related to obesity, and the rising prevalence of maternal obesity, the results of the present study emphasize the importance of preventing obesity that may also affect the later reproductive health of the offspring.

Association between vertebral cross-sectional area and lumbar disc displacement – a population-based study

PurposeVertebral dimensions may constitute a potential risk factor for degenerative changes in the spine. Previous studies have found a positive association between vertebral height and both type 2 Modic changes and intervertebral disc height loss. Also, vertebral endplate size has been associated with disc degeneration. However, only a few studies have investigated the association between vertebral dimensions and lumbar disc displacement (LDD). This study aimed to investigate the association between vertebral cross-sectional area (CSA) and LDD among the general middle-aged Finnish population. We hypothesized that larger vertebral CSA is associated with LDD.Materials and methodsThe study was conducted by using data from the Northern Finland Birth Cohort 1966 (NFBC1966). At the age of 46, a subpopulation of NFBC1966 underwent clinical examinations including magnetic resonance imaging (MRI) (n = 1249). MRI scans were used to measure L4 CSA and evaluate the presence of LDD (bulge, protrusion, and extrusion/sequestration) in the adjacent discs. The association between L4 CSA and LDD was analysed using logistic regression, with adjustment for sex, education, body mass index, leisure-time physical activity, smoking, diet, and L4 height.ResultsLarger L4 CSA was associated with LDD; an increase of 1 cm2 in vertebral CSA elevated the odds of LDD relative to no LDD by 10% (adjusted odds ratio 1.10, 95% CI 1.01–1.19). The association was similar among either sex.ConclusionsLarger L4 vertebral CSA was associated with LDD in our study sample. Even though smaller vertebral size exposes our vertebrae to osteoporotic fractures, it simultaneously seems to protect us from LDD.

Women with PCOS have an increased risk for cardiovascular disease regardless of diagnostic criteria-a prospective population-based cohort study.

Polycystic ovary syndrome (PCOS) is associated with many cardiovascular disease (CVD) risk factors, such as obesity, type 2 diabetes mellitus and hypertension. However, it remains debatable whether the presence of multiple CVD risk factors translates to increased CVD events. A prospective, population-based Northern Finland Birth Cohort 1966. Individuals with an expected date of birth in 1966 in Northern Finland have been followed from birth. Women in the cohort were classified as having PCOS according to either the National Institute of Health (NIH) criteria (n = 144) or the Rotterdam criteria (n = 386) at age 31, and they were compared to women without any PCOS features. The study population was re-examined at age 46, and the incidence of major adverse cardiovascular events (MACE), including myocardial infarction (MI), stroke, heart failure and cardiovascular mortality, was recorded up to age 53. During the 22-year follow-up, both women with NIH-PCOS and women with Rotterdam-PCOS had a significantly higher risk for cardiovascular events than control women. The BMI-adjusted hazard ratio (HR) for MACE in the Rotterdam-PCOS group and the NIH-PCOS group was 2.33 (1.26-4.30) and 2.47 (1.18-5.17), respectively. The cumulative hazard curves in both diagnostic categories began to diverge at age 35. Regarding the individual CVD endpoints, MI was significantly more prevalent in both women with NIH-PCOS (P = .010) and women with Rotterdam-PCOS (P = .019), when compared to control women. PCOS should be considered a significant risk factor for CVD. Future follow-up will show how the risk of CVD events develops after menopausal age.

Attention deficit hyperactivity and oppositional defiant disorder symptoms in adolescence and risk of substance use disorders-A general population-based birth cohort study.

