Power, effects, confidence, and significance: an investigation of statistical practices in nursing research

Objectives: To (a) assess the statistical power of nursing research to detect small, medium, and large effect sizes; (b) estimate the experiment-wise Type I error rate in these studies; and (c) assess the extent to which (i) a priori power analyses, (ii) effect sizes (and interpretations thereof), and (iii) confidence intervals were reported. Design: Statistical review. Data sources: Papers published in the 2011 volumes of the 10 highest ranked nursing journals, based on their 5-year impact factors. Review methods: Papers were assessed for statistical power, control of experiment-wise Type I error, reporting of a priori power analyses, reporting and interpretation of effect sizes, and reporting of confidence intervals. The analyses were based on 333 papers, from which 10,337 inferential statistics were identified. Results: The median power to detect small, medium, and large effect sizes was .40 (interquartile range [. IQR]. = .24-.71), .98 (IQR= .85-1.00), and 1.00 (IQR= 1.00-1.00), respectively. The median experiment-wise Type I error rate was .54 (IQR= .26-.80). A priori power analyses were reported in 28% of papers. Effect sizes were routinely reported for Spearman's rank correlations (100% of papers in which this test was used), Poisson regressions (100%), odds ratios (100%), Kendall's tau correlations (100%), Pearson's correlations (99%), logistic regressions (98%), structural equation modelling/confirmatory factor analyses/path analyses (97%), and linear regressions (83%), but were reported less often for two-proportion z tests (50%), analyses of variance/analyses of covariance/multivariate analyses of variance (18%), t tests (8%), Wilcoxon's tests (8%), Chi-squared tests (8%), and Fisher's exact tests (7%), and not reported for sign tests, Friedman's tests, McNemar's tests, multi-level models, and Kruskal-Wallis tests. Effect sizes were infrequently interpreted. Confidence intervals were reported in 28% of papers. Conclusion: The use, reporting, and interpretation of inferential statistics in nursing research need substantial improvement. Most importantly, researchers should abandon the misleading practice of interpreting the results from inferential tests based solely on whether they are statistically significant (or not) and, instead, focus on reporting and interpreting effect sizes, confidence intervals, and significance levels. Nursing researchers also need to conduct and report a priori power analyses, and to address the issue of Type I experiment-wise error inflation in their studies. © 2013 .

Sources of payments practices rigidity

This paper studies the joint determination of the wage payments period between firms and employees. The aggregate timeseries analysis reaches two conclusions: a) the average payments period keep an equilibrium relationship with the previous inflation peak, this indicates some degree of irreversibility of payments practices. b) the low previous inflation peak .;:;_asticity of ave r age payments periods reveal.s a high degree of rigidity of payments practices.The framework developed in the paper incorporates the fol.l.owing sources of payments practices rigidity: a)interactions between optimal. payments period decisions and optimal. number of trips to the bank. b)the occurrence of Pare to inneficiencies in the bargaining process between firms and empl.oyees due to wage regulation. c) integer restrictions on payments frequencies produced by upper bounds on the payments period. The empirical. part of the paper assesses the rel.evance of these different sources of payments practices rigidity using Brazil.ian micro data.

A snapshot of management practices and nutritional recommendations used by feedlot nutritionists in Brazil

Feedlot consulting nutritionists were invited to participate in a survey of feedlot nutritional and management practices in Brazil. Thirty-one nutritionists completed the survey on a Web site that was designed for collection of survey data. The survey consisted of 94 questions that included general information (n = 10); commodity information (n = 12); and questions about the use of coproducts (n = 5), roughage source and levels (n = 5), finishing diet adaptation methods (n = 7), supplements and micronutrients (n = 8), feed mixers (n = 6), feeding management (n = 3), cattle management and type of cattle fed (n = 16), formulation practices (n = 17), information resources used for nutritional recommendations (n = 2), and 2 additional questions. One final question addressed the primary challenges associated with applying nutritional recommendations in practice. The number of animals serviced yearly by each nutritionist averaged 121,682 (minimum = 2,000; maximum = 1,500,000; mode = 120,000; total = 3,163,750). Twenty-two respondents (71%) worked with feedlots that feed less than 5,000 animals/yr. Labor, along with availability and precision of equipment, seemed to be the main challenges for the nutritionists surveyed. Most of the nutritionists surveyed used TDN as the primary energy unit for formulation. More than 50% of the clients serviced by the 31 nutritionists did not manage feed bunks to control the quantity of feed offered per pen, and 36.6% fed cattle more than 4 times daily. The NRC (1996) and Journal of Animal Science were the most used sources of information by these nutritionists. Overall, general practices and nutritional recommendations provided by the 31 nutritionists surveyed were fairly consistent. Present data should aid in development of new research, future National Research Council models, and recommendations for Brazilian feeding systems in which Bos indicus cattle predominate.

