Relevance of cohort studies for the study of transplant infectious diseases.

The debate on the merits of observational studies as compared with randomized trials is ongoing. We will briefly touch on this subject, and demonstrate the role of cohort studies for the description of infectious disease patterns after transplantation. The potential benefits of cohort studies for the clinical management of patients outside of the expected gain in epidemiological knowledge are reviewed. The newly established Swiss Transplantation Cohort Study and in particular the part focusing on infectious diseases will serve as an illustration. A neglected area of research is the indirect value of large, multicenter cohort studies. These benefits can range from a deepened collaboration to the development of common definitions and guidelines. Unfortunately, very few data exist on the role of such indirect effects on improving quality of patient management. This review postulates an important role for cohort studies, which should not be viewed as inferior but complementary to established research tools, in particular randomized trials. Randomized trials remain the least bias-prone method to establish knowledge regarding the significance of diagnostic or therapeutic measures. Cohort studies have the power to reflect a real-world situation and to pinpoint areas of knowledge as well as of uncertainty. Prerequisite is a prospective design requiring a set of inclusive data coupled with the meticulous insistence on data retrieval and quality.

Cohort Profile: The Interdisciplinary Study of Inequalities in Smoking (ISIS)

The Interdisciplinary Study of Inequalities in Smoking (ISIS) is a cohort study investigating the joint effects of residents' socio-demographic characteristics and neighbourhood attributes on the social distribution of smoking in a young adult population. Smoking is a behaviour with an increasingly steep social class gradient; smoking prevalence among young adults is no longer declining at the same rate as among the rest of the population, and there is evidence of growing place-based disparities in smoking. ISIS was established to examine these pressing concerns. The ISIS sample comprises non-institutionalized individuals aged 18-25 years, who are proficient in English and/or French and who had been living at their current address in Montréal, Canada, for at least 1 year at time of first contact. Two waves of data have been collected: baseline data were collected November 2011-September 2012 (n = 2093), and a second wave of data was collected January-June 2014 (n = 1457). Data were collected from respondents using a self-administered questionnaire, developed by the research team based on sociological theory, which includes questions concerning social, economic, cultural and biological capital, and activity space as well as smoking behaviour. Data are available upon request from [katherine.frohlich@umontreal.ca].

Description of the SAGhE Cohort: A Large European Study of Mortality and Cancer Incidence Risks after Childhood Treatment with Recombinant Growth Hormone.

BACKGROUND The long-term safety of growth hormone treatment is uncertain. Raised risks of death and certain cancers have been reported inconsistently, based on limited data or short-term follow-up by pharmaceutical companies. PATIENTS AND METHODS The SAGhE (Safety and Appropriateness of Growth Hormone Treatments in Europe) study assembled cohorts of patients treated in childhood with recombinant human growth hormone (r-hGH) in 8 European countries since the first use of this treatment in 1984 and followed them for cause-specific mortality and cancer incidence. Expected rates were obtained from national and local general population data. The cohort consisted of 24,232 patients, most commonly treated for isolated growth failure (53%), Turner syndrome (13%) and growth hormone deficiency linked to neoplasia (12%). This paper describes in detail the study design, methods and data collection and discusses the strengths, biases and weaknesses consequent on this. CONCLUSION The SAGhE cohort is the largest and longest follow-up cohort study of growth hormone-treated patients with follow-up and analysis independent of industry. It forms a major resource for investigating cancer and mortality risks in r-hGH patients. The interpretation of SAGhE results, however, will need to take account of the methods of cohort assembly and follow-up in each country.

Country of birth, country of residence, and menopausal transitions and symptoms: British birth cohort and Australian Longitudinal Study on Women's Health

Objective: To explore endocrine-related and general symptoms among three groups of middle-aged women defined by country of birth and country of residence, in the context of debates about biological, cultural and other factors in menopause. Methods: British-born women participating in a British birth cohort study (n=1,362) and age-matched Australian-born (n=1,724) and British-born (n=233) Australian women selected from the Australian Longitudinal Study on Women's Health (ALSWH) responded to two waves of surveys at ages 48 and 50. Results: Australian-Australian and British-Australian women report reaching menopause later than British-British women, even after accounting for smoking status and parity. Hormone replacement therapy (HRT) use was lower and hysterectomy was more common among both Australian groups, probably reflecting differences in health services between Britain and Australia. The Australian-Australian and British-Australian groups were more likely to report endocrine-related symptoms than the British-British group, even after adjusting for menopausal status. British-British women were more likely to report some general symptoms. Conclusions: Symptom reporting is high among Australian and British midlife women and varies by country of residence, country of birth and menopausal status. Implications: The data do not support either a simple cultural or a simple biological explanation for differences in menopause experience.

