Mean residual life cure models for right-censored data with and without length-biased sampling.

We propose a semiparametric mean residual life mixture cure model for right-censored survival data with a cured fraction. The model employs the proportional mean residual life model to describe the effects of covariates on the mean residual time of uncured subjects and the logistic regression model to describe the effects of covariates on the cure rate. We develop estimating equations to estimate the proposed cure model for the right-censored data with and without length-biased sampling, the latter is often found in prevalent cohort studies. In particular, we propose two estimating equations to estimate the effects of covariates in the cure rate and a method to combine them to improve the estimation efficiency. The consistency and asymptotic normality of the proposed estimates are established. The finite sample performance of the estimates is confirmed with simulations. The proposed estimation methods are applied to a clinical trial study on melanoma and a prevalent cohort study on early-onset type 2 diabetes mellitus.

Maximum likelihood estimation for length-biased and interval-censored data with a nonsusceptible fraction.

Left-truncated data are often encountered in epidemiological cohort studies, where individuals are recruited according to a certain cross-sectional sampling criterion. Length-biased data, a special case of left-truncated data, assume that the incidence of the initial event follows a homogeneous Poisson process. In this article, we consider an analysis of length-biased and interval-censored data with a nonsusceptible fraction. We first point out the importance of a well-defined target population, which depends on the prior knowledge for the support of the failure times of susceptible individuals. Given the target population, we proceed with a length-biased sampling and draw valid inferences from a length-biased sample. When there is no covariate, we show that it suffices to consider a discrete version of the survival function for the susceptible individuals with jump points at the left endpoints of the censoring intervals when maximizing the full likelihood function, and propose an EM algorithm to obtain the nonparametric maximum likelihood estimates of nonsusceptible rate and the survival function of the susceptible individuals. We also develop a novel graphical method for assessing the stationarity assumption. When covariates are present, we consider the Cox proportional hazards model for the survival time of the susceptible individuals and the logistic regression model for the probability of being susceptible. We construct the full likelihood function and obtain the nonparametric maximum likelihood estimates of the regression parameters by employing the EM algorithm. The large sample properties of the estimates are established. The performance of the method is assessed by simulations. The proposed model and method are applied to data from an early-onset diabetes mellitus study.

Household structure and concurrent stunting and overweight among young children in Indonesia.

OBJECTIVE: To examine the association of household type and household composition with concurrent stunting and overweight in young children from urban and rural Indonesia. DESIGN: This study is a secondary data analysis using a nationally representative cross-sectional survey. Household structure was analysed as household type, household size, number of working adults, number of dependent adults and children, and household head's gender. We defined 'concurrent stunting and overweight' as height-for-age Z-score <-2 and weight-for-height Z-score >+2 based on WHO growth standards. Multivariable logistic regression to test the aforementioned association was performed separately for urban and rural areas. SETTING: Data were from Indonesia Basic Heath Research 2013. PARTICIPANTS: Children aged 2-5 years (n 45 050). RESULTS: The prevalence of concurrent stunting and overweight children was 5·6 %. In rural areas, this prevalence differed significantly by household types and the highest prevalence was among children in nuclear two-parent households (6·8 %). In rural areas, children in extended households had lower odds of concurrent stunting and overweight than those from nuclear households (OR = 0·73, 95 % CI 0·59, 0·92). In urban areas, household size and number of working adults were significantly associated with the decreased odds of concurrent stunting and overweight in children. CONCLUSIONS: Household structure was associated with children's concurrent stunting and overweight in urban and rural regions of Indonesia. The patterns of the association might differ between urban and rural regions, but no significant interaction term was found.

Adolescents' Physical Activity and the Association With Perceived Social Support of Parents and Peers in Indonesia.

