Intense and problematic social media use and sleep difficulties of adolescents in 40 countries

INTRODUCTION

Social media has become a ubiquitous part of everyday life; however, evidence suggests patterns of social media use can affect sleep health in children and adolescents. This study aimed to examine the associations of intense and problematic social media use (SMU) with sleep-onset difficulties in adolescence.

METHODS

We analysed data from 212,613 adolescents aged 11-15 years (51.1% girls) from 40 European and North American countries that participated in the 2017/2018 Health Behaviour in School-aged Children survey. Intense SMU assessed how often respondents had online contact through social media, and problematic SMU was assessed by symptoms of addiction to social media. Sleep-onset difficulties were assessed using a self-reported item. Multilevel mixed-effects logistic regression was used to obtain the estimates.

RESULTS

Sleep-onset difficulties were more common among girls than boys (27.1% vs 20.8%). Intense SMU was significantly associated with sleep-onset difficulties in boys in 17 countries and in girls in 25 countries, while problematic SMU was significantly associated in most of the participating countries. Overall, exposure to problematic SMU alone was highly associated with sleep-onset difficulties both in girls (OR 2.20, 2.04-2.38) and boys (OR 1.88, 1.73-2.04), while the association estimates for intense SMU were smaller and comparable across gender (Girls: OR 1.27, 1.23-1.31; Boys: OR 1.22, 1.18-1.27). Sensitivity analyses supported the above findings.

CONCLUSIONS

Intense and/or problematic SMU were associated with sleep-onset difficulties across gender with associations being higher for problematic compared to intense SMU. Prospective research with objective measures is needed to understand the causal mechanisms underlying these relationships.

The associations of secondhand smoke exposure with neurodevelopmental disorders and critical time window identification: A systematic review and meta-analysis

BACKGROUND

Secondhand smoke (SHS) exposure was harmful for brain development. However, the association between SHS exposure and NDDs diagnosis were unclear.

OBJECTIVES

To evaluate associations between SHS exposure and NDDs diagnosis, identify critical time windows, and summarize the strength of evidence.

METHODS

To investigate the associations of SHS exposure and the development of NDDs, we searched Ovid, EMBASE, Web of Science, Cochrane Library, and PubMed for all the relevant studies up to 31 March 2023. The risk estimates and standardized mean differences (SMD) for the individuals with any NDDs who were exposed to SHS exposure compared with those unexposed or low-exposed.

RESULTS

The results showed that a total of 31,098 citations were identified, of which 54 studies were included. We identified significant associations between SHS exposure and the risks of NDDs including specific types of NDDs like attention deficit hyperactivity disorder (ADHD) and learning disabilities (LD) despite the observed heterogeneity for NDDs and ADHD. We also observed a significant association between cotinine exposure and ADHD. However, inconsistent ratings between the two quality-of-evidence methods for all the meta-analyses indicated the current evidence of the associations and the potential exposure window remained inconclusive.

DISCUSSION

Our findings suggested that SHS exposure was associated with a higher risk of developing ADHD and LD, with inconclusive quality-of-evidence. In addition, period-specific associations remained unclear based on current evidence.

Association between maternal gestational diabetes and allergic diseases in offspring: a birth cohort study

BACKGROUND

Previous studies have linked gestational diabetes (GDM) with allergies in offspring. However, the effect of specific glucose metabolism metrics was not well characterized, and the role of polyunsaturated fatty acids (PUFAs), a modifier of metabolism and the immune system, was understudied. We aimed to investigate the association between maternal GDM and allergic diseases in children and the interaction between glucose metabolism and PUFAs on allergic outcomes.

METHODS

This prospective cohort study included 706 mother-child dyads from Guangzhou, China. Maternal GDM was diagnosed via a 75-g oral glucose tolerance test (OGTT), and dietary PUFAs were assessed using a validated food frequency questionnaire. Allergic disease diagnoses and the age of onset were obtained from medical records of children within three years old.