Externalizing symptoms are associated with risk of future substance use disorder (SUD). Few longitudinal studies exist using general population-based samples which assess the spectrum of attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) symptoms. We aimed to study the associations between adolescent ADHD symptoms and subsequent SUD and additionally examine whether the risk of SUD is influenced by comorbid oppositional defiant disorder (ODD) symptoms. The Northern Finland Birth Cohort 1986 was linked to nationwide health care register data for incident SUD diagnoses until age 33 years (n = 6278, 49.5% male). ADHD/ODD-case status at age 16 years was defined using parent-rated ADHD indicated by Strengths and Weaknesses of ADHD symptoms and Normal Behaviors (SWAN) questionnaire with 95% percentile cut-off. To assess the impact of ODD comorbidity on SUD risk, participants were categorized into four groups based on their ADHD/ODD case status. Cox-regression analysis with hazard ratios (HRs) and 95% confidence intervals (CIs) were used to study associations between adolescent ADHD/ODD case statuses and subsequent SUD. In all, 552 participants (8.8%) presented with ADHD case status at the age of 16 years, and 154/6278 (2.5%) were diagnosed with SUD during the follow-up. ADHD case status was associated with SUD during the follow-up (HR = 3.84, 95% CI 2.69-5.50). After adjustments for sex, family structure, and parental psychiatric disorder and early substance use the association with ADHD case status and SUD remained statistically significant (HR = 2.60, 95% CI 1.70-3.98). The risk of SUD remained elevated in individuals with ADHD case status irrespective of ODD symptoms. ADHD in adolescence was associated with incident SUD in those with and without symptoms of ODD. The association of ADHD and SUD persisted even after adjustment for a wide range of potential confounds. This emphasizes the need to identify preventative strategies for adolescents with ADHD so as to improve health outcomes.

Cardiovascular and Metabolic Profile of Subjects with Acne in a Cohort of Middle-aged Patients: A General Population Study of 1,932 Subjects.

Acne vulgaris is one of the most common inflammatory skin diseases, but there are few studies of adult acne and its association with general health. The aim of this study was to examine the prevalence and clinical characteristics of adult acne at the population level among 1,932 subjects belonging to the Northern Finland Birth Cohort 1966 Study. In addition, cardiovascular and metabolic profiles of acne cases and their controls were analysed. The prevalence of adult acne was 7.9% (n = 150) with no statistical difference between the sexes. The majority of subjects presented with papulopustular acne (77.1%). Comedo acne (10.8% of all subjects) was more common in females than in males (p < 0.005). Males with acne had more abnormality in their metabolic factors than did acne-free controls; plasma glucose and insulin levels at 60 min after the 75 g glucose load were higher in males with acne than in controls (p < 0.01 for both). Corresponding associations were not seen in females. In conclusion, adult acne is common in middle-age, presenting a slightly different clinical picture in females than in males. In addition, male subjects with acne may have a higher risk of metabolic disturbances than do controls, and thus, comprehensive evaluation of patients with adult acne is needed.

A prognostic risk score for development and spread of chronic pain

Chronic pain is a complex condition influenced by a combination of biological, psychological and social factors. Using data from the UK Biobank (n = 493,211), we showed that pain spreads from proximal to distal sites and developed a biopsychosocial model that predicted the number of coexisting pain sites. This data-driven model was used to identify a risk score that classified various chronic pain conditions (area under the curve (AUC) 0.70–0.88) and pain-related medical conditions (AUC 0.67–0.86). In longitudinal analyses, the risk score predicted the development of widespread chronic pain, the spreading of chronic pain across body sites and high-impact pain about 9 years later (AUC 0.68–0.78). Key risk factors included sleeplessness, feeling ‘fed-up’, tiredness, stressful life events and a body mass index >30. A simplified version of this score, named the risk of pain spreading, obtained similar predictive performance based on six simple questions with binarized answers. The risk of pain spreading was then validated in the Northern Finland Birth Cohort (n = 5,525) and the PREVENT-AD cohort (n = 178), obtaining comparable predictive performance. Our findings show that chronic pain conditions can be predicted from a common set of biopsychosocial factors, which can aid in tailoring research protocols, optimizing patient randomization in clinical trials and improving pain management.

The association between chronotype and wages at mid-age

Sleep has been shown to affect economic outcomes, including wages. The mechanisms by which sleep affects wages remain unclear. We examine the relationship between chronotype – morning larks, evening owls – and wages at mid-age. We propose a novel model relating chronotype to wages in consideration of human, social, and health capital constructs. Empirically, we explore the effects of chronotype mediated through life course choices, such as work experience, trust, and health behaviour. The data come from the 46-year-old follow-up study of the Northern Finland Birth Cohort (1966) and from registers of the Finnish Tax Administration. We find evening chronotype to have a significant indirect negative effect on wages, which occurs through accumulating less work experience and through poor health outcomes. The effect is largest for male workers, with a total indirect effect on average wages of − 4%. We also provide evidence that chronotype has a long-term association with wages between 29 and 50 years of age. We conclude that evening-type workers are less suited to typical working hours and accumulate less human, social and health capital which in turn negatively affects their wages. Our findings are of great socio-economic importance because evening chronotypes make up a significant part of the population.

