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PubMed1998

Consanguinity and the age of menopause in the United Arab Emirates.

OBJECTIVE: The study examined the association between some biosocial factors, consanguinity and age at natural menopause in the United Arab Emirates (UAE). METHOD: A cross-sectional population-based study using a multi-stage sampling design and face-to-face interview. RESULTS: In a sample of 800 UAE females aged 40 years and above, there were 742 (85.8%) respondents. The median age of natural menopause was 48 years. The bodyweight, parity number, occupation, smoking habits and consanguinity in marriage were the significant variables associated with the age at natural menopause. There were statistically significant differences between women in consanguineous and non-consanguineous marriages with regard to BMI (P < 0.002), occupation (P < 0.008), weight (P < 0.0001), age (P < 0.03), age of menopause (P < 0.005), parity (P < 0.0001), mother's age at menopause (P < 0.007) and sister's age at menopause (P < 0.002). CONCLUSION: The study showed that among UAE women, consanguinity of marriage, maternal and sister's age at menopause, BMI, parity number and smoking habits significantly influence the natural age of menopause.

Age of Onset↗
PubMed2004

[MIR family medicine program: cross-professional interaction in a complex reality].

OBJECTIVE: To find the view of trainers (tutors and teaching assistants) of third-year family and community medicine (FCM) residents concerning their own teaching activity in areas such as training, the skills and qualities required to be a teacher and the inter-professional relationships that are current and that are needed in a primary care teaching team. DESIGN: Qualitative study developed between June 2000 and May 2002. Sample design with a volunteer population. SETTING: FCM teaching unit under the Primary Care Administration of Murcia. PARTICIPANTS AND/OR CONTEXTS: Tutors and teaching assistants in the FCM residents' programme. METHOD: Semi-structured interview for information gathering. Contents analysis to construct results on the basis of the semiological analysis of the textual discourse. Systematic return of the results. RESULTS: Belonging to the teaching team is the highest motivation for taking part in teaching. It gives the tutors more benefits (affective, care load) than difficulties (organisational adaptation). The tutor profile is sustained by his/her scientific-technical and personal qualities; that of the nurse, by his/her community qualities. Collaboration between nurse and tutor is informal and the teaching strategies most employed by tutors are guidance, guide-lines and encouragement of residents' autonomy. Nurses collaborate with teaching by transmitting a model of professional development and facilitating teamwork. CONCLUSIONS: The complexity of the training process stands out. Postgraduate FCM training is cross-professional, not exclusively circumscribed by the tutor-resident teaching relationship. The qualitative paradigm is shown to be useful for obtaining a vision of the teaching process from the perspective of different actors.

Attitude of Health Personnel↗
PubMed2004

Prevalence of diabetes, obesity, hypertension and hyperlipidemia in the central area of Argentina.

OBJECTIVES: There is little information available about the prevalence of chronic metabolic diseases in many Latin American countries. Between 1995 and 1998, studies on the prevalence of obesity, hypertension, hyperlipidemia and diabetes were carried out in four cities located in central Argentina: Dean Funes, Oncativo, Pehuajo and Venado Tuerto. The data provided by these surveys are reanalysed here in order to determine prevalence of obesity, hypertension, hyperlipidemia and diabetes using new epidemiological criteria. METHODS: Representative samples of the population, based on a multistage probabilistic sampling design, were taken from each of the four cities. The sample size was calculated to obtain a precision of 4% for the prevalence assessment. The subjects included were aged 20 years and over. Standardization of the prevalence rates used the entire study sample as the reference population. RESULTS: Age-standardised prevalence rates for the cities ranged between 22.4% and 30.8% for obesity, 27.9% and 43.6% for hypertension, 24.2% and 36.4% for hyperlipidemia, and 6.5% and 7.7% for diabetes mellitus. All these prevalences increased with age. 58.1% of the obese subjects and 51.2% of the diabetic subjects had hypertension, while 43.2% of the obese subjects and 52.8% of the diabetic subjects had hyperlipidemia. CONCLUSIONS: While the prevalence of diabetes mellitus was between 6% and 8%, the prevalence of obesity was close to 26% and hypertension and hyperlipidemia affected one third of the population. These data can be considered as indicative of the prevalences of these four diseases in the population aged 20 years and over, in the central region of Argentina.

