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Research trends in the Journal of Nurse-Midwifery 1987-1992.

To identify selected research trends, 69 research reports were analyzed from a sample of feature articles that were published in the Journal of Nurse-Midwifery between 1987 and 1992. Systematic appraisal was performed to classify these articles according to topic, design, sampling methodology, sample size, and funding. The largest proportion of studies were conducted on clinical topics (83%). Descriptive study designs were utilized most frequently (67%). Nonprobability sampling (81%) far exceeded probability sampling (19%); however, in 1992, probability sampling increased to 75%. With the exception of 1988, funding steadily increased over the study period. These results suggest that research has primarily focused upon clinical issues and has utilized descriptive designs and nonprobability sampling.

Female↗

Sample size and optimal designs for reliability studies.

A method is developed to calculate the required number of subjects k in a reliability study, where reliability is measured using the intraclass correlation rho. The method is based on a functional approximation to earlier exact results. The approximation is shown to have excellent agreement with the exact results and one can use it easily without intensive numerical computation. Optimal design configurations are also discussed; for reliability values of about 40 per cent or higher, use of two or three observations per subject will minimize the total number of observations required.

Analysis of Variance↗

The ecological condition of Gulf of Mexico resources from Perdido Key to Port St. Joe, Florida, USA: part I. coastal beach resources.

Using the approach established by EPA's Environmental Monitoring and Assessment Program (EMAP), a shoreline monitoring survey was conducted in August and September 1999, encompassing the Florida Panhandle from Perdido Key, Florida to Port St. Joe, Florida. The objective of this survey was to demonstrate the use of a probabilistic survey for monitoring and estimating the condition of swimmable beach areas. Thirty stations were sampled using a probabilistic sampling design. Hydrographic data were collected in addition to samples for water chemistry. Bacterial indicators, enterococci and fecal coliforms, were enumerated from the water according to the EPA Beaches Environmental Assessment Closure and Health (BEACH) Program and Florida state guidelines. Additional criteria for site condition included the presence or absence of primary and secondary dunes, anthropogenic debris and vegetation. Based on EMAP evaluation guidelines and Florida state criteria, a baseline assessment of the condition of the Gulf of Mexico beach resources surveyed is presented.

Data Collection↗

False allegations of abuse and neglect when parents separate.

OBJECTIVE: The 1998 Canadian Incidence Study of Reported Child Abuse and Neglect (CIS-98) is the first national study to document the rate of intentionally false allegations of abuse and neglect investigated by child welfare services in Canada. This paper provides a detailed summary of the characteristics associated with intentionally false reports of child abuse and neglect within the context of parental separation. METHOD: A multistage sampling design was used, first to select a representative sample of 51 child welfare service areas across Canada. Child maltreatment investigations conducted in the selected sites during the months of October-December 1998 were tracked, yielding a final sample of 7,672 child maltreatment investigations reported to child welfare authorities because of suspected child abuse or neglect. RESULTS: Consistent with other national studies of reported child maltreatment, CIS-98 data indicate that more than one-third of maltreatment investigations are unsubstantiated, but only 4% of all cases are considered to be intentionally fabricated. Within the subsample of cases wherein a custody or access dispute has occurred, the rate of intentionally false allegations is higher: 12%. Results of this analysis show that neglect is the most common form of intentionally fabricated maltreatment, while anonymous reporters and noncustodial parents (usually fathers) most frequently make intentionally false reports. Of the intentionally false allegations of maltreatment tracked by the CIS-98, custodial parents (usually mothers) and children were least likely to fabricate reports of abuse or neglect. CONCLUSIONS: While the CIS-98 documents that the rate of intentionally false allegations is relatively low, these results raise important clinical and legal issues, which require further consideration.

Canada↗

Is spermatozoan acrosin a predictor of fertilization and embryo quality in the human?

