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PubMed1997

The prevalence of rheumatic diseases in a Filipino urban population: a WHO-ILAR COPCORD Study. World Health Organization. International League of Associations for Rheumatology. Community Oriented Programme for the Control of the Rheumatic Diseases.

OBJECTIVE: To determine the point prevalence of musculoskeletal complaints and rheumatic diseases in a Filipino urban community. METHODS: A descriptive cross-sectional 2 phase survey was conducted in an urban community in Metropolitan manila. Phase I (screening) used face-to-face interviews, while phase II (examination) involved case identification of the rheumatic diseases. We sampled 670 households (3065 adults) using a multistage cluster sampling method. A pilot study was conducted to pretest the questionnaire for cross-cultural adaptation and validation, field procedures, sampling design, and data management plan. Standardized translated COPCORD questionnaires (blind translation and blind back-translation) were administered by trained interviewers. Two weeks after Phase I, Phase II was conducted at local health centers. The COPCORD questionnaire screened the number of cases with musculoskeletal complaints. Identification of cases with rheumatic disease was based on American College of Rheumatology (ACR) criteria. RESULTS: Respondents completed 3006 questionnaires (phase I response rate 98%). Of these 489 respondents had musculoskeletal complaints. Functional disability was reported in 25% among these respondents. We examined 353 (phase II response rate 72%), revealing 294 with rheumatic conditions. In 26 persons there were no abnormalities, while 32 had nonrheumatic conditions at examination. The most common rheumatic diseases were osteoarthritis (OA) (n = 124) and soft tissue rheumatism (n = 115). CONCLUSION: The prevalence of musculoskeletal complaints was 16.3% (95% CI 8.6-24.0) of the adult population in a FIlipino urban community. The total prevalence of rheumatic disease is 9.8% (95% CI 8.2-11.4). The prevalence of OA was 4.1% (95% CI 3.3-4.9) and soft tissue rheumatism 3.8% (95% CI 2.9-4.8). The prevalence of rheumatoid arthritis, 0.17% (95% CI 0-9.36), was notably low compared to the prevalence in other developing countries.

Adolescent↗
PubMed1997

Antibiotic prescribing for adults with colds, upper respiratory tract infections, and bronchitis by ambulatory care physicians.

CONTEXT: Antibiotic use is associated with increased rates of antibiotic-resistant organisms. A previous study has shown that colds, upper respiratory tract infections, and bronchitis account for nearly one third of all antibiotic prescribing by ambulatory care physicians. How frequently antibiotics are prescribed for these conditions and for and by whom is not known. OBJECTIVES: To measure antibiotic prescription rates and to identify predictors of antibiotic use for adults diagnosed as having colds, upper respiratory tract infections, and bronchitis in the United States. DESIGN: Sample survey of practicing physicians participating in the National Ambulatory Medical Care Survey, 1992. SETTING: Office-based physician practices. SUBJECTS: Physicians (n=1529) completing patient record forms for adult office visits (n=28787). MAIN OUTCOME MEASURES: Antibiotic prescriptions for colds, upper respiratory tract infections, and bronchitis. RESULTS: Office visits for colds, upper respiratory tract infections, and bronchitis resulted in approximately 12 million antibiotic prescriptions, accounting for 21% of all antibiotic prescriptions to adults in 1992. A total of 51 % of patients diagnosed as having colds, 52% of patients diagnosed as having upper respiratory tract infections, and 66% of patients diagnosed as having bronchitis were treated with antibiotics. Female sex (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.05-2.62) and rural practice location (OR, 2.25; 95% CI, 1.33-3.80) were associated with greater antibiotic prescription rates, whereas black race (OR, 0.44; 95% CI, 0.21-0.93) was associated with lower antibiotic prescription rates. Patient age, Hispanic ethnicity, geographic region, physician specialty, and payment sources were not associated with antibiotic prescription rates in the bivariate analysis. Multivariate logistic regression analysis identified only rural practice location (adjusted OR, 2.58; 95% CI, 1.39-4.76) to be independently associated with more frequent antibiotic prescriptions for colds, upper respiratory tract infections, and bronchitis. CONCLUSION: Although antibiotics have little or no benefit for colds, upper respiratory tract infections, or bronchitis, these conditions account for a sizable proportion of total antibiotic prescriptions for adults by office-based physicians in the United States. Overuse of antibiotics is widespread across geographical areas, medical specialties, and payment sources. Therefore, effective strategies for changing prescribing behavior for these conditions will need to be broad based.

