The Context Dependency of the Self-Report Version of the Strength and Difficulties Questionnaire (SDQ): A Cross-Sectional Study between Two Administration Settings

Background

The Strength and Difficulties Questionnaire (SDQ) is a screening instrument for psychosocial problems in children and adolescents, which is applied in “individual” and “collective” settings. Assessment in the individual setting is confidential for clinical applications, such as preventive child healthcare, while assessment in the collective setting is anonymous and applied in (epidemiological) research. Due to administration differences between the settings it remains unclear whether results and conclusions actually can be used interchangeably. This study therefore aims to investigate whether the SDQ is invariant across settings.

Methods

Two independent samples were retrieved (mean age = 14.07 years), one from an individual setting (N = 6,594) and one from a collective setting (N = 4,613). The SDQ was administered in the second year of secondary school in both settings. Samples come from the same socio-geographic population in the Netherlands.

Results

Confirmatory factor analysis showed that the SDQ was measurement invariant/equivalent across settings and gender. On average, children in the individual setting scored lower on total difficulties (mean difference = 2.05) and the psychosocial problems subscales compared to those in the collective setting. This was also reflected in the cut-off points for caseness, defined by the 90th percentiles, which were lower in the individual setting. Using cut-off points from the collective in the individual setting therefore resulted in a small number of cases, 2 to 3%, while ∼10% is expected.

Conclusion

The SDQ has the same connotation across the individual and collective setting. The observed structural differences regarding the mean scores, however, undermine the validity of the cross-use of absolute SDQ-scores between these settings. Applying cut-off scores from the collective setting in the individual setting could, therefore, result in invalid conclusions and potential misuse of the instrument. To correctly apply cut-off scores these should be retrieved from the applied setting.     

Psychometric properties and construct validity of the Weight-Related Eating Questionnaire in a diverse population

This study evaluates the 16‐item, four‐factor Weight‐Related Eating Questionnaire (WREQ), which assesses theory‐based aspects of eating behavior, across diverse, nonclinical subgroups. A total of 621 men and women aged 18–81 years (34.3 ± 16.4) with a mean BMI of 25.7 ± 6.1 kg/m² (range 15.5–74.1 kg/m²) were recruited from general education classes at the University of Hawai'i, Manoa and an online survey panel of Hawai'i residents to complete a web‐based survey. Participants were predominantly white (23%), Asian/Asian‐mix (42%), or Native Hawaiian/Pacific Islander (18%). The WREQ's factor structure was successfully replicated by confirmatory factor analysis (CFA) for the entire sample and by weight status, gender, age, and race with strong internal consistency. Four‐week test‐retest reliability (n = 31) for the subscales was excellent with interclass correlations of 0.849–0.932. Tests of population invariance confirmed the generalizability of the WREQ across all subgroups having provided no evidence that the factor structure, factor loadings, or indicator intercepts varied significantly between the groups. Multivariate regression analyses showed that emotional eating was independently associated with BMI (β = 0.272, P < 0.001) as well as moderate‐ and long‐term weight change rates (weight gain) in young adults (β = 0.152, P = 0.042) and adults (β = 0.217, P = 0.001). Compensatory restraint was negatively associated with weight gain in adults (β = ?0.133, P = 0.039). Routine restraint and emotional eating were highest among dieters. All associations remained significant after accounting for gender, age, and race. The hypothesized WREQ measurement model demonstrated very good construct validity, confirming the unbiased generalizability of the WREQ measure across sex, age, race, and BMI subgroups, and excellent criterion‐related validity with respect to current BMI, weight change, and weight control status.     