Association of accelerometer-measured physical activity and midlife income: A Northern Finland Birth Cohort 1966 Study.

This study investigated the association between physical activity (PA) and midlife income. The population-based data comprised employed members of the Northern Finland Birth Cohort 1966 (N = 2797). Using binned scatterplots and polynomial regressions, we evaluated the association between accelerometer-measured moderate PA (MPA), vigorous PA (VPA), and moderate-to-vigorous PA (MVPA) at 46 years old and register-based income at 50 years old. The models were adjusted for sex, marital status, number of children, education, adolescent PA, occupational physical strenuousness, and time preference. We found MPA (p < 0.001), VPA (p < 0.05), and MVPA (p < 0.001) to associate curvilinearly with income. In subgroup analyses, a curvilinear association was found between MPA (p < 0.01) and MVPA (p < 0.01) among those with physically strenuous work, VPA among all females (p < 0.01) and females with physically light work (p < 0.01), and MPA and MVPA among all males and males with physically strenuous work (p < 0.05; p < 0.01; p < 0.05; p < 0.05, respectively) and income. The highest income benefits occurred at PA volumes higher than current PA guidelines. Linear associations between PA and income were found among females for MPA (p < 0.05) and MVPA (p < 0.05), among those with physically light work for MPA (p < 0.05), VPA (p < 0.05), and MVPA (p < 0.05), and among females with physically strenuous work for VPA (p < 0.05). We conclude that PA up to the current recommended level is associated with income, but MPA exceeding 505.4 min/week, VPA exceeding 216.4 min/week, and MVPA exceeding 555.0 min/week might have a negative association with income.

Vitamin D Status in Women with a History of Infertility and Decreased Fecundability: A Population-Based Study.

Infertility and fecundability problems have been linked with lower 25-hydroxyvitamin D (25(OH)D) concentrations, but studies conducted with small, heterogenous or selected populations have shown inconsistent results. This study included women at age 31 from prospective population-based Northern Finland Birth Cohort 1966. Serum 25(OH)D concentrations were evaluated between women with or without previous infertility examinations or treatments (infertility group, n = 375, reference group, n = 2051) and time to pregnancy (TTP) of over 12 months (decreased fecundability group, n = 338) with a wide range of confounders. Furthermore, 25(OH)D concentrations were also compared among reproductive outcomes. The mean 25(OH)D concentration was lower and 25(OH)D < 30 nmol/L was more frequent in women with a history of infertility compared to reference group. Moreover, 25(OH)D > 75 nmol/L was more frequent in the reference group. The mean 25(OH)D concentration was lower in women who had had multiple miscarriages. Both history of infertility (β = -2.7, 95% confidence interval (CI) -4.6, -0.7) and decreased fecundability associated with lower 25(OH)D concentration (β = -4.1, 95% CI -7.4, -0.8) after adjustments. In conclusion, this population-based study demonstrated that previous infertility and decreased fecundability were associated with lower 25(OH)D.

Association of obesity and weight gain with alveolar bone loss: Results of the Northern Finland Birth Cohort 1966 study.

To investigate whether long-term obesity, long-term central obesity and weight gain are associated with alveolar bone loss. A sub-population (n = 1318) of the Northern Finland Birth Cohort 1966 was categorized based on body mass index (BMI: normal weight, overweight and obesity) and waist circumference (WC: no central obesity, central obesity) at ages 31 and 46. These categories were combined to define whether the participants stayed in the same categories or passed on to a higher category (weight gain). Alveolar bone level (BL) data were collected at age 46. The associations of long-term obesity and weight gain with BL ≥ 5 mm were stronger in smokers than in the total population and in never smokers. Males who passed on to higher BMI and WC categories showed a higher likelihood for BL ≥ 5 mm (range in relative risks [RRs] 1.3-2.2) than males who stayed in the same categories (range in RRs 0.7-1.1). The associations with BL ≥ 5 mm were weak or non-existent in females. The relation between obesity and periodontal diseases seems more complex than previously presumed. The role of gender and smoking should be taken into account in future studies.

