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By comparing four similar groups of young adolescent males who completed questionnaires about their sexual behavior different numbers of times at various intervals, we explore the hypothesis that repeated questionnaire completion will affect sexual behavior. We find little support for the hypothesis even when the number of questionnaire administrations is very high.
Investigations suggesting that the order of obtaining resting and cardiovascular reactivity measurements moderates values have provided inconsistent results and have not analyzed data from children; the generalizability of results is uncertain. In this investigation, all children enrolled in the eighth-grade classrooms of the public schools of an entire county (n = 451) participated in standardized reactivity assessments. The order of resting and reactivity measurements was randomized by examination day (a total of 19 days). Analyses indicated that all comparisons of order effects on mean resting blood pressure and heart rate, as well as reactivity (both change from resting and absolute values and both mean and maximal values), were nonsignificant. Results indicate that measurement order is not always a necessary consideration in studies of reactivity; the conditions under which measurement order is a consideration requires clarification.
BACKGROUND: Previous studies have indicated that the 60-, 30-, 28- and 12-item versions of the General Health Questionnaire (GHQ) are liable to retest effects, especially when administered multiple times with short intervals. The aim of this study was to examine data from a large general population sample for evidence of any retest effects over 7 yearly applications. METHODS: A core panel was drawn from the British Household Panel Survey of those respondents who had completed the GHQ-12 seven times from 1991 to 1997 (n = 4749). The panel results were compared with cross-sectional data from the Health Surveys for England for the same years. The analyses were conducted separately for males and females broken down by age groupings. RESULTS: No evidence of retest effects was found. For males, the panel results did not diverge significantly from the cross-sectional results. For females, the panel results did indicate a divergence from the cross-sectional results, but this was due to the age composition of the panel and differing age trajectories. CONCLUSION: The GHQ-12 is a consistent and reliable instrument when used in general population samples with relatively long intervals between applications.
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INTRODUCTION: It is important yet difficult to maintain currency in clinical oncology practice. The emergence of new diagnostic technologies and new paradigms for cancer treatment combine to produce a rapidly changing clinical approach to patients aided by the increasing use of multidisciplinary care teams and development of evidence-based protocols. METHODS: Teams of experts review the literature in a given area and produce management guidelines and protocols for use by practicing clinicians. Traditionally within Hematology/Oncology, these guidelines have been directed to management of a given tumor type. However, in recent years, attention has increasingly turned to supportive oncology; for example, there are now management guidelines for conditions such as neutropenic fever [Hughes et al. Clinical Infectious Diseases 34(6):730-751, 2002], antiemetic (The Antiemetic Subcommittee of the Multinational Association of Supportive Care in Cancer Annals of Oncology 17:20-28, 2006) and most recently, mucositis [Rubenstein et al. Cancer 100(9 Suppl):2026-2046, 2004]. It is critical that any guideline process should include education, evaluation, and timely update in its remit, because guidelines become highly compromised if their existence is not widely known, if they do not facilitate clinical practice, or if they are not reflective of contemporary medical literature. RESULTS: The Mucositis Study Group (MSG) of the Multinational Association for Supportive Care in Cancer/International Society for Oral Oncology was created in 1998 to specifically address the multiprofessional approach to clinical care, research, and education associated with mucosal injury in cancer patients. A specific outcome has been the development of evidence-based guidelines for the management of mucositis [Rubenstein et al. Cancer 100(9 Suppl):2026-2046, 2004; The Mucositis Study Group of MASCC/ISSO 2005]. The original guidelines [Rubenstein et al. Cancer 100(9 Suppl):2026-2046, 2004] and a companion paper discussing the science behind mucositis [Sonis et al. Cancer 100(9):1995-2025, 2004], were published in 2004. The MSG has recently updated the guidelines [The Mucositis Study Group of MASCC/ISSO 2005]. DISCUSSION: This paper discusses the process involved and the lessons learned that might help other groups planning to undertake a similar project.
The widespread problem of low and non-compliance to antimalarial chemoprophylaxis during pregnancy demands that attention be focused on alternative approaches to programming, product acceptability and demand for preventive services. This study describes the testing of three interventions to determine their effect on use of chloroquine (currently the most widely used drug for chemoprophylaxis) during pregnancy. The strategies evolved from community-based formative research undertaken to learn about the local concept of malaria and issues surrounding malaria prevention and treatment during pregnancy. The resulting interventions were tested in four clinics, and included a change in the health education message given during antenatal sessions, distribution of a sugar-coated chloroquine tablet, and an intervention combining the two strategies. The results showed a 45% increase in chloroquine use when the health education message was changed, and a 64% increase when the product was changed. High use levels were maintained with the combined intervention; an additive effect was seen. The study shows that improving the product was the most important factor in increasing the use of the program, and that changing the health education message can also make an impact on use.
The efficacy of electromyographic biofeedback (EMG-BF) for neuromuscular reeducation in the stroke patient has been difficult to establish. The purpose of this study was to assess EMG-BF efficacy through meta-analysis. We searched the English-language clinical studies of biofeedback, stroke, and cerebral vascular disease between 1966 and 1991 using MEDLINE, PsycINFO, REHABDATA, and Dissertation Abstracts International. Studies were included in the analysis if (1) the patients sustained a cerebral vascular accident that resulted in hemiplegia, (2) the study had a randomized or matched control group, (3) the study measured a functional outcome, and (4) EMG-BF was the independent variable. Eight studies met the inclusion criteria (n = 192). Their average effect size was 0.81. The 95% confidence interval for the effect size was 0.5 to 1.12. These results indicate that EMG-BF is an effective tool for neuromuscular reeducation in the hemiplegic stroke patient.
