Irritable bowel syndrome in the general population : epidemiology, comorbidity and societal costs

Background: Irritable bowel syndrome (IBS) is a common functional gastrointestinal (GI) disorder characterised by abdominal pain and abnormal bowel function. It is associated with a high rate of healthcare consumption and significant health care costs. The prevalence and economic burden of IBS in Finland has not been studied before. The aims of this study were to assess the prevalence of IBS according to various diagnostic criteria and to study the rates of psychiatric and somatic comorbidity in IBS. In addition, health care consumption and societal costs of IBS were to be evaluated. Methods: The study was a two-phase postal survey. Questionnaire I identifying IBS by Manning 2 (at least two of the six Manning symptoms), Manning 3 (at least three Manning symptoms), Rome I, and Rome II criteria, was mailed to a random sample of 5 000 working age subjects. It also covered extra-GI symptoms such as headache, back pain, and depression. Questionnaire II, covering rates of physician visits, and use of GI medication, was sent to subjects fulfilling Manning 2 or Rome II IBS criteria in Questionnaire I. Results: The response rate was 73% and 86% for questionnaires I and II. The prevalence of IBS was 15.9%, 9.6%, 5.6%, and 5.1% according to Manning 2, Manning 3, Rome I, and Rome II criteria. Of those meeting Rome II criteria, 97% also met Manning 2 criteria. Presence of severe abdominal pain was more often reported by subjects meeting either of the Rome criteria than those meeting either of the Manning criteria. Presence of depression, anxiety, and several somatic symptoms was more common among subjects meeting any IBS criterion than by controls. Of subjects with depressive symptoms, 11.6% met Rome II IBS criteria compared to 3.7% of those with no depressiveness. Subjects meeting any IBS criteria made more physician visits than controls. Intensity of GI symptoms and presence of dyspeptic symptoms were the strongest predictors of GI consultations. Presence of dyspeptic symptoms and a history of abdominal pain in childhood also predicted non-GI visits. Annual GI related individual costs were higher in the Rome II group (497 ) than in the Manning 2 group (295 ). Direct expenses of GI symptoms and non GI physician visits ranged between 98M for Rome II and 230M for Manning 2 criteria. Conclusions: The prevalence of IBS varies substantially depending on the criteria applied. Rome II criteria are more restrictive than Manning 2, and they identify an IBS population with more severe GI symptoms, more frequent health care use, and higher individual health care costs. Subjects with IBS demonstrate high rates of psychiatric and somatic comorbidity regardless of health care seeking status. Perceived symptom severity rather than psychiatric comorbidity predicts health care seeking for GI symptoms. IBS incurs considerable medical costs. The direct GI and non-GI costs are equivalent to up to 5% of outpatient health care and medicine costs in Finland. A more integral approach to IBS by physicians, accounting also for comorbid conditions, may produce a more favourable course in IBS patients and reduce health care expenditures.

Socioeconomic Status, Occupational Factors and Lifestyle as Predictors of Hospitalisation for Back Disorders

The aim of this dissertation was to examine the determinants of severe back disorders leading to hospital admission in Finland. First, back-related hospitalisations were considered from the perspective of socioeconomic status, occupation, and industry. Secondly, the significance of psychosocial factors at work, sleep disturbances, and such lifestyle factors as smoking and overweight was studied as predictors of hospitalisation due to back disorders. Two sets of data were used: 1) the population-based data comprised all occupationally active Finns aged 25-64, and included hospitalisations due to back disorders in 1996 and 2) a cohort of employees followed up from 1973 to 2000 having been hospitalised due to back disorders. The results of the population-based study showed that people in physically strenuous industries and occupations, such as agriculture and manufacturing, were at an increased risk of being hospitalised for back disorders. The lowest hospitalisation rates were found in sedentary occupations. Occupational class and the level of formal education were independently associated with hospitalisation for back disorders. This stratification was fairly consistent across age-groups and genders. Men had a slightly higher risk of becoming hospitalised compared with women, and the risk increased with age among both genders. The results of the prospective cohort study showed that psychosocial factors at work such as low job control and low supervisor support predicted subsequent hospitalisation for back disorders even when adjustments were made for occupational class and physical workload history. However, psychosocial factors did not predict hospital admissions due to intervertebral disc disorders; only admissions due to other back disorders. Smoking and overweight predicted, instead, only hospitalisation for intervertebral disc disorders. These results suggest that the etiological factors of disc disorders and other back disorders differ from each other. The study concerning the association of sleep disturbances and other distress symptoms with hospitalisation for back disorders revealed that sleep disturbances predicted subsequent hospitalisation for all back disorders after adjustment for chronic back disorders and recurrent back symptoms at baseline, as well as for work-related load and lifestyle factors. Other distress symptoms were not predictive of hospitalisation.

