Previous Cross-sectional Analyses Research Articles

Antecedent predictors of children's initiation of sipping/tasting alcohol.

BackgroundSipping or tasting alcohol is one of the earliest alcohol-use behaviors in which young children engage, yet there is relatively little research on this behavior. Previous cross-sectional analyses determined that child sipping or tasting is associated with the child's attitude toward sipping and with a family environment supportive of alcohol use, but not with variables reflecting psychosocial proneness for problem behavior as formulated in Problem Behavior Theory (Jessor and Jessor, Problem Behavior and Psychosocial Development: A Longitudinal Study of Youth, 1977, Academic Press, New York). This study extended these analyses longitudinally to identify antecedent predictors of the childhood initiation of sipping or tasting alcohol in a multiwave study.MethodsA sample of 452 children (238 girls) aged 8 or 10 and their families was drawn from Allegheny County, PA, using targeted-age directory sampling and random digit dialing procedures. Children were interviewed using computer-assisted interviews. Antecedent variables collected at baseline (Wave 1) were examined as predictors of the initiation of sipping/tasting alcohol in childhood (before age 12) among Wave 1 abstainers (n = 286).ResultsNinety-four children initiated sipping/tasting alcohol in a nonreligious context between baseline and turning age 12. Initiation of sipping/tasting did not generally relate to baseline variables reflecting psychosocial proneness for problem behavior. Instead, as found in the previous cross-sectional analyses, the variables most predictive of initiating sipping/tasting were perceived parents' approval for child sipping, parents' reported approval for child sipping, parents' current drinking status, and children's attitudes toward sipping/tasting alcohol.ConclusionsThese longitudinal analyses replicate the earlier cross-sectional results. Young children's sipping/tasting of alcohol reflects parental modeling of drinking and parental approval of child sipping and does not represent a precocious manifestation of a psychosocial proneness to engage in problem behavior.

CD8 T-cell reactivity to islet antigens is unique to type 1 while CD4 T-cell reactivity exists in both type 1 and type 2 diabetes

Previous cross-sectional analyses demonstrated that CD8+ and CD4+ T-cell reactivity to islet-specific antigens was more prevalent in T1D subjects than in healthy donors (HD). Here, we examined T1D-associated epitope-specific CD4+ T-cell cytokine production and autoreactive CD8+ T-cell frequency on a monthly basis for one year in 10 HD, 33 subjects with T1D, and 15 subjects with T2D. Autoreactive CD4+ T-cells from both T1D and T2D subjects produced more IFN-γ when stimulated than cells from HD. In contrast, higher frequencies of islet antigen-specific CD8+ T-cells were detected only in T1D. These observations support the hypothesis that general beta-cell stress drives autoreactive CD4+ T-cell activity while islet over-expression of MHC class I commonly seen in T1D mediates amplification of CD8+ T-cells and more rapid beta-cell loss. In conclusion, CD4+ T-cell autoreactivity appears to be present in both T1D and T2D while autoreactive CD8+ T-cells are unique to T1D. Thus, autoreactive CD8+ cells may serve as a more T1D-specific biomarker.

Two-year stability of the late positive potential across middle childhood and adolescence

The late positive potential (LPP) may be a useful measure of individual differences in emotional processing across development, but little is known about the stability of the LPP across time. We assessed the LPP and behavioral measures of emotional interference following pleasant, unpleasant, and neutral images in 8- to 13-year-old youth. Approximately two years later, the same participants completed the task again (N=34). Results indicated that the LPP is moderately-to-highly reliable across development. Stability was lower and more inconsistent for behavioral measures. In addition, consistent with previous cross-sectional analyses, a decrease in occipital activity was observed at the second assessment. Results indicate that the LPP appears to be a stable measure of emotional processing, even across a fairly large period of development.

Using group-based latent class transition models to analyze chronic disability data from the National Long-Term Care Survey 1984-2004.

Latent class transition models track how individuals move among latent classes through time, traditionally assuming a complete set of observations for each individual. In this paper, we develop group-based latent class transition models that allow for staggered entry and exit, common in surveys with rolling enrollment designs. Such models are conceptually similar to, but structurally distinct from, pattern mixture models of the missing data literature. We employ group-based latent class transition modeling to conduct an in-depth data analysis of recent trends in chronic disability among the U.S. elderly population. Using activities of daily living data from the National Long-Term Care Survey (NLTCS), 1982-2004, we estimate model parameters using the expectation-maximization algorithm, implemented in SAS PROC IML. Our findings indicate that declines in chronic disability prevalence, observed in the 1980s and 1990s, did not continue in the early 2000s as previous NLTCS cross-sectional analyses have indicated.