The reduced Morningness–Eveningness Questionnaire: Psychometric properties and related factors in a young Swedish population

During puberty, there is a delay in sleep patterns and the circadian clock, and the prevalence of sleep difficulties is high among young adults. Thus, it is important to be able to measure chronotype (CT) in this group, both in the clinic and for broader epidemiological studies, to better understand the sleep difficulties observed. The reduced version of one of the most widely used questionnaire to measure CT, the Horne & Östberg Morningness–Eveningness Questionnaire (MEQ), has been developed and validated in many languages. The aim of the present study was to investigate the reliability and validity of the Swedish reduced MEQ (rMEQ) and to investigate factors correlated with rMEQ scores in a random sample of young Swedish participants. We sent the rMEQ, sleep questions, demographic questions, the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale, and the Hospital Anxiety and Depression Scale (HADS-A and HADS-D) to 1000 randomly selected individuals aged 16–26 years in Uppsala, Sweden (response rate = 68%). A parallel analysis of the rMEQ revealed a single factor solution. Inter-item correlations within the questionnaire were between 0.08 and 0.46. One of the rMEQ items displayed weak correlations with the other questions. Cronbach’s alpha of the rMEQ was 0.68. Low rMEQ scores (eveningness) were correlated with more frequent late bedtimes and difficulties getting up in the morning. Lower rMEQ scores were significantly related to male sex, no educational activity or work, nicotine use, younger age, and higher ISI and HADS-D scores. Even though the inter-item correlations of the rMEQ were very low to moderate, the rMEQ had a Cronbach’s alpha not far off from acceptable levels, and the strong correlations of the rMEQ scores with responses to the sleep questions indicated that the rMEQ had an adequate validity. To conclude, the rMEQ can be used to effectively estimate CT when a short questionnaire is required; however, caution should be taken when interpreting the results considering the reliability of the questionnaire.     

Between nurture and nature: the shifting determinants of female fertility in Danish twin cohorts

Behaviors related to fertility constitute primary candidates for investigating the relevance of evolutionary influences and biological dispositions on contemporary human behaviors. Using female Danish twin cohorts born 1870-1968, we document important transformations in the relative contributions of "nurture" and "nature" to within-cohort variations in early and complete fertility, and we point toward a systematic relation between the socioeconomic context of cohorts and the relevance of genetic and shared environmental factors. This transformation is most striking for early fertility where genetic factors strengthen over time and are consistent with up to 50 percent of the variation in early fertility in most recent cohorts. Understanding this emerging relevance of genetic factors is of central importance because early fertility constitutes an important determinant of complete fertility levels in low-fertility societies, and because teenage motherhood and early childbearing are often associated with negative life-cycle consequences. Moreover, our results emphasize the need for socially and contextually informed analyses of nature and nurture that allow both factors to influence human reproductive behavior over time.     

Screening Foster Children for Mental Disorders: Properties of the Strengths and Difficulties Questionnaire

Background

High prevalence of mental disorders among foster children highlight the need to examine the mental health of children placed out of home. We examined the properties of the Strengths and Difficulties Questionnaire (SDQ) in screening school-aged foster children for mental disorders.

Methods

Foster parents and teachers of 279 foster children completed the SDQ and the diagnostic interview Developmental and Well-Being Assessment (DAWBA). Using the diagnoses derived from the DAWBA as the standard, we examined the performance of the SDQ scales as dimensional measures of mental health problems using receiver operating characteristic (ROC) analyses. Recommended cut-off scores were derived from ROC coordinates. The SDQ predictive algorithms were also examined.

Results

ROC analyses supported the screening properties of the SDQ Total difficulties and Impact scores (AUC = 0.80–0.83). Logistic regression analyses showed that the prevalence of mental disorders increased linearly with higher SDQ Total difficulties scores (X² = 121.47, df = 13, p<.001) and Impact scores (X² = 69.93, df = 6, p<.001). Our results indicated that there is an additive value of combining the scores from the Total difficulties and Impact scales, where scores above cut-off on any of the two scales predicted disorders with high sensitivity (89.1%), but moderate specificity (62.1%). Scores above cut-off on both scales yielded somewhat lower sensitivity (73.4%), but higher specificity (81.1%). The SDQ multi-informant algorithm showed low discriminative ability for the main diagnostic categories, with an exception being the SDQ Conduct subscale, which accurately predicted the absence of behavioural disorders (LHR− = 0.00).

