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External Validity (external + validity)

Distribution by Scientific Domains

Medical Sciences	74%
Psychology	9%
Business, Economics, Finance and Accounting	6%
3 Other Domains	11%

Distribution within Medical Sciences

Psychiatry	16%
Neurology	12%
12 Other Subdomains	60%

Selected Abstracts

How Attrition Impacts the Internal and External Validity of Longitudinal Research

JOURNAL OF SCHOOL HEALTH, Issue 7 2005
Adam E. Barry
[source]

The Bech,Rafaelsen Melancholia Scale (MES) in clinical trials of therapies in depressive disorders: a 20-year review of its use as outcome measure

ACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2002
P. Bech
Bech P. The Bech,Rafaelsen Melancholia Scale (MES) in clinical trials of therapies in depressive disorders A 20-year review of its use as outcome measure. Acta Psychiatr Scand 2002: 106: 252,264. © Blackwell Munksgaard 2002. Objective:,To evaluate the psychometric properties of the Bech,Rafaelsen Melancholia Scale (MES) by reviewing clinical trials in which it has been used as outcome measure. Method:,The psychometric analysis included internal validity (total scores being a sufficient statistic), interobserver reliability, and external validity (responsiveness in short-term trials and relapse prevention in long-term trials). Results:,The results showed that the MES is a unidimensional scale, indicating that the total score is a sufficient statistic. The interobserver reliability of the MES has been found adequate both in unipolar and bipolar depression. External validity including both relapse, response and recurrence indicated that the MES has a high responsiveness and sensitivity. Conclusion:,The MES has been found a valid and reliable scale for the measurement of changes in depressive states during short-term as well as long-term treatment. [source]

Development and Validation of the Headache Needs Assessment (HANA) Survey

HEADACHE, Issue 4 2001
Joyce A. Cramer BS
Objective.,To develop and validate a brief survey of migraine-related quality-of-life issues. The Headache Needs Assessment (HANA) questionnaire was designed to assess two dimensions of the chronic impact of migraine (frequency and bothersomeness). Methods.,Seven issues related to living with migraine were posed as ratings of frequency and bothersomeness. Validation studies were performed in a Web-based survey, a clinical trial responsiveness population, and a retest reliability population. Headache characteristics (eg, frequency, severity, and treatment), demographic information, and the Headache Disability Inventory were used for external validation. Results.,The HANA was completed in full by 994 adults in the Web survey, with a mean total score of 77.98 ± 40.49 (range, 7 to 175). There were no floor or ceiling effects. The HANA met the standards for validity with internal consistency reliability (Cronbach , = .92, eigenvalue for the single factor = 4.8, and test-retest reliability = 0.77). External validity showed a high correlation between HANA and Headache Disability Inventory total scores (0.73, P<.0001), and high correlations with disease and treatment characteristics. Conclusions.,These data demonstrate the psychometric properties of the HANA. The brief questionnaire may be a useful screening tool to evaluate the impact of migraine on individuals. The two-dimensional approach to patient-reported quality of life allows individuals to weight the impact of both frequency and bothersomeness of chronic migraines on multiple aspects of daily life. [source]

A meta-analysis of national research: Effects of teaching strategies on student achievement in science in the United States

JOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 10 2007
Carolyn M. Schroeder
This project consisted of a meta-analysis of U.S. research published from 1980 to 2004 on the effect of specific science teaching strategies on student achievement. The six phases of the project included study acquisition, study coding, determination of intercoder objectivity, establishing criteria for inclusion of studies, computation of effect sizes for statistical analysis, and conducting the analyses. Studies were required to have been carried out in the United States, been experimental or quasi-experimental, and must have included effect size or the statistics necessary to calculate effect size. Sixty-one studies met the criteria for inclusion in the meta-analysis. The following eight categories of teaching strategies were revealed during analysis of the studies (effect sizes in parentheses): Questioning Strategies (0.74); Manipulation Strategies (0.57); Enhanced Material Strategies (0.29); Assessment Strategies (0.51); Inquiry Strategies (0.65); Enhanced Context Strategies (1.48); Instructional Technology (IT) Strategies (0.48); and Collaborative Learning Strategies (0.95). All these effect sizes were judged to be significant. Regression analysis revealed that internal validity was influenced by Publication Type, Type of Study, and Test Type. External validity was not influenced by Publication Year, Grade Level, Test Content, or Treatment Categories. The major implication of this research is that we have generated empirical evidence supporting the effectiveness of alternative teaching strategies in science. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 1436,1460, 2007 [source]