Effect of management practices on screw-worm among sheep in São Paulo State, Brazil

The screw-worm Cochliomyia hominivorax (Coquerel), whose larvae develop in wild and domestic animals as well as in man, is one of the major causes of myiasis in Brazil. Sheep raising is expanding in the state of São Paulo, where information about the infestation of screw-worm is necessary for appropriate control measures. The present data were obtained from questionnaires sent to all sheep breeders belonging to 'Associação Paulista de Criadores de Ovinos' - ASPACO (São Paulo State Association of Sheep Breeders). Response reliability was tested by random visits paid to 10.6% of the respondents. The results show that screw-worm is the most frequent ectoparasite in the flocks and is responsible for the greatest economic losses. Its occurrence is strongly associated with flock size, reaching 100% in hocks consisting of more than 500 animals. Infestation is higher in spring and summer and lowest in the fall. The number of cases increases in the presence of some management practices such as tail amputation. Furthermore, several other associations between the indicators surveyed were also found to be significant. The data obtained will permit the elaboration of strategies for the control of this parasitosis.

Effect of Cultivation Practices on the beta-Glucan Content of Agaricus subrufescens Basidiocarps

Processo FAPESP: 12/15101-4

An assessment of the business value of traceability practices in the italian fishery processing industry

Traceability is often perceived by food industry executives as an additional cost of doing business, one to be avoided if possible. However, a traceability system can in fact comply the regulatory requirements, increase food safety and recall performance, improving marketing performances and, as well as, improving supply chain management. Thus, traceability affects business performances of firms in terms of costs and benefits determined by traceability practices. Costs and benefits affect factors such as, firms’ characteristics, level of traceability and ,lastly, costs and benefits perceived prior to traceability implementation. This thesis was undertaken to understand how these factors are linked to affect the outcome of costs and benefits. Analysis of the results of a plant level survey of the Italian ichthyic processing industry revealed that processors generally adopt various level of traceability while government support appears to increase the level of traceability and the expectations and actual costs and benefits. None of the firms’ characteristics, with the exception of government support, influences costs and level of traceability. Only size of firms and level of QMS certifications are linked with benefits while precision of traceability increases benefits without affecting costs. Finally, traceability practices appear due to the request from “external“ stakeholders such as government, authority and customers rather than “internal” factors (e.g. improving the firm management) while the traceability system does not provide any added value from the market in terms of price premium or market share increase.

A cross cultural study of vaginal practices and sexuality: Implications for sexual health

Between 2005 and 2006, we investigated vaginal practices in Yogyakarta, Indonesia; Tete, Mozambique; KwaZulu-Natal, South Africa; and Bangkok and Chonburi, Thailand. We sought to understand women's practices, their motivations for use and the role vaginal practices play in women's health, sexuality and sense of wellbeing. The study was carried out among adult women and men who were identified as using, having knowledge or being involved in trade in products. Further contacts were made using snowball sampling. Across the sites, individual interviews were conducted with 229 people and 265 others participated in focus group discussions. We found that women in all four countries have a variety of reasons for carrying out vaginal practices whose aim is to not simply 'dry' the vagina but rather decrease moisture that may have other associated meanings, and that they are exclusively "intravaginal" in operation. Practices, products and frequency vary. Motivations generally relate to personal hygiene, genital health or sexuality. Hygiene practices involve external washing and intravaginal cleansing or douching and ingestion of substances. Health practices include intravaginal cleansing, traditional cutting, insertion of herbal preparations, and application of substances to soothe irritated vaginal tissue. Practices related to sexuality can involve any of these practices with specific products that warm, dry, and/or tighten the vagina to increase pleasure for the man and sometimes for the woman. Hygiene and health are expressions of femininity connected to sexuality even if not always explicitly expressed as such. We found their effects may have unexpected and even undesired consequences. This study demonstrates that women in the four countries actively use a variety of practices to achieve a desired vaginal state. The results provide the basis for a classification framework that can be used for future study of this complex topic.