This study examined the trends of adolescents' physical activity (PA) and its association with parental and peer support, based on the Indonesia Global School-Based Health Survey. Between 2007 and 2015, prevalence of PA in adolescents declined from 24.4% to 16.5%. Prevalence of active transportation (AT) decreased from 47.2% to 32.3%. Prevalence of sedentary leisure behavior (SLB) declined from 33.6% to 27.2%. Girls' SLB was inversely associated with parental supervision SLB in 2007 (odds ratio [OR] = 0.49; 95% CI = 0.30-0.80) and in 2015 (adjusted OR [AOR] = 0.55; 95% CI = 0.43-0.71), and so was boys' SLB in 2015 (OR = 0.75; 95% CI = 0.59-0.95). Boys' AT was inversely associated with peer support in 2015 (OR = 0.73; 95% CI = 0.59-0.91). Parental control was associated with PA in girls (OR = 1.71; 95% CI = 1.23-2.37), in boys (OR = 1.65; 95% CI = 1.07-2.54), and with SLB among girls in 2015 (OR = 1.28; 95% CI = 1.11-1.47). Hence, adolescents' PA was associated with perceived social support.

Dietary knowledge, preferences and behaviors in Ramadan among Muslim patients with type 2 diabetes.

AIMS: To explore the association between dietary knowledge, attitude, and practices during Ramadan among Muslim patients with type 2 diabetes. METHODS: Recruited after Ramadan from public clinics and a hospital in Banda Aceh, Indonesia, 401 outpatients recalled their food consumption frequencies of high-fiber food, deep-fried food, and high-sugar dessert, and relevant knowledge and attitudes. Multivariable logistic regression models were applied to examine the research questions. RESULTS: Vegetable consumption and preference were both high among the patients. However, only 4.5% knew that brown rice is rich in fiber, and 19% agreed that whole-grain foods were accessible. Deep-fried food consumption and its availability at home was common, even though the majority considered it should be avoided. Patients with a lower preference for deep-fried foods were less likely to consume deep-fried foods during Ramadan (OR = 0.239, 95% CI = 0.109-0.523, p = 0.001). Knowledge of the glycemic index's health implication was associated with more high-fiber foods consumption (OR = 2.733, 95% CI = 1.179-6.332, p = 0.019). Yet, knowing the potential risk of added sugar on blood glucose level was associated with high-sugar dessert consumption (OR = 2.997, 95% CI = 1.482-6.060, p = 0.002). CONCLUSION: The patients' low consumption of whole-grain food and common comsumption of deep-fried food during Ramadan would be the first priority to be improved. Along with dietary knowledge and attitude, food environment could be an important factor that influences patients' dietary behaviors.

Hepatic extravasation complicated by umbilical venous catheterization in neonates: A 5-year, single-center experience.

BACKGROUND: Care of newborns in the neonatal intensive care unit generally involves umbilical venous catheterization (UVC) for central vein access to enable medical needs. The study aimed to evaluate the sonographic appearance, risk factors, and outcomes of UVC-related hepatic extravasation (HE) in neonates. METHODS: A 5-year retrospective study where 33 neonates were enrolled with a diagnosis age ranging from 2 to 25 days. 78.8% of the subjects had UVC malpositioning shown on initial radiography. All neonates sonographically diagnosed with HE, and follow-up ultrasound (US) was performed. RESULTS: The main findings of HE on US were hyperechoic or heterogeneous lesions of a lobulated (51.7%) or wedge shape (48.3%), located mainly in the left lobe (72.7%). The mean time to resolution of HE was 2.25 months. Seven (21.2%) patients showed hepatic vascular thrombosis at follow-up. Two (6%) patients had abnormal liver function, which subsequently normalized. CONCLUSION: Malposition of the UV catheter was the predisposing factor for UVC-related HE in neonates. US facilitates detection of UVC malpositioning and diagnosis of HE, as well as delayed complications. A shorter duration of UVC placement is associated with favorable outcomes of UVC-related HE in neonates.

NASA Mission X Program for Healthy Eating and Active Living among Taiwanese Elementary School Students.

PURPOSE: This study assessed the effects of an intervention program adapted from the NASA Mission X (MX) program on children's Healthy Eating Active Living (HEAL) knowledge and behaviors and anthropometry. METHODS: This clustered randomized control trial recruited 8 elementary schools in remote rural areas of Northern Taiwan. The intervention was the 8-week MX program. All the 3rd and 4th graders were invited to the study (n = 245). Children's weight, height, HEAL knowledge and behaviors were measured pre- and post-intervention. RESULTS: The intervention group had significantly more improvements than control group in physical activity knowledge score (+0.91 vs. +0.25, p = 0.002), diet knowledge score (+0.62 vs. +0.17, p = 0.044), and score of interests in NASA and space exploration (+0.34 vs. -0.07, p < 0.0001). BMI increased from 18.4 to 18.6 (p < 0.05) for the control group but did not change for the intervention group. The changes in BMI between groups did not differ significantly. CONCLUSION AND PRACTICE IMPLICATIONS: This randomized controlled trial showed that the NASA MX program was feasible and acceptable among children in Taiwan, and improved children's HEAL knowledge. (ClinicalTrials.gov registration: NCT03355131).