Adult↗
PubMed2003

Pseudo-outbreak of Pseudomonas aeruginosa and Serratia marcescens related to bronchoscopes.

OBJECTIVE: To investigate an apparent outbreak involving simultaneous isolation of Pseudomonas aeruginosa and Serratia marcescens from bronchoalveolar lavage (BAL) samples. DESIGN: Retrospective and prospective cohort studies using chart review, environmental sampling, and ribotyping of all available isolates. Cleaning and disinfection procedures for the bronchoscopes were also evaluated. SETTING: A 380-bed private hospital in São Paulo, Brazil PATIENTS: Forty-one patients who underwent bronchoscopic procedures between December 1994 and October 1996 and from whom P. aeruginosa and S. marcescens were concomitantly isolated. Bronchoscopes and related items were microbiologically assessed. RESULTS: P. aeruginosa and S. marcescens were simultaneously isolated from BAL samples 12.6% of the time (41 of 324) during the epidemic period versus 1.8% of the time (1 of 54) in the pre-epidemic period (P = .035). Ribotyping revealed two strains of P. aeruginosa and one of S. marcescens that were isolated from BAL samples of patients with no signs of respiratory tract infection, suggesting a pseudo-outbreak. Evaluation of bronchoscope disinfection revealed that inappropriate methods were being used. Implementation of simple control measures resulted in a significant decrease in simultaneous isolation of these species. CONCLUSION: Prevention of pseudo-outbreaks requires meticulous use of preventive measures for infection-prone medical procedures.

Brazil↗
PubMed1987

The prevalence of childhood sexual assault. The Los Angeles Epidemiologic Catchment Area Project.

This study reports childhood sexual assault data collected as part of a community-based population study on mental health. A household sample, stratified by catchment area, was selected using a two-stage probability technique. A total of 3,132 adults (18 years or older) were interviewed between January 1983 and August 1984. The sample was 46% Hispanic and 42% non-Hispanic white, 47% male and 53% female. Childhood sexual assault was defined as incidents before age 16 years which involved pressure or force for sexual contact. The prevalence (weighted for sampling design and nonresponse) of childhood sexual assault for the total sample was 5.3%. Rates were higher for non-Hispanic whites (8.7%) compared with Hispanics (3.0%), women (6.8%) compared with men (3.8%), and younger persons at the time of interview (6.5%) compared with older persons (3.9%). Most assaults were by an acquaintance and occurred for the first time around age 10 years. Data from a subsample of assaulted respondents show that childhood sexual assaults are not usually accomplished through physical aggression, but rather through persuasion, and through the psychological threat of the assailant being bigger or stronger. Research is needed on the natural history and sequelae of childhood sexual assault.

Adolescent↗
PubMed1999

Drinking habits among older persons: findings from the NHANES I Epidemiologic Followup Study (1982-84). National Health and Nutrition Examination Survey.

OBJECTIVES: To describe alcohol use and its sociodemographic correlates among persons aged 65 years and older in a US probability sample. DESIGN: Cross-sectional analysis of a national probability sample-based cohort study. SETTING: Multiple sites throughout the United States. PARTICIPANTS: A total of 3448 persons aged 65 and older who participated in the first wave of the NHANES I Epidemiologic Followup Study (1982-84). MEASUREMENTS: We describe the alcohol use behaviors and demographic characteristics of 3448 persons aged 65 and older. Least squares regression models were used to assess associations between older persons' sociodemographic characteristics and alcohol use. RESULTS: Sixty percent of the sample reported having 12 or more drinks of alcohol in at least 1 year of their lives. Seventy-nine percent of these older drinkers were currently drinking. Twenty-five percent of all drinkers drank daily (31% men, 19% women). Using gender-specific definitions (men >2 drinks/day; women >1 drink/day), 16% of men drinking alcohol and 15% of women drinking alcohol were heavy drinkers. Younger age, male gender, and higher income were associated with greater alcohol use. CONCLUSIONS: Most older persons who ever drank alcohol in their lifetimes were currently drinking. In addition, a substantial number of older persons were drinking currently at levels that may place them at risk of adverse health consequences.