RESULTS

Approximately 19.4% of women had GDM, and 51.3% of children had any allergic diseases. GDM was positively associated with any allergic diseases (hazard ratio [HR] 1.40; 95% confidence interval (CI) 1.05-1.88) and eczema (HR 1.44; 95% CI 1.02-1.97). A unit increase in OGTT after two hours (OGTT-2 h) glucose was associated with an 11% (95% CI 2%-21%) higher risk of any allergic diseases and a 17% (95% CI 1-36%) higher risk of food allergy. The positive associations between OGTT-2 h glucose and any allergic diseases were strengthened with decreased dietary a-linolenic acid (ALA) and increased n-6 PUFAs, linoleic acid (LA), LA/ALA ratio, and n-6/n-3 PUFA ratio.

CONCLUSIONS

Maternal GDM was adversely associated with early-life allergic diseases, especially eczema. We were the first to identify OGTT-2 h glucose to be more sensitive in inducing allergy risk and that dietary PUFAs might modify the associations.

Association of diet quality during pregnancy with maternal glucose metabolism in Chinese women

Overall diet quality during pregnancy has played an important role on maternal glucose metabolism. However, evidence based on the adherence to the dietary guideline is limited, especially for Asian populations. We aimed to examine the association between adherence to the Chinese dietary guideline measured by the Diet Balance Index for Pregnancy (DBI-P) and maternal glucose metabolism, including gestational diabetes mellitus (GDM) status, fasting and 2-h plasma glucose. Data were obtained from the baseline survey of the Yuexiu birth cohort. We recruited 942 pregnant women at 20-28 weeks of gestation in 2017-2018. Dietary intakes during the past month were collected using a validated semi-quantitative FFQ. The scores of DBI-P were calculated to assess dietary quality. Lower absolute values of the scores indicate higher adherence to the Chinese dietary guidelines. All participants underwent a 75 g of oral glucose tolerance test (OGTT). Multiple linear regression and logistic regression were conducted. The Benjamini-Hochberg method was used to adjust multiple comparisons across DBI-P food components. The value of high bound score indicator, reflecting excessive total food intake, was positively associated with OGTT-2h glucose levels (β = 0·037, P = 0·029). After adjustment for multiple comparisons, the score of animal food intake was positively associated with OGTT-2 h glucose levels (β = 0·045, P = 0·045) and risk of GDM (OR = 1·105, P = 0·030). In conclusion, excessive total food intake was associated with higher postprandial glucose in pregnant women. Lower compliance with the dietary guideline for animal food was associated with both higher postprandial glucose and increased risk of GDM during pregnancy.

Infant feeding practices and autism spectrum disorder in US children aged 2-5 years: the national survey of children's health (NSCH) 2016-2020

OBJECTIVE

To investigate the relationship between infant feeding practices and autism spectrum disorder (ASD) among children aged 2-5 years in the United States (US).

METHODS

Data from the 2016-2020 National Survey of Children's Health, a nationally representative cross-sectional survey, were utilized for this study. Questionnaires were administered to parents of children aged 2-5 years to gather information on ASD diagnosis, infant feeding practices, and demographic factors (e.g., child sex, ethnic group, and maternal age at birth). Logistic regression with sample weights was employed to assess the association between infant feeding practices and ASD, while controlling for demographic variables. Polynomial regression models were used to examine trends in exclusive breastfeeding and ever breastfeeding rates among children with and without ASD.