Gender differences in children's classroom behaviour and teacher-child relationships in early childhood: An Australian Study

Background: In the early school years, children need positive attitudes to school and experiences that promote academic and social competence. Positive relationships between children and teachers make a significant contribution to school achievement and social competence. Girls are more likely to display positive classroom behaviours and positive approaches to learning than boys. Gender differences have also been noted in teacher-child relationships. This study investigated the relationship between gender differences in classroom behaviour and gender differences in teacher-child relationships in the early years. Method: Data were drawn from The Longitudinal Study of Australian Children (LSAC). LSAC is a cross-sequential cohort study funded by the Australian Government. In these analyses, Wave 1 (2004) and Wave 2 (2006) data for 4464 children in the Kindergarten Cohort were used. Children, at Wave 2, were in the early years of formal school. They had a mean age of 6.8 years (SD= 0.24). Measures included a 6-item measure of Approaches to Learning (task persistence, independence) and teacher ratings on the SDQ. Teachers rated their relationships with children on the short form of the STRS. Results: Girls were found to have more positive relationships with their teachers and to display more positive classroom behaviours than boys. Teachers described their relationships with boys as less close than their relationships with girls and rated girls as displaying more positive approaches to learning and fewer problem behaviours than boys. Positive teacher – child relationships were significantly related to more positive classroom behaviours. The quality of the teacher-child relationship at time 1 (Wave 1) was the best predictor of the quality of the teacher-child relationship at time 2 (Wave 2). Conclusions: Findings highlight the importance of developing positive learning related classroom behaviours in understanding successful school transition and the key role played by early positive teacher-child relationships in promoting school adjustment.

Molecular epidemiology of respiratory viruses in a paediatric cohort from Indonesia

Acute lower respiratory tract infections (ALRTIs) are a common cause of morbidity and mortality among children under 5 years of age and are found worldwide, with pneumonia as the most severe manifestation. Although the incidence of severe disease varies both between individuals and countries, there is still no clear understanding of what causes this variation. Studies of community-acquired pneumonia (CAP) have traditionally not focused on viral causes of disease due to a paucity of diagnostic tools. However, with the emergence of molecular techniques, it is now known that viruses outnumber bacteria as the etiological agents of childhood CAP, especially in children under 2 years of age. The main objective of this study was to investigate viruses contributing to disease severity in cases of childhood ALRTI, using a two year cohort study following 2014 infants and children enrolled in Bandung, Indonesia. A total of 352 nasopharyngeal washes collected from 256 paediatric ALRTI patients were used for analysis. A subset of samples was screened using a novel microarray pathogen detection method that identified respiratory syncytial virus (RSV), human metapneumovirus (hMPV) and human rhinovirus (HRV) in the samples. Real-time RT-PCR was used both for confirming and quantifying viruses found in the nasopharyngeal samples. Viral copy numbers were determined and normalised to the numbers of human cells collected with the use of 18S rRNA. Molecular epidemiology was performed for RSV A and hMPV using sequences to the glycoprotein gene and nucleoprotein gene respectively, to determine genotypes circulating in this Indonesian paediatric cohort. This study found that HRV (119/352; 33.8%) was the most common virus detected as the cause of respiratory tract infections in this cohort, followed by the viral pathogens RSV A (73/352; 20.7%), hMPV (30/352; 8.5%) and RSV B (12/352; 3.4%). Co-infections of more than two viruses were detected in 31 episodes (defined as an infection which occurred more than two weeks apart), accounting for 8.8% of the 352 samples tested or 15.4% of the 201 episodes with at least one virus detected. RSV A genotypes circulating in this population were predominantly GA2, GA5 and GA7, while hMPV genotypes circulating were mainly A2a (27/30; 90.0%), B2 (2/30; 6.7%) and A1 (1/30; 3.3%). This study found no evidence of disease severity associated either with a specific virus or viral strain, or with viral load. However, this study did find a significant association with co-infection of RSV A and HRV with severe disease (P = 0.006), suggesting that this may be a novel cause of severe disease.