Conclusions

The results support the use of the SDQ Total difficulties and Impact scales when screening foster children for mental health problems. Cut-off values for both scales are suggested. The SDQ multi-informant algorithms are not recommended for mental health screening of foster children in Norway.     

Telomeres and telomerase: more than the end of the line

Early studies of telomerase suggested that telomeres are maintained by an elegant but relatively simple and highly conserved mechanism of telomerase-mediated replication. As we learn more, it has become clear that the mechanism is elegant but not as simple as first thought. It is also evident that, although many species use similar, sometimes identical, DNA sequences for telomeres, these species express their own individuality in the way they regulate these sequences and, perhaps, in the additional tasks that they have imposed on their telomeric DNA. The striking similarities between telomeres in different species have revealed much about chromosome ends; the differences are proving to be equally informative. In addition to the differences between species that use telomerase, there are also a few exceptional organisms with atypical telomeres for which no telomerase activity has been detected. This review addresses recent studies, the insights they offer, and, perhaps more importantly, the questions they raise. Received: 14 January 1999 / Accepted: 15 January 1999     

Recombination and loss of complementation: a more than two-fold cost for parthenogenesis

Certain types of asexual reproduction lead to loss of complementation, that is unmasking of recessive deleterious alleles. A theoretical measure of this loss is calculated for apomixis, automixis and endomitosis in the cases of diploidy and polyploidy. The effect of the consequent unmasking of deleterious recessive mutations on fitness is also calculated. Results show that, depending on the number of lethal equivalents and on the frequency of recombination, the cost produced by loss of complementation after few generations of asexual reproduction may be greater than the two-fold cost of meiosis. Maintaining complementation may, therefore, provide a general short-term advantage for sexual reproduction. Apomixis can replace sexual reproduction under a wide range of parameters only if it is associated with triploidy or tetraploidy, which is consistent with our knowledge of the distribution of apomixis.     

Evidence for more than one pathway in the formation of purine deoxyribonucleotides

The biosynthesis of purine deoxyribonucleotides was studied in the context of general purine nucleotide metabolism in the chick with the aid of radioactive nucleic acid precursors. Our results showed that in chick liver and intestine, the nucleoside phosphate reductase system so firmly established in E. coli [1] and L. leichmanni [2] is not exclusively responsible for the biosynthesis of purine deoxyribonucleotides.     

Macrophages in the embryo and beyond: much more than just giant phagocytes

Originally recognized as an essential part of the innate and acquired immune systems, macrophages emerged as omnipresent and influential regulators of embryo- and organo-genesis, as well as of tissue and tumor growth. Macrophages are present essentially in all tissues, beginning with embryonic development and, in addition to their role in host defense and in the clearance of apoptotic cells, are being increasingly recognized for their trophic function and role in regeneration. Some tissue macrophages are also found to possess a substantial potential for autonomous self-renewal. Macrophages are associated with a significant proportion of malignant tumors and are widely recognized for their angiogenesis-promoting and trophic roles, making them one of the new promising targets for cancer therapies. Recent expression profiling of embryonic macrophages from different tissues revealed remarkable consistency of their gene expression profiles, independent of their tissue of origin, as well as their similarities with tumor-associated macrophages. Macrophages are also capable of fusion with other cells in tissue repair and metastasizing tumors, as well as with each other in the immune response and osteoclastogenesis.     

Unique properties of polyphenol stilbenes in the brain: more than direct antioxidant actions; gene/protein regulatory activity