The Örebro Musculoskeletal Pain Screening Questionnaire-Short Form and 2-year follow-up of registered work disability.

The Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ) was developed to identify psychological and functioning-related risk factors among individuals with musculoskeletal pain at risk of work disability. This study aimed to examine whether the short version of the ÖMPSQ (ÖMPSQ-SF) can be used for this purpose, using registry-based outcomes. The ÖMPSQ-SF was completed by the members of the Northern Finland Birth Cohort 1966 at the age of 46 years (baseline). These data were enriched with national registers, including information on sick leaves and disability pensions (indicators of work disability). The associations between the ÖMPSQ-SF categories (low-, medium- and high risk) and work disability over a 2-year follow-up were analysed using negative binomial regression and binary logistic regression models. We made adjustments for sex, baseline education level, weight status and smoking. Overall, 4063 participants provided full data. Of these, 90% belonged to the low-risk, 7% to the medium-risk and 3% to the high-risk group. Compared to the low-risk group, the high-risk group had a 7.5 [Wald 95% confidence interval (CI) 6.2-9.0] times higher number of sick leave days and 16.1 (95% CI 7.1-36.8) times higher odds of disability pension after adjustments in the 2-year follow-up. : Our study suggests that the ÖMPSQ-SF could be used for predicting registry-based work disability at midlife. Those allocated to the high-risk group seemed to have a particularly great need of early interventions to support their work ability.

Attention-deficit/hyperactivity disorder is not associated with overweight in adolescence but is related to unhealthy eating behavior and limited physical activity

Purpose The aim of the study was to examine the possible relation between adolescent ADHD and high BMI, studying also eating behavior and physical activity. Methods The data were collected from the Northern Finland Birth Cohort 1986. The follow-up at the age of 16 consisted of a self-assessment form and clinical examination where height and weight were measured and questionnaires on physical activity and eating habits was completed. ADHD diagnosis was based on a diagnostic interview with adolescents and parents according to DSM-IV-TR criteria. The participants were divided into the following study groups: individuals with adolescent ADHD (n = 90), those with only childhood ADHD (n = 40), and community controls (n = 269). Results Results showed no significant differences in BMI, but adolescents with ADHD seemed to have unhealthier eating habits than controls; they ate less often vegetables and breakfast, devoured more often, and consumed more fast food, soft drinks, sweets, and potato crisps daily. Individuals with adolescent ADHD reported light exercise more often but strenuous exercise more seldom than controls. Those with only childhood ADHD did not significantly differ from community controls regarding health behaviors. Conclusions There was no relation between ADHD and high BMI but adolescents with ADHD had unhealthier eating habits than those without ADHD. It is conceivable that unhealthy eating behaviors in adolescence might be a risk factor for the development of later overweight; however, the longitudinal associations between ADHD, unhealthy eating behaviors and overweight have not been considered in the present study and remain to be examined further.

Association of health-related factors with self-reported sleep and awake bruxism in Northern Finland Birth Cohort 1966 - a cross-sectional study

ABSTRACT Objective The study aimed to investigate the association of sleep bruxism (SB) and awake bruxism (AB) with health-related factors. Methods Data on bruxism and diagnosed diseases, use of psychoactive substances and regular identified psychoactive drugs were collected from 1,962 subjects in the Northern Finland Birth Cohort 1966 through a questionnaire. The associations were analyzed using chi-square tests and binary regression models, adjusting for gender and education, and for anxiety/depression symptoms. Results Migraine and gastric/duodenal disorders, use of serotonergic antidepressants and a high number of psychoactive drugs associated significantly with AB and SB. Gastrointestinal diseases associated with SB. Poor general health and hand eczema associated with AB. Based on the multivariate model, depression/anxiety symptoms seemed to mediate the associations of bruxism with depression, hand eczema, self-reported gastric/duodenal disorders and the number of identified drugs. Conclusion Several diseases, depression/anxiety symptoms and psychoactive medications were associated with SB and AB, the associations being stronger with AB than SB.