Design and rationale of a Prospective, Observational European Multicenter study on the efficacy of acute surgical decompression after traumatic Spinal Cord Injury: the SCI-POEM study

Objectives:Despite many years of research, there is currently no treatment available that results in major neurological or functional recovery after traumatic spinal cord injury (tSCI). In particular, no conclusive data related to the role of the timing of decompressive surgery, and the impact of injury severity on its benefit, have been published to date. This paper presents a protocol that was designed to examine the hypothesized association between the timing of surgical decompression and the extent of neurological recovery in tSCI patients.Study design: The SCI-POEM study is a Prospective, Observational European Multicenter comparative cohort study. This study compares acute (<12 h) versus non-acute (>12 h, <2 weeks) decompressive surgery in patients with a traumatic spinal column injury and concomitant spinal cord injury. The sample size calculation was based on a representative European patient cohort of 492 tSCI patients. During a 4-year period, 300 patients will need to be enrolled from 10 trauma centers across Europe. The primary endpoint is lower-extremity motor score as assessed according to the 'International standards for neurological classification of SCI' at 12 months after injury. Secondary endpoints include motor, sensory, imaging and functional outcomes at 3, 6 and 12 months after injury.Conclusion:In order to minimize bias and reduce the impact of confounders, special attention is paid to key methodological principles in this study protocol. A significant difference in safety and/or efficacy endpoints will provide meaningful information to clinicians, as this would confirm the hypothesis that rapid referral to and treatment in specialized centers result in important improvements in tSCI patients.Spinal Cord advance online publication, 17 April 2012; doi:10.1038/sc.2012.34.

Helping understand nutritional gaps in the elderly (HUNGER) : a prospective study of patient factors associated with inadequate nutritional intake in older medical inpatients

BACKGROUND: Malnutrition, and poor intake during hospitalisation, are common in older medical patients. Better understanding of patient-specific factors associated with poor intake may inform nutritional interventions. AIMS: To measure the proportion of older medical patients with inadequate nutritional intake, and identify patient-related factors associated with this outcome. METHODS: Prospective cohort study enrolling consecutive consenting medical inpatients aged 65 years or older. Primary outcome was energy intake less than resting energy expenditure estimated using weight-based equations. Energy intake was calculated for a single day using direct observation of plate waste. Explanatory variables included age, gender, number of co-morbidities, number of medications, diagnosis, usual residence, nutritional status, functional and cognitive impairment, depressive symptoms, poor appetite, poor dentition, and dysphagia. RESULTS: Of 134 participants (mean age 80 years, 51% female), only 41% met estimated resting energy requirements. Mean energy intake was 1220 kcal/day (SD 440), or 18.1 kcal/kg/day. Factors associated with inadequate energy intake in multivariate analysis were poor appetite, higher BMI, diagnosis of infection or cancer, delirium and need for assistance with feeding. CONCLUSIONS: Inadequate nutritional intake is common, and patient factors contributing to poor intake need to be considered in nutritional interventions.

Pregnancy losses in young Australian women : findings from the Australian Longitudinal Study on Women's Health

INTRODUCTION: Little research has examined recognized pregnancy losses in a general population. Data from an Australian cohort study provide an opportunity to quantify this aspect of fecundity at a population level. METHOD: Participants in the Australian Longitudinal Study on Women's Health who were aged 28-33 years in 2006 (n = 9,145) completed up to 4 mailed surveys over 10 years. Participants were categorized according to the recognized outcome of their pregnancies, including live birth, miscarriage/stillbirth, termination/ectopic, or no pregnancy. RESULTS: At age 18-23, more women reported terminations (7%) than miscarriages (4%). By 28-33 years, the cumulative frequency of miscarriage (15%) was as common as termination (16%). For women aged 28-33 years who had ever been pregnant (n = 5,343), pregnancy outcomes were as follows: birth only (50%); loss only (18%); and birth and loss (32%), of which half (16%) were birth and miscarriage. A comparison between first miscarriage and first birth (no miscarriage) showed that most first miscarriages occurred in women aged 18-23 years who also reported a first birth at the same survey (15%). Half (51%) of all first births and first miscarriages in women aged 18-19 ended in miscarriage. Early childbearers (<28 years) often had miscarriages around the same time period as their first live birth, suggesting proactive family formation. Delayed childbearers (32-33 years) had more first births than first miscarriages. CONCLUSION: Recognized pregnancy losses are an important measure of fecundity in the general population because they indicate successful conception and maintenance of pregnancy to varying reproductive endpoints.