Adult↗
PubMed1997

Clinicopathologic significance of the expression of mutated p53 protein and the proliferative activity of cancer cells in patients with esophageal squamous cell carcinoma.

BACKGROUND: The aim of this study was to investigate the relation between the expression of mutated p53 protein and the proliferative activity of cancer cells in esophageal squamous cell carcinoma. In addition, the clinical and biologic significance of p53 status and the proliferative activity of cancer cells were evaluated in these patients. STUDY DESIGN: Samples of esophageal tumors from 94 patients were subjected to immunohistochemical staining with a monoclonal antibody against p53 and with the monoclonal antibody Ki-67. The immunoreactivity against p53 and the proliferative activity of cancer cells were compared with the clinicopathologic findings in each sample. Prognostic factors including p53 status and Ki-67 labeling index (LI; percentage of Ki-67-immunostained cells) were evaluated for 81 surviving patients by univariate and multivariate analysis. RESULTS: The mean Ki-67 LI of 50 p53-positive patients was higher than that of 44 p53-negative patients (p = 0.009). The Ki-67 LI increased according to the progression of tumors. Overexpression of mutated p53 protein was observed in 40.9% of tumors that invaded to the submucosa, and this percentage was not significantly changed in tumors with invasion to the adventitia. Metastases to the regional lymph nodes were observed in 3 of 22 patients with tumors that invaded to the submucosa, and these 3 tumors had both over-expression of mutated p53 protein and high Ki-67 LI. In 81 surviving patients, only lymph node metastasis (p = 0.045) and the curability of tumors (p < 0.001) were identified as independent prognostic factors by multivariate analysis. CONCLUSIONS: Overexpression of mutated p53 protein is detected in the early stage of esophageal cancer. This mutated p53 protein may not play an important role for tumor invasion. When tumor invasion is limited to the submucosa, cancer cells that overexpress mutated p53 protein may acquire high proliferative activity. Such cells might have considerable potential for metastasis to the lymph nodes.

Adult↗
PubMed1997

Street youth, their peer group affiliation and differences according to residential status, subsistence patterns, and use of services.

This study characterizes subcultural differences within an inner-city street youth population. Variations in residential status, subsistence patterns, and service utilization according to peer group affiliation were explored. A brief structured interview was administered to 752 youth, ages 12 to 23 years, who had been living on the streets for two or more consecutive months, or who were fully integrated into the "street economy." Subjects were recruited for the study using a stratified probability sampling design, with 30% recruited from community-based service sites and 70% from street locations and at natural "hang-outs." Five street youth groups were identified: "punks/skinheads," "druggies," "hustlers," "gang members," and "loners." The results demonstrated unique patterns with respect to places stayed/slept, means of financial support and economic subsistence, and use of available services according to peer group affiliation. The implications of these findings and recommendations for future research and service provision are discussed.

Adolescent↗
PubMedDate not supplied

HIV/AIDS risk factors among adolescent students in Puerto Rico, 1994.

PURPOSE: Identify several HIV risk behaviors among adolescent students. METHODS: The sample (n = 3,648) was selected using a two-staged stratified cluster sampling design, and weighted to represent all junior high and high school students. RESULTS: About 28.8% of the students reported ever having sexual activity. Less than half of the sexually active (44.5%) used condoms during their last sexual activity; 27.6% used them always. Only 54.7% knew correctly > 75% of the HIV knowledge questions. A HIV risk scale was constructed using five risk factors. About 15.9% of the students did not have any risk factor, 36.2% had one, 47.9% had two or more. Males and high school students had significantly more risk factors. Half of the students will abstain from having sex next year because they don't want to get HIV/AIDS. CONCLUSIONS: It is important to implement effective HIV prevention programs for adolescents in order to change their attitudes and behaviors.

Adolescent↗
PubMed1997

Metaphor, symbolic play, and logical thought in early childhood.

Development of the ability to understand diverse types of metaphor was examined in terms of play context (symbolic vs. constructive-object play), Piagetian operational level (preoperational vs. concrete-operational), and medium of presentation (pictures vs. words). Forty 4-year-olds and 80 6-year-olds (40 preoperational, 40 concrete-operational) were presented with six different types of metaphorical relationships (color, shape, physiognomic, cross-modal, psychological-physical, and taxonomic matches) in both pictures and words in a match-to-sample design. Results indicated that (a) constructive-object play, rather than symbolic play, facilitated the understanding of perceptual and taxonomic metaphor, suggesting differences in early styles of metaphoric usage; (b) despite previous findings, the study failed to replicate a relationship between operativity and metaphoric understanding; and (c) younger children did significantly better in the pictorial medium, suggesting a picture-superiority effect for more perceptible metaphorical relations (perceptual and physiognomic), whereas older children showed a word-superiority effect for more conceptual metaphors (psychological-physical and taxonomic).