Age Distribution↗
PubMed1999

Estimating the true extent of cognitive decline in the old old.

OBJECTIVE: To measure cognitive change using a brief measure over a period of 9 years and to adjust for attrition in the sample. DESIGN: The Cambridge City over 75 Cohort (CC75C), a complete sample of the 75 years and older age group from five group general practices in the city of Cambridge with a systematic one-third of a further practice, all followed on four occasions. SETTING: Cambridge city, UK, the respondents' place of residence. PARTICIPANTS: A total of 2106 subjects were included at study entry. MEASUREMENTS: A brief interview, administered by a trained interviewer, containing a short cognitive scale and the Mini-Mental State Examination (MMSE) at baseline, 2.4 years, 6 years, and 9 years. RESULTS: Decline in MMSE scores occurred across the population and was greater in the oldest age groups. Attrition at later stages of the follow-up was associated with greater decline at earlier stages. Adjusting the results for loss to the sample leads to considerably higher estimates of decline, with the older age groups declining faster from lower levels. CONCLUSIONS: To date, cognitive decline in the very old has been considerably underestimated by longitudinal studies. If studies of population samples are to reflect the health and social needs of this frail group accurately, adjustments for the effect of attrition must be included before true decline can be estimated.

Age Factors↗
PubMed2003

Sexual behaviour of adolescents in Nigeria: cross sectional survey of secondary school students.

OBJECTIVES: To determine whether family structure (polygamous or monogamous) is associated with sexual activity among school students in Nigeria. DESIGN: Cross sectional school survey with a two stage, clustered sampling design. PARTICIPANTS: 4218 students aged 12-21 years attending 39 schools in Plateau state, Nigeria. Responses from 2705 students were included in the analysis. MAIN OUTCOME MEASURE: Report of ever having had sexual intercourse. Variables of interest included sexual history, age, sex, religion, family polygamy, educational level of parents, having a dead parent, and sense of connectedness to parents and school. RESULTS: Overall 909 students (34%) reported ever having had sexual intercourse, and 1119 (41%) reported a polygamous family structure. Sexual activity was more common among students from polygamous families (42% of students) than monogamous families (28%) (chi2=64.23; P<0.0001). Variables independently associated with sexual activity were male sex (adjusted odds ratio 2.52 (95% confidence interval 2.05 to 3.12)), older age (1.62 (1.24 to 2.14)), lower sense of connectedness with parents (1.87 (1.48 to 2.38)), having a dead parent (1.59 (1.27 to 2.00)), family polygamy (1.58 (1.29 to 1.92)), lower sense of connectedness with school (1.25 (1.09 to 1.44)), and lower educational level of parents (1.14 (1.05 to 1.24)). Multistep logistic regression analysis showed that the effect of polygamy on sexual activity was reduced by 27% by whether students were married and 22% by a history of forced sex. CONCLUSIONS: Secondary school students in Nigeria from a polygamous family structure are more likely to have engaged in sexual activity than students from a monogamous family structure. This effect is partly explained by a higher likelihood of marriage during adolescence and forced sex. Students' sense of connectedness to their parents and school, regardless of family structure, decreases the likelihood of sexual activity, and fostering this sense may help reduce risky sexual behaviour among Nigerian youth.

Adolescent↗
PubMed1999

True pedigree errors more frequent than apparent errors for single nucleotide polymorphisms.

Single nucleotide polymorphisms (SNPs) are currently being developed for use in disequilibrium analyses. These SNPs consist of two alleles with varying degrees of polymorphism. A natural design for use with SNPs is the 'haplotype relative risk' sampling design in which a father, mother, and child are typed at an SNP locus. Given such a trio of genotypes, we ask: what is the probability that a pedigree error (a change from one allele to the other) at an SNP locus will be detected using only Mendel's laws as a check? We calculate the probability of detecting such errors for a hypothetical SNP locus with varying degrees of polymorphism and for various true error rates. For the sets of allele frequencies considered, we find that the detection rates range between 25 and 30%, the detection rate being lowest when the two alleles have equal frequencies and the highest when one allele has a frequency of 10%. Based on this detection rate, we determine that the true error rate is roughly 3.3-4 times that of the apparent error rate at an SNP locus. The greatest discrepancy between true and apparent error rates occurs when allele frequencies are equal.