OBJECTIVE: To investigate whether acrosin is a more reliable criterion than conventional parameters for assessing semen samples. DESIGN: Total acrosin was estimated biochemically in semen samples obtained for routine screening for infertility and for IVF-ET procedures. SETTING: Assisted Conception Unit, St. James's University Hospital, Leeds, United Kingdom. PATIENTS: Four hundred sixty-three couples being investigated for causes of infertility, and 132 couples undergoing IVF-ET for any indication except antisperm antibodies between 1990 and 1991 were included in the study. INTERVENTIONS: Semen samples were collected as part of routine investigation. Samples from men with consistently high viscosity were collected in alpha-chymotrypsin. MAIN OUTCOME MEASURES: Total spermatozoan acrosin in motile spermatozoa and motile spermatozoan density in couples being assessed for IVF-ET and fertilization and embryo quality in those receiving treatment are considered. RESULTS: Total acrosin levels were less variable (within subject) than either total or motile spermatozoan concentration at ejaculation. Although severely oligozoospermic ejaculates had the lowest levels of total acrosin, overall, there was no significant correlation of spermatozoan concentration between total acrosin levels and percentage fertilization. CONCLUSIONS: Total spermatozoan acrosin activity correlates positively with fertilization rates but not with spermatozoan count. Motile spermatozoan density for insemination may be adjusted to achieve > 7.5 microIU acrosin per oocyte, without compromising fertilization or further embryo development to blastocysts in vitro.

Acrosin↗

Factors associated with the initiation of smoking by Kuwaiti males.

PURPOSE: To estimate the age patterns in cumulative probability of smoking initiation among Kuwaiti adult males and to study the differentials in smoking initiation in relation to factors such as age-cohort, marital status, educational level, income, type of residence, and history of smoking among family members and friends. METHODS: A stratified three stage cluster sampling design was implemented for the selection of the sample. A self-administered questionnaire was completed by 1798 Kuwaiti adult males working in different ministries. RESULTS AND IMPLICATIONS: Of the 1798 respondents, 34.4% were classified as current smokers, 17.7% as former smokers and 47.9% as non-smokers. The highest probability of smoking initiation (among current and former smokers) was found for the age group 15-20 years, where almost 29% of the respondents initiated smoking. In the univariate analysis, marital status, education, income, type of residence, and history of smoking among family members and friends showed significant variation in the age-patterns of initiation. In the Cox proportional hazard regression model, education, type of residence, and history of smoking among family members and friends were found to be independently associated with the risk of initiation. The highest risk of initiation (Relative Risk (RR) = 1.85; 95% CI: 1.62-2.10) was found among those who had a history of smoking in family and friends. Individuals in the lowest education category (RR = 1.64; 95% CI: 1.32-2.04) and those residing in apartments (RR = 1.65; 95% CI: 1.43-1.92) were at a higher risk of initiation compared with those who had university education or those who resided in villas. The results of the study should prompt further efforts to develop tobacco control policies in Kuwait and the other Arabian Gulf countries to help establish norms for not initiating smoking through persistent messages to not start or to stop smoking. There is also a need to enhance awareness about the influence of smokers in family or friends on other people to initiate smoking.

Adolescent↗

Apolipoprotein E epsilon4 and risk of mortality in African American and white older community residents.

PURPOSE: The goal of this study was to determine whether the epsilon4 allele of apolipoprotein E is predictive of mortality in a community-based sample. DESIGN AND METHODS: Of the stratified random household sample of 4,162 participants age 65 years and older enrolled in the Duke site of the Established Populations for Epidemiologic Studies of the Elderly, those included in the present study were the 1,998 who were genotyped for apolipoprotein E (alleles epsilon2, epsilon3, and epsilon4) six years after baseline, and for whom survival status eight years later was known by search of the National Death Index. Information on demographic characteristics, physical and mental health status, functional status, and health services use was determined by structured questionnaires administered in person in the home. RESULTS: The epsilon4 allele did not predict mortality for the group as a whole, or for those who were cognitively impaired. It did predict mortality for those who reported having had a heart attack or stroke. IMPLICATIONS: The apolipoprotein epsilon4 allele-although a risk factor for Alzheimer's disease, heart disease, and stroke-was only found to be a risk factor for mortality for those community residents who had had a heart attack or stroke. Otherwise, for this community-based sample, 71 years of age and older, it did not predict time to death and was not a risk factor for mortality.