The Bech,Rafaelsen Melancholia Scale (MES) in clinical trials of therapies in depressive disorders: a 20-year review of its use as outcome measure

ON THE PREFERENCES OF PRINCIPALS AND AGENTS

ECONOMIC INQUIRY, Issue 2 2010
MARCO CASTILLO
One of the reasons why market economies are able to thrive is that they exploit the willingness of entrepreneurs to take risks that laborers might prefer to avoid. Markets work because they remunerate good judgment and punish mistakes. Indeed, modern contract theory is based on the assumption that principals are less risk averse than agents. We investigate if the risk preferences of entrepreneurs are different from those of laborers by implementing experiments with a random sample of the population in a fast-growing, small-manufacturing, economic cluster. As assumed by theory, we find that entrepreneurs are more likely to take risks than hired managers. These results are robust to the inclusion of a series of controls. This lends support to the idea that risk preferences is an important determinant of selection into occupations. Finally, our lotteries are good predictors of financial decisions, thus giving support to the external validity of our risk measures and experimental methods (JEL C93, D81, D86). [source]

The challenge of external validity in policy-relevant systematic reviews: a case study from the field of substance misuse

ADDICTION, Issue 1 2010
Mark Pearson
ABSTRACT Aim To critically evaluate the methods utilized in the conduct of a systematic review in the field of substance misuse Design Participant-observation in the review process, semi-structured interviews with review team members and management and structured observation of the process of guidance development. Setting An ,arm's-length' government body. Participants Review team members, management and the committee responsible for producing evidence-based guidance for policy and practice. Measurements Data from interviews and (participant-)observation were reflected upon critically in order to increase understanding of the systematic review process. Findings The application of systematic review methods produced an evidence base that did not inform the development of guidance to the extent that it could have done: (i) an emphasis upon internal research validity produced an evidence base with an emphasis on short-term interventions at the level of the individual; (ii) criteria for appraising the external validity of studies were not developed sufficiently; and (iii) the systematic review of evidence and development of guidance are strongly reliant upon the judgement of reviewers and committee members. Conclusions Prioritizing internal validity in a systematic review risks producing an evidence base that is not informed adequately by the wider determinants of health and which does not give sufficient consideration to external validity. The use of appropriate methods requires that commissioners of systematic reviews are clear at the outset how the review is proposed to be utilized. Review methods such as meta-ethnography and realist synthesis could contribute to making the frameworks within which judgements are made more explicit. [source]

Depressive symptoms among mothers of children with epilepsy: A review of prevalence, associated factors, and impact on children

EPILEPSIA, Issue 11 2009
Mark A. Ferro
Summary The impact of epilepsy is not limited to the child experiencing seizures, but affects all members of the family. As primary caregivers, mothers are particularly at risk for experiencing increased depressive symptoms and risk for clinical depression. The objective of this systematic review was to critically assess available evidence regarding the prevalence, associated factors, and impact of maternal depressive symptoms on child outcomes in epilepsy. Using a modified version of the Quality Index, studies were rigorously evaluated in terms of reporting, external validity, and internal validity. Limitations in the study designs and analytic techniques of previous research are discussed, and study methods to overcome these barriers are presented in order to advance this research area. Up to 50% of mothers of children with epilepsy are at risk for clinical depression. Correlates of maternal depressive symptoms include a number of modifiable risk factors such as role ambiguity, worry, and satisfaction with relationships. In addition, studies suggest that depressive symptoms in mothers have a negative impact on child outcomes in epilepsy including behavior problems and health-related quality of life. The overall mean score on the Quality Index was 9.7, indicating a midrange quality score, suggesting a need for more methodologically robust studies. [source]

Periodontal microbiota and clinical periodontal status in a rural sample in southern Thailand