Age Factors↗
PubMedDate not supplied

[Internal and external environment of the Puerto Rican adolescent in the use of alcohol, drugs and violence].

PURPOSE: Identify risk factors associated to violent behavior among adolescent students. METHODS: A survey was conducted using a two-staged stratified cluster sampling design. It represents all junior and high school students of Puerto Rico. Students from 117 schools were administered an anonymous questionnaire. RESULTS: Alcohol use was reported by 78.7% of students, and 14% reported illegal drug use. About 25% committed one violent act during the previous year, and 22% committed two acts or more. Drug use, alcohol use, not getting along with their parents, being a male, school failure and drug use by siblings were identified as risk factors for violent behavior. Church attendance was identified as a protective factor. DISCUSSION: Primary physicians can play an important role in violence prevention through early identification of family violence.

Adolescent↗
PubMed1998

Analysis of age of onset data from case-control family studies.

Age of onset data from case-control family studies are frequently used to study the relationship between disease and environmental or genetic factors. Dependence of age of onset within family and case-control sampling designs must be taken into account in analyzing such data. In this paper, we propose a parametric likelihood approach to study the relationship between disease risk and covariates, allowing for any correlations in age of onset of disease between family members and to study the familial association in age of onset of disease due to genetic factors, after adjusting for other shared covariates within the family. The method provides a way to combine the information relating disease incidence to risk factors in relatives with the information contained in the case/control contrasts in order to obtain more precise estimates of the effects of the putative risk factors. A data set from a case-control family study of lung cancer is used to illustrate the method. The analysis indicated that history of smoking, passive smoking, and history of chronic obstructive pulmonary disease are positively associated with lung cancer risk, and that, after adjustment for these risk factors, there is little evidence of familial aggregation in lung cancer risk.

Adult↗
PubMed1998

Pattern of attendance to dentists and hygienists in the County of Göteborgs and Bohus län during 1990-1992.

AIM: To describe the dental care consumption in a random sample of the population of a Swedish county 1990-1992 and to compare this with results from other Swedish studies, especially those using different self-reporting methods. SUBJECTS: One sixtieth of all adult inhabitants in the County of Göteborgs and Bohus län (all individuals born on the 17th day of an odd month) formed the sample. DESIGN: All insurance claims sent from both public and private dentists to the local insurance offices were registered in a data base. Thus every treatment registration was collected into this data base, independently, whether it was made in a private clinic or in the Public Dental Service and whether or not by a dental hygienist or other grade. Since almost all dental care in Sweden was performed within the dental insurance system, these registrations could be regarded as very near to the total dental care consumption of this group. The registrations were related to the age of the patient, the type of care (acute/regular), regularity, dental hygienist treatment and other factors. RESULTS: It was found that the youngest and the oldest patients visited a dentist less often, that approximately a quarter received hygienist care, that many received emergency treatment sometime during the observation period but that a majority also had regular dental care. Studies using a self-reporting technique reported a systematically higher level of consumption than those using insurance claim registration. CONCLUSIONS: Dental care consumption studies using self-reporting methods will probably overestimate the actual consumption. Emergency treatment is frequent even among patients who go to a dentist regularly.

Adult↗
PubMed1998

NIH Consensus Conference. Acupuncture.

