25. Multiple Imputation for Nonresponse in Surveys. By D. B. Rubin. ISBN 0 471 08705 X. Wiley, Chichester, 1987. 258 pp. £30.25.

Multiple Imputation for Nonresponse in Surveys

Importance Between 1980 and 2000, the prevalence of obesity increased significantly among adult men and women in the United States; further significant increases were observed through 2003-2004 for men but not women. Subsequent comparisons of data from 2003-2004 with data through 2011-2012 showed no significant increases for men or women. Objective To examine obesity prevalence for 2013-2014 and trends over the decade from 2005 through 2014 adjusting for sex, age, race/Hispanic origin, smoking status, and education. Design, Setting, and Participants Analysis of data obtained from the National Health and Nutrition Examination Survey (NHANES), a cross-sectional, nationally representative health examination survey of the US civilian noninstitutionalized population that includes measured weight and height. Exposures Survey period. Main Outcomes and Measures Prevalence of obesity (body mass index ≥30) and class 3 obesity (body mass index ≥40). Results This report is based on data from 2638 adult men (mean age, 46.8 years) and 2817 women (mean age, 48.4 years) from the most recent 2 years (2013-2014) of NHANES and data from 21 013 participants in previous NHANES surveys from 2005 through 2012. For the years 2013-2014, the overall age-adjusted prevalence of obesity was 37.7% (95% CI, 35.8%-39.7%); among men, it was 35.0% (95% CI, 32.8%-37.3%); and among women, it was 40.4% (95% CI, 37.6%-43.3%). The corresponding prevalence of class 3 obesity overall was 7.7% (95% CI, 6.2%-9.3%); among men, it was 5.5% (95% CI, 4.0%-7.2%); and among women, it was 9.9% (95% CI, 7.5%-12.3%). Analyses of changes over the decade from 2005 through 2014, adjusted for age, race/Hispanic origin, smoking status, and education, showed significant increasing linear trends among women for overall obesity ( P  = .004) and for class 3 obesity ( P  = .01) but not among men ( P  = .30 for overall obesity; P  = .14 for class 3 obesity). Conclusions and Relevance In this nationally representative survey of adults in the United States, the age-adjusted prevalence of obesity in 2013-2014 was 35.0% among men and 40.4% among women. The corresponding values for class 3 obesity were 5.5% for men and 9.9% for women. For women, the prevalence of overall obesity and of class 3 obesity showed significant linear trends for increase between 2005 and 2014; there were no significant trends for men. Other studies are needed to determine the reasons for these trends.

https://jamanetwork.com/journals/jama/articlepdf/2526639/joi160058.pdf

Trends in Obesity Among Adults in the United States, 2005 to 2014.

MUCKE aims to mine a large volume of images, to structure them conceptually and to use this conceptual structuring in order to improve large-scale image retrieval. The last decade witnessed important progress concerning low-level image representations. However, there are a number problems which need to be solved in order to unleash the full potential of image mining in applications. The central problem with low-level representations is the mismatch between them and the human interpretation of image content. This problem can be instantiated, for instance, by the incapability of existing descriptors to capture spatial relationships between the concepts represented or by their incapability to convey an explanation of why two images are similar in a content-based image retrieval framework. We start by assessing existing local descriptors for image classification and by proposing to use co-occurrence matrices to better capture spatial relationships in images. The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images. Consequently, we introduce methods which tackle these two problems and compare results to state of the art methods. Note: some aspects of this deliverable are withheld at this time as they are pending review. Please contact the authors for a preview.

http://ieeexplore.ieee.org/iel2/4524/12820/00592460.pdf

Image Processing

Introduction to the practice of statistics, (3rd edition), by David S. Moore and George P. McCabe. Pp. 825 (with appendices and CD-ROM). £27.95. 1999. ISBN 0 7167 3502 4 (W. H. Freeman).

(2008). Introduction to Variance Estimation. Journal of the American Statistical Association: Vol. 103, No. 483, pp. 1324-1325.

Introduction to Variance Estimation

Objective

To develop a clinical decision rule to predict the presence of interstitial lung disease (ILD) in systemic sclerosis (SSc; scleroderma) and to estimate the prevalence of SSc-ILD.



Methods

Patient data were extracted from the Canadian Scleroderma Research Group registry. Three algorithms for the clinical decision rule were considered based on lung auscultation, chest radiography (CXR), and % predicted forced vital capacity (FVC). High-resolution computed tomography (HRCT) scans were used as the gold standard to determine the diagnostic properties of the 3 algorithms. Multiple imputation was used to impute HRCT data when missing, thereby avoiding bias due to differential referral for HRCT.



Results

This study included 1,168 patients. Of the patients with HRCT scans, 65% had evidence of ILD, compared to 26% by physical examination and 22% by CXR. The FVC of those who did not have HRCT was 8.8% greater than those who did (95% confidence interval [95% CI] 6.0–11.6%). Algorithm A, which identified the presence of ILD based on crackles on lung auscultation and/or findings on CXR, had a likelihood ratio of 3.9, compared to 3.2 for Algorithm B (which included patients with FVC <70%) and 2.2 for Algorithm C (which included patients with FVC <80%). The prevalence of ILD in the cohort was estimated to be 52% (95% CI 46–59%).



Conclusion

We developed a simple clinical decision rule to predict SSc-ILD with good test characteristics. The prevalence of ILD in a large, unselected SSc cohort was estimated to be 52%.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/acr.21583

Clinical decision rule to predict the presence of interstitial lung disease in systemic sclerosis.