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2002
P. N. Papapanou
We sought to determine (i) the association of subgingival bacterial profiles to clinical periodontal status in a population with limited access to dental care in Thailand, and (ii) the external validity of our earlier findings from a similar study in rural China. We examined 356 subjects, 30,39 yr old and 50,59 yr old, with respect to clinical periodontal status and subgingival plaque at maximally 14 sites per subject. Checkerboard hybridizations were used to analyse a total of 4343 samples. The prevalence of the 27 species investigated ranged between 87.2% and 100%. Discriminant analysis based on microbial profiles classified correctly 67.5% of all deep (, 5 mm) and 64.2% of all shallow sites, and 67.4% of all subjects with and 69.3% of all subjects without , 3 deep pockets. High colonization by ,red complex' bacteria was four times as likely (95% Confidence Limits (CL) 2.5,6.6) in subjects with ,,10 sites with attachment loss of ,,5 mm, and 4.3 times as likely (95% CL 2.6,7.1) in subjects with , 30 such sites. The data confirmed (i) the ubiquitous prevalence of the bacteria investigated in subjects with no regular access to dental care; and (ii) the high odds for periodontal pathology conferred by increased levels of specific periodontal bacteria. [source]

An RCT of massage therapy to improve pain and mood in advanced cancer patients: can we have both internal and external validity?

FOCUS ON ALTERNATIVE AND COMPLEMENTARY THERAPIES AN EVIDENCE-BASED APPROACH, Issue 1 2009
Article first published online: 3 JUN 2010
[source]

Comparing welfare estimates from payment card contingent valuation and discrete choice experiments

HEALTH ECONOMICS, Issue 4 2009
Mandy Ryan
Abstract This study presents the first comparison of willingness to pay estimates derived from the payment card (PC) contingent valuation and discrete choice experiment (DCE) methods. A within-sample experiment was used to elicit women's preferences for Chlamydia screening. The willingness to pay estimate derived from the DCE was larger than that derived from the PC. To investigate why the willingness to pay estimates were different, a range of validity tests were conducted. Both methods produced theoretically valid results, and there was no difference in the reported difficulty of completing the tasks. Evidence of a prominence effect was found in the PC responses. Responses to the DCE satisfied tests of non-satiation. Responses to both methods were compared with revealed preference data. There were significant differences between stated screening intention in both methods and actual screening uptake. Future work should address the external validity of stated preference methods. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Generalizability in Communication Research

HUMAN COMMUNICATION RESEARCH, Issue 4 2002
Michael A. Shapiro
In communication research, attempts to enhance external validity usually focus on techniques to enhance the surface representativeness attained in a particular study. Such surface representativeness is a useful tool. However, a larger ability to generalize emerges from a constantly evolving scientific discourse across multiple studies about how social meanings and social behaviors impact outcomes. The resulting conceptual knowledge enables us to generalize about communication across a much wider range of persons, settings, times, and messages than does surface similarity. The findings of a study should be examined in light of its contribution to theory. The surface representativeness of a study is usually not a good indicator of contribution to theory. The discipline of communication, particularly journal editors and reviewers, bears a heavy responsibility to think about generalizability in the complex ways the topic requires. [source]

Cognitive impairment in depressed outpatients as measured with the Dementia Checklist: a simple method for primary care and in field research

INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 1 2002
M. Linden
Abstract The Dementia Checklist is a 12-item dementia rating scale for physicians who, for whatever reason, cannot be specifically trained. It addresses symptoms of cognitive decline that can easily be identified, and that are typical for different stages of cognitive impairment. This allows an easy classification of the severity of dementia. In a first study, the dementia checklist was used in 937 geriatric outpatients who were treated by neuropsychiatrists for depression. All items contribute to the accuracy of measurement (Cronbach's , = 0.84). Differences in cognitive impairment depending on age (,2 = 51.7; p , 0.001) and depression (,2 = 47.6; p , 0.001) indicate external validity of the dementia checklist and 5.7% of the outpatients were rated as demented. The Dementia Checklist provides a very economical and easy-to-use assessment of cognitive decline. Copyright © 2002 Whurr Publishers Ltd. [source]