Study of sleep and evaluation of sumatriptan and rizatriptan in the acute treatment of migraine in children and adolescents

Migraine is a common disease in children and adolescents, affecting roughly 10% of school-aged children. Recent studies have revealed an increasing incidence of childhood migraine, but migraine remains an underrecognized and undertreated condition in the pediatric population. Migraine attacks are painful and disabling and can affect a child´s life in many ways. Effective drug treatment is usually needed. The new migraine drugs, triptans, were introduced at the beginning of the 1990s and have since been shown to be very effective in the treatment of migraine attacks in adults. Although they are widely used in adults, the acute treatment of migraine in children and adolescents is still based on paracetamol and nonsteroidal anti-inflammatory drugs. Some children can control their attacks satisfactorily with simple analgesics, but at least one-third need more powerful treatments. When this thesis work commenced, hardly any information existed on the efficacy and safety of triptans in children. The study aim of the thesis was to identify more efficient treatments of migraine for children and adolescents by investigating the efficacy of sumatriptan nasal spray and oral rizatriptan compared with placebo in them. Sleep has an impact on migraine in many aspects. Despite the clinical relevance and common manifestation of sleep in the context of migraine in children, very little research data on the true frequency of sleep exist. As sleeping is so often related to childhood migraine, it can be a confounding factor in clinical drug trials of migraine treatments in children and adolescents. How the results of a sleeping child should be analyzed is under continual debate. The aim of the thesis was also to clarify this as well as to evaluate the frequency of sleeping during migraine attacks in children and factors affecting frequency. Both nasal sumatriptan and oral rizatriptan were effective (superior to placebo), and well tolerated in treatment of migraine attacks in children and adolescents aged 8-17 and 6-17 years, respectively. No serous adverse effects were observed. The results of this work suggest that nasal sumatriptan 20 mg and rizatriptan 10 mg can be effectively and safely used to treat migraine attacks in adolescents aged over 12 years if more effective drugs than NSAIDs are needed. No difference was observed in efficacy or safety of nasal sumatriptan and rizatriptan between children aged younger than 12 years and older children, but because the treated number of patients under 12 years is still small, more studies are needed before sumatriptan or rizatriptan can be recommended for use in this population. Sleeping during migraine attacks was very common, and most children at least occasionally slept during an attack. Falling asleep was especially common in children under eight years of age and during the first hour after the onset of attack. Children who were able to sleep soon after attack onset were more likely pain-free at two hours. Sleeping probably both improves recovery from a migraine attack and is a sign of headache relief. Falling asleep should be classified as a sign of headache relief in clinical drug trials when studying migraine treatments in children and adolescents.

Very Low Birth Weight Infants as Young Adults : Focus on aspects of cognition, behavior and sleep