Background:The relationship between ambient temperature and risk of delivery is poorly understood. We examined the association between heat and risk of delivery among preterm and term pregnancies with the use of a time-to-event design to minimize bias from seasonal variation in conception rates.Meth

Extreme heat and risk of early delivery among preterm and term pregnancies.

Objective

To determine the effects of cigarette smoking on vascular, gastrointestinal, and respiratory outcomes in patients with systemic sclerosis (SSc).



Methods

Subjects were patients enrolled in the Canadian Scleroderma Research Group cohort. Smoking history was obtained by patient self-report. The effect of smoking was assessed using multiple regression analysis of each SSc clinical outcome of interest (vascular, gastrointestinal, and respiratory). Smoking was modeled both as categorical variables (current, past, and never) and using the Comprehensive Smoking Index (CSI), which integrates smoking intensity, duration of smoking, and time since cessation into a single covariate of smoking effect. All regression models were adjusted for age, sex, disease duration, and limited or diffuse skin involvement.



Results

This study included 606 patients with SSc, of whom 87% were women and 90% were white, and the mean age was 55 years, mean disease duration was 11 years, and 36% had diffuse disease. Of these patients, 16% were current smokers, 42% were past smokers, and 42% were never smokers. The regression analyses showed that smoking had a significant negative effect on almost all vascular, gastrointestinal, and respiratory outcomes. The effects of smoking were in some cases long-lasting (e.g., persistent respiratory abnormalities), and smoking cessation appeared beneficial with respect to some outcomes (e.g., reduced severity of Raynaud's phenomenon).



Conclusion

Physicians caring for patients with SSc should prioritize smoking cessation as a recommendation to patients, and resources directed to supporting smoking cessation in patients with SSc should be more readily available.

Cigarette smoking in patients with systemic sclerosis

Aims To determine if impulsivity and socio-economic status (SES) interact to influence gambling onset in youth. Design Longitudinal study of grade 7 students followed for 8 years. Setting Montreal, Canada. Participants A total of 628 adult students aged 12.6 years on average at cohort inception. Measurements Impulsivity and SES (parent education, area deprivation) were collected during secondary school. Age of gambling onset was collected retrospectively when participants were aged 20.3 years. Cox proportional hazards regression was used to model the associationbetweentimetofirstreportof gamblingandinteractiontermsforeachof impulsivityandparenteducation, and impulsivity and area deprivation accounting for sex and ethnicity. Findings Median (interquartile range) age of gambling onset was 17.0 (4.0) years. Impulsivity independently increased the risk of gambling onset among participants with no university-educated parent [hazard ratio (HR) 1.3; 95% confidence interval 1.1‐1.5] and those living in highly deprived areas (HR 1.7; 1.5‐2.0). Impulsivity was not associated with gambling onset among high SES youth. Among participants with high impulsivity, risks were elevated for those with no university-educated parent relative to one or more university-educated parent (HR 1.7; 1.1‐2.7), and for participants living in deprived relative to advantaged areas (HR 5.0; 2.6‐9.6). SES was not associated with gambling onset among participants with low impulsivity. Conclusions ImpulsivityisariskfactorforgamblingonsetamonglowbutnothighSESyouth,andlowSESinfluences gambling onset primarily among impulsive youth. Gambling prevention programmes may need to consider potential interaction between impulsivity and SES.

Impulsivity and socio-economic status interact to increase the risk of gambling onset among youth.

Objective. The aim of this study was to compare oral abnormalities and oral health-related quality of life (HRQoL) of patients with SSc with the general population. Methods. SSc patients and healthy controls were enrolled in a multisite cross-sectional study. A standardized oral examination was performed. Oral HRQoL was measured with the Oral Health Impact Profile (OHIP). Multivariate regression analyses were performed to identify associations between SSc, oral abnormalities and oral HRQoL. Results. We assessed 163 SSc patients and 231 controls. SSc patients had more decayed teeth (SSc 0.88, controls 0.59,P=0.0465) and periodontal disease [number of teeth with pocket depth (PD) > 3m m or clinical attachment level (CAL) 55.5 mm; SSc 5.23, controls 2.94, P < 0.0001]. SSc patients produced less saliva (SSc 147.52 mg/min, controls 163.19 mg/min,P=0.0259) and their interincisal distance was smaller (SSc 37.68 mm, controls 44.30 mm, P < 0.0001). SSc patients had significantly reduced oral HRQoL compared with controls (mean OHIP score: SSc 41.58, controls 26.67, P < 0.0001). Multivariate regression analyses confirmed that SSc was a significant independent predictor of missing teeth, periodontal disease, interincisal distance, saliva production and OHIP scores. Conclusion. Subjects with SSc have impaired oral health and oral HRQoL compared with the general population. These data can be used to develop targeted interventions to improve oral health and HRQoL in SSc.

/pdf/the-canadian-systemic-sclerosis-oral-health-study-orofacial-2q4iw3kpsk.pdf

The Canadian systemic sclerosis oral health study: orofacial manifestations and oral health-related quality of life in systemic sclerosis compared with the general population

Ernest Lo

Papers

Clinical decision rule to predict the presence of interstitial lung disease in systemic sclerosis.

Extreme heat and risk of early delivery among preterm and term pregnancies.

Cigarette smoking in patients with systemic sclerosis

Impulsivity and socio-economic status interact to increase the risk of gambling onset among youth.

The Canadian systemic sclerosis oral health study: orofacial manifestations and oral health-related quality of life in systemic sclerosis compared with the general population