Can LDL-cholesterol targets be achieved in a population at high risk? Results of the non-interventional study ACT II

:Objective:Lowering low-density lipoprotein cholesterol (LDL-C) levels can reduce vascular clinical endpoints in outcome studies. Despite this evidence, previous cross-sectional analyses reported a mean LDL-C target attainment of <50%. This non-interventional, longitudinal study aimed to asses the rate of target attainment by intensified LDL-C lowering therapy in a high-risk population under routine medical care.Design:This was an open-label, non-interventional, observational, non-comparative longitudinal study.Methods:A total of 1682 outpatients at high cardiovascular risk, not at LDL-C target despite statin therapy, were documented. Treating physicians administered an intensified therapy at their discretion. In all, 794 patients completed all the examinations at baseline after 3 and 12 months. The achieved LDL-C reductions was evaluated based on expert consensus reflecting the 2007 guidelines issued by the European Society of Cardiology (ESC) on cardiovascular disease prevention.Registration:www.clinicaltrials.gov, identification number NCT 01381679Results:In the study, 40.3% achieved the individual LDL-C target of <1.8 mmol/L (70 mg/dl) or <2.5 mmol/L (100 mg/dl); 73% received a simvastatin/ezetimibe fixed-dose combination; 3% received add-on ezetimibe and 23% statin therapy at maintained or increased doses; 1% received no drug treatment at all. LDL-C declined after 12 months by −31.0% (ratio 0.69, 95% CI 0.67–0.71, p < 0.001), triglycerides by −11.8% (ratio 0.88, 95% CI 0.85–0.91, p < 0.01) and high-density lipoprotein cholesterol (HDL-C) increased by 11.9% (ratio 1.12, 95% CI 1.10–1.14, p < 0.01).Conclusion:Intensified therapy was effective, but target attainment was still low at 40.3% or 13.9% with regard to the new 2011 guidelines issued by the European Atherosclerosis Society (EAS) and the ESC on dyslipidemias. Enhanced screening of LDL-C levels and the use of statins at highest tolerated dose and concomitant combination therapy is recommended in order to achieve LDL-C targets outlined by current guidelines. Limitations include the design as a non-interventional study. However, this study reflects real life conditions.

Dairy Products and the Metabolic Syndrome in a Prospective Study, DESIR

Objective: In previous cross-sectional analyses of the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort, we have found inverse associations between dairy product consumption and metabolic syndrome (MetS) traits. We have now analyzed in a prospective way the influence of dairy product and calcium consumption at inclusion on the 9-year cumulative incidence of the MetS and associated traits in the French prospective study with a 9-year follow-up, DESIR.Methods: After exclusion of diabetic subjects and those being on a diet at inclusion, 3417 men and women who completed a food frequency at baseline could be studied. Logistic regression models were used to study associations between dairy products and dietary calcium density at baseline and incident MetS and impaired fasting glycemia/type 2 diabetes (IFG/T2D) after adjusting for gender, age, and lifestyle parameters (alcohol, smoking, physical activity, fat intake). An additional model adjusting for the same covariates and for body mass index (BMI) was also used. Associations between dairy products and continuous variables were studied by repeated measures analysis of covariance, using the same covariates.Results: Total dairy product consumption, dairy (except cheese) consumption, and dietary calcium density were inversely associated with incident MetS and IFG/T2D. Cheese consumption was negatively associated with incident MetS but not with glycemic disorders. All parameters were associated with lower diastolic blood pressure and triglycerides (average over the 9-year period) and with a lower BMI gain in the same period. Higher total dairy and cheese intake and calcium density were associated with a lower increase in waist circumference and triglycerides during the 9-year follow-up.Conclusion: In the French general population, these results show beneficial effects of dairy product consumption on the metabolic syndrome and glycemic disorders. Therefore, dairy product consumption could be protective against cardiovascular risk.

Nonresponse in repeat population-based voluntary counseling and testing for HIV in rural Malawi

Despite the increasing number of population-based surveys in sub-Saharan Africa that provide testing and counselingfor HIV over the past decade, understanding the nature ofnonresponse in these surveys, especially panel HIV surveys, is still limited. This article uses longitudinal HIV data collected from rural Malawi in 2004 and 2006 to examine nonresponse in repeat population-based testing. It shows that nonresponse in repeat testing led to significant bias in the estimates of HIV prevalence and to inconsistent conclusions about the predictors of HIV status. In contrast, previous cross-sectional analyses found that nonresponse does not significantly bias the estimates of HIV prevalence. The difference in conclusions from cross-sectional and longitudinal analyses of nonresponse can be attributed to two factors. the different definitions of what constitutes nonresponse in both contexts, and the risk profiles of the missed populations. In particular, although refusal and temporary absence are the major sources ofnonresponse in the cross-sectional contexts, attrition attributable to mortality and out-migration are additional sources of nonresponse in repeat testing. Evidence shows that out-migrants have higher HIV prevalence than nonmigrants, which could account for significant bias in the estimates ofprevalence among participants in both tests observed in this study.