Controversy concerning platelet dose

ISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue 1 2007
N. M. Heddle
The highest level of support for evidence based decisions is the randomized controlled trial (RCT); however, RCT results are only useful if the study has strong internal and external validity. There have been a number of clinical trials that have addressed the issue of the optimal platelet dose; however, none of these studies have provided definitive data on the optimal platelet dose due to a variety of methodological issues associated with the study designs. Currently two randomized controlled trials have been implemented to address the issue of optimal platelet dose. The results of these trials will not be available until 2007,2008. The BEST (Biomedical Excellence for Safer Transfusion) Collaborative has initiated a platelet dose study comparing the frequency of WHO bleeding Grade 2 with low and standard dose platelets. The Transfusion Medicine/ Haemostasis Clinical Trials Network (CTN) is also performing a platelet dose study comparing three treatment strategies (high, standard and low dose platelets). There were numerous methodological issues that had to be considered when designing these two studies. More recently some European investigators have questioned the need for prophylactic platelet transfusions and several studies are currently underway to investigate the efficacy of changing this practice. [source]

Enhancing Delphi research: methods and results

JOURNAL OF ADVANCED NURSING, Issue 5 2004
Holly Powell Kennedy PhD CNM FACNM
Background., The Delphi method provides an opportunity for experts (panelists) to communicate their opinions and knowledge anonymously about a complex problem, to see how their evaluation of the issue aligns with others, and to change their opinions, if desired, after reconsideration of the findings of the group's work. Delphi studies have the potential to provide valuable information, yet few researchers have taken further steps to support or refine their findings. Without this step there is a potential threat to the applicability, or external validity, of the results. Aims., The purpose of this article is to present an argument for further inquiry to enhance and support Delphi findings, and specific approaches to this will be considered. Methods., Methods to enhance, expand, or refine Delphi study findings are described. Mixed method design within a Delphi study on midwifery practice is described, and a follow-up narrative study to examine the findings is presented. Findings., Selected results from the follow up narrative study are presented to convey how the narrative data clarified the Delphi findings. Together, the studies provide a more robust depiction of midwifery practice, process, and outcomes. Although there were similarities to the dimensions identified previously, there was a more dynamic focus and explanation of the interaction between the midwife, the woman who had received midwifery care, and the health care system. Study limitations., Lack of diversity in the sample and the midwives' familiarity with the author's past research represent a potential threat to the findings. Prolonged interviews and multiple narratives were gathered in an effort to control for this. Conclusion., Delphi studies are research exercises conducted by a panel of experts. Designing studies to further enhance, clarify, or refine their findings from the context of practice holds promise for their ability to influence clinical care. [source]

A case for case studies: exploring the use of case study design in community nursing research

JOURNAL OF ADVANCED NURSING, Issue 4 2000
Ann Bergen BA MSc RGN DipN DNCert Cert Ed DNT
A case for case studies: exploring the use of case study design in community nursing research The case study has become an accepted vehicle for conducting research in a variety of disciplines. However, the meaning behind the term is not always made explicit by researchers and this has given rise to a number of assumptions which are open to challenge, and to questions about the robustness of the method. This paper explores some of the issues arising from one particular definition of case study research, used in a study by Yin which examined the practice of case management in community nursing. Four main areas are discussed. First, defining ,case' is seen to pose questions about the relationship of the phenomenon to its context, the degree of researcher control over case definition, the limits to what may constitute a ,case' and what is meant by the term ,unit of analysis'. Second, the relevance of external validity to case study research is supported through the use of a number of tactics, in particular Yin's concept of replication logic, which involves generalizing to theory, rather than to empirical data. Third, the use of method triangulation (multiple methods of data collection) is advanced as a means of enhancing construct validity in research where data converge around a particular theory. Finally, the relationship of the case study to theory construction, through the prior development of ,propositions' is discussed. Each of these issues is applied to the design and conduct of a research study based closely on Yin's multiple case study framework. Thirteen ,cases' were selected of case management practice and data were collected through interviews and examination of literature and documentation, to explore the suitability of community nurses for the role. It is concluded that, given the appropriate subject matter, context and research aims, the case study method may be seen as a credible option in nursing research. [source]