Major advances in the treatment of preterm infants have occurred during the last three decades. Survival rates have increased, and the first generations of preterm infants born at very low birth weight (VLBW; less than 1500 g) who profited from modern neonatal intensive care are now in young adulthood. The literature shows that VLBW children achieve on average lower scores on cognitive tests, even after exclusion of individuals with obvious neurosensory deficits. Evidence also exists for an increased risk in VLBW children for various neuropsychiatric disorders such as attention-deficit hyperactivity disorder (ADHD) and related behavioral symptoms. Up till now, studies extending into adulthood are sparse, and it remains to be seen whether these problems persist into adulthood. The aim of this thesis was to study ADHD-related symptoms and cognitive and executive functioning in young adults born at VLBW. In addition, we aimed to study sleep disturbances, known to adversely affect both cognition and attention. We hypothesized that preterm birth at VLBW interferes with early brain development in a way that alters the neuropsychological phenotype; this may manifest itself as ADHD symptoms and impaired cognitive abilities in young adulthood. In this cohort study from a geographically defined region, we studied 166 VLBW adults and 172 term-born controls born from 1978 through 1985. At ages 18 to 27 years, the study participants took part in a clinic study during which their physical and psychological health was assessed in detail. Three years later, 213 of these individuals participated in a follow-up. The current study is part of a larger research project (The Helsinki Study of Very Low Birth Weight Adults), and the measurements of interest for this particular study include the following: 1) The Adult Problem Questionnaire (APQ), a self-rating scale of ADHD-related symptoms in adults; 2) A computerized cognitive test battery designed for population studies (CogState®) which measures core cognitive abilities such as reaction time, working memory, and visual learning; 3) Sleep assessment by actigraphy, the Basic Nordic Sleep Questionnaire, and the Morningness-Eveningness Questionnaire. Actigraphs are wrist-worn accelerometers that separate sleep from wakefulness by registering body movements. Contrary to expectations, VLBW adults as a group reported no more ADHD-related behavioral symptoms than did controls. Further subdivision of the VLBW group into SGA (small for gestational age) and AGA (appropriate for gestational age) subgroups, however, revealed more symptoms on ADHD subscales pertaining to executive dysfunction and emotional instability among those born SGA. Thus, it seems that intrauterine growth retardation (for which SGA served as a proxy) is a more essential predictor for self-perceived ADHD symptoms in adulthood than is VLBW birth as such. In line with observations from other cohorts, the VLBW adults reported less risk-taking behavior in terms of substance use (alcohol, smoking, and recreational drugs), a finding reassuring for the VLBW individuals and their families. On the cognitive test, VLBW adults free from neurosensory deficits had longer reaction times than did term-born peers on all tasks included in the test battery, and lower accuracy on the learning task, with no discernible effect of SGA status over and above the effect of VLBW. Altogether, on a group level, even high-functioning VLBW adults show subtle deficits in psychomotor processing speed, visual working memory, and learning abilities. The sleep studies provided no evidence for differences in sleep quality or duration between the two groups. The VLBW adults were, however, at more than two-fold higher risk for sleep-disordered breathing (in terms of chronic snoring). Given the link between sleep-disordered breathing and health sequelae, these results suggest that VLBW individuals may benefit from an increased awareness among clinicians of this potential problem area. An unexpected finding from the sleep studies was the suggestion of an advanced sleep phase: The VLBW adults went to bed earlier according to the actigraphy registrations and also reported earlier wake-up times on the questionnaire. In further study of this issue in conjunction with the follow-up three years later, the VLBW group reported higher levels of morningness propensity, further corroborating the preliminary findings of an advanced sleep phase. Although the clinical implications are not entirely clear, the issue may be worth further study, since circadian rhythms are closely related to health and well-being. In sum, we believe that increased understanding of long-term outcomes after VLBW, and identification of areas and subgroups that are particularly vulnerable, will allow earlier recognition of potential problems and ultimately lead to improved prevention strategies.

Associations between personality traits and sleep quality and quantity in young adults

This thesis examines the associations between personality traits and sleep quantity and quality in young adults. Additionally the possible effects of birth status on these associations are examined. The data used in this thesis is part of a birth cohort study (Helsinki Study of Very Low Birth Weight Adults). The personality traits are based on the five-factor model of personality. The sleep quantity and quality are based on actigraphy assessments. Four hypothesis were made about the personality and sleep associations: (1) neuroticism is related to a lesser quality of sleep, (2) there will be more significant associations between personality traits and sleep quality than between personality traits and sleep quantity, (3) the Very Low Birth Weight (VLBW) as well as, (4) the Small for Gestational Age (SGA) status will affect the associations. Linear regressions were used to study the associations between personality traits and sleep quality and quantity. Whenever an association was significant, it was tested whether this association was moderated first, by the VLBW and second, by the SGA status of the participant. The results were mostly in line with previous research especially demonstrating the negative association between neuroticism and the quality of sleep and suggesting that vulnerability to stress decreases sleep quality. Also it was found that agreeableness and conscientiousness were associated with better sleep quality and extraversion was associated with lower sleep quantity. In addition SGA status moderated the personality and sleep associations. It is proposed that there are two factors behind the interaction. First, prenatally developing mechanisms have an effect on the development of sleep as well as personality. Second, differences in the postnatal environment, for instance the parenting practices, can account for this finding. Future research could focus especially on what kind of prenatal disturbances SGA infants have in the development of mechanisms related to sleep and personality. Also focusing on the differences in parental interaction might shed more light on the results.