Non-intervention Studies Research Articles

Analysis of Nonintervention Studies: Technical Supplement

Analysis of Nonintervention Studies: Technical Supplement

Commentary on Vangeli et al. (2011): Towards an improved understanding of smoking relapse predictors – recipe for success?

Commentary on Vangeli <i>et al</i>. (2011): Towards an improved understanding of smoking relapse predictors – recipe for success?

THE APHEKOM PROJECT – A LITERATURE REVIEW OF AIR POLLUTION INTERVENTIONS AND THEIR IMPACT ON PUBLIC HEALTH

Background and Aims: Intervention studies play an important role in supporting and complementing scientific validation of results of epidemiological non-intervention studies linking air pollution a...

Cancer family caregivers during the palliative, hospice, and bereavement phases: A review of the descriptive psychosocial literature

Because caregiving to an adult with cancer is a dynamic process, a caregiver's perceived burden and psychosocial concerns may be different at different phases of the patient's disease. There is evidence of escalation in caregiver anxiety, depression, and psychological distress as the patient's functional status declines and as the patient nears death. The purpose of this review was to organize the literature in a meaningful way that can potentially capture the unique needs of caregivers to patients receiving palliative and/or hospice care, and caregivers who are in the post-death bereavement phase. A systematic review was conducted. Major databases were searched for non-intervention descriptive studies that included psychosocial variables of family caregivers to adults with cancer during the palliative, hospice, or bereavement phases. The 19 studies reviewed were conducted in six countries and varied considerably by samples, outcome measures, methodologies, and analytic approaches. Despite limiting to the palliative, hospice, and bereavement phases, inconsistent results were found for key variables, such as age, gender, and relationship to the patient. When patient-caregiver dyad analysis was conducted, with rare exception, there was mutuality between the patient's condition and the caregiver's response. Across the 19 studies, 89 unique instruments were used, almost half of which were study specific with no psychometric testing reported. CONCLUSIONS/SIGNIFICANCE OF RESEARCH: As a direct consequence of assuming the caregiver role, cancer family caregivers in the palliative, hospice, and bereavement phases are at increased risk for physical and mental morbidity. Often, the psychological burden of the caregiver exceeds that of the critically ill patient. It is possible that distressed caregivers have a deleterious influence on patient well-being. This review demonstrates the need to develop research standards, especially regarding measurement instruments, so that caregiver research can mature and interventions can be developed to support family caregivers.

Protocol for a systematic review of the effects of schools and school-environment interventions on health: evidence mapping and syntheses.

BackgroundSchools may have important effects on students' and staff's health. Rather than treating schools merely as sites for health education, 'school-environment' interventions treat schools as settings which influence health. Evidence concerning the effects of such interventions has not been recently synthesised.Methods/designSystematic review aiming to map and synthesise evidence on what theories and conceptual frameworks are most commonly used to inform school-environment interventions or explain school-level influences on health; what effects school-environment interventions have on health/health inequalities; how feasible and acceptable are school-environment interventions; what effects other school-level factors have on health; and through what processes school-level influences affect health.We will examine interventions aiming to promote health by modifying schools' physical, social or cultural environment via actions focused on school policies and practices relating to education, pastoral care and other aspects of schools beyond merely providing health education. Participants are staff and students age 4-18 years.We will review published research unrestricted by language, year or source. Searching will involve electronic databases including Embase, ERIC, PubMed, PsycInfo and Social Science Citation Index using natural-language phrases plus reference/citation checking.Stage 1 will map studies descriptively by focus and methods. Stage 2 will involve additional inclusion criteria, quality assessment and data extraction undertaken by two reviewers in parallel. Evidence will be synthesised narratively and statistically where appropriate (undertaking subgroup analyses and meta-regression and where no significant heterogeneity of effect sizes is found, pooling these to calculate a final effect size).DiscussionWe anticipate: finding a large number of studies missed by previous reviews; that non-intervention studies of school effects examine a greater breadth of determinants than are addressed by intervention studies; and that intervention effect estimates are greater than for school-based health curriculum interventions without school-environment components.