High Pesticide Exposure Events Among Farmers and Spouses Enrolled in the Agricultural Health Study

We completed a nested case-control analysis of factors associated with reporting a high pesticide exposure event (HPEE) by pesticide applicators and spouses during the five years since enrollment in the Agricultural Health Study (AHS). Cases and controls were identified from the 16,415 private pesticide applicators and 14,045 spouses with completed five-year follow-up interviews as of October 2000. Among the applicators, 306 cases with at least one HPEE in the five years since enrollment and 612 controls, randomly selected from those without a reported HPEE, were identified for analysis. Among the spouses, 63 cases were identified and 126 controls were selected. Risk for a new HPEE was increased among applicators reporting at enrollment ever having an HPEE with an odds ratio (OR) of 3.8 (95% CI: 2.7, 5.3). Compared to applicators who applied pesticides fewer than 5 days per year, the ORs ranged from 1.4 (95% CI: 0.9, 2.2) for 6 to 10 days per year to 2.2 (95% CI: 1.4, 3.6) for more than 20 application days per year. The incidence of HPEE among Iowa applicators was much greater (8.8/1000 applicators) than among North Carolina applicators (2.0/1000). Spouses reported fewer HPEEs compared to applicators (2/1000 spouses). Overall, the observed risk factors for new HPEEs among applicators are similar to risk factors observed in previous cross-sectional analyses of HPEE history. Further, only 13% of applicators and 22% of spouses with symptoms resulting from HPEE sought medical care, suggesting that pesticide poisoning surveillance data may seriously underreport the frequency of such events.

Influence of short stature on the change in pulse pressure, systolic and diastolic blood pressure from age 36 to 53 years: an analysis using multilevel models

Previous cross-sectional analyses of this cohort have shown that short height and leg length are associated with higher pulse pressure and systolic blood pressure in middle age. It is unclear how these adult measures of childhood growth influence the change in blood pressure as it increases with age. Multilevel models were fitted to investigate associations between components of height and the change in blood pressure between 36, 43, and 53 years in a prospective national cohort of 1472 men and 1563 women followed-up since birth in 1946. Shorter height and leg length, but not trunk length, were associated with higher blood pressure, similarly in men and women. Longitudinal analyses showed that the effects of both height and leg length on pulse pressure and systolic blood pressure became significantly stronger with age. For example, the change in systolic blood pressure was found to be -0.021 mm Hg (95% confidence interval -0.029 to -0.013) per year lower for every centimetre increase in leg length (P < or = 0.001). In other words, the increase in systolic blood pressure over a 10 year period of a participant whose legs were 10 centimetres shorter was 2.1 mm Hg higher (P < or = 0.001), compared with a taller participant. Associations were independent of a number of potential confounders. These results support the hypothesis that short people may be more susceptible to the effects of ageing on the arterial tree. Childhood growth may contribute to the tracking of cardiovascular risk throughout life.

Life satisfaction and adverse effects in renal transplant recipients: a longitudinal analysis.

Previous cross-sectional analyses have identified significant associations between quality of life (QOL), comorbidities and adverse effects in renal transplant recipients. This report examines the longitudinal relationship between adverse effects and QOL, with particular attention to the relative impact of adverse effects associated with immunosuppression. The Transplant Learning Center (TLC) is a program designed to improve QOL and preserve graft function in transplant recipients. Self-selected enrollees filled out questionnaires at roughly 3-month intervals. Each questionnaire included QOL scales developed for the program. Repeated measures multiple regression analysis was used to examine the relationship between the QOL scales, comorbidities, adverse effects, adjusting for other factors. A total of 4247 TLC enrollees were included in the analysis, with a mean time since transplant of 5.1 yr. Comorbidities and adverse effects were common, with high blood pressure reported by 87% of respondents and unusual hair growth reported by 69.6%. In bivariate analysis, emotional/psychological problems and headaches had the largest impact on QOL. In multivariate analysis, emotional/psychological problems decreased sexual interest or ability, and headache had the largest adverse QOL effect. We have identified QOL issues that have been previously underemphasized in transplant recipients. These findings open new areas of research to further explore and define these issues. They provide new opportunities for interventions to address factors adversely impacting QOL and to develop strategies to improve QOL in these patients. Clinicians should actively solicit information about adverse effects of medications, particularly information about sexual and relationship issues, when evaluating renal recipients. These issues should be taken into account when making therapeutic decisions.