A cross-sectional analysis of patterns of obesity in a cohort of working nurses and midwives in Australia, New Zealand, and the United Kingdom

Objective The aim of this study was to examine the prevalence of overweight and obesity and the association with demographic, reproductive work variables in a representative cohort of working nurses and midwives. Design A cross sectional study of self reported survey data. Settings Australia, New Zealand and the United Kingdom. Methods Measurement outcomes included BMI categories, demographic (age, gender, marital status, ethnicity), reproductive (parity, number of births, mother's age at first birth, birth type and menopausal status) and workforce (registration council, employment type and principal specialty) variables. Participants 4996 respondents to the Nurses and Midwives e-Cohort study who were currently registered and working in nursing or midwifery in Australia (n=3144), New Zealand (n=778) or the United Kingdom (n=1074). Results Amongst the sample 61.87% were outside the healthy weight range and across all three jurisdictions the prevalence of obesity in nurses and midwives exceeded rates in the source populations by 1.73% up to 3.74%. Being overweight or obese was significantly associated with increasing age (35–44 yrs aOR 1.71, 95% CI 1.41–2.08; 45–55 yrs aOR 1.90, 95%CI 1.56–2.31; 55–64 aOR 2.22, 95% CI 1.71–2.88), and male gender (aOR 1.46, 95% CI 1.15–1.87). Primiparous nurses and midwives were more likely to be overweight or obese (aOR 1.37, 95% CI 1.06–1.76) as were those who had reached menopause (aOR 1.37, 95% CI 1.11–1.69). Nurses and midwives in part-time or casual employment had significantly reduced risk of being overweight or obese, (aOR 0.81, 95% CI 0.70–0.94 and aOR 0.75, 95% CI 0.59–0.96 respectively), whilst working in aged carried increased risk (aOR 1.37, 95% CI 1.04–1.80). Conclusion Nurses and midwives in this study have higher prevalence of obesity and overweight than the general population and those who are older, male, or female primiparous and menopausal have significantly higher risk of overweight or obesity as do those working fulltime, or in aged care. The consequences of overweight and obesity in this occupational group may impact on their workforce participation, their management of overweight and obese patients in their care as well as influencing their individual health behaviours and risks of occupational injury and chronic disease.

The ability of YSR DSM-oriented depression scales to predict DSM-IV depression in young adults : a longitudinal study

Background The Achenbach child behaviour checklist (CBCL/YSR) is a widely used screening tool for affective problems. Several studies report good association between the checklists and psychiatric diagnoses; although with varying degrees of agreement. Most are cross-sectional studies involving adolescents referred to mental health services. This paper aims to evaluate the performance of the youth self report (YSR) empirical and DSM-oriented internalising scales in predicting later depressive disorders in young adults. Methods Sample was 2431 young adults from an Australian birth cohort study. The strength of association between the empirical and DSM-oriented scales assessed at 14 and 21 years and structured-interview derived depression in young adulthood (18 to 22 years) were tested using odds ratios, ROC analyses and related diagnostic efficiency tests (sensitivity, specificity, positive and negative predictive values). Results Adolescents with internalising symptoms were twice (OR 2.3, 95%CI 1.7 to 3.1) as likely to be diagnosed with DSM-IV depression by age 21. Use of DSM-oriented depressive scales did not improve the concordance between the internalising behaviour and DSM-IV diagnosed depression at age 14 (ORs ranged from 1.9 to 2.5). Limitations Some loss to follow-up over the 7-year gap between the two waves of follow-up. Conclusion DSM-oriented scales perform no better than the standard internalising or anxious/depressed scales in identifying young adults with later DSM-IV depressive disorder.

Screening in early childhood for risk of later mental health problems : a longitudinal study

Depression in childhood or adolescence is associated with increased rates of depression in adulthood. Does this justify efforts to detect (and treat) those with symptoms of depression in early childhood or adolescence? The aim of this study was to determine how well symptoms of anxiety/depression (A-D) in early childhood and adolescence predict adult mental health. The study sample is taken from a population-based prospective birth cohort study. Of the 8556 mothers initially approached to participate 8458 agreed, of whom 7223 mothers gave birth to a live singleton baby. Children were screened using modified Child Behaviour Checklist (CBCL) scales for internalizing and total problems (T-P) at age 5 and the CBCL and Youth Self Report (YSR) A-D subscale and T-P scale at age 14. At age 21, a sub-sample of 2563 young adults in this cohort were administered the CIDI-Auto. Results indicated that screening at age 5 would detect few later cases of significant mental ill-health. Using a cut-point of 20% for internalizing at child age 5 years the CBCL had sensitivities of only 25% and 18% for major depression and anxiety disorders at 21 years, respectively. At age 14, the YSR generally performed a little better than the CBCL as a screening instrument, but neither performed at a satisfactory level. Of the children who were categorised as having YSR A-D at 14 years 30% and 37% met DSM-IV criteria for major depression and anxiety disorders, respectively, at age 21. Our findings challenge an existing movement encouraging the detection and treatment of those with symptoms of mental illness in early childhood.