An evidence-based review of aging of the body systems following spinal cord injury

Systematic review. To systematically review evidence on aging of the body systems after spinal cord injury (SCI). Toronto, Ontario and Vancouver, British Columbia, Canada. Electronic databases (MEDLINE/PubMed, CINAHL, EMBASE and PsycINFO), were searched for studies published between 1980 and 2009. The search was augmented by reviewing the reference lists of relevant papers. Non-intervention studies that were longitudinal or cross-sectional with able-bodied controls that were at minimum matched on chronological age were included for review. Levels of evidence were assigned to the study design using a modified Sackett scale. Of the 74 studies selected for inclusion, 16 were longitudinal in design. The hypothesis that SCI represents a model for premature aging is supported by a large proportion of level 5 evidence for the cardiovascular and endocrine systems, level 2, 4 and 5 evidence for the musculoskeletal system, and limited level 5 evidence for the immune system. Only a few level 4 and 5 studies for the respiratory system were found. The evidence on the genitourinary system, gastrointestinal system, and for skin and subcutaneous tissues provide level 4 and 5 evidence that premature aging may not be occurring. The evidence on the nervous system does not provide evidence of premature aging as a result of SCI. Premature aging appears to occur in some systems after SCI. Additional longitudinal studies are required to confirm these findings.

A follow-up note on prescriptive statements in nonintervention research studies.

Robinson, Levin, Thomas, Pituch, and Vaughn (2007) examined 74 articles reporting nonintervention studies (i.e., studies with no researcher-manipulated variables) that appeared in 5 educational journals in 1994. Of these articles, 22 contained prescriptive statements (e.g., if teachers or students did X, then student outcome Y would result). In the present study, we examined 243 journal articles published between 1995 and 2005 that cited any of the 22 earlier studies and found that (a) 25 articles (10%) repeated the prescriptive statement and (b) 411 subsequent articles between 2005 and mid-2008 cited the 25 articles that contained repeated prescriptions, with 1 article alone cited 132 times. Thus, recommendations based on nonintervention research were found, to some extent, to be perpetuated by educational researchers. Implications of these findings for educational researchers and consumers are discussed, as well as future directions for this type of research.

Individual patient data meta-analysis in intensive care medicine and contextual effects

The review by Reade et al. [1] stated that ‘‘In intensive care, the context in which an intervention is delivered may be as influential as the intervention itself.’’ I wish to further emphasize the need for cautious screening for possible contextual effects as part of any meta-analysis, but particularly a meta-analysis using individual patient data and also of interventions undertaken in intensive care units. I use as an example the meta-analysis of antibiotic prophylaxis to prevent respiratory infections [2] cited by these authors [1]. Figure 1 displays the control and intervention group ventilator-associated pneumonia-incidence proportion (VAP-IP) data for the studies as abstracted in this meta-analysis [2] in relation to a funnel plot derived using the VAP-IP data of 44 nonintervention studies [3] that demonstrate three contextual issues relevant to the interpretation of the intervention under study [2]. Firstly, the VAP-IPs among the control groups of this meta-analysis [2] are highly variable, much more so than for the VAP-IPs of the intervention groups. Secondly, half of these control groups have a VAP-IP in excess of 45% in contrast to the VAP-IP of 184 control and intervention groups of 96 non-antibiotic VAP prevention studies for which a VAP-IP [45% is rare [3]. Thirdly, this variability is not confined to the smaller groups and hence is not explained by publication bias. These contextual effects had not been explained in this nor subsequent meta-analyses of this topic and would be further obscured in a meta-analysis using individual patient data. [2]. This contextual effect could be a consequence of inapparent outbreaks within the unit resulting from the antibiotic prevention methods, an explanation that is supported by the high proportion of S. aureus among the VAP-related isolates among both the control and intervention groups of studies of antibiotic methods of VAP prevention, but not studies of nonantibiotic methods of VAP prevention [4]. As this mechanism relates to cross infection operating at the level of the intensive care unit, it is difficult to recognize within any single study examined in isolation and would be easily overlooked in a meta-analysis particularly if using individual patient data rather than aggregated data. This highlights the need to identify and explain any heterogeneity among the study results and the possible influence of contextual effects before they are combined into a meta-analysis, whichever method is used.