Category specific semantic loss in dementia of Alzheimer's type. Functional-anatomical correlations from cross-sectional analyses.

In the context of focal brain injury, selective loss of semantic knowledge in the domain of either natural kinds or artefacts is usually considered to reflect the differential importance of temporal and frontoparietal regions to the representations of perceptual and functional attributes, respectively. It is harder to account far as a feature of a more diffuse process, and previous cross-sectional analyses of patients with dementia of Alzheimer's type (DAT) have differed over whether category effects occur. In our series of 58 patients with probable DAT, we demonstrated a significant group advantage for artefacts, and explored possible reasons for the inconsistency of this finding in other studies. A multiple single-case strategy revealed not only individuals with consistent advantages for artefacts but also individuals with consistent advantages for natural kinds. By ranking the individuals according to measures of naming performance and global intellectual ability, we showed that the strength of the group advantage for artefacts was dependent on the former but not the latter variable. The findings are discussed in the context of two competing theories of semantic breakdown in DAT. One differentiates between domains of knowledge in terms of the structure of semantic representations within a single distributed network; the other emphasizes the importance of different brain regions in the category distinction. We conclude that our findings are in keeping with the predictions of the latter hypothesis.

Denominational Pluralism and Chur Ch Membership in Contemporary Sweden

AbstractRecent theoretical developments within the sociology of religion assume a positive relationship between religious pluralism and religious participation. The relationship is explained by rational choice theory, which suggests that the more competition churches face, the more likely they are to adapt their services to the demands of their potential members and participants. Such market adaptation is expected to result in a diversified supply of religious services and hence to increase the likelihood that consumers can find a religious suply well adapted to their individual tastes. In order to overcome the weaknesses of previous cross-sectional analyses, this study investigates whether increases in denominational pluralism are followed by the theoretically expected increases in denominational membership. The results for the free church sector of 269 Swedish municipalitites show that, other things equal, increases in free church pluralism led to a comparatively better development of free church membership. The effect of the increases in religous pluralism was particularily evident where the level of free church pluralism was relatively low at the beginning of the period under study.

Fibrinogen, coronary heart disease and mortality from all causes in smokers and nonsmokers. The Study of Men Born in 1933

To analyse the relation between fibrinogen concentration and incidence of coronary heart disease and mortality from all causes. A secondary aim was to investigate whether the effect of fibrinogen, as in previous cross-sectional analyses from this population, was restricted to nonsmokers. Prospective population study. City of Göteborg, Sweden. A total of 664 men from a population sample of 1016 men aged 50 in 1983, without prior myocardial infarction. Development of coronary heart disease (myocardial infarction, coronary death or, in men with angina, revascularization, or scintigraphic evidence of coronary disease) and death from all causes, in relation to fibrinogen concentration and smoking status at baseline, during 9 years' follow-up. Rates of coronary heart disease during follow-up in the lowest, middle and highest third of the fibrinogen distribution were 4.6, 6.4 and 10.3%, respectively, but this did not remain significant after controlling for smoking and other risk factors (adjusted odds ratio [OR] for the highest, compared to the lowest third 1.5 [0.7-3.4]). Percentages of men who died from any cause were 3.2, 5.9 and 10.7 in the lowest, middle and highest thirds of fibrinogen, respectively. After adjustment for smoking and other risk factors, this difference remained significant (relative risk 2.6 [1.2-5.9]). In men who were smokers at baseline, fibrinogen was not significantly related to coronary heart disease or mortality. Men who did not smoke in the lowest, middle, and highest third of the fibrinogen distribution had rates of coronary heart disease of 1.8, 3.6 and 10.3%, respectively, and of deaths from all causes of 1.8, 2.9 and 8.4%, respectively. The adjusted OR remained significant at 5.4 (1.4-20.0) for coronary heart disease, as did the adjusted relative risk for mortality at 3.8 (1.01-14.4). Plasma fibrinogen is an independent predictor of premature death, and also of coronary heart disease, in middle-aged men and in nonsmokers. A high fibrinogen concentration, particularly in a nonsmoker, deserves attention.