RESULTS

A total of 35,050 children aged 2-5 years were analyzed, including 616 diagnosed with ASD, after excluding participants with missing information on breastfeeding and ASD diagnosis. Of these children with ASD, 76.6% (n = 472) had a breastfeeding history, with 67.5% (n = 416) engaged in partial breastfeeding and 9.1% (n = 56) exclusively breastfed. Adjusted odds ratios for each additional month of breastfeeding compared to never being breastfed were 0.98 (95% CI, 0.96-1.01). The adjusted odds ratios for breastfeeding durations of > 0-6 months, > 6-12 months, > 12-24 months, and > 24 months were 0.81 (95% CI, 0.50-1.31), 0.65 (95% CI, 0.36-1.18), 0.81 (95% CI, 0.44-1.49), and 0.48 (95% CI, 0.23-1.01), respectively. Compared to children who were never breastfed, the adjusted odds ratio for children who were ever breastfed was 0.74 (95% CI, 0.47-1.18). Among children with ASD, the proportion of ever breastfeeding declined from 82.0% in 2017 to 64.3% in 2020, while exclusive breastfeeding decreased from 12.0% in 2016 to 4.2% in 2020.

CONCLUSIONS AND RELEVANCE

Although no significant association was found between infant feeding practices and ASD among US children aged 2-5 years, the rates of breastfeeding, particularly exclusive breastfeeding, were suboptimal among children with ASD. This highlights the need for specific policies and practices to promote and support breastfeeding among parents of children with ASD or those at high risk of having a child with ASD.

Assessment of Determinants of Paediatric Diarrhoea Case Management Adherence in Pakistan

Worldwide, diarrhoea in children under five years of age is the second leading cause of death. Despite having high morbidity and mortality, diarrhoeal diseases can be averted by simple and cost-effective interventions. The Integrated Management of Childhood Illness (IMCI) has proposed the use of Oral Rehydration Salt (ORS) and zinc together with adequate food and fluid intake for the management of acute non-dysenteric watery diarrhoea in children. In the past, few studies examined the determinants of adherence to diarrhoea case management. Therefore, this study measured the determinants of therapeutic and dietary adherence to diarrhoea case management using the third and fourth wave of Pakistan Demographics and Health Surveys (PDHS) datasets. Data from 4068 children between 0 to 59.9 months with positive history of diarrhoea were included, while data on children with dysentery, severe dehydration, and co-morbid condition was excluded. This study reported therapeutic adherence in less than 10% of children in Pakistan, while dietary adherence was reported in 39.2% of children (37.7% in 2012–2013 and 40.7% in 2017–2018). A significant improvement in therapeutic (0.8% in 2012–2013 and 8.1% in 2017–2018) and dietary adherence (37.7% in 2012–2013 and 40.7% in 2017–2018) was reported in the 2017–2018 survey compared to the 2012–2013 survey. In general, children over the age of one year (compared to children <1 year) and of the richer/richest socioeconomic class (compared to poorest/poorer socioeconomic class) showed higher therapeutic and dietary adherence. Therapeutic and dietary adherence among diarrhoeal children can be improved by increasing the awareness and accessibility of ORS, zinc, and essential foods.

Effects of Polybrominated Diphenyl Ethers on Hormonal and Reproductive Health in E-Waste-Exposed Population: A Systematic Review

Electronic waste management is a global rising concern that is primarily being handled by informal recycling practices. These release a mix of potentially hazardous chemicals, which is an important public health concern. These chemicals include polybrominated diphenyl ethers (PBDEs), used as flame retardants in electronic parts, which are persistent in nature and show bioaccumulative characteristics. Although PBDEs are suspected endocrine disruptors, particularly targeting thyroid and reproductive hormone functions, the relationship of PBDEs with these health effects are not well established. We used the Navigation Guide methodology to conduct a systematic review of studies in populations exposed to e-waste to better understand the relationships of these persistent flame retardants with hormonal and reproductive health. We assessed nineteen studies that fit our pre-determined inclusion criteria for risk of bias, indirectness, inconsistency, imprecision, and other criteria that helped rate the overall evidence for its quality and strength of evidence. The studies suggest PBDEs may have an adverse effect on thyroid hormones, reproductive hormones, semen quality, and neonatal health. However, more research is required to establish a relationship of these effects in the e-waste-exposed population. We identified the limitations of the data available and made recommendations for future scientific work.