Trends in publications regarding evidence-practice gaps: a literature review.

BackgroundWell-designed trials of strategies to improve adherence to clinical practice guidelines are needed to close persistent evidence-practice gaps. We studied how the number of these trials is changing with time, and to what extent physicians are participating in such trials.MethodsThis is a literature-based study of trends in evidence-practice gap publications over 10 years and participation of clinicians in intervention trials to narrow evidence-practice gaps. We chose nine evidence-based guidelines and identified relevant publications in the PubMed database from January 1998 to December 2007. We coded these publications by study type (intervention versus non-intervention studies). We further subdivided intervention studies into those for clinicians and those for patients. Data were analyzed to determine if observed trends were statistically significant.ResultsWe identified 1,151 publications that discussed evidence-practice gaps in nine topic areas. There were 169 intervention studies that were designed to improve adherence to well-established clinical guidelines, averaging 1.9 studies per year per topic area. Twenty-eight publications (34%; 95% CI: 24% - 45%) reported interventions intended for clinicians or health systems that met Effective Practice and Organization of Care (EPOC) criteria for adequate design. The median consent rate of physicians asked to participate in these well-designed studies was 60% (95% CI, 25% to 69%).ConclusionsWe evaluated research publications for nine evidence-practice gaps, and identified small numbers of well-designed intervention trials and low rates of physician participation in these trials.

Barriers and Opportunities for Recruitment for Nonintervention Studies on HIV Risk: Perspectives of Street Drug Users

This study used focus-group discussions in response to a video vignette to examine attitudes toward recruitment for nonintervention research involving HIV testing. Participants were 100 ethnically diverse, economically disadvantaged urban drug users, who were recruited from New York City and Hartford, Connecticut in the spring and summer of 2006. Content analyses revealed themes including (1) fears of stigma and legal trouble balanced by trustworthiness of the recruiter; (2) fears of learning one's HIV status balanced by prospects for health benefits, and (3) the right to receive fair monetary compensation balanced by risks of coercion during periods of cravings. Limitations and implications for recruitment practices have been discussed here.

Barriers and Opportunities for Recruitment for Nonintervention Studies on HIV Risk: Perspectives of Street Drug Users

This study used focus-group discussions in response to a video vignette to examine attitudes toward recruitment for nonintervention research involving HIV testing. Participants were 100 ethnically diverse, economically disadvantaged urban drug users, who were recruited from New York City and Hartford, Connecticut in the spring and summer of 2006. Content analyses revealed themes including (1) fears of stigma and legal trouble balanced by trustworthiness of the recruiter; (2) fears of learning one's HIV status balanced by prospects for health benefits, and (3) the right to receive fair monetary compensation balanced by risks of coercion during periods of cravings. Limitations and implications for recruitment practices have been discussed here.

The Incidence of “Causal” Statements in Teaching-and-Learning Research Journals

The authors examined the methodologies of articles in teaching-and-learning research journals, published in 1994 and in 2004, and classified them as either intervention (based on researcher-manipulated variables) or nonintervention. Consistent with the findings of Hsieh et al., intervention research articles declined from 45% in 1994 to 33% in 2004. For nonintervention articles, the authors recorded the incidence of “causal” statements (e.g., if teachers/schools/parents did X, then student/child outcome Y would likely result). Nonintervention research articles containing causal statements increased from 34% in 1994 to 43% in 2004. It appears that at the same time intervention studies are becoming less prevalent in the teaching-and-learning research literature, researchers are more inclined to include causal statements in nonintervention studies.

