John Petkov

In search of lost sleep: Secular trends in the sleep time of school-aged children and adolescents

BACKGROUND Sleep deficits are associated with a wide range of detrimental physical and mental health outcomes. There is concern that children are not getting enough sleep, and that sleep duration has been declining. However, evidence is sparse. METHODS A systematic review of world literature was conducted to locate studies reporting the sleep duration of children aged 5-18 years. Monte Carlo simulation was used to generate pseudodata from summary data, which were combined with raw data and analysed by linear regression of sleep duration on year of measurement at the age × sex × day type × country level. RESULTS Data were available on 690,747 children from 20 countries, dating from 1905 to 2008. From these data, 641 regressions were derived. The sample-weighted median rate of change was -0.75 min nightly per year, indicating a decrease of more than 1 h per night over the study period. Rates of change were negative across age, sex and day type categories, but varied according to region, with Europe, the USA, Canada and Asia showing decreases and Australia, the UK and Scandinavia showing increases. CONCLUSION Over the last 103 years, there have been consistent rapid declines in the sleep duration of children and adolescents.

Effects of n-3 fatty acids, EPA v. DHA, on depressive symptoms, quality of life, memory and executive function in older adults with mild cognitive impairment: a 6-month randomised controlled trial.

Depressive symptoms may increase the risk of progressing from mild cognitive impairment (MCI) to dementia. Consumption of n-3 PUFA may alleviate both cognitive decline and depression. The aim of the present study was to investigate the benefits of supplementing a diet with n-3 PUFA, DHA and EPA, for depressive symptoms, quality of life (QOL) and cognition in elderly people with MCI. We conducted a 6-month double-blind, randomised controlled trial. A total of fifty people aged >65 years with MCI were allocated to receive a supplement rich in EPA (1·67 g EPA + 0·16 g DHA/d; n 17), DHA (1·55 g DHA + 0·40 g EPA/d; n 18) or the n-6 PUFA linoleic acid (LA; 2·2 g/d; n 15). Treatment allocation was by minimisation based on age, sex and depressive symptoms (Geriatric Depression Scale, GDS). Physiological and cognitive assessments, questionnaires and fatty acid composition of erythrocytes were obtained at baseline and 6 months (completers: n 40; EPA n 13, DHA n 16, LA n 11). Compared with the LA group, GDS scores improved in the EPA (P=0·04) and DHA (P=0·01) groups and verbal fluency (Initial Letter Fluency) in the DHA group (P=0·04). Improved GDS scores were correlated with increased DHA plus EPA (r 0·39, P=0·02). Improved self-reported physical health was associated with increased DHA. There were no treatment effects on other cognitive or QOL parameters. Increased intakes of DHA and EPA benefited mental health in older people with MCI. Increasing n-3 PUFA intakes may reduce depressive symptoms and the risk of progressing to dementia. This needs to be investigated in larger, depressed samples with MCI.

Self-management support and training for patients with chronic and complex conditions improves health-related behaviour and health outcomes

The Sharing Health Care SA chronic disease self-management (CDSM) project in rural South Australia was designed to assist patients with chronic and complex conditions (diabetes, cardiovascular disease and arthritis) to learn how to participate more effectively in the management of their condition and to improve their self-management skills. Participants with chronic and complex conditions were recruited into the Sharing Health Care SA program and offered a range of education and support options (including a 6-week peer-led chronic disease self-management program) as part of the Enhanced Primary Care care planning process. Patient self-reported data were collected at baseline and subsequent 6-month intervals using the Partners in Health (PIH) scale to assess self-management skill and ability for 175 patients across four data collection points. Health providers also scored patient knowledge and self-management skills using the same scale over the same intervals. Patients also completed a modified Stanford 2000 Health Survey for the same time intervals to assess service utilisation and health-related lifestyle factors. Results show that both mean patient self-reported PIH scores and mean health provider PIH scores for patients improved significantly over time, indicating that patients demonstrated improved understanding of their condition and improved their ability to manage and deal with their symptoms. These results suggest that involvement in peer-led self-management education programs has a positive effect on patient self-management skill, confidence and health-related behaviour.

The internal consistency and construct validity of the partners in health scale: validation of a patient rated chronic condition self-management measure.