Association of Pesticides and Kidney Function among Adults in the US Population 2001-2010

Chronic kidney disease of unknown cause is prevalent in a range of communities; however, its etiology remains unclear. We examined the association between pesticide exposures and the risk of kidney function loss using four waves of the National Health and Nutrition Examination Survey (NHANES) to identify a pathological pathway. We pooled data from four cross-sectional waves of NHANES, with 41,847 participants in total. Exposure to malathion increased the risk of low kidney function (aOR = 1.26, 95% CI = 1.01-1.56) in the adjusted model. Increased risk of low kidney function was not found among those exposed to 2,4-D (aOR = 0.88, 95% CI = 0.72-1.09), 3,5,6-trichloropyridinol (aOR = 0.96, 95% CI = 0.83-1.12), and 3-PBA (aOR = 1.03, 95% CI = 0.94-1.13). Our findings provide evidence of altered kidney function in people exposed to malathion, highlighting the potential of organophosphate pesticides' role in renal injury.

228Relationship of pesticide exposure with kidney function in NHANES: lessons from low level chronic exposure

Background

Exposure to pesticides has been linked to many health outcomes. More recently, chronic kidney disease not related to diabetes or hypertension (CKDu) has been postulated to be related to rural occupational exposures in agricultural workers in several Low to Middle Income Country (LMIC) regions such as Mesoamerica and the Subcontinent. Our study wished to examine the relationship between pesticide exposure and kidney function.

Methods

We used the resources of pooled population from NHANES 2001-2004, 2007-2010 (n = 29,053). We examined pesticide exposure (logged, continuous) with kidney function as measured by glomerular filtration rate (derived from urinary creatinine) with and without presence of hypertension and diabetes. Logistic regression was adjusted for a range of cofactors such as age, sex, SES, tobacco, and heavy metals. Cadmium was used as a positive control.

Results

Pesticides 2,4-D, chlorpyrifos, malathion and 3-phenoxybenzoic acid (the major metabolite of deltamethrin) were associated with the increasing risk of kidney dysfunction (not with hypertension or diabetes) after adjusting for a range of known risk factors (OR 1.80 (1.47-2.21); 2.16 (1.57-2.98); 1.20 (0.94-1.54) and 1.40 (1.19-1.64), respectively). Cd was not associated with kidney dysfunction (OR 0.99 (0.81-1.21)), or acephate (OR 0.43 (0.13-1.48)).

Conclusions

Chronic or acute pesticide exposure may increase the risk of kidney dysfunction, which is not related to hypertension or diabetes in particular. It may have a different pathological pathway from heavy metal exposures and CKD. This has repercussions for interventions in LMIC agricultural practices.

Key messages

Pesticides are associated with kidney dysfunction not related to hypertension and diabetes.

Association of Allergic Symptoms in the First 2 Years of Life With Sleep Outcomes Among Chinese Toddlers

Background: Previous studies have linked allergic symptoms to sleep in children, but the associations might be different when considering different types of allergic symptoms or sleep outcomes. Moreover, the combined effects of multiple allergic symptoms remain unclear in early life. This study aimed to investigate the associations between multiple allergic symptoms and sleep outcomes in early life. Methods: We included 673 toddlers aged 2 years from a birth cohort in Guangzhou, China. We identified allergic symptoms (skin, eyes and nose, gastrointestinal tract, mouth and lips, and wheeze) within 2 years via standard questionnaires. Sleep outcomes including sleep duration and quality over the past month were assessed based on the Chinese version of the Brief Infant Sleep Questionnaire. Associations between allergic symptoms and sleep outcomes were examined using multivariable linear regression and logistic regression. Results: Compared to children without allergic symptoms, children with allergic nasal and ocular symptoms had higher odds of frequent nighttime awakenings (OR = 1.41; 95% CI: 1.03, 1.93) and irregular sleep (OR = 1.45, 95% CI: 1.05, 2.00); children with allergic gastrointestinal symptoms slept 0.28 h less during nighttime (95% CI: -0.48, -0.07) and 0.25 h less per day (95% CI: -0.43, -0.08), and had 59% higher odds of irregular sleep (95% CI: 1.24, 2.04). We also found significant association of multiple allergic symptoms with shortened nighttime sleep duration and increased irregular sleep. Whereas, allergic skin, mouth and lips, and wheeze symptoms were not significantly associated with sleep outcomes. Conclusion: Allergic symptoms within 2 years of age were adversely associated with sleep outcomes, which highlight the importance of early screening of allergic symptoms in toddlers in order to improve their sleep outcomes.