Black or African American↗

Plasma lipid peroxides: relationships to cardiovascular risk factors and prevalent cardiovascular disease.

BACKGROUND: The epidemiology of plasma lipid peroxides, which may play a role in atherogenesis, has not been well defined. AIM: To study the relationships of plasma lipid peroxides to cardiovascular risk factors in a random population sample. DESIGN: Random, age- and sex-stratified population sample. METHODS: We studied 739 men and women aged 25-74 years. Lipid peroxides were assayed by the thiobarbituric acid (TBA) assay for malondialdehyde (MDA) in stored plasma samples. RESULTS: Lipid peroxide levels increased with age. In men, lipid peroxides were significantly associated with smoking habit. Lipid peroxides correlated with non-fasting serum triglycerides (r = 0.33; p < 0.0001) in both sexes. Weaker associations were observed for cholesterol, high-density lipoprotein cholesterol (inversely), body mass index, fibrinogen and white cell count; as well as an inverse association with serum vitamin C in men. DISCUSSION: These findings clarify the relationships of plasma lipid peroxides to cardiovascular risk factors; and are consistent with the hypothesis that lipid peroxidation may be one mechanism through which several risk factors may promote cardiovascular disease.

Adult↗

Testing a model: a developmental perspective of adolescent male sexuality.

PURPOSE: This study tested a model of adolescent male sexuality and evaluated its usefulness for predicting sexual behaviors among a diverse sample. DESIGN AND METHODS: Secondary analysis using a national sample was conducted. Sexuality was conceptualized as depending on family, peers, and school. Neighborhood was hypothesized to influence sexuality indirectly. Sexuality was hypothesized to influence sexual behaviors and age at first sex. Structural equation modeling techniques were used with ethnic comparisons. RESULTS: Family was the strongest predictor of sexuality. Males who were closer to their family were sexually conservative; males closer to peers were sexually permissive. Neighborhood's influence was moderated through family and school. Ethnic differences were not found. PRACTICE IMPLICATIONS: Sexuality assessments and strengthening family relationships are essential.

Adolescent↗

Reference ranges for biochemical and haematological values in farmed saltwater crocodile (Crocodylus porosus) yearlings.

OBJECTIVE: To determine reference ranges for healthy yearling farmed saltwater crocodiles by performing routine biochemical and haematological laboratory tests on blood samples. DESIGN: A clinico-pathological study. PROCEDURE: Blood samples were collected from 120 healthy yearlings from four Northern Territory crocodile farms and body weight and length were measured. All animals had been fasted for 2 days before sample collection. Routine biochemical analytes were determined on 120 samples and haematological values determined on 30 samples (from one farm). RESULTS: Reference ranges for biochemical and haematological values were determined for farmed yearling saltwater crocodiles in the Northern Territory. CONCLUSION: The results were comparable with published reference ranges for other crocodilian species. Other published results of haematological values from saltwater crocodiles were from very young (6-week-old) hatchlings and older (2- to 4-year-old) crocodiles. Differences in values were presumed to be caused by age-related factors.

Aging↗

Effectiveness of a primary care intervention to support reading aloud: a multicenter evaluation.