Age, period and birth cohort effects on the prevalence of overweight and obesity among Taiwanese adolescents: a national population-based study.

BACKGROUND: The age-period-cohort effects on youth overweight and obesity among junior and senior high school students in Taiwan is not clear. METHODS: We utilized the 2006-14 nationally representative School Physical Fitness Dataset. Based on the International Obesity Task Force cut-off criteria, a log-linear age-period-cohort analysis was performed to determine the influence of age, period and cohort on the trend in being overweight, obese and severely obese for both sexes. RESULTS: The final dataset included 1073173 individuals (n = 520 382 boys and 552 791 girls). For girls, the prevalence of overweight and obesity declined with age, and the prevalence of overweight declined over time. For boys, the prevalence of overweight and obesity declined with age and over time from 2006 to 2014. The prevalence of severe obesity declined over time and increased with age for the boys. The younger birth cohorts had greater odds of being overweight, obese and severely obese than the older birth cohorts. CONCLUSIONS: After differentiating the age-period-cohort effects, the data suggested a decreasing temporal trend in overweight and obesity among adolescents in Taiwan from 2006 to 2014. Among the birth cohorts of the 1990s, the younger cohorts had greater odds of being overweight and obese than the older cohorts when they reached adolescence.

Gender differences and burden of chronic conditions: impact on quality of life among the elderly in Taiwan.

BACKGROUND: Multiple chronic conditions affect people's health-related quality of life (QoL) and the distributions of the conditions may differ between genders. Our goal was to examine gender differences in chronic conditions and QoL among community-living elderly in Taiwan and to examine whether differences in QoL between genders, if present, were attributable to the distribution of chronic conditions. METHODS: We used data from the Nutrition and Health Survey in Taiwan (NAHSIT, 2005-2008), which interviewed a representative sample of the Taiwanese population. The survey questions included the SF-36 questionnaire to assess participants' QoL and items for participants' medical history. We used multiple linear regressions to examine the difference in QoL between genders. RESULTS: We included 1179 elders for our analysis; men accounted for 52% (612/1179). The mean age was 73; women were slightly younger. The mean (standard deviation) of SF-36 physical and mental health component score (PCS and MCS) was 44.5 (11.1) and 55.6 (9.0), respectively, and women reported a significantly lower PCS than men (difference - 4.85, p < 0.001). Urinary incontinence, arthritis, stroke, and kidney disease were associated with a clinically meaningful decrease in PCS (≤ - 6.5 points). The difference in PCS between genders was not attenuated after we accounted for chronic conditions in regression analysis. CONCLUSIONS: Our findings suggest that women tend to report that their physical health-related QoL is poorer than that of men, and such a difference does not seem to be attributable to the distribution of chronic conditions. Elderly men and women may perceive health-related QoL differently.

Secular trends and associated factors of age at natural menopause in Taiwanese women.

OBJECTIVE: Age at natural menopause (ANM) is considered an indicator for chronic disease and mortality risk in later life. Research suggests that ANM appears to vary across geographic regions and ethnicities. The aim of this study was to explore the secular trends and factors associated with ANM in Taiwanese women. METHODS: We used data from three cross-sectional phases of the Nutrition and Health Survey in Taiwan. In all, 4,111 women aged 35 years and over were included. Information on ANM and sociodemographics, lifestyle, and health factors were collected using household questionnaires. A Cox proportional-hazards model was used to determine the association of ANM with relevant factors, and a life table method was used to estimate median ANM. RESULTS: Life table method estimated the median ANM to be 50 years. ANM was getting later for women born in younger cohorts (hazard ratio [HR] 0.87 per 10-year difference, 95% confidence interval [CI] 0.81-0.95). ANM was also later among women who achieved higher educational levels (HR 0.91 per one-category difference, 95% CI 0.86-0.96) and who had been married (HR 0.64, 95% CI 0.42-0.96). ANM occurred later for parous than for nulliparous women. Multivariable analysis found no significant associations of ANM with age at menarche, smoking, or alcohol drinking. CONCLUSIONS: The results suggest that women in the younger cohorts, with higher educational levels, and who are parous and married may have later ANM. The trend effect of secular time and educational levels on ANM may reflect the influences of socioeconomic/nutritional status in their childhood or throughout their lifetime.