The Voting Rights Act, District Elections, and the Success of Black Candidates in Municipal Elections

Over the last 20 years blacks and other minority groups have used the Voting Rights Act to challenge the legality of at-large election systems and promote the election of representatives by district. In this article we compare electoral outcomes over time in order to determine the effects of district elections on the success of black city council candidates in municipal elections. Consistent with previous cross-sectional analyses, we find that district elections aided black candidates in the early 1980s. However, our results also show that blacks have achieved substantially greater success in at-large elections over the last 10 years, thereby reducing the difference in representation among cities with different election systems. Our results are robust when interracial demographic differences and possible selection biases are taken into account. We conclude that the diminished efficacy of district elections is likely due to a reduction in the racial polarization of voters.

Tenure choice: Cross-sectional and longitudinal analyses

Longitudinal data sets and modeling strategies have become more common in the social sciences. With their emergence, a tendency has arisen to criticize previous cross-sectional analyses. Some argue that cross-sectional analyses of certain geographical processes may have provided biased estimates of the model parameters. Others have gone further, suggesting that the results are misleading and must be viewed with suspicion. Our experience with both cross-sectional and longitudinal analysis of the processes of residential mobility and housing choice suggests otherwise. In our experience, it is not a matter of inferiority of cross-sectional analysis but of how (given the far fewer adequate panel data sets) each of these methods can enrich and complement each other. We will argue that longitudinal studies add to and enrich our understanding of the process of mobility and housing choice gained from earlier cross-sectional work. In particular, we want to emphasize that panel studies allow us to relate the event of changing residence to other events in the household life cycle, such as the advent of children, job change, increases in household income, and changes in marital status. Indeed, panel data allow us to demonstrate that the event of moving from a rental dwelling to ownership is embedded in a whole sequence of events. Those other events include forming a stable relationship (marriage), having children, and increasing the household income (Clark et al., 1994). In this article, we compare the results of analyses of residential mobility and tenure choice from cross-sectional and longitudinal data and models. In doing so, we place particular emphasis on our own research and experience. Our research has used existing data files. For instance, we have made use of the Netherlands Housing Demand Survey sample surveys (held at four-year intervals), the Annual Housing Surveys for the United States, and the Panel Study of Income Dynamics for the United States. Therefore, our research has always dealt with revealed preference that is, the actual housing choice of households and not with stated preference (see Timmermans, et. al., in this issue). Of course, existing data files do not allow

A Reexamination of Risk Factors for Ventilatory Impairment

Previous cross-sectional analyses of data from the Tucson Epidemiological Study of Airways Obstructive Diseases have shown significant relationships of ventilatory impairment to a variety of risk factors, including smoking, chronic productive cough, a history of childhood respiratory illnesses, atopy, blood eosinophilia, and serum immunoglobulin E (IgE). In the present report, we reexamine these relationships in subjects 40 to 74 yr of age to determine the effect of excluding known asthmatics who, as a group, have markedly impaired lung function. After exclusion of asthmatics, atopy, eosinophilia, and IgE no longer appear to be significant risk factors for ventilatory impairment, and nonasthmatic nonsmokers show almost no remaining ventilatory impairment. In current smokers, quantitative relationships of FEV1 to pack-years of cigarette consumption and to chronic productive cough are changed little by excluding asthmatics. In nonasthmatic ex-smokers, however, age at quitting smoking adds significantly to prediction of FEV1 after accounting for pack-years. Young ex-smokers closely resemble nonsmokers, but they become increasingly similar to current smokers as their age at quitting increases. A history of respiratory trouble before 16 yr of age continues to appear to increase susceptibility to smoking effects, even after exclusion of asthmatics. But, as in previous studies, the possible bias of preferential recall of childhood illnesses by impaired subjects limits interpretations of this observation. On the other hand, present findings suggest that such factors as atopy, eosinophilia, and elevated serum IgE may well be risk factors for persistent asthma, but they have no relationship to nonasthmatic forms of chronic obstructive pulmonary disease (COPD).(ABSTRACT TRUNCATED AT 250 WORDS)

Sudden Infant Death Syndrome and Maternal Age

During a 12-year period (1969 through 1980), 431 episodes of sudden infant death syndrome (SIDS) occurred in King County, Washington. Longitudinal analysis of these data confirms the inverse association of SIDS occurrence with maternal age, which has been reported repeatedly from previous cross-sectional analyses. Risk of SIDS increases with increasing birth order, but the inverse maternal age gradient remains constant within each birth-order category. Available evidence suggests that maternal age may be a more important clue to SIDS causation than previously supposed. Assessment of established SIDS risk factors in relation to maternal age deserves further attention. The role of nutrition of pregnancy in relation to maternal age and SIDS risk may also be a productive avenue for future investigation.