OBJECTIVE: To provide clinicians, patients, and the general public with a responsible assessment of the use and effectiveness of acupuncture to treat a variety of conditions. PARTICIPANTS: A nonfederal, nonadvocate, 12-member panel representing the fields of acupuncture, pain, psychology, psychiatry, physical medicine and rehabilitation, drug abuse, family practice, internal medicine, health policy, epidemiology, statistics, physiology, biophysics, and the representatives of the public. In addition, 25 experts from these same fields presented data to the panel and a conference audience of 1200. Presentations and discussions were divided into 3 phases over 2 1/2 days: (1) presentations by investigators working in areas relevant to the consensus questions during a 2-day public session; (2) questions and statements from conference attendees during open discussion periods that were part of the public session; and (3) closed deliberations by the panel during the remainder of the second day and morning of the third. The conference was organized and supported by the Office of Alternative Medicine and the Office of Medical Applications of Research, National Institutes of Health, Bethesda, Md. EVIDENCE: The literature, produced from January 1970 to October 1997, was searched through MEDLINE, Allied and Alternative Medicine, EMBASE, and MANTIS, as well as through a hand search of 9 journals that were not indexed by the National Library of Medicine. An extensive bibliography of 2302 references was provided to the panel and the conference audience. Expert speakers prepared abstracts of their own conference presentations with relevant citations from the literature. Scientific evidence was given precedence over clinical anecdotal experience. CONSENSUS PROCESS: The panel, answering predefined questions, developed their conclusions based on the scientific evidence presented in the open forum and scientific literature. The panel composed a draft statement, which was read in its entirety and circulated to the experts and the audience for comment. Thereafter, the panel resolved conflicting recommendations and released a revised statement at the end of the conference. The panel finalized the revisions within a few weeks after the conference. The draft statement was made available on the World Wide Web immediately following its release at the conference and was updated with the panel's final revisions within a few weeks of the conference. The statement is available at http://consensus.nih.gov. CONCLUSIONS: Acupuncture as a therapeutic intervention is widely practiced in the United States. Although there have been many studies of its potential usefulness, many of these studies provide equivocal results because of design, sample size, and other factors. The issue is further complicated by inherent difficulties in the use of appropriate controls, such as placebos and sham acupuncture groups. However, promising results have emerged, for example, showing efficacy of acupuncture in adult postoperative and chemotherapy nausea and vomiting and in postoperative dental pain. There are other situations, such as addiction, stroke rehabilitation, headache, menstrual cramps, tennis elbow, fibromyalgia, myofascial pain, osteoarthritis, low back pain, carpal tunnel syndrome, and asthma, in which acupuncture may be useful as an adjunct treatment or an acceptable alternative or be included in a comprehensive management program. Further research is likely to uncover additional areas where acupuncture interventions will be useful.

Acupuncture Therapy↗
PubMed1998

Abnormal sonographic endometrial findings in asymptomatic postmenopausal women: possible role of antihypertensive drugs.

OBJECTIVE: The purpose of this study was to evaluate the possible effect of the antihypertensive agent nifedipine (a calcium channel antagonist) on the endometrium of asymptomatic menopausal women by using transvaginal sonography, hysteroscopy, and endometrial sampling. DESIGN: Eighty-five asymptomatic postmenopausal women with an ultrasonographically detected endometrial thickness of more than 7 mm were examined. The study group comprised 43 women treated with nifedipine (30-60 mg/day) for mild to moderate hypertension for at least 1 year, and the control group comprised 42 normotensive women. All participants underwent transvaginal sonography, hysteroscopy, and, if necessary, endometrial biopsy. RESULTS: Of the 85 patients, 53 were found to have atrophic endometrium, 36 (83.7%) in the study group and 17 (40.5%) in the control group. The difference between the groups was statistically significant (p < 0.05). There were three cases of hyperplasia and three cases of carcinoma of the endometrium, with similar rates in the two groups. CONCLUSIONS: Among asymptomatic postmenopausal patients with sonographically thickened endometrium, atrophic endometrium was found to be significantly more prevalent in those using calcium channel antagonists to control hypertension than in those who were normotensive controls. The presence of endometrial hyperplasia and malignancy in the study group underscores the importance of meticulous endometrial evaluation whenever sonographically thickened endometrium is encountered.

Aged↗
PubMed1999

Estimating and generalizing with clustered sampling in general practice.

General practice research focusing on patients may involve risk factors, morbidity, medication use or patient satisfaction. When collecting information about patients it is often easier, cheaper and more appropriate to enlist the support of a number of general practitioners (GPs) who provide access to a number of patients. Such studies utilise a 'cluster sampling' (CS) design, as clusters or groups of patients around a GP are used for the investigation. In analysing data from these studies it is necessary to consider the impact that the study design will have on the variance structure of data collected.

Australia↗
PubMed1994

Estimating sample sizes for repeated measurement designs.

Formulas for estimating sample sizes that are required to provide specified power for analysis of variance (ANOVA) tests of significance in a two-group repeated measurements design are presented and evaluated. Power and sample size requirements depend on the pattern of treatment effects and the pattern of correlations among the repeated measurements, as well as on parameters common to sample size estimation for cross-sectional comparisons of treatment effects in simple randomized designs. Simplifying assumptions permit generation of these numerous parameter estimates from predictions of the magnitude of the standardized "effect size" at end of trial and the single correlation between the baseline and endpoint measurements. Monte Carlo methods are used to verify the actual power of different tests of significance for treatment effects in repeated measurement designs using sample sizes estimated by the formulas. The sample size implications of different patterns of treatment effects, levels of correlation, and numbers of repeated measurements are evaluated.