OBJECTIVE: Failure to read at grade level predicts life-long economic and social disability. Early exposure to reading aloud may prevent reading problems. This study seeks to determine whether institution of Reach Out and Read (ROR) programs is associated with increased reading aloud in a national sample. DESIGN: Before-after intervention study: separate convenience samples were studied before and after institution of ROR programs at multiple sites. PARTICIPANTS AND SETTING: A convenience sample of parents of children age 6-72 months seeking routine health care at 19 clinical sites in 10 states. INTERVENTIONS: The ROR model incorporates anticipatory guidance about reading aloud and distribution of free picture books at health supervision visits from 6 months through 5 years as well as reading aloud in the waiting room. MAIN OUTCOME MEASURES: Parents were interviewed about their attitudes and practices related to reading aloud, using questions drawn from validated instruments. RESULTS: The sample included 1647 subjects (730 intervention, 917 comparison). After controlling for multiple potential confounding factors, significant associations were found between exposure to ROR and reading aloud as a favorite parenting activity (Adjusted Odds Ratio [AOR] 1.6, P < .001); reading aloud at bedtime (Adjusted Odds Ratio [AOR*rsqb; 1.5, P < .001); reading aloud 3 or more days per week (AOR 1.8, P < .001); and ownership of > or = 10 picture books (AOR 1.6, P < .001). CONCLUSIONS: In a national sample, implementation of ROR programs was associated with increased parental support for reading aloud. This study provides evidence of the effectiveness of a primary care intervention strategy to promote reading aloud to young children.

Child↗

Estimating distributions of numbers of organisms in food products.

Procedures of sampling and measurement contribute variability and uncertainty to exposure models that predict incidence and levels of organisms in food products. This paper focuses on methods that account for sampling and measurement error in fitting distributions of organisms in food products for use in exposure models for microbial risk assessment. Define y to be a measured density on a sample selected with stipulated probability from a population, and define x to be the "true" density for that sample. Designate the conditional distribution of y given the sample with "true" value x as g(y/x), and let F(x) be the unknown cumulative density of x. The distribution of the observed values y, h(y), can be expressed through the integral equation h(y) = integral of g(y/x) dF(x). Knowledge of g(y/x) and h(y) enables an estimate of the unknown distribution of the organism's F(x). In applications to risk assessment, use of continuous distributions described by a few parameters is desirable. Also desirable may be imputation or assignment of possible nonzero values for nondetect observations--those results below the limit of detection of the methodology--that may not be truly zero. This paper explores the use of the above formulation for estimating distributions of organisms used for microbial risk assessment and presents some simple examples.

Clostridium perfringens↗

Sample collection factors affect the sensitivity of the diagnostic test for Tritrichomonas foetus in bulls.

The current diagnostic test for Tritrichomonas foetus involves the culture of collected preputial or vaginal samples. In an earlier study, which evaluated sampling tools for use with bulls, it was observed that the sensitivity of the diagnostic test was higher for 2nd samples collected from the right side of the prepuce than it was for samples collected 1st from the left side. The study described in this paper was conducted to evaluate which of these factors was responsible for the effect on diagnostic sensitivity. Twenty-nine bulls infected with T. foetus were repeatedly sampled in a 2-factor cross-over design. Samples taken from the right side of the prepuce were 4 times as likely to be positive as samples taken from the left side (P = 0.03). Other factors did not have a significant effect on the outcome of the diagnostic test. Unexpected factors may affect the sensitivity of the diagnostic test for T. foetus.

Animals↗

The Alberta Heart Health Survey: methods and results.