A review of the benefits of whole body exercise during and after treatment for breast cancer

JOURNAL OF CLINICAL NURSING, Issue 1 2007
Marilyn N Kirshbaum PhD RN (NY) RGN DipAdultOnc
Aim., A current critical review of the literature was deemed necessary to evaluate the strength of evidence to inform clinical practice. Background., Recently, there has been a noticeable increase in empirical literature surrounding the benefits of exercise for breast cancer patients. Methods., A systematic search strategy was used to identify relevant literature. Twenty-nine articles were retained for critical review, appraised for quality and synthesized. Results., Many early studies had limited internal and external validity. Recent studies were considerably more rigorous and robust. Consistent support for all types of aerobic exercise was most evident in studies of patients during adjuvant cancer treatments (chemotherapy and radiotherapy), compared with post-treatment studies. The evidence which suggested that aerobic exercise limits cancer-related fatigue was particularly strong. For other patient concerns, the empirical support was less robust, however, the potential for beneficial and measurable patient outcomes was indicated for cardiopulmonary function, overall quality of life, global health, strength, sleep, self-esteem and reduced weight gain, depression, anxiety and tiredness. Conclusions., Additional studies with higher methodological quality are required in this clinically relevant area to substantiate current indications particularly for patient subgroups (e.g. older people, those with advanced cancer and the disadvantaged). Relevance to clinical practice., It is important for all healthcare professionals involved in the care of individuals affected by breast cancer to be aware of the evidence surrounding the benefits of exercise and to encourage patients to increase physical activity and improve their overall health and well-being. [source]

Development and validation of the chinese rehearsal scale for preadolescent chinese children,,§

JOURNAL OF CLINICAL PSYCHOLOGY, Issue 4 2010
Fiona C.M. Ling
Abstract Roger (1997) defined rehearsal as "the tendency to rehearse or ruminate on emotionally upsetting events" (p. 71). The Rehearsal Scale for Children,Chinese (RSC-C) was developed from the original 14-item Rehearsal Scale of the Emotion Control Questionnaire (Roger & Nesshoever, 1987) after translation and modification for Hong Kong Chinese preadolescents (aged 6,12 years). Confirmatory factor analysis using structural equation modeling revealed that with 1 item deleted from the original scale, the RSC-C possessed good internal validity and satisfactory test-retest reliability within a 1-year period. The new 13-item RSC-C also showed good external validity and internal reliability (,=.76). Convergent and discriminant validity was evidenced against the Emotional Problem and the Prosocial Behavior Subscales of the Strengths and Difficulties Questionnaire (Goodman, 1997), respectively. No gender differences in rehearsal scores were found. It was concluded that the 13-item RSC-C could be useful for measuring rehearsal in Chinese preadolescents. © 2010 Wiley Periodicals, Inc. J Clin Psychol 66: 1,10, 2010. [source]

Sampling in research on interpersonal aggression

AGGRESSIVE BEHAVIOR, Issue 3 2008
Morten Birkeland Nielsen
Abstract The aim of this study was to investigate the usefulness of convenience samples in research on interpersonal aggression among adults. It was hypothesised that convenience sampled targets of aggression differs from targets in general with regards to both demographic characteristics and degree of aggression exposed to. A convenience sample comprising support-seeking targets of workplace bullying was compared with a representative sample of Norwegian targets of bullying. The results showed that the two samples differed significantly on all demographic variables investigated, except gender. A far higher percentage of the convenience sample had blown the whistle on illegal, immoral or illegitimate practice at their workplace, whereas they also reported significantly more frequent and more intense exposure to aggression. The findings confirm that convenience samples have low external validity when generalising to the general population. Such samples should therefore mainly be used to investigate tendencies in, and the phenomenology of, interpersonal aggression, in studies where generalisability is not the principal objective. Aggr. Behav. 34:265,272, 2008. © 2007 Wiley-Liss, Inc. [source]