Analysis of Variance↗
PubMed2003

Microarray experimental design: power and sample size considerations.

Gene expression analysis using high-throughput microarray technology has become a powerful approach to study systems biology. The exponential growth in microarray experiments has spawned a number of investigations into the reliability and reproducibility of this type of data. However, the sample size requirements necessary to obtain statistically significant results has not had as much attention. We report here statistical methods for the determination of the sufficient number of subjects necessary to minimize the false discovery rate while maintaining high power to detect differentially expressed genes. Two experimental designs were considered: 1) a comparison between two groups at a single time point, and 2) a comparison of two experimental groups with sequential time points. Computer programs are available for the methods discussed in this paper and are adaptable to more complicated situations.

Oligonucleotide Array Sequence Analysis↗
PubMed2005

A new design of groundwater sampling device and its application.

Compounds in the atmosphere contaminate samples of groundwater. An inexpensive and simple method for collecting groundwater samples is developed to prevent contamination when the background concentration of contaminants is high. This new design of groundwater sampling device involves a glass sampling bottle with a Teflon-lined valve at each end. A cleaned and dried sampling bottle was connected to a low flow-rate peristaltic pump with Teflon tubing and was filled with water. No headspace volume was remained in the sampling bottle. The sample bottle was then packed in a PVC bag to prevent the target component from infiltrating into the water sample through the valves. In this study, groundwater was sampled at six wells using both the conventional method and the improved method. The analysis of trichlorofluoromethane (CFC-11) concentrations at these six wells indicates that all the groundwater samples obtained by the conventional sampling method were contaminated by CFC-11 from the atmosphere. The improved sampling method greatly eliminated the problems of contamination, preservation and quantitative analysis of natural water.

Chlorofluorocarbons, Methane↗
PubMed2001

Design issues and sample size when exposure measurement is inaccurate.

Measurement error often leads to biased estimates and incorrect tests in epidemiological studies. These problems can be corrected by design modifications which allow for refined statistical models, or in some situations by adjusted sample sizes to compensate a power reduction. The design options are mainly an additional replication or internal validation study. Sample size calculations for these designs are more complex, since usually there is no unique design solution to obtain a prespecified power. Thus, additionally to a power requirement, an optimal design should also fulfill the criteria of minimizing overall costs. In this review corresponding strategies and formulae are described and appraised.

Bias↗
PubMed2006

Variance estimation, design effects, and sample size calculations for respondent-driven sampling.

Hidden populations, such as injection drug users and sex workers, are central to a number of public health problems. However, because of the nature of these groups, it is difficult to collect accurate information about them, and this difficulty complicates disease prevention efforts. A recently developed statistical approach called respondent-driven sampling improves our ability to study hidden populations by allowing researchers to make unbiased estimates of the prevalence of certain traits in these populations. Yet, not enough is known about the sample-to-sample variability of these prevalence estimates. In this paper, we present a bootstrap method for constructing confidence intervals around respondent-driven sampling estimates and demonstrate in simulations that it outperforms the naive method currently in use. We also use simulations and real data to estimate the design effects for respondent-driven sampling in a number of situations. We conclude with practical advice about the power calculations that are needed to determine the appropriate sample size for a study using respondent-driven sampling. In general, we recommend a sample size twice as large as would be needed under simple random sampling.

Analysis of Variance↗
PubMed2005

The Mayo Clinic family study of Parkinson's disease: study design, instruments, and sample characteristics.

We describe here the Mayo Clinic Family Study of Parkinson's disease (PD), including the overall study design (historical cohort study of relatives from birth to onset of PD or censoring), the data collection instruments, the strategies implemented to prevent or measure biases, and the sample obtained. These methodological details may provide assistance to other investigators designing studies of the familial aggregation of PD or other aging-related chronic diseases. We investigated the incidence of PD and other neurodegenerative diseases among 1,001 first-degree relatives of 162 patients with PD and 851 relatives of 147 controls representative of the population of Olmsted County, Minn., USA. In addition, we studied 2,713 first-degree relatives of 411 patients with PD referred to the Mayo Clinic. Finally, we studied a group of 625 spouses of either cases or controls. Relatives with PD or other neurodegenerative diseases were ascertained using the family study method.

Adult↗