Alleles↗
PubMed2006

A national survey of tobacco cessation programs for youths.

OBJECTIVES: We collected data on a national sample of existing community-based tobacco cessation programs for youths to understand their prevalence and overall characteristics. METHODS: We employed a 2-stage sampling design with US counties as the first-stage probability sampling units. We then used snowball sampling in selected counties to identify administrators of tobacco cessation programs for youths. We collected data on cessation programs when programs were identified. RESULTS: We profiled 591 programs in 408 counties. Programs were more numerous in urban counties; fewer programs were found in low-income counties. State-level measures of smoking prevalence and tobacco control expenditures were not associated with program availability. Most programs were multisession, school-based group programs serving 50 or fewer youths per year. Program content included cognitive-behavioral components found in adult programs along with content specific to adolescence. The median annual budget was 2000 dollars. Few programs (9%) reported only mandatory enrollment, 35% reported mixed mandatory and voluntary enrollment, and 56% reported only voluntary enrollment. CONCLUSIONS: There is considerable homogeneity among community-based tobacco cessation programs for youths. Programs are least prevalent in the types of communities for which national data show increases in youths' smoking prevalence.

Adolescent↗
PubMed2006

Risk factors associated with Cryptosporidium infection on dairy farms in a New York State watershed.

A cross-sectional study was carried out to determine the prevalence of Cryptosporidium parvum-like oocyst shedding on dairy farms in a watershed in New York State and to identify the factors that put animals at risk. A proportional sample of dairy herds in the targeted area was obtained, and animals were selected using a stratified sampling design to ensure representation of the population at risk. Fecal samples were collected per rectum and analyzed for the presence of C. parvum-like oocysts using the quantitative centrifugation concentration flotation technique and a proprietary enzyme-linked immunoassay. Additionally, isolates of Cryptosporidium were examined via bidirectional DNA sequencing. Data on putative risk factors were collected at the time of sampling and analyzed for association using logistic regression. The herd prevalence was 42% and the overall animal prevalence was 3.2%. The prevalence among animals less than 60 d of age was 20%. The likelihood of shedding Cryptosporidium decreased with the age of the animal and varied with the type of barn water source. Both the number of unweaned calves present at the time of the study, and whether the calves were tied vs. not tied increased the risk of infection. There was significant agreement between the flotation and PCR techniques. Sequencing revealed that 50% of the isolates were Cryptosporidium bovis, an isolate thought to be nonzoonotic.

Age Factors↗
PubMedDate not supplied

Prevalence of tobacco use among school going youth in North Indian States.

BACKGROUND: Tobacco use, which is the cause of several respiratory diseases, generally starts in the teens. Global Youth Tobacco Survey (GYTS) is an international initiative to investigate the tobacco use in school going youth of 13 to 15 years of age. This report describes the GYTS findings in the North Indian region. METHODS: A two-stage cluster sample was used with selection of schools on probability proportional to enrollment size followed by systematic equal probability sampling with a random start of classes from each school. The 85-item questionnaire included 'core GYTS' and other additional questions. Data analysis was performed using EpiInfo 3.2 software and the results accounted for the complex sampling design and weighting factors in the data set. RESULTS: The sample consisted of 9319 students out of the total eligible population of 30488 from 100 schools. The prevalence of ever-use of tobacco varied between 2.9 to 8.5% in boys and 1.5 to 9.8% in girls. The prevalence was highest in Chandigarh and lowest in Punjab. Between 16 to 46% of students were exposed to the habit of tobacco among parents or friends. There were 10 to 34% students who were passively exposed to environmental tobacco smoke. CONCLUSION: Tobacco use is present in up to 10 percent of school going youth in the region. A majority of them had desired to quit. Tobacco control and cessation programmes therefore, remain important health issues.