Status and interrelationship of toenail elements in Pacific children

OBJECTIVE

Elemental deficiencies or in excess effects growth and development. Pacific population are at a disadvantage due to food insecurity as compared to New Zealand European households. This study aims to evaluate the status and interrelationship of elements (essential, non-essential and toxic) in nine-year-old Pacific children who were part of the Pacific Island Families Study living in New Zealand.

MATERIALS AND METHODS

This observational study included 278 eligible nine-year-old children. Essential elements (including calcium, chromium, cobalt, copper, iodine, iron, magnesium, manganese, selenium, zinc, molybdenum), non-essential and toxic elements (arsenic, aluminum, antimony, boron, cadmium, lead, mercury, nickel,) were determined in toenails and after acid digestion, analysed using inductively coupled plasma mass spectrometry. Principal component analysis and multivariate analysis of covariance was used to identify differences in the groups of elements and the inter-correlations between elements.

RESULTS

The mean calcium (868μg/g Ca), selenium (0.35μg/g Se) and zinc (129μg/g Zn) concentrations were lower while the mean cadmium (0.21μg/g Cd) lead (0.86μg/g Pb) and mercury (0.72μg/g Hg) concentrations were higher than the optimal health requirements. Ethnic differences in relation to toenail elemental concentrations were observed for aluminium and iron. Gender differences were observed for aluminium, antimony, arsenic and lead. Selenium and molybdenum were inversely associated with mercury. Manganese, zinc and calcium were positively associated.

CONCLUSIONS

This research contributes to the understanding of the elemental concentrations for Pacific children by using tissue samples from toenails, which improves the completeness of sampling than other tissues and provides a longer exposure time frame. The study also reports several inter-correlations between essential, non-essential and toxic elements in Pacific Island population.

Domain specific effects of postnatal toenail methylmercury exposure on child behaviour

OBJECTIVE

Very little is known about the relationship between postnatal methylmercury concentrations (via toenails as bioindicator) and behavioural characteristics of Pacific Island children living in New Zealand. The aim of this study was to explore the association between total mercury exposure and different domains of behavioural problems in Pacific children.

MATERIALS AND METHODS

A sample of nine-year-old Pacific Island children resident in Auckland, New Zealand participated in this study. Total mercury was determined in biological samples (toenail clippings) on behavioural problems as identified by mothers (using the child behaviour checklist). Specific behavioural domains, particularly aggression, rule breaking, attention and social problems were studied in relation to mercury exposure using toenails. The determination of mercury concentration in toenail clippings, after acid digestion was carried out using inductively coupled plasma mass spectrometry.

RESULTS

The observational study was conducted between July 2010 and July 2011 in which 278 eligible nine-year-old Pacific Island children were enrolled (Girls n=58%; boys n=42%).

FINDINGS

showed that 21% of the children had total toenail mercury concentrations (1.5μg/g to 6μg/g) higher than the United State Environmental Protection Agency recommended levels (RfD; 1μg/g Hg) for optimal health in children. Aggressive behaviour was associated with total toenail mercury exposure after adjusting for gender, ethnicity and income levels (OR: 2.15 95% CI 1.45, 3.18 p-value <0.05; OR 1.38 95% CI 0.83, 1.2 p value <0.05, respectively).