'Initiators of Discursive Practices': Authorship, attribution, and intent in the debates between philosophes and anti-philosophes

This article focuses on the “social side” of pseudonymity—on how writers and readers compete to influence the critical destiny of a pseudonymous work. By analyzing pseudonymity and attribution in both the specific context of Voltaire’s 1760 staging of the play, Le café ou l’écossaise, and in larger debates in the emerging fields of anonymity, pseudonymity, and attribution studies, I hope to show how literary scholars at present can address the individuality of each pseudonymous case while not letting go of trans-historical, general problems of anonymous strategies. Voltaire’s use of multiple pseudonyms before and after releasing L’Ecossaise, a comédie sérieuse in which Voltaire attacks his enemy Elie-Cathérine Fréron, supports his philosophe friends at a crucial moment in history, and exemplifies his emerging taste for serious comedy and British drama calls into question traditional takes on pseudonymity, anonymity, and attribution by refusing to fit into the binary arguments of anonymous vs. attributed and authorial intent vs. the reader’s control.

Predictors of vaginal practices for sex and hygiene in KwaZulu-Natal, South Africa: findings of a household survey and qualitative inquiry

Vaginal practices in sub-Saharan Africa may increase HIV transmission and have important implications for development of microbicides and future HIV prevention technologies. It remains unclear which women undertake vaginal practices and what factors predict prevalence, practice type and choice of products. Using cross-sectional data from mixed research methods, we identify factors associated with vaginal practices among women in KwaZulu-Natal, South Africa. Data were gathered through focus group discussions, in-depth and key-informant interviews, followed by a province-wide, multi-stage cluster household survey, using structured questionnaires in face-to-face interviews with 867 women. This paper details six types of vaginal practices, which--despite their individual distinctiveness and diverse motivations--may be clustered into two broad groups: those undertaken for purposes of 'hygiene' (genital washing, douching and application) and those for 'sexual motivations' (application, insertion, ingestion and incisions). Multivariate analysis found significant associations between 'hygiene' practices and media access, religiosity and transactional sex. 'Sexual' practices were associated with partner concurrency, religiosity and use of injectable hormonal contraceptives. Future interventions relating to vaginal practices as well as microbicides need to reflect this characterisation of practices as sexual- and/or hygiene-related.

Prevalence, motivations, and adverse effects of vaginal practices in Africa and Asia: findings from a multicountry household survey

Background: Women worldwide use various vaginal practices to clean or modify their vulva and vagina. Additional population-level information is needed on prevalence and motivations for these practices, characteristics of users, and their adverse effects. Methods: This was a household survey using multistage cluster sampling in Tete, Mozambique; KwaZulu-Natal, South Africa; Yogyakarta, Indonesia; and Chonburi, Thailand. In 2006–2007, vaginal practices and their motivations were examined using structured interviews with women 18–60 years of age (n=3610). Results: Prevalence, frequency, and motivations varied markedly. Two thirds of women in Yogyakarta and Chonburi reported one or more practices. In Yogyakarta, nearly half ingest substances with vaginal effects, and in Chonburi, external washing and application predominate. In Tete, half reported three or four current practices, and a quarter reported five or more practices. Labial elongation was near universal, and 92% of those surveyed cleanse internally. Two third's in KwaZulu-Natal practiced internal cleansing. Insertion of traditional solid products was rare in Chonburi and Yogyakarta, but one tenth of women in KwaZulu-Natal and nearly two thirds of women in Tete do so. Multivariate analysis of the most common practice in each site showed these were more common among less educated women in Africa and young urban women in Asia. Explicit sexual motivations were frequent in KwaZulu-Natal and Tete, intended for pleasure and maintaining partner commitment. Practices in Chonburi and Yogyakarta were largely motivated by femininity and health. Genital irritation was common at African sites. Conclusions: Vaginal practices are not as rare, exotic, or benign as sometimes assumed. Limited evidence of their biomedical consequences remains a concern; further investigation of their safety and sexual health implications is warranted.