Multi‐level modeling to explain methamphetamine use among gay and bisexual men

The popularity of methamphetamine among gay men has been documented; however, few studies have examined the complex behavioral and psychological motivations behind methamphetamine use, particularly over time. This study aimed to (i) identify the trajectories for methamphetamine use; (ii) explore factors related to methamphetamine use; and (iii) determine factors which predict changes in usage over a year. This analysis utilized hierarchical linear modeling to identify the trajectories for methamphetamine use and explore factors related to patterns of methamphetamine use. A sample of 293 gay and bisexual men who indicated methamphetamine use at baseline were drawn from Project BUMPS (Boys Using Multiple Party Substances), which was a longitudinal, mixed-methodologies study of 450 club drug-using gay and bisexual men. Participants were assessed via quantitative measures in four waves of data collection over the course of a year (baseline, 4, 8 and 12 months post-baseline). Frequency of methamphetamine use is related to reliance on the drug to avoid unpleasant emotions and physical discomfort, outcome expectancies for use and combining the drug with Viagra. Those with higher levels of drug-related sensation-seeking and those who combine use with Viagra show more consistent use over time, although a decrease in use is noted for most of the sample. Longitudinal analyses support the idea that methamphetamine is used by gay men to mask feelings of discomfort and to enhance sensations as well as sexual pleasure. Longitudinal non-intervention studies of drug use may have intervention-like effects.

Diagnostic and Therapeutic Considerations: Third Molar Teeth

Numerous non-controversial indications for removal of third molar teeth exist. Nevertheless, recent costcontainment efforts by third party payers and government agencies have focused on the asymptomatic third molar as a public health policy issue. These efforts have led, in turn, to current research aimed at establishing specific treatment criteria. Ongoing studies on the bacteriology of the periodontium surrounding the partially erupted third molar have found microorganisms characteristic of periodontal disease. Non-intervention outcome studies, while in their infancy, have provided some data regarding the longterm fate of third molars that are not extracted. Economic analyses and statistical modeling to assess costeffectiveness of extraction versus non-extraction are themselves controversial. Although the data are not yet conclusive, this lecture will attempt to present the available evidence, both pro and con, regarding specific conditions affecting third molars, with emphasis on periodontal disease, orthodontic requirements, and the truly non-pathologic third molar. Implicit in the decision in favor of extraction is knowledge of the potential complications of this surgical procedure. The discussion of complications will provide in-depth information on postoperative infection, alveolar osteitis, nerve injury, and mandibular fracture.

In vivo measurements of the cerebral perfusion and cardiovascular effects of the novel guanidine ME10092 in the non-human primate, Papio ursinus

The novel guanidines N-(3,4-dimethoxy-2-chlorobenzylideneamino)-guanidine (ME 10092) and N-(3,4-dimethoxy-2-chlorobenzylideneamino)-N 1-hydroxyguanidine (PR5) were recently reported to exhibit promising cardioprotective activities in myocardial ischaemia and reperfusion in rats. The current study investigated for the first time pharmacological effects of ME10092 in the primate, viz. the Cape baboon Papio ursinus. The effects of ME10092 (1 and 2 mg/kg doses) on the cerebral blood flow, heart rates and the systolic and diastolic blood pressure were investigated after intravenous injection to the baboon under anaesthesia. The cerebral perfusion effects of ME10092 were assessed using Single Photon Emission Computed Tomography according to the split-dose approach and 99mTc-hexamethyl-propylene amine oxime as brain perfusion tracer. The observation that the recovery times from the anaesthesia were unacceptably prolonged excluded doses beyond 2 mg/kg. The data indicate that no cerebral perfusion changes were induced at both the 1 and 2 mg/kg doses of ME10092. Both these doses of ME10092 showed blood pressure and heart rate effects, with the latter being more significant. Decreases in heart rate were seen directly after ME10092 administration reaching levels of about 20% for the 2 mg/kg dose and about 15% for the 1 mg/kg dose at around 6 min post drug administration. A transient decrease in both systolic and diastolic blood pressure was observed for the higher dose. The blood pressure data further suggest an attenuation of the anaesthesia induced increase in pressure usually present in non-intervention studies. ME10092 clearly exhibits mycocardial effects in the non-human primate, similar to the effects previously observed in the ischaemia-reperfusion rat model, where ME10092 showed strong protection.