The 'French Paradox' has been typically associated with moderate consumption of wine, especially red wine. A polyphenol 3,4',5-trihydroxy-trans-stilbene (a member of the non-flavonoids family), better known as resveratrol, has been purported to have many health benefits. A number of these valuable properties have been attributed to its intrinsic antioxidant capabilities, although the potential level of resveratrol in the circulation is likely not enough to neutralize free radical scavenging. The brain and the heart are uniquely vulnerable to hypoxic conditions and oxidative stress injuries. Recently, evidence suggests that resveratrol could act as a signaling molecule within tissues and cells to modulate the expression of genes and proteins. Stimulation of such proteins and enzymes could explain some the intracellular antioxidative properties. The modulation of genes could suffice as an explanation of some of resveratrol's cytoprotective actions, as well as its influence on blood flow, cell death, and inflammatory cascades. Resveratrol stimulation of the expression of heme oxygenase is one example. Increased heme oxygenase activity has led to significant protection against models of in vitro and in vivo oxidative stress injury. Resveratrol could provide cellular resistance against insults; although more work is necessary before it is prescribed as a potential prophylactic in models of either acute or chronic conditions, such as stroke, amyotrophic lateral sclerosis, Parkinson, Alzheimer, and a variety of age-related vascular disorders.     

Seeing more than meets the eye: processing of illusory contours in animals

This review article illustrates that mammals, birds and insects are able to perceive illusory contours. Illusory contours lack a physical counterpart, but monkeys, cats, owls and bees perceive them as if they were real borders. In all of these species, a neural correlate for such perceptual completion phenomena has been described. The robustness of neuronal responses and the abundance of cells argue that such neurons might indeed represent a neural correlate for illusory contour perception. The internal state of an animal subject (i.e., alert and behaving) seems to be an important factor when correlating neural activity with perceptual phenomena. The fact that the neural network necessary for illusory contour perception has been found in relatively early visual brain areas in all tested animals suggests that bottom-up processing is largely sufficient to explain such perceptual abilities. However, recent findings in monkeys indicate that feedback loops within the visual system may provide additional modulation. The detection of illusory contours by independently evolved visual systems argues that processing of edges in the absence of contrast gradients reflects fundamental visual constraints and not just an artifact of visual processing.     

Roaming Companion Cats as Potential Causes of Conflict and Controversy: A Representative Questionnaire Study of the Danish Public

Cats have grown in popularity as companion animals, but there are also people who strongly dislike them. Companion cats allowed to roam freely outdoors are seen by some as a nuisance. This paper, drawing on research conducted in Denmark, aims to quantify potentially conflicting attitudes to cats among the public that may feed into cat-related conflicts and controversies. Questionnaire data were collected from a representative sample of the Danish population (n = 2,003), where 21% (n = 415) owned cats and 79% (n = 1,588) did not. In all, 65% of respondents confirmed that they liked cats, 21% reported that they did not, and 14% were undecided. The main reasons for disliking cats concerned “behavior,” not hazards such as the spread of diseases and predation. Of the 21% of the surveyed Danes who reported that they currently had a cat in the household, 72% allowed their cat to roam outdoors. Sixty percent of the respondents did not perceive this as a problem. However, the potential for conflict was demonstrated by the fact that 27% of respondents regarded outdoor roaming as problematic. Of these, about a quarter saw free-roaming cats as a big problem and as a cause of strife between neighbors. Comparatively fewer of those who owned cats saw their animals as a cause of problems. Thus, only 12% of those owning outdoor cats thought that problems were caused when their cats defecated in a neighbor’s garden, which compares with the 17% of the total population who are bothered by other people’s cats defecating in their gardens. Our data show that while the majority of Danes believe cats should be allowed to roam in public spaces, a significant minority strongly dislikes cats and would prefer restrictions on roaming.     

De novo lipogenesis in the liver in health and disease: more than just a shunting yard for glucose

Hepatic de novo lipogenesis (DNL) is the biochemical process of synthesising fatty acids from acetyl‐CoA subunits that are produced from a number of different pathways within the cell, most commonly carbohydrate catabolism. In addition to glucose which most commonly supplies carbon units for DNL, fructose is also a profoundly lipogenic substrate that can drive DNL, important when considering the increasing use of fructose in corn syrup as a sweetener. In the context of disease, DNL is thought to contribute to the pathogenesis of non‐alcoholic fatty liver disease, a common condition often associated with the metabolic syndrome and consequent insulin resistance. Whether DNL plays a significant role in the pathogenesis of insulin resistance is yet to be fully elucidated, but it may be that the prevalent products of this synthetic process induce some aspect of hepatic insulin resistance.     