Hygiene practices: Are they protective factors for eczema symptoms?

INTRODUCTION: Exact etiology and proper treatment of eczema are still unknown. The hygiene hypothesis and epidermal barrier dysfunction hypothesis attempted to give some plausible explanations for these issues but they still remain unclear. The identification of factors, including hygiene practices, related to eczema symptoms (ES) could shed some light on these matters. Therefore, this study aimed to determine risk factors related to ES and the ES prevalence in two disparate areas in terms of urbanization in Aceh, Indonesia. METHODS: A cross-sectional study with convenience sampling was conducted among schoolchildren living in urban and rural Aceh. Data on ES, socio-demographic characteristics, environmental factors, partial ablution and other hygiene related factors were collected by parental questionnaires. In addition, children's anthropometric measurements were also collected. RESULTS: The prevalence of current ES in the study population was 21%. When stratifying by residency, the prevalence of ES in urban and rural area was 20.93% versus 21.05%. Partial ablution was independently associated with a reduced risk of ES (OR = 0.36; 95% CI 0.13-0.96). Important risk factors for ES were paternal history of allergic disease (OR = 4.09%; 95% CI 1.51-11.11) and belonging to the older group of schoolchildren (10-13 years old) (OR = 2.57; 95% CI 1.03-6.40). CONCLUSIONS: There were no significant differences in the prevalence of ES between urban and rural settings, and partial ablution had a protective effect on ES. These findings support the epidermal barrier dysfunction hypothesis as a possible pathway of eczema.

Employment status and temporal patterns of energy intake: Nutrition and Health Survey in Taiwan, 2005-2008.

OBJECTIVE: To (i) identify the major temporal patterns of energy intake among adults; (ii) examine the association between employment status and the patterns; and (iii) examine the association between dietary quality and the patterns. DESIGN: Secondary analysis based on the cross-sectional population-based nutrition survey in Taiwan, 2005-2008. Based on energy intake levels at six time intervals of a day derived from 24 h recall data, we applied cluster analysis to identify major temporal patterns of energy intake. Self-reported employment status was categorized into six groups: full-time, part-time, no job, student, homemaker and retired. Multinomial logistic regression models were fitted to test the association between temporal patterns of energy intake and employment groups. SETTING: Non-institutionalized community dwellers. SUBJECTS: Non-pregnant adults (≥19 years old) with total energy intake between 2092 and 20920 kJ/d (500 and 5000 kcal/d; n 4508). RESULTS: Five major patterns were identified, which can be seen as the traditional meal pattern and its variants. About 20 % of adults had the traditional pattern. The most prevalent pattern was the delayed morning meal pattern (33 %), which had lower Ca and P intakes than the traditional pattern. About 14 % of adults had the delayed lunchtime pattern, which had lower protein, PUFA, fibre, Ca, P, vitamin D and vitamin E intakes than the traditional. Adjusted prevalence of the delayed lunchtime pattern was highest among full-time students (34 %), followed by part-time workers (24 %), and was lower in retired (8 %), homemakers (11 %) and full-time employed adults (12 %). CONCLUSION: Adults' temporal patterns of energy intake, which varied with their employment status, affected their dietary quality.

Association between obesity with low muscle mass and dialysis mortality.