Adolescent↗
PubMed1988

Attributable risk estimation from matched case-control data.

A methodology is proposed for obtaining summary estimators, variances, and confidence intervals for attributable risk measures from data obtained through a case-control study design where one or more controls have been matched to each case. The sampling design for obtaining these data is conceptualized as a simple random sample of cases being equivalent to a simple random sample of matched sets. By combining information across the strata determined by the matched sets, this approach provides all of the benefits associated with the Mantel-Haenszel procedure for the estimators of attributable risk among the exposed and population attributable risk. Asymptotic variances are derived under the assumption that the frequencies of the unique response patterns follow the multinomial distribution. Simulation results indicate that these methods fare very well with respect to bias and coverage probability.

Analysis of Variance↗
PubMed2003

Triacylglycerol markers of mature human milk.

OBJECTIVES: To determine which triacylglycerol (TAG) species in mature human milk are less affected by external factors and may thus be considered as TAG markers, as well as to determine which species are most influenced by these external conditions. Furthermore, we examine the correlation between the TAG markers and their fatty acids (FAs). SETTING AND SUBJECTS: Six healthy women from Barcelona (Catalonia, Spain). DESIGN AND INTERVENTIONS: In order to obtain the maximum variability of sampling conditions, 40 mature human milk samples were collected from different mothers, on different days, at different times of the day, and from different breasts during and after both the baby's and mother's meal. TAG and FA profiles were determined and correlated. The TAG composition was determined by high-performance liquid chromatography with an evaporative light-scattering detector, and also with atmospheric pressure chemical ionisation mass spectrometry. FAs compositions were determined by gas chromatography. RESULTS: The results were analysed using the SPSS statistical package and proved to be more variable than might have been found in a more restrictive sample design. Nevertheless, despite these conditions, some TAG species were found in relatively constant levels in mature human milk, and could thus be considered as markers of the mature milk TAG profile. TAG species that we can classify in this group were: LaMO, CaPO, LaCaO, LaPCa, LaOL, MPLn, LLO, LaOO, MPL, and MOL. The names do not indicate the location of fatty acids in the glycerol molecule. On the other hand, concentrations of other TAG species vary considerably between samples and consequently these may be understood to be especially affected by the external factors. TAGs like PaLS, MPO, PaOO, PPP, MPS, SPP, LOO, PPO, MOS, SSP, POL, and SOS are in this second group. Correlation between the TAG markers and their FAs was examined by Pearson's test and a significant correlation was found for some FAs. CONCLUSIONS: The TAG species present in mature human milk are affected in different ways by external factors such as dietary intake, nutritional status, length of lactation, time of the day, etc. Some TAGs may be considered as markers of mature human milk as they are relatively constant under a wide range of sampling conditions and do not depend on the factors mentioned. SPONSORSHIP: This study was supported by the Fundació Mestres Jané.

Adult↗
PubMed1990

Hispanic Health and Nutrition Examination Survey: methodological considerations.

The Hispanic Health and Nutrition Examination Survey (HHANES) was the first special population survey undertaken by the National Center for Health Statistics. The HHANES was designed to assess the health and nutritional status and needs of Mexican Americans, mainland Puerto Ricans and Cuban Americans. Data were collected using five data collection techniques: direct physical examinations, diagnostic testing, anthropometry, laboratory analyses, and interviews. Unlike other surveys conducted by the National Center for Health Statistics, the HHANES was not designed as a national survey. The HHANES was a survey of three Hispanic subgroups of the population in selected areas of the United States with a survey universe that included approximately 76 percent of the 1980 Hispanic-origin population in the United States. This article discusses statistical issues that should be addressed by researchers when analyzing HHANES data. Specifically, analysts need to account for the complex sample design, nonresponse bias, potential non-coverage bias, and the regional nature of the HHANES sample.

Acculturation↗
PubMed2002

[Evaluation of the quality of Anales Españoles de Pediatría versus Medicina Clínica].