OBJECTIVE: The Alberta Heart Health Survey is a population-based investigation of cardiovascular disease (CVD) risk factor prevalence and awareness among Albertans 18 to 74 years of age. DESIGN: A stratified, two-stage, replicated probability sample design developed by Statistics Canada was used to select 3437 individuals (2740 were located) from the Alberta Health Care Insurance Plan enrollment list. Trained community health nurses (n = 36) from 13 public health units conducted home interviews (n = 2237, response rate 82%) and subsequent clinic visits (n = 1993) from February to June 1990, using a core protocol common to similar studies conducted in other provinces, as part of the Canadian Heart Health Initiative. SETTING: The home interview collected data on individual and household demographic characteristics, smoking, alcohol consumption, physical activity, treatment and control of high blood pressure and high blood cholesterol, and family history of CVD. Clinic visits included blood collection for analysis of total plasma cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides; weight, height, waist and hip circumference, and two blood pressure measurements. Standardized protocols were used. Lipid analyses were conducted by the Lipid Research Laboratory, University of Toronto. Data management and analysis were conducted at the University of Alberta. MAIN RESULTS: The overall risk factor prevalence estimates were: high blood pressure 14%; smoking 27%; total cholesterol of at least 5.2 mmol/L, 36%; HDL cholesterol less than 0.9 mmol/L, 10%; LDL cholesterol of at least 3.4 mmol/L, 29%; body mass index 25 or more, 51%; sedentary lifestyle 37%. One or more of the three major risk factors (smoking, high blood pressure, high blood cholesterol) occurred in 57% (70% in those with 12 years of education or less). CONCLUSIONS: While the prevalence rates for the major risk factors are among the lowest in Canada, they are unacceptably high.

Adult↗

Use of randomised controlled trials for producing cost-effectiveness evidence: potential impact of design choices on sample size and study duration.

BACKGROUND: A number of approaches to conducting economic evaluations could be adopted. However, some decision makers have a preference for wholly stochastic cost-effectiveness analyses, particularly if the sampled data are derived from randomised controlled trials (RCTs). Formal requirements for cost-effectiveness evidence have heightened concerns in the pharmaceutical industry that development costs and times might be increased if formal requirements increase the number, duration or costs of RCTs. Whether this proves to be the case or not will depend upon the timing, nature and extent of the cost-effectiveness evidence required. OBJECTIVE: To illustrate how different requirements for wholly stochastic cost-effectiveness evidence could have a significant impact on two of the major determinants of new drug development costs and times, namely RCT sample size and study duration. DESIGN: Using data collected prospectively in a clinical evaluation, sample sizes were calculated for a number of hypothetical cost-effectiveness study design scenarios. The results were compared with a baseline clinical trial design. RESULTS: The sample sizes required for the cost-effectiveness study scenarios were mostly larger than those for the baseline clinical trial design. Circumstances can be such that a wholly stochastic cost-effectiveness analysis might not be a practical proposition even though its clinical counterpart is. In such situations, alternative research methodologies would be required. For wholly stochastic cost-effectiveness analyses, the importance of prior specification of the different components of study design is emphasised. However, it is doubtful whether all the information necessary for doing this will typically be available when product registration trials are being designed. CONCLUSIONS: Formal requirements for wholly stochastic cost-effectiveness evidence based on the standard frequentist paradigm have the potential to increase the size, duration and number of RCTs significantly and hence the costs and timelines associated with new product development. Moreover, it is possible to envisage situations where such an approach would be impossible to adopt. Clearly, further research is required into the issue of how to appraise the economic consequences of alternative economic evaluation research strategies.

Cost-Benefit Analysis↗

A statistical survey of dioxin-like compounds in United States beef: a progress report.

The USEPA and the USDA have completed the first statistically designed survey of the occurrence and concentration of CDDs and CDFs in the fat of beef animals raised for human consumption in the United States. Back fat was sampled from 63 carcasses at federally inspected slaughter establishments nationwide. The sample design called for sampling beef animal classes in proportion to national annual slaughter statistics. All samples were analyzed using a modification of EPA method 1613, using isotope dilution, High Resolution GC/MS to determine the rate of occurrence of 2,3,7,8-substituted CDDs/CDFS. The whole weight method detection limits ranged from 0.05 ng kg-1 for TCDD to 3 ng kg-1 for OCDD. The results of this survey showed a mean concentration (reported as I-TEQ, lipid adjusted) in U.S. beef animals of 0.35 ng kg-1 and 0.89 ng kg-1 when either non-detects are treated as 0 value or assigned a value of 1/2 the detection limit, respectively.

Animals↗