Association between participation in the Northern Finland Birth Cohorts and cardiometabolic disorders

Background We studied the association between participation in the longitudinal follow-up study and cardiometabolic disorders in two longitudinal studies which started prospectively in the antenatal period: the Northern Finland Cohort 1966 (NFBC1966) and the Northern Finland Birth Cohort 1986 (NFBC1986). Both birth cohorts have been followed up since birth with multiple follow-ups including questionnaires, and clinical examinations. Methods The NFBC studies were compared to comparison cohorts of individuals who were born in the same area as the study cohorts, but in different years. The data for the comparison cohort were obtained from registers. The cumulative incidence rates of hospital-treated cardiometabolic disorders were calculated for study and comparison cohorts covering the age of 7–50 years in NFBC1966 and the age of 0–29 years in NFBC1986. Cardiometabolic-related causes of death were analysed in NFBC1966 and the comparison cohort from the age of 0–50 years. The analysed cardiometabolic disorders were diabetes mellitus, coronary artery disease, hyperlipidaemia, obesity, hypertension, and cerebrovascular disorders. The risk ratio (RR) with 95% confidence intervals (CI) was calculated by sex. Results In NFBC1966, no differences in cumulative incidences of cardiometabolic disorders or cardiometabolic-related deaths compared to the comparison cohort were found. Male members of NFBC1986 had decreased risk of obesity (RR: 0.45, 95% CI: 0.27–0.75) and any cardiometabolic disorders (RR: 0.75, 95% CI: 0.59–0.95) compared to the comparison cohort. Conclusions The results suggest that participation in the NFBC1986 may have a weak positive health effect among men. Agreement to follow-up studies focusing on diet, substance use, and physical activity, may slightly decrease the incident risk of cardiometabolic disorders in the study population. KEY MESSAGES Even mild interventions, such as follow-up studies in the prospective follow-up studies, might affect participants’ behaviour and consequently the incidence of cardiometabolic disorders The fact that follow-up itself might affect the study population in terms of risk factors, has to be taken into account when estimating the representativeness of the followed population.

Depression mediates the relationship between alexithymia and obesity in the Northern Finland Birth Cohort 1966 (NFBC1966)

BackgroundThe fact that a complex relationship exists between alexithymia and body mass index (BMI) is well established, but the underlying mechanisms remain poorly understood. Here, we explore the relationship between alexithymia and depressive symptoms in relation to adiposity measures, including the direct and indirect effect of alexithymia and depressive symptoms on obesity over a 15-year time-period, in the Northern Finland Birth Cohort 1966 (NFBC1966). MethodsThe study included individuals from the Northern Finland Birth Cohort 1966 (NFBC1966) who had available data for adiposity measures (body mass index and waist-to-hip ratio), alexithymia (measured by the 20-Item Toronto Alexithymia Scale: TAS-20), depressive symptoms (measured by the 13-item depression subscale of Hopkins Symptom Checklist: HSCL-13) at age of 31 years (n = 4773) and 46 years (n = 4431). Pearson's (r) correlation, and multiple linear regression were used to investigate the relationships between alexithymia, depressive symptoms, and adiposity measures. The potential mediating role of depressive symptoms was examined via Hayes' procedure (PROCESS). ResultsPositive correlations were confirmed between adiposity measures (BMI and WHR) and the TAS-20 score (and its subscale), but not between obesity and HSCL-13 score. The strongest correlation was between the DIF (difficulty identifying feelings) subscale of the TAS-20 and HSCL-13 at both time points (31 y: r(3013) = 0.41, p < 0.01, 46 y: r(3013) = 0.43, p < 0.01). Depressive symptoms completely (z = 2.55 (±0.00003), p = 0.01) and partly (z = 2.16 (±0.0001), p = 0.03) mediated the alexithymia-obesity relationship over the 15-year time-period. LimitationsOther psychological and environmental factors such as interoception, dietary intake and physical activities may also play a role as a potential mediating factor in alexithymia-obesity relationship. ConclusionsOur findings provide additional insights of theoretical framework of depressive symptoms mediation effect in the relationship between alexithymia and obesity. Alexithymia and depression should, therefore, be considered in the design of future clinical obesity research.

Prevalence of residual amblyopia in adulthood and its association on educational outcome and quality of life in the Northern Finland Birth Cohort.