OBJECTIVES: To compare the scientific methodology and quality of articles published in Anales Españoles de Pediatría and Medicina Clínica. MATERIAL AND METHODS: A stratified and randomized selection of 40 original articles published in 2001 in Anales Españoles de Pediatría and Medicina Clínica was made. Methodological errors in the critical analysis of original articles (21 items), epidemiological design, sample size, statistical complexity and levels of scientific evidence in both journals were compared using the chi-squared and/or Student's t-test. RESULTS: No differences were found between Anales Españoles de Pediatría and Medicina Clínica in the critical evaluation of original articles (p > 0.2). In original articles published in Anales Españoles de Pediatría, the designs were of lower scientific evidence (a lower proportion of clinical trials, cohort and case-control studies) (17.5 vs 42.5 %, p 0.05), sample sizes were smaller (p 0.003) and there was less statistical complexity in the results section (p 0.03). CONCLUSIONS: To improve the scientific quality of Anales Españoles de Pediatría, improved study designs, larger sample sizes and greater statistical complexity are required in its articles.

Bibliometrics↗
PubMed2006

Effects of coancestry on accuracy of individual assignments to population of origin: examples using Great Lakes lake trout (Salvelinus namaycush).

Methods for assigning individuals to population of origin are widely used in ecological genetics, resources management, and forensics. Characteristics of genetic data obtained from putative source populations that enhance accuracy of assignment are well established. How non-independence within and among unknown individuals to be classified [i.e., gene correlations within individual (inbreeding) and gene correlations among individuals within group (coancestry)] affect assignment accuracy is poorly understood. We used empirical data for six microsatellite loci and offspring from full-sib crosses of hatchery strains of lake trout (Salvelinus namaycush; Salmonidae) representing known levels of coancestry (mean theta = 0.006 and 0.06) within families to investigate how gene correlations can affect assignment. Additional simulations were conducted to further investigating the influence of allelic diversity (2, 6 or 10 alleles per locus) and inbreeding (F = 0.00, 0.05, and 0.15) on assignment accuracy for cases of low and high inter-population variance in allele frequency (mean F (st) = 0.01 and 0.1, respectively). Inbreeding had no effect on accuracy of assignments. In contrast, variance in assignment accuracy across replicated simulations, and for each empirical case study increased with increasing coancestry, reflecting non-independence of probabilities of correct assignment among members of kin groups. Empirical estimates of assignment error rates should be interpreted with caution if appreciable levels of coancestry are suspected. Additional emphasis should be placed on sampling designs (spatially and temporally) that define or minimize the potential for sampling related individuals.

Animal Population Groups↗
PubMed2005

Prevalence and severity of malnutrition and age at menarche; cross-sectional studies in adolescent schoolgirls in western Kenya.

OBJECTIVE: Nutritional status is an important marker of overall health and linear growth retardation has serious long-term physiological and economic consequences. Approximately 35 and 29% of preschool children in sub-Saharan Africa are stunted and underweight, respectively. There is relatively little information available about the nutritional status in adolescents, the age group with the highest growth velocity after infancy. We conducted a series of cross-sectional surveys to determine the prevalence and main risk groups for malnutrition and to describe the associations between age, sexual maturation and nutritional status in adolescent schoolgirls in western Kenya. DESIGN: Three cross-sectional surveys; one in Mumias, using random sampling in all schools, and two surveys in Asembo, using a multi-stage random sample design. SETTING: Public primary schools in two different rural malaria endemic areas in western Kenya with high levels of malnutrition in preschool children. SUBJECTS: In all, 928 randomly selected adolescent schoolgirls aged 12-18 y. RESULTS: Overall prevalence of stunting and thinness was 12.1 and 15.6%, respectively. Of the total, 2% were severely stunted. Menarche and start of puberty were delayed by approximately 1.5-2 y compared to a US reference population. The prevalence of stunting and thinness decreased with age and mean height for age z-scores converged towards the median of the US reference curve. Girls who had not yet started menstruating were more likely to be stunted than the girls of the same age who were post-menarche. CONCLUSIONS: Stunting and thinness are common in young adolescent schoolgirls in these poor rural settings in western Kenya, but the prevalence decreases with age, providing observational support that children catch up on incomplete growth attained earlier in life due to a maturational delay of 1.5-2 y allowing prolonged growth.

Adolescent↗