Psychometric Properties of the Eating Disorder Examination Questionnaire (EDE-Q) and Norms for Rural and Urban Adolescent Males and Females in Mexico

Aims

To contribute new evidence to the controversy about the factor structure of the Eating Disorder Examination Questionnaire (EDE-Q) and to provide, for the first time, norms based on a large adolescent Mexican community sample, regarding sex and area of residence (urban/rural).

Methods

A total of 2928 schoolchildren (1544 females and 1384 males) aged 11-18 were assessed with the EDE-Q and other disordered eating questionnaire measures.

Results

Confirmatory factor analysis of the attitudinal items of the EDE-Q did not support the four theorized subscales, and a two-factor solution, Restraint and Eating-Shape-Weight concern, showed better fit than the other models examined (RMSEA = .054); measurement invariance for this two-factor model across sex and area of residence was found. Satisfactory internal consistency (ω ≥ .80) and two-week test-retest reliability (ICCa ≥ .84; κ ≥ .56), and evidence for convergent validity with external measures was obtained. The highest attitudinal EDE-Q scores were found for urban females and the lowest scores were found for rural males, whereas the occurrence of key eating disorder behavioural features and compensatory behaviours was similar in both areas of residence.

Conclusions

This study reveals satisfactory psychometric properties and provides population norms of the EDE-Q, which may help clinicians and researchers to interpret the EDE-Q scores of adolescents from urban and rural areas in Mexico.     

Defining protein expression in the urothelium: a problem of more than transitional interest

The transitional epithelium of the bladder, the urothelium, is a challenging tissue to study due to its fragility, complex cellular makeup, stratified composition, and intimate connections to both neural and connective tissue elements. With the increasing focus on the urothelium as a mechanosensory tissue with complex autocrine and paracrine signaling activities, there have arisen a number of unresolved controversies in the urothelial literature regarding whether certain important sensory and signaling proteins are expressed by the urothelium. Prominent examples of this include the transient receptor potential (TRP) family member TRPV1 and the purinergic receptor P2X(3). The problem is more than one of scientific bookkeeping since studies utilizing genetic models (primarily knockout mice) claim additional credibility for urothelial functions when phenotypes are discovered. Furthermore, both of the above-mentioned receptors are important therapeutic targets for various bladder disorders including inflammatory and neuropathic pain. The reasons for the confusion about urothelial expression are manifold, but they likely include low expression levels in some cases, poor specificity of antibodies (sometimes lacking adequate controls), the presence of nonurothelial cells resident within the urothelium, and the fact that the urothelium is particularly prone to aspecific adsorption of antibodies. In this review, we attempt to summarize some of the pitfalls with currently accepted practices in this regard, as well as to describe a set of guidelines which will improve the reliability of conclusions related to urothelial expression. It is hoped that this will be of value to investigators studying the urothelium, to those attempting to interpret conflicts in the literature, and hopefully also those charged with reviewing unpublished work. These recommendations will outline a set of "baseline" and "best practice" guidelines by which both researchers and reviewers will be able to evaluate the evidence presented.     

Organic matter concentrations and textural properties of muds from different depths in four fish ponds

Percentages of small particles and organic matter in pond muds increased along transects from shallow to deep water in four fish ponds which had never been drained. Gradients in texture and organic matter were similar to those reported for nearby ponds which had been drained periodically.Research supported by Hatch Project Alabama No. 398.     

On the structure and function of apolipoproteins: more than a family of lipid-binding proteins

Exchangeable apolipoproteins have been the subject of intense biomedical investigation for decades. However, only in recent years the elucidation of the three-dimensional structure reported for several members of the apolipoprotein family has provided insights into their functions at a molecular level for the first time. Moreover, the role of exchangeable apolipoproteins in several cellular events distinct from lipid metabolism has recently been described. This review summarizes these contributions, which have not only allowed the identification of the apolipoprotein domains that determine substrate binding specificity and/or affinity but also the plausible molecular mechanism(s) involved.