The limitations of randomized controlled trials in predicting effectiveness

JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 2 2010
Nancy Cartwright PhD FBA
Abstract What kinds of evidence reliably support predictions of effectiveness for health and social care interventions? There is increasing reliance, not only for health care policy and practice but also for more general social and economic policy deliberation, on evidence that comes from studies whose basic logic is that of JS Mill's method of difference. These include randomized controlled trials, case,control studies, cohort studies, and some uses of causal Bayes nets and counterfactual-licensing models like ones commonly developed in econometrics. The topic of this paper is the ,external validity' of causal conclusions from these kinds of studies. We shall argue two claims. Claim, negative: external validity is the wrong idea; claim, positive: ,capacities' are almost always the right idea, if there is a right idea to be had. If we are right about these claims, it makes big problems for policy decisions. Many advice guides for grading policy predictions give top grades to a proposed policy if it has two good Mill's-method-of difference studies that support it. But if capacities are to serve as the conduit for support from a method-of-difference study to an effectiveness prediction, much more evidence, and much different in kind, is required. We will illustrate the complexities involved with the case of multisystemic therapy, an internationally adopted intervention to try to diminish antisocial behaviour in young people. [source]

A Systematic Review of the Performance of Methods for Identifying Carious Lesions

JOURNAL OF PUBLIC HEALTH DENTISTRY, Issue 4 2002
James D. Bader DDS
Abstract This systematic review evaluates evidence describing histologically validated performance of methods for identifying carious lesions. A search identified 1,407 articles, of which 39 were included that described 126 assessments of visual, visuaVtactile, radiographic (film and digital), fiber optic transillumination, electrical conductance, and laser fluorescence methods. A subsequent update added four studies contributing 10 assessments. The strength of the evidence was judged to be poor for all applications, signifying that the available information is insufficient to supporf generalizable estimates of the sensitivity and specificity of any given application of a diagnostic method. The literature is problematic with respect to complete reporting of methods, variations in histological validation methods, the small number of in vivo studies, selection of teeth, small numbers of examiners, and other factors threatening both internal and external validity. Future research must address these problems as well as expand the range of assessments to include primary teeth and root surfaces. [source]

CONSUMER PERCEPTION OF IRRADIATED FRUIT: A CASE STUDY USING CHOICE-BASED CONJOINT ANALYSIS

JOURNAL OF SENSORY STUDIES, Issue 2 2010
ROSIRES DELIZA
ABSTRACT Papaya is a popular fruit among Brazilian consumers, but one problem is that fruit ripens quickly due to the high temperatures of the country. Irradiation is an effective way of slowing down ripening, hereby increasing shelf-life, but consumer acceptance of this novel technology is paramount for its successful introduction by industry. Using conjoint analysis, this research measures consumer acceptance of irradiated papaya fruit in a sample of urban Brazilian consumers. The study assesses the joint influence of product appearance, price and information about the use of irradiation for consumer choice. Real fruit was used and consumer responses were collected through intercept interviews in supermarkets. These two empirical aspects add external validity to the research. The responses from a convenience sample of 168 consumers from Rio de Janeiro revealed that the product appearance, as a proxy for product quality, was the most important factor influencing decision to purchase papaya. Price was of lesser importance. The participants in this study did not reject papaya due to the labelled information about the use of irradiation. This suggests irradiation as a viable alternative for fruit producers. Consumers demonstrated no knowledge about food irradiation, and education initiatives may be useful as a strategy to aid commercial introduction of irradiated papaya in Brazil. PRACTICAL APPLICATIONS This study has important practical implications for Brazilian agribusinesses because it contributes to our understanding of the relationship between market changes, consumer behavior, food products and processing technologies. It has shown that sensory appearance was the key factor influencing Brazilian consumers' choice of papaya, however, more education and information regarding irradiation technology should be provided. The results suggest that irradiation could be used in Brazil and provide a viable alternative to fruit producers. As a consequence, these results are useful for strategic planning of consumer education regarding food irradiation (with emphasis on the benefits of processing and addressing the myths), something which could, eventually, contribute to a more favorable consumer response to the technology. [source]

Quality of Reporting of Clinical Trials of Dogs and Cats and Associations with Treatment Effects