CONCLUSIONS

Overall, this research contributes to the understanding of total toenail mercury concentrations for Pacific people in New Zealand using toenail clippings as biomarkers in terms of associations with child behavioural problems. Mercury in toenails demonstrated a moderate association with a specific behavioural domain - aggressive behaviour.

Overcoming the barriers experienced in conducting a medication trial in adults with aggressive challenging behaviour and intellectual disabilities

BACKGROUND

Aggressive challenging behaviour in people with intellectual disability (ID) is frequently treated with antipsychotic drugs, despite a limited evidence base.

METHOD

A multi-centre randomised controlled trial was undertaken to investigate the efficacy, adverse effects and costs of two commonly prescribed antipsychotic drugs (risperidone and haloperidol) and placebo.

RESULTS

The trial faced significant problems in recruitment. The intent was to recruit 120 patients over 2 years in three centres and to use a validated aggression scale (Modified Overt Aggression Scale) score as the primary outcome. Despite doubling the period of recruitment, only 86 patients were ultimately recruited.

CONCLUSIONS

Variation in beliefs over the efficacy of drug treatment, difficulties within multidisciplinary teams and perceived ethical concerns over medication trials in this population all contributed to poor recruitment. Where appropriate to the research question cluster randomised trials represent an ethically and logistically feasible alternative to individually randomised trials.

Neuroleptics in the treatment of aggressive challenging behaviour for people with intellectual disabilities: a randomised controlled trial (NACHBID)

OBJECTIVE(S)

To assess the effects and cost-effectiveness of haloperidol, risperidone and placebo on aggressive challenging behaviour in adults with intellectual disability.

DESIGN

A double-blind randomised controlled trial of two drugs and placebo administered in flexible dosage, with full, independent assessments of aggressive and aberrant behaviour, global improvement, carer burden, quality of life and adverse drug effects at baseline, 4, 12 and 26 weeks, and comparison of total care costs in the 6 months before and after randomisation. At 12 weeks, patients were given the option of leaving the trial or continuing until 26 weeks. Assessments of observed aggression were also carried out with key workers at weekly intervals throughout the trial.

SETTING

Patients were recruited from all those being treated by intellectual disability services in eight sites in England, one in Wales and one in Queensland, Australia.

PARTICIPANTS

Patients from all severity levels of intellectual disability; recruitment was extended to include those who may have been treated with neuroleptic drugs in the past.

EXCLUSION CRITERIA

treatment with depot neuroleptics/another form of injected neuroleptic medication within the last 3 months; continuous oral neuroleptic medication within the last week; those under a section of the Mental Health Act 1983 or Queensland Mental Health Act 2000.

INTERVENTIONS

Randomisation to treatment with haloperidol (a typical neuroleptic drug), risperidone (an atypical neuroleptic drug) or placebo using a permuted blocks procedure. Dosages were: haloperidol 1.25-5.0 mg daily; risperidone 0.5-2.0 mg daily.

MAIN OUTCOME MEASURES

Primary: reduction in aggressive episodes between baseline and 4 weeks using Modified Overt Aggression Scale. Secondary: Aberrant Behaviour Checklist; Uplift/Burden Scale; 40-item Quality of Life Questionnaire; Udvalg for Kliniske Undersøgelser scale; Clinical Global Impressions scale. Economic costs recorded using a modified version of Client Service Receipt Inventory for 6 months before and after randomisation.

RESULTS

There were considerable difficulties in recruitment because of ethical and consent doubts. Twenty-two clinicians recruited a total of 86 patients. Mean daily dosages were 1.07 mg rising to 1.78 mg for risperidone and 2.54 mg rising to 2.94 mg for haloperidol. Aggression declined dramatically with all three treatments by 4 weeks, with placebo showing the greatest reduction (79%, versus 57% for combined drugs) (p = 0.06). Placebo-treated patients showed no evidence of inferior response in comparison to patients receiving neuroleptic drugs. An additional study found that clinicians who had not participated in clinical trials before were less likely to recruit. Mean total cost of accommodation, services, informal care and treatment over the 6 months of the trial was 16,336 pounds for placebo, 17,626 pounds for haloperidol and 18,954 pounds for risperidone.