The outcome problem in psychotherapy has usually been studied without much regard to the theories underlying the methods used. It is suggested that theories are vital to scientific advancement, and that without them we cannot even specify criteria to judge outcomes. Numerous studies since the 1950s have in essence failed to disconfirm the view that various forms of psychotherapy do not show greater effectiveness than spontaneous remission or placebo treatment. An effort is made to clarify the nature of spontaneous remission and placebo treatment, and to discuss the consequences of the many empirical findings and meta-analyses published over the past 50 years. A theory is suggested linking spontaneous remission, placebo treatment, psychotherapy and behaviour therapy, leading to a discussion of ethical considerations and cost-effectiveness issues.
Reading and interpreting research studies is an important and necessary activity of clinical practitioners. Correct evaluation of research findings requires appreciation of certain fundamentals of research methodology and statistics. This article, the third of the series, will review issues pertinent to statistical significance testing.
The analysis of cancer prevention trials necessitates specialized procedures. Differences in the analysis plan between cancer prevention and therapy trials are emphasized. Discussion is focused upon (a) how trial conduct influences the analysis, (b) how noncompliance affects the analysis and the considerations this raises during the design and conduct of the trial, (c) how delays in the effect of the intervention impinges upon the analysis, and (d) statistical methods available to carry out the analysis. The analysis of a cancer prevention trial represents a final step in the evaluation of the study intervention and requires an adaptive planning procedure.
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This article considers some of the practical problems inherent in interim analyses and stopping rules for randomized clinical trials. Topics covered include group sequential designs, trials with unplanned interim analyses, estimation problems in clinical trials with planned interim analyses, and the balance between individual and collective ethics. Particular attention is paid to the fact that clinical trials that stop early are prone to exaggerate the magnitude of treatment effect. Accordingly, a Bayesian "shrinkage" method of analysis is proposed to help quantify the extent to which surprisingly large point and interval estimates of treatment difference in clinical trials that stop early should be moderated.
Statements regarding the absence of suicidal and other self-harmful behaviour among Australian Aborigines are now untenable. The preceding paper presented the wider context of suicides in custody by examining suicide and other self-harmful behaviour in the Aboriginal population of the Kimbereley region of Western Australia. The emergence of suicide in that population was further located within an increase in deaths from non-natural causes over the last two decades. Following a brief history of the region, this paper develops an even wider context--suicidal behaviour among indigenous groups elsewhere. The relevance of these findings to the trends among Kimberely Aborigines is explored, leading to the central theme of the paper, the importance of an understanding of the socio-historical context in evaluating emerging patterns of harmful behaviour, and their relationship to alcohol use. Results obtained during a survey of the patterns and consequences of alcohol use from a stratified random sample of 516 Kimbereley Aborigines are presented. The author concludes by using the behaviours described in this and the preceding paper to examine the way in which Aboriginal 'problems' are constructed by the wider society, and 'solutions' defined.
This paper explores the practicalities of using the technique of depth interviewing with people who have learning difficulties. The authors set out to provide other researchers with guidance in the use of the life story approach and to demonstrate its utility with this vulnerable and devalued group of informants. They conclude that depth interviewing can provide new knowledge not accessible through other methods of data collection, and offers a way of giving people with learning difficulties a voice in the making of their own history.
Health-related quality of life (HRQL) measures have been developed from the utilitarian ethical perspective of public health medicine which may be contrasted with individual-centered indicators; these emphasise the unique experience of a patient. The impairment-disability-handicap framework provides a more complete description of disease consequences and health outcomes than a generic HRQL indicator. The assessment of reliability and validity of HRQL indicators is often carried out inappropriately: population repeatability is measured when an indicator will be used to examine changes in individuals; between observer variation may be large compared with variation between populations. Content and construct validity are usually measured but the more important predictive validity is neglected. Effect sizes of HRQL indicators are likely to be inflated by use of between subject estimates of variance but the more appropriate within subject variance is seldom reported. HRQL indicators are of very limited value for many clinical and public health tasks: monitoring health of individuals and populations; evaluating the effects of health and social policy; allocating resources; evaluating the effects of treatment. Alternative methods of assessment derived from the impairment-disability-handicap conceptual framework are preferable.
"Statistically significant" results may lack practical or clinical significance, and the description of results in reports of research studies is frequently incomplete or misleading in presentation of data necessary to assess such significance (effect sizes). Various common presentations are discussed, and one method of presentation of results is proposed that not only encompasses all the others, but enhances the scope of useful information conveyed in a research report. The results of the Infant Health and Development Program (IHDP) are used to illustrate the method.
This study examines respondent editing of survey responses to questions regarding substance use. Previous research has identified several types of interviewer effects that may be associated with respondent editing, including direct and social distance effects. Little is known, however, regarding how these potential effects may influence self-reported substance use behavior. Data analyzed for this study were collected as part of a survey of substance use among homeless persons conducted in Cook County, Illinois. A total of 481 respondents were sampled at random in emergency and transitional shelters, soup kitchens, drop-in centers, and single room occupancy (SRO) hotels. Overall, a direct, gender-based effect was observed, with homeless respondents of both genders more willing to reveal substance use behaviors to male interviewers. Some race- and age-related direct effects were also identified, with White and older interviewers obtaining more reports of substance use. These findings yield important evidence regarding respondent editing of self-reported substance use and have implications for the common practice of demographically matching interviewers and respondents.