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010
J.M. Sargeant
Background: To address concerns about the quality of reporting of randomized controlled trials, and the potential for biased treatment effects in poorly reported trials, medical journals have adopted a common set of reporting guidelines, the Consolidated Standards of Reporting Trials (CONSORT) statement, to improve the reporting of randomized controlled trials. Hypothesis: The reporting of clinical trials involving dogs and cats might not be ideal, and this might be associated with biased treatment effects. Animals: Dogs and cats used in 100 randomly selected reports of clinical trials. Methods: Data related to methodological quality and completeness of reporting were extracted from each trial. Associations between reporting of trial features and the proportion of positive treatment effects within trials were evaluated by generalized linear models. Results: There were substantive deficiencies in reporting of key trial features. An increased proportion of positive treatment effects within a trial was associated with not reporting: the method used to generate the random allocation sequence (P < .001), the use of double blinding (P < .001), the inclusion criteria for study subjects (P= .003), baseline differences between treatment groups (P= .006), the measurement used for all outcomes (P= .002), and possible study limitations (P= .03). Conclusions and Clinical Importance: Many clinical trials involving dogs and cats in the literature do not report details related to methodological quality and aspects necessary to evaluate external validity. There is some evidence that these deficiencies are associated with treatment effects. There is a need to improve reporting of clinical trials, and guidelines, such as the CONSORT statement, can provide a valuable tool for meeting this need. [source]

Launching invasive, first-in-human trials against Parkinson's disease: Ethical considerations,

MOVEMENT DISORDERS, Issue 13 2009
Jonathan Kimmelman PhD
Abstract The decision to initiate invasive, first-in-human trials involving Parkinson's disease presents a vexing ethical challenge. Such studies present significant surgical risks, and high degrees of uncertainty about intervention risks and biological effects. We argue that maintaining a favorable risk-benefit balance in such circumstances requires a higher than usual degree of confidence that protocols will lead to significant direct and/or social benefits. One critical way of promoting such confidence is through the application of stringent evidentiary standards for preclinical studies. We close with a series of recommendations for strengthening the internal and external validity of preclinical studies, reducing their tendency toward optimism and publication biases, and improving the knowledge base used to design and evaluate preclinical studies. © 2009 Movement Disorder Society [source]

Knowledge of results and learning to tell the time in an adult male with an intellectual disability: a single-subject research design

OCCUPATIONAL THERAPY INTERNATIONAL, Issue 1 2008
Samantha L Applegate
Abstract The present study investigated whether knowledge of results, in the form of visual and audible feedback, would increase the accuracy of time-telling in an individual with an intellectual disability. A 19-year-old male with mild intellectual disability participated in this A1,B1,A2,B2 single-subject study design. The task involved correctly identifying the time given on a computer. Data, based on the Wilcoxon signed-rank test, showed that the participant demonstrated a greater number of correct responses during the intervention phases. Incorporating knowledge of results into a learning strategy for this individual with intellectual disability resulted in an increased ability to accurately identify the correct time on an analogue clock. There is a need to replicate the study design to increase the external validity and generalization of results. The strategies described in the present study may also be useful for occupational therapists who teach individuals with intellectual disability to gain skills in their everyday activities of daily living (ADLs). Copyright © 2007 John Wiley & Sons, Ltd. [source]

Control Group Methods for HPT Program Evaluation and Measurement

PERFORMANCE IMPROVEMENT QUARTERLY, Issue 2 2002
Greg Wang
ABSTRACT This research contributes to the methodologies in HPT program evaluation and measurement that are fairly lacking to date. First, a theoretical foundation for a control group is established based on a brief review of control group applications in various fields. Then, four types of control groups applicable to HPT program evaluation and measurement are defined and classified, and threats to internal and external validity in control group applications are explored. Lastly, four evaluation and measurement scenarios are presented for an E-learning program to demonstrate the applicability of the control group methods for HPT program evaluation and ROI measurement. [source]

Cluster Subtypes within the Preparation Stage of Change for Sun Protection Behavior