BACKGROUND/AIM: To examine the association between body composition and dialysis mortality. METHODS: Adult patients who underwent haemodialysis in Taoyuan General Hospital from 2012 to 2016 were enrolled. We reviewed their baseline characteristics and followed up their treatment over 5 years after dialysis. Patients with body mass index >25 kg/m2 were defined as obese. High or low muscle mass were classified by skeletal muscle mass index (SMMI) based on consensus from Chinese population. All age-matched subjects were classified into four groups: (A) optimal; (B) obesity; (C) low muscle mass; and (D) obesity with low muscle mass. Adjusted hazard ratios for mortality and cumulative survival curves were evaluated by Cox proportional hazard model and Kaplan-Meier method. The discriminative power of SMMI was calculated according to the area under the curve and the receiver operating characteristic curve. RESULTS: From a total of 176 age-matched patients, the incidence rates of mortality for different groups were 3.7, 7.8, 10.3 and 16.5 per 1000 person-months. After adjusting for continuous variables, SMMI was independently associated with mortality. The difference between groups A and D was more significant in women than in men after multivariate adjustment (adjusted hazard ratios: 7.465 vs 1.682) (P = 0.035 and 0.553). The discriminative power of SMMI to predict 5-year mortality was 0.700 for men and 0.750 for women, and the best cut-off values were 11.1 and 8.4 kg/m2 CONCLUSIONS: Low muscle mass was associated with dialysis mortality. Obesity with low muscle mass was a predictor for dialysis mortality in women.

Is the 90th Percentile Adequate? The Optimal Waist Circumference Cutoff Points for Predicting Cardiovascular Risks in 124,643 15-Year-Old Taiwanese Adolescents.

Adolescent obesity has increased to alarming proportions globally. However, few studies have investigated the optimal waist circumference (WC) of Asian adolescents. This study sought to establish the optimal WC cutoff points that identify a cluster of cardiovascular risk factors (CVRFs) among 15-year-old ethnically Chinese adolescents. This study was a regional population-based study on the CVRFs among adolescents who enrolled in all the senior high schools in Taipei City, Taiwan, between 2011 and 2014. Four cross-sectional health examinations of first-year senior high school (grade 10) students were conducted from September to December of each year. A total of 124,643 adolescents aged 15 (boys: 63,654; girls: 60,989) were recruited. Participants who had at least three of five CVRFs were classified as the high-risk group. We used receiver-operating characteristic curves and the area under the curve (AUC) to determine the optimal WC cutoff points and the accuracy of WC in predicting high cardiovascular risk. WC was a good predictor for high cardiovascular risk for both boys (AUC: 0.845, 95% confidence interval [CI]: 0.833-0.857) and girls (AUC: 0.763, 95% CI: 0.731-0.795). The optimal WC cutoff points were ≥78.9 cm for boys (77th percentile) and ≥70.7 cm for girls (77th percentile). Adolescents with normal weight and an abnormal WC were more likely to be in the high cardiovascular risk group (odds ratio: 3.70, 95% CI: 2.65-5.17) compared to their peers with normal weight and normal WC. The optimal WC cutoff point of 15-year-old Taiwanese adolescents for identifying CVRFs should be the 77th percentile; the 90th percentile of the WC might be inadequate. The high WC criteria can help health professionals identify higher proportion of the adolescents with cardiovascular risks and refer them for further evaluations and interventions. Adolescents' height, weight and WC should be measured as a standard practice in routine health checkups.

Relationship between frequency of eating and cardiovascular disease mortality in U.S. adults: the NHANES III follow-up study.

PURPOSE: This study examined longitudinal relationship between baseline daily eating frequency and all-cause and cardiovascular disease (CVD) mortality among U.S. adults. METHODS: The Third National Health and Nutrition Examination Survey (1988-1992) participants were followed through 2006. Nonpregnant adults >17 years old (n = 6884) whose dietary recall was of good quality and had fasted at least 8 hours before physical examinations were eligible for this analysis. Frequency of eating was derived from 24-hour dietary recalls. Main outcomes included all-cause and CVD mortality during follow-up, based on National Death Index data. RESULTS: During follow-up (median time: 176 months), 1280 subjects died, 503 of them from CVD. Adults reporting eating ≥6 times/day had a lower hazard ratio for CVD mortality than those reporting eating 4 times/day (hazard ratio = 0.68; 95% confidence interval, 0.43-1.08; test for trend, P = .011). The gradient of CVD mortality risk by eating frequency was significant for the groups with ≥2500 kcal of total energy intake (test for trend, P = .037). CONCLUSIONS: Eating frequency was inversely associated with CVD mortality, which was especially marked for people reporting high total energy intake. Nevertheless, public health recommendations should be cautious, as eating frequency was positively associated with total energy intake, which could promote weight gain.