PurposeThe purpose of this study was to test the internal consistency and construct validity of the revised 12-item self-rated Partners in Health (PIH) scale used to assess patients’ chronic condition self-management knowledge and behaviours.MethodsBaseline PIH data were collected for a total of 294 patients with a range of co-morbid chronic conditions including diabetes, cardiovascular disease and arthritis. Scale data for the initial sample of 176 patients were analysed for internal consistency and construct validity using Reliability Analysis and Factor Analysis. Construct validity was tested in a separate sample of 118 patients using confirmatory factor analysis and a structural equation model.ResultsGood internal consistency was indicated with a Cronbach’s alpha coefficient of 0.82 in the initial sample. Factor analysis for this sample revealed four key factors (knowledge, coping, management of condition and adherence to treatment) across the twelve items of the scale. These four key factors were then confirmed by applying the exploratory structural equation model to the separate sample.ConclusionThe PIH scale exhibits construct validity and internal consistency. It therefore is both a generic self-rated clinical tool for assessing self-management in a range of chronic conditions as well as an outcome measure to compare populations and change in patient self-management knowledge and behaviour over time. The four domains of self-management provide a valid measure of patient competency in relation to the self-management of their chronic condition(s).

The Language of Breathlessness Differentiates Between Patients With COPD and Age-Matched Adults

BACKGROUND If descriptors of the sensation of breathlessness are able to differentiate between medical conditions, the language of breathlessness could potentially have a role in differential diagnosis. This study investigated whether the language used to describe the sensation of breathlessness accurately categorized older individuals with and without a prior diagnosis of COPD. METHODS Using a parallel-group design, participants with and without a prior diagnosis of COPD volunteered words and phrases and endorsed up to three statements to describe their sensation of breathlessness. Cluster analysis (v-fold cross-validation) was applied, and subjects were clustered by their choice of words. Cluster membership was then compared to original group membership (COPD vs non-COPD), and predictive power was assessed. RESULTS Groups were similar for age and gender (COPD, n = 94; 48 men; mean age, 70 +/- 10 years [+/- SD]; vs non-COPD, n = 55; 21 men; mean age, 69 +/- 13 years) but differed significantly in breathlessness-related impairment, intensity, and quality of life (p < 0.0001). Cluster membership corresponded accurately with original group classifications (volunteered, 85%; and up to three statements, 68% agreement). Classification based on a single best descriptor (volunteered [62%] or endorsed [55%]) was less accurate for group membership. CONCLUSIONS Language used to describe the sensation of breathlessness differentiated people with and without a prior diagnosis of COPD when descriptors were not limited to a single best word or statement.

Brief Mindfulness-Based Therapy for Chronic Tension-Type Headache: A Randomized Controlled Pilot Study

BACKGROUND Mindfulness-based therapy (MBT) has been demonstrated to be effective for reducing chronic pain symptoms; however, the use of MBT for Chronic Tension-Type Headache (CTH) exclusively has to date not been examined. Typically, MBT for chronic pain has involved an 8-week program based on Mindfulness Based Stress Reduction. Recent research suggests briefer mindfulness-based treatments may be effective for chronic pain. AIMS To conduct a pilot study into the efficacy of brief MBT for CTH. METHOD We conducted a randomized controlled trial of a brief (6-session, 3-week) MBT for CTH. RESULTS Results indicated a significant decrease in headache frequency and an increase in the mindfulness facet of Observe in the treatment but not wait-list control group. CONCLUSION Brief MBT may be an effective intervention for CTH.

Central mechanisms of stress-induced headache

Stress is the most commonly reported trigger of an episode of chronic tension-type headache (CTTH); however, the causal significance has not been experimentally demonstrated to date. Stress may trigger CTTH through hyperalgesic effects on already sensitized pain pathways in CTTH sufferers. This hypothesis could be partially tested by examining pain sensitivity in an experimental model of stress-induced headache in CTTH sufferers. Such examinations have not been reported to date. We measured pericranial muscle tenderness and pain thresholds at the finger, head and shoulder in 23 CTTH sufferers (CTH-S) and 25 healthy control subjects (CNT) exposed to an hour-long stressful mental task, and in 23 CTTH sufferers exposed to an hour-long neutral condition (CTH-N). Headache developed in 91% of CTH-S, 4% of CNT, and 17% of CTH-N subjects. Headache sufferers had increased muscle tenderness and reduced pain thresholds compared with healthy controls. During the task, muscle tenderness increased and pain thresholds decreased in the CTH-S group compared with CTH-N and CNT groups. Pre-task muscle tenderness and reduction in pain threshold during task were predictive of the development and intensity of headache following task. The main findings are that stress induced a headache in CTTH sufferers, and this was associated with pre-task muscle tenderness and stress-induced reduction in pain thresholds. The results support the hypothesis that stress triggers CTTH through hyperalgesic effects on already increased pain sensitivity in CTTH sufferers, reducing the threshold to noxious input from pericranial structures.