Effects of Silvicultural Practices on Soil Carbon and Nitrogen in a Nitrogen Saturated Central Appalachian (USA) Hardwood Forest Ecosystem

Silvicultural treatments represent disturbances to forest ecosystems often resulting in transient increases in net nitrification and leaching of nitrate and base cations from the soil. Response of soil carbon (C) is more complex, decreasing from enhanced soil respiration and increasing from enhanced postharvest inputs of detritus. Because nitrogen (N) saturation can have similar effects on cation mobility, timber harvesting in N-saturated forests may contribute to a decline in both soil C and base cation fertility, decreasing tree growth. Although studies have addressed effects of either forest harvesting or N saturation separately, few data exist on their combined effects. Our study examined the responses of soil C and N to several commercially used silvicultural treatments within the Fernow Experimental Forest, West Virginia, USA, a site with N-saturated soils. Soil analyses included soil organic matter (SOM), C, N, C/N ratios, pH, and net nitrification. We hypothesized the following gradient of disturbance intensity among silvicultural practices (from most to least intense): even-age with intensive harvesting (EA-I), even-age with extensive harvesting, even-age with commercial harvesting, diameter limit, and single-tree harvesting (ST). We anticipated that effects on soil C and N would be greatest for EA-I and least with ST. Tree species exhibited a response to the gradient of disturbance intensity, with early successional species more predominant in high-intensity treatments and late successional species more predominant in low-intensity treatments. Results for soil variables, however, generally did not support our predictions, with few significant differences among treatments and between treatments and their paired controls for any of the measured soil variables. Multiple regression indicated that the best predictors for net nitrification among samples were SOM (positive relationship) and pH (negative relationship). This finding confirms the challenge of sustainable management of N-saturated forests.

The Increasing Importance of Administrative Practices in the Shaping of the Welfare State

Dans cet article, nous analysons les changements de l' Etat-providence suédois a l' exemple des services municipaux de soins pour personnes agées. On montre qu'il est possible de tracer des processus de transformation à trois niveaux. Analysées comme phénomènes complèmentaires cela montre à quelle envergure les pratiques administratives sont devenues le lieu primordial de la mise en forme de l' Etat-providence. L'incorporation du managérialisme, comme mode prévalent de gouvernance et d'organisation de services et des politiques sociales mène a la conclusion qu'on devient temoin d'une transformation d' un regime (d Etat-providence) moral et politique à un regime administratif. Dans le dernier paragraphe, nous argumentons que cette transformation affaiblit la citoyenneté sociale et transfère les valeurs et principes de la politique sociale a la sphère administrative. Nous argumentons dès lors que cette perspective analytique a des implications plus larges pour la charactérization des “Welfare regimes” et pour l'analyse des différences transnationales.

An exploratory study of screening practices and barriers for postpartum depression in Texas

Purpose. To evaluate the prevalence of Postpartum Depression (PPD) screening among practicing obstetrician-gynecologists in Texas, and to identify factors and barriers associated with routine depression screening practices.^ Subjects. One hundred and eighty-nine fellows and junior fellows of the Texas Association of Obstetricians & Gynecologists (District XI).^ Methods. A survey questionnaire was developed and sent to 2,028 obstetriciangynecologists, asking about their current screening practices related to PPD. The survey questions were related to the physician's demographics, the patient population, screening practices, barriers to screening, and perceptions about resources in the community. Responses were analyzed to determine associations between these factors and the physician's screening practices. ^ Results. The respondents (n=189) constituted 9.3% of the surveyed population, thus the findings cannot be considered representative of all practicing Ob-Gyns in Texas. However, the following trends were observed. Of the respondents, 85.4% reported routinely screening for PPD, while 14.6% did not. However, of those that screened, only 20.2% used the Edinburgh Postnatal Depression Scale and 7.6% screened with the Postpartum Depression Screening Scale, both validated screening tools. The majority (77.2%) reported using an informal patient interview to screen. For those who did not routinely screen, inadequate training and inadequate resources to screen for PPD were the top two barriers. Physician's age was associated with routine screening practice, as older physicians were less likely to screen routinely. Primary insurance coverage of the patient population was also associated with screening practice; physicians with Medicaid and uninsured patients were less likely to screen routinely. Lastly, physicians that believed that adequate resources existed in their communities for the treatment of PPD were more likely to screen than those that did not.^ Conclusions. The present study is the first attempt at assessing Postpartum Depression screening practices and barriers in Texas. Although the response rate was low, the findings related to informal screening methods and inadequate training indicated that education and training with regards to PPD screening and validated screening tools among Ob-Gyns stand to be improved. Connecting physicians to psychiatric resources may also improve screening rates. This first look at screening practices in Texas serves as a platform for future research in order to gain definitive insight into the diagnosis and treatment of PPD, and ultimately design interventions to improve detection rates and treatment.^