Patellar tendon ultrasonography in asymptomatic active athletes reveals hypoechoic regions : a study of 320 tendons

OBJECTIVE: To compare patellar tendon sonographic findings in active, currently asymptomatic, elite athletes with those in nonathletic controls. DESIGN: Cross-sectional cohort study with convenience control sample. SETTING: The Victorian Institute of Sport Tendon Study Group, an institutional elite athlete study group in Australia. PATIENTS AND PARTICIPANTS: Two hundred elite male and female athletes from the sports of basketball, cricket, netball, and Australian rules football. Forty athletes who had current symptoms of jumper's knee were excluded from analysis, leaving 320 subject tendons in athletes who were currently asymptomatic. Twenty-seven nonathletic individuals served as controls. MAIN OUTCOME MEASURE: Sonographic patellar tendon appearance. We measured the dimensions of subject tendons and noted the presence or absence of hypoechoic regions and tendon calcification. Dimensions of hypoechoic regions were measured, and approximate cross-sectional areas were calculated. Chi-squared analysis was used to test the prevalence of hypoechoic regions in subjects and controls and men and women. RESULTS: In currently asymptomatic subjects, hypoechoic regions were more prevalent in athlete tendons (22%) than in controls (4%), in male subject tendons (30%) than in female subjects (14%), and in basketball players (32%) than in other athletes (9%) (all p < 0.01). Bilateral tendon abnormalities were equally prevalent in men and women but more prevalent in basketball players (15%) than in other athletes (3%) (p < 0.05). Sonographic hypoechoic regions were present in 35 of 250 (14%) patellar tendons in athletes who had never had anterior knee pain. CONCLUSIONS: Patellar tendon sonographic hypoechoic areas were present in asymptomatic patellar tendons of a proportion of elite athletes but rarely present in controls. This has implications for clinicians managing athletes with anterior knee pain.

Long-term survival after intensive care unit discharge in Thailand : a retrospective study

Introduction Economic evaluations of interventions in the hospital setting often rely on the estimated long-term impact on patient survival. Estimates of mortality rates and long-term outcomes among patients discharged alive from the intensive care unit (ICU) are lacking from lower- and middle-income countries. This study aimed to assess the long-term survival and life expectancy (LE) amongst post-ICU patients in Thailand, a middle-income country. Methods In this retrospective cohort study, data from a regional tertiary hospital in northeast Thailand and the regional death registry were linked and used to assess patient survival time after ICU discharge. Adult ICU patients aged at least 15 years who had been discharged alive from an ICU between 1 January 2004 and 31 December 2005 were included in the study, and the death registry was used to determine deaths occurring in this cohort up to 31st December 2010. These data were used in conjunction with standard mortality life tables to estimate annual mortality and life expectancy. Results This analysis included 10,321 ICU patients. During ICU admission, 3,251 patients (31.5%) died. Of 7,070 patients discharged alive, 2,527 (35.7%) were known to have died within the five-year follow-up period, a mortality rate 2.5 times higher than that in the Thai general population (age and sex matched). The mean LE was estimated as 18.3 years compared with 25.2 years in the general population. Conclusions Post-ICU patients experienced much higher rates of mortality than members of the general population over the five-year follow-up period, particularly in the first year after discharge. Further work assessing Health Related Quality of Life (HRQOL) in both post-ICU patients and in the general population in developing countries is needed.

Prospective observational study of dementia and delirium in the acute hospital setting

Background: Dementia and delirium appear to be common among older patients admitted to acute hospitals, although there are few Australian data regarding these important conditions. Aim: The aim of this study was to determine the prevalence and incidence of dementia and delirium among older patients admitted to acute hospitals in Queensland and to profile these patients. Method: Prospective observational cohort study (n = 493) of patients aged 70 years and older admitted to general medical, general surgical and orthopaedic wards of four acute hospitals in Queensland between 2008 and 2010. Trained research nurses completed comprehensive geriatric assessments and obtained detailed information about each patient’s physical, cognitive and psychosocial functioning using the interRAI Acute Care and other standardised instruments. Nurses also visited patients daily to identify incident delirium. Two physicians independently reviewed patients’ medical records and assessments to establish the diagnosis of dementia and/or delirium. Results: Overall, 29.4% of patients (n = 145) were considered to have cognitive impairment, including 102 (20.7% of the total) who were considered to have dementia. This rate increased to 47.4% in the oldest patients (aged 90 years). The overall prevalence of delirium at admission was 9.7% (23.5% in patients with dementia), and the rate of incident delirium was 7.6% (14.7% in patients with dementia). Conclusion: The prevalence of dementia and delirium among older patients admitted to acute hospitals is high and is likely to increase with population aging. It is suggested that hospital design, staffing and processes should be attuned better to meet these patients’ needs.