Affective Descriptors of the Sensation of Breathlessness Are More Highly Associated With Severity of Impairment Than Physical Descriptors in People With COPD

BACKGROUND Previous studies of the qualitative sensation of breathlessness have suggested that greater sensory discomfort is reported as airflow obstruction increases. This study investigated relationships between the language of breathlessness and severity of impairment in subjects with COPD. METHODS Using a prospective, observational approach, subjects completed a structured interview in which they volunteered words to describe their sensation of breathlessness and endorsed statements from a preexisting descriptor list. Global impairment was assessed by the BMI, airflow obstruction, dyspnea, and exercise capacity (BODE) index. Independent t tests and logistic regression analyses (odds ratios) were used to assess relationships between language categories and severity of impairment. RESULTS In this group of 91 people (47 men, 70 +/- 10 years of age, percent predicted FEV(1) 54 +/- 23), subjects volunteering extreme affective descriptors (frightening, awful, worried) had greater impairment (BODE index, perceived respiratory disability, functional exercise capacity, and airways obstruction), and this language category was significantly associated with increasing BODE index scores (odds ratio [OR] = 1.49; 95% CI, 1.18 to 1.86; P = .001). Descriptors denoting heavy, rapid, more, shallow, or does not go in or out all the way were significantly less likely to be selected as BODE index scored increased (OR = 0.75; 95% CI, 0.16 to 0.93). CONCLUSIONS Affective descriptors or the emotional response to the sensation of breathlessness have a significant relationship with severity of COPD impairments. Affective descriptors may reflect the degree of threat imposed by the sensation and predict the likelihood of long-term behavioral changes.

Parental nutrition knowledge and attitudes as predictors of 5-6-year-old children's healthy food knowledge.

OBJECTIVE Young childrens knowledge about healthy food may influence the formation of their eating behaviours, and parents have a major influence on the development of childrens knowledge in the early years. DESIGN We investigated the extent to which parental nutrition knowledge and attitudes around food predicted young childrens knowledge of healthy foods, controlling for other influences such as socio-economic status (SES) and parent education levels in a cross-sectional research design. Children were given a healthy food knowledge activity and parents completed questionnaires. SETTING Twenty primary schools in Adelaide, Australia, stratified by SES. SUBJECTS We recruited 192 children aged 5-6 years and their parents. RESULTS Structural equation modelling showed that parent nutrition knowledge predicted childrens nutrition knowledge (r = 0·30, P < 0·001) independently of attitudes, SES and education level. CONCLUSIONS Nutrition education for parents, targeted at low-SES areas at higher risk for obesity, may contribute to the development of healthy food knowledge in young children.

Associations between parenting styles and nutrition knowledge and 2-5-year-old children's fruit, vegetable and non-core food consumption.

OBJECTIVE During the early years, parents have a major influence on children’s diets and developing food choices. We investigated parenting styles as predictors of 2–5-year-old children’s diets and whether general nutrition knowledge (GNK) mediated these influences. DESIGN Cross-sectional research. Questionnaires measured demographic and lifestyle variables, family environment, parenting styles and feeding practices, child diet and GNK. Regression models tested GNK as a mediator of relationships between parenting variables and child diet (fruit/vegetable and non-core food consumption), controlling for confounders and family environment. SETTING Questionnaires were completed by main caregivers at home. SUBJECTS Parents of children aged 2–5 years (n 269). RESULTS Higher child fruit/vegetable consumption was associated with lower overreactive parenting and restriction, higher authoritative parenting and dining together as a family; with lax parenting approaching statistical significance (P50?083) and 19% of variance explained by the model. GNK was not a significant predictor. Conversely, non-core food consumption was associated with higher over-reactive and lax parenting as well as child age, increased takeaway food consumption and higher television viewing; GNK had a small effect (P = 0.043) and 28% of variance was explained by the model. GNK was a significant mediator only for authoritative parenting on non-core food (effect = -0.005). CONCLUSIONS These findings highlight that young children’s diets may be improved by interventions targeting a range of positive and supportive parenting practices in conjunction with nutrition knowledge education for parents of young children. Further insights will come from closer attention to the nature and role of restrictive feeding practices v. laxness and longitudinal research.