The purpose of the current study was to evaluate the prevalence of residual amblyopia in adults in a population screened and treated in childhood. We also wanted to evaluate the association of amblyopia on school success, level of education, and quality of life. This is a follow-up study of 2708 subjects of the Northern Finland Birth Cohort. At the age of 46, the subjects took part in ophthalmic examinations, including the measurement of best-corrected visual acuity (BCVA) and refraction. Residual amblyopia was defined as BCVA 20/30 or less (logMAR ≥0.2) in one or both eyes or a two-line interocular visual acuity difference and absence of any pathological ocular factors. The quality of life was assessed with a 15D questionnaire, and educational outcome, school success, and episodic memory with a CANTAB-PAL (paired associates learning) test were evaluated. The prevalence of amblyopia in the current adult population aged 46 years was 1.3% (n= 36). At 14 years, the amblyopia subjects had had significant differences in mean spherical equivalent between the amblyopic and fellow eye and strabismus more often than controls. No significant differences were observed in the CANTAB-PAL test or in educational outcome. However, amblyopia subjects had significant difficulties in the 15D questionnaire in terms of vision (54% vs. 34%, p= 0.01). Due to screening and treatment in childhood, the number of adults with residual amblyopia was low. Despite minor visual impairment and discomfort, they cope very well in life in terms of educational outcome and quality of life.

Family structure and multisite musculoskeletal pain in adolescence: a Northern Finland Birth Cohort 1986 study

BackgroundFamily structure is suggested to be associated with adolescent pain, but evidence on its association with multisite MS pain is sparse. The purpose of this cross-sectional study was to investigate the potential associations between family structure (‘single-parent family’, ‘reconstructed family’, and ‘two-parent family’) and multisite musculoskeletal (MS) pain in adolescence.MethodsThe dataset was based on the 16-year-old Northern Finland Birth Cohort 1986 adolescents with available data on family structure, multisite MS pain, and a potential confounder (n = 5,878). The associations between family structure and multisite MS pain were analyzed with binomial logistic regression and modelled as unadjusted, as the evaluated potential confounder, mother’s educational level, did not meet the criteria for a confounder.ResultsOverall, 13% of the adolescents had a ‘single-parent family’ and 8% a ‘reconstructed family’. Adolescents living in a single-parent family had 36% higher odds of multisite MS pain compared to adolescents from two-parent families (the reference) (Odds Ratio [OR]: 1.36, 95% Confidence Interval [CI]: 1.17 to 1.59). Belonging to a ‘reconstructed family’ was associated with 39% higher odds of multisite MS pain (OR 1.39, 1.14 to 1.69).ConclusionFamily structure may have a role in adolescent multisite MS pain. Future research is needed on causality between family structure and multisite MS pain, to establish if there is a need for targeted support.

Association between participation in the Northern Finland Birth Cohort 1966 study and use of psychiatric care services.

In most population-based epidemiological follow-up studies the aim is not to intervene in the life of the participants. Although the idea is not to intervene, being a member of the longitudinal follow-up study and studies conducted during follow-up may affect the target population. A population-based study including mental health enquiries might reduce the unmet need for psychiatric treatment by motivating people to seek treatment for their psychiatric ill-health. We examined the use of psychiatric care services in the population born in the year 1966 in Northern Finland, of whom 96.3% are participants in the prospective Northern Finland Birth Cohort 1966 (NFBC1966). As a study cohort we used people born in 1966 in Northern Finland (n = 11 447). The comparison cohort included all the people born in the years 1965 and 1967 in the same geographical area (n = 23 339). The follow-up period was from age 10 to 50 years. The outcome measure was the use of psychiatric care services, which was analysed using Cox Proportional Hazard regression and Zero-Truncated Negative Binomial Regression. People born in 1966 in Northern Finland did not differ from those born in 1965 and 1967 in terms of the outcome measure. We found no association between participation in an epidemiological follow-up study and the use of psychiatric care services. The NFBC1966 may be regarded as a representative at the population level in terms of psychiatric outcomes despite the personal follow-up of the birth cohort. The associations of participation in epidemiological follow-up studies have previously been under-examined, and the results need to be replicated.