Stunting and weight statuses of adolescents differ between public and private schools in urban Gambia.

OBJECTIVES: This study assessed the disparity in nutritional status of adolescents between public and private schools in urban Gambia. METHODS: This is a school-based cross-sectional study in six private and six public upper basic schools in urban Gambia. This study recruited 491 students from public and 469 students from private schools (13-15 years of age). RESULTS: The prevalence of stunting (WHO height-for-age Z < -2SD) was 13.4 % for public school students and 4.5 % for private schools. After adjustment for children's sex, age, and family socioeconomic status, the differences in prevalence of stunting and underweight were significant between public and private schools. Private school students are more likely to be overweight/obese (WHO BMI-for-age Z > +1SD) (OR = 2.85, 95 % CI 1.55-5.22), but less likely to be thin (BMI-for-age Z < -2SD) (OR = 0.61 [0.39-0.96]), compared to public school students. Children from lower income families had lower odds for overweight/obese than normal weight, compared to those from higher income families (OR = 0.34 [0.15-0.76]). CONCLUSIONS: Public and private schools in urban regions of the Gambia may face different nutritional challenges due to differences in school environment and resources.

Measurements and profiles of body weight misperceptions among Taiwanese teenagers: a national survey.

Children and adolescents tend to lose weight, which may be associated with misperceptions of weight. Previous studies have emphasized establishing correlations between eating disorders and an overestimated perception of body weight, but few studies have focused on an underestimated perception of body weight. The objective of this study was to explore the relationship between misperceptions of body weight and weight-related risk factors, such as eating disorders, inactivity, and unhealthy behaviors, among overweight children who underestimated their body weight. We conducted a cross-sectional, descriptive study between December 1, 2006 and February 15, 2007. A total of 29,313 children and adolescents studying in grades 4-12 were enrolled in this nationwide, cross-sectional survey, and they were asked to complete questionnaires. A multivariate logistic regression using maximum likelihood estimates was used. The prevalence of body weight misperception was 43.2% (26.4% overestimation and 16.8% underestimation). Factors associated with the underestimated perception of weight among overweight children were parental obesity, dietary control for weight loss, breakfast consumption, self-induced vomiting as a weight control strategy, fried food consumption, engaging in vigorous physical activities, and sleeping for >8 hours per day (odds ratios=0.86, 0.42, 0.88, 1.37, 1.13, 1.11, and 1.17, respectively). In conclusion, the early establishment of an accurate perception of body weight may mitigate unhealthy behaviors.

Patient-health care professional gender or race/ethnicity concordance and its association with weight-related advice in the United States.

OBJECTIVE: Examine association between adult patients' and health care providers' (HCPs) gender or race/ethnicity concordance and patients' reported receiving weight-related advice from HCP's in USA. METHODS: Using Medical Expenditure Panel Survey (MEPS) 2004-2007 data, studied prevalence of weight-related advice (on exercise and diet) given to patients and its association with patients/HCPs concordance in gender (n=9,686) and race/ethnicity (n=8,825). RESULTS: Overall, 46% of patients received HCP advice on diet and 49% on exercise. Overweight females seeing female HCPs were more likely to receive exercise advice than those seeing male HCPs (OR=1.44 [95% CI: 1.10-1.89]). Race/ethnicity concordance was associated with lower odds of advice-receiving in certain populations (OR=0.80 [0.67-0.97] for exercise and OR=0.42 [0.19-0.91] for diet among white patients, OR=0.47 [0.23-0.98] for exercise among Hispanic overweight patients). CONCLUSIONS: Patient/HCP gender or race/ethnicity concordance was not positively associated with HCPs providing weight-related advice. Patients with female HCPs or with racial/ethnic discordant HCPs (especially black or Asian HCPs) were more likely to receive advice. PRACTICE IMPLICATIONS: Health care providers need be empowered, particularly white and male HCPs, to improve delivery of weight-related advice. It may reflect better of receiving weight-related advice based on patients' recall.