CONCLUSIONS

There were no significant important benefits conferred by treatment with risperidone or haloperidol, and treatment with these drugs was not cost-effective. While neuroleptic drugs may be of value in the treatment of aggressive behaviour in some patients with intellectual disability, the underlying pathology needs to be evaluated before these are given. The specific diagnostic indications for such treatment require further investigation. Prescription of low doses of neuroleptic drugs in intellectual disability on the grounds of greater responsiveness and greater liability to adverse effects also needs to be re-examined.

Risperidone, haloperidol, and placebo in the treatment of aggressive challenging behaviour in patients with intellectual disability: a randomised controlled trial

BACKGROUND

Aggressive challenging behaviour is frequently reported in adults with intellectual disability and it is often treated with antipsychotic drugs. However, no adequate evidence base for this practice exists. We compared flexible doses of haloperidol (a typical, first-generation antipsychotic drug), risperidone (an atypical, second-generation antipsychotic), and placebo, in the treatment of this behaviour.

METHODS

86 non-psychotic patients presenting with aggressive challenging behaviour from ten centres in England and Wales, and one in Queensland, Australia, were randomly assigned to haloperidol (n=28), risperidone (n=29), or placebo (n=29). Clinical assessments of aggression, aberrant behaviour, quality of life, adverse drug effects, and carer uplift (positive feelings about the care of the disabled person) and burden, together with total costs, were recorded at 4, 12, and 26 weeks. The primary outcome was change in aggression after 4 weeks' treatment, which was recorded with the modified overt aggression scale (MOAS). Analysis was by intention to treat. This study is registered as ISRCTN 11736448.

FINDINGS

80 patients had adherence of 80% or more to prescribed drug. Aggression decreased substantially with all three treatments by 4 weeks, with the placebo group showing the greatest change (median decrease in MOAS score after 4 weeks=9 [95% CI 5-14] for placebo, 79% from baseline; 7 [4-14] for risperidone, 58% from baseline; 6.5 [5-14] for haloperidol, 65% from baseline; p=0.06). Furthermore, although no important differences between the treatments were recorded, including adverse effects, patients given placebo showed no evidence at any time points of worse response than did patients assigned to either of the antipsychotic drugs.

INTERPRETATION

Antipsychotic drugs should no longer be regarded as an acceptable routine treatment for aggressive challenging behaviour in people with intellectual disability.

Repeatability of self-reported information for population-based studies of cancer

PURPOSE

To measure the repeatability of a cancer risk factor questionnaire in a population-based case-control study.

METHODS

Questionnaires were completed on two occasions by patients with cancer of the ovary (n=25) or esophagus (n=23) and by 37 controls without cancer. We assessed general cancer risk factors including height and weight (for calculating body mass index (BMI)), smoking and anti-inflammatory (NSAID) use. Risk factors specific for ovarian and esophageal cancers were also assessed. Agreement was measured by the correlation coefficient and weighted kappa statistic (kw) for continuous and categorical variables respectively.

RESULTS

We observed very high levels of agreement for BMI (kw=0.84) and smoking history, including ages at initiation and quitting (Pearson correlation = 0.87 and 0.86 respectively). There was moderate to substantial agreement for use of anti-inflammatory drugs (aspirin kw =0.52, other NSAIDS kw =0.72). Agreement for lifetime prevalence of medical conditions varied from almost perfect (e.g. history of benign breast disease (k =0.86)) to moderate (e.g. heartburn (k =0.57)). Item repeatability was not materially altered by case-control status, age or sex of respondents or interval between completions.

CONCLUSIONS

Self-reported cancer risk factor information demonstrates moderate to almost perfect levels of agreement, suggesting these items are suitable for risk estimation and epidemiologic inference.