APPLIED PSYCHOLOGY: HEALTH AND WELL-BEING, Issue 1 2010
Marimer Santiago-Rivas
Objective: Numerous effective tailored interventions for smoking cessation and other behaviors have been developed based on the Transtheoretical Model. Recent studies have identified clusters within each stage of change. The goal of this study is to determine if replicable clusters exist within the Preparation stage of change for sun protection. Method: Secondary data analysis of baseline data from a sample of participants in a home-based expert system intervention was performed. Two random samples of approximately 128 participants were selected from subjects in the Preparation stage (N = 258). Cluster analyses were performed using Ward's Method on the standardised scores from the three scales of Pros, Cons, and Self-Efficacy. Interpretability of the pattern, pseudo F test, and dendograms were used to determine the number of clusters. Results: A four-cluster solution replicated across subsamples. Differences between clusters on eight of the nine Processes of Change, and on behavioral measures, were found. Discussion: The cluster solutions were robust, easily interpretable, and demonstrated good initial external validity. They replicated patterns found for other behaviors that have demonstrated long-term predictability and can provide the basis for a tailored intervention. [source]

Methodological considerations of measuring disability in bipolar disorder: validity of the Multidimensional Scale of Independent Functioning

BIPOLAR DISORDERS, Issue 1-2 2007
Stefanie Berns
Objective:, Recent studies have highlighted the prevalence, severity and persistence of the disability associated with bipolar disorder (BPD). Reliable instruments are needed to support research into the factors associated with disability and treatment response. Contextual factors (e.g., availability of supported employment programs) can affect functionality, posing a challenge to such investigations. We present preliminary findings regarding the validity of the Multidimensional Scale of Independent Functioning (MSIF) in BPD. The MSIF provides discrete ratings of support separate from both role responsibility and performance quality in work, residential and educational environments. These distinctions allow the ,correction' for variability explained by contextual factors that allows the comparison of studies conducted in different environments and time. Methods:, Participants with BPD were administered the MSIF, the Social Adjustment Scale II (SAS-II) and an interview recording objective data regarding work, school and residential activities as part of an ongoing longitudinal study of BPD disability. Results:, Construct validity estimated using standardized Cronbach's alpha coefficient was 0.76 (n = 58). MSIF global ratings were significantly lower (reflecting higher functionality) for subjects engaged in productive activity compared with participants who were not active (t = ,3.6, p = 0.001) demonstrating external validity. Inter-rater reliability estimates ranged from 0.86 to 0.99 (n = 49). Significant, high correlations were demonstrated between comparable MSIF and SAS-II global ratings (criterion validity = 0.70,0.79) and low correlations were found between non-comparable ratings (discriminant validity = ,0.07 to ,0.35) (n = 14). Conclusion:, We conclude that the MSIF is a valid and reliable instrument optimally designed for studying determinants of disability and treatment response in BPD. [source]

A systematic review of the reliability of frequency-volume charts in urological research and its implications for the optimum chart duration

BJU INTERNATIONAL, Issue 1 2007
Tet L. Yap
There are four reviews in this section; two of these relate to prostate cancer, one to paediatric urology, and one to bladder function. The prostate cancer mini-reviews concern two important areas that are talking points in urological oncology. Multidisciplinary team management, which is a very attractive idea to many, remains controversial in the eyes of some. This concept is discussed in detail, as is another controversial idea, the use of high-intensity focused ultrasound in the treatment of prostate cancer. OBJECTIVE To determine how the reliability of frequency-volume charts (FVCs) vary with their duration when used to assess patients with lower urinary tract symptoms (LUTS) and whether the duration influences patient compliance. METHODS Peer-reviewed studies involving patients with LUTS were searched systematically, with the selected studies assessed for their internal and external validity and statistical quality. Details of the patients and type of FVC used were summarized, and reliability coefficients and levels of compliance were extracted for commonly assessed FVC variables. RESULTS In all, 13 studies were considered to meet the review criteria; they assessed the reliability of FVCs lasting 1, 2, 3 and 7 days. The reliability coefficients for 3- and 7-day FVCs were generally >0.8; those for shorter charts tended to be lower, but strong conclusions could not be drawn due to study limitations. There was no obvious relationship between the duration of the FVC and the level of compliance. CONCLUSIONS Strong recommendations cannot be made about what duration of an FVC should be used to assess or monitor patients with LUTS. The current consensus on using FVCs of ,,3 days seems to be the most defensible policy, but more research of high quality is required, especially into the relationship of FVC duration with compliance. [source]