Statistical power of articles published in three health psychology-related journals.

Power was calculated for 8,266 statistical tests in 187 journal articles published in the 1997 volumes of Health Psychology (HP), Addictive Behaviors (AB), and the Journal of Studies on Alcohol (JSA). Power to detect small, medium, and large effects was .34. .74. and .92 for HP; .34, .75, and .90 for AB; and .41, .81. and .92 for JSA. Mean power estimates are .36, .77, and .91, giving a good estimation for the field of health psychology. J. Cohen (1988) recommended that power to detect effects should be approximately .80. Using this criterion, the articles in these journals have adequate power to detect medium and large effects. Intervention studies have much less power to detect effects than nonintervention studies do. Results are encouraging for this field, although studies examining small effects are still very much underpowered. This issue is important, because most intervention effects in health psychology are small.

Statistical power of articles published in three health-psychology related journals.

Power was calculated for 8,266 statistical tests in 187 journal articles published in the 1997 volumes of Health Psychology (HP), Addictive Behaviors (AB), and the Journal of Studies on Alcohol (JSA). Power to detect small, medium, and large effects was .34. .74. and .92 for HP; .34, .75, and .90 for AB; and .41, .81. and .92 for JSA. Mean power estimates are .36, .77, and .91, giving a good estimation for the field of health psychology. J. Cohen (1988) recommended that power to detect effects should be approximately .80. Using this criterion, the articles in these journals have adequate power to detect medium and large effects. Intervention studies have much less power to detect effects than nonintervention studies do. Results are encouraging for this field, although studies examining small effects are still very much underpowered. This issue is important, because most intervention effects in health psychology are small.

Evidence-based cognitive rehabilitation: Recommendations for clinical practice

Cicerone KD, Dahlberg C, Kalmar K, Langenbahn DM, Malec JF, Bergquist TF, Felicetti T, Giacino JT, Harley JP, Harrington DE, Herzog J, Kneipp S, Laatsch L, Morse PA. Evidence-based cognitive rehabilitation: recommendations for clinical practice. Arch Phys Med Rehabil 2000;81:1596-615. Objective: To establish evidence-based recommendations for the clinical practice of cognitive rehabilitation, derived from a methodical review of the scientific literature concerning the effectiveness of cognitive rehabilitation for persons with traumatic brain injury (TBI) or stroke. Data Sources: A MEDLINE literature search using combinations of these key words as search terms: attention, awareness, cognition, communication, executive, language, memory, perception, problem solving, reasoning, rehabilitation, remediation, and training. Reference lists from identified articles also were reviewed; a total bibliography of 655 published articles was compiled. Study Selection: Studies were initially reviewed according to the following exclusion criteria: nonintervention studies; theoretical, descriptive, or review papers; papers without adequate specification of interventions; subjects other than persons with TBI or stroke; pediatric subjects; pharmacologic interventions; and non-English language papers. After screening, 232 articles were eligible for inclusion. After detailed review, 61 of these were excluded as single case reports without data, subjects other than TBI and stroke, and nontreatment studies. This screening yielded 171 articles to be evaluated. Data Extraction: Articles were assigned to 1 of 7 categories according to their primary area of intervention: attention, visual perception and constructional abilities, language and communication, memory, problem solving and executive functioning, multi-modal interventions, and comprehensive-holistic cognitive rehabilitation. All articles were independently reviewed by at least 2 committee members and abstracted according to specified criteria. The 171 studies that passed initial review were classified according to the strength of their methods. Class I studies were defined as prospective, randomized controlled trials. Class II studies were defined as prospective cohort studies, retrospective case-control studies, or clinical series with well-designed controls. Class III studies were defined as clinical series without concurrent controls, or studies with appropriate single-subject methodology. Data Synthesis: Of the 171 studies evaluated, 29 were rated as Class I, 35 as Class II, and 107 as Class III. The overall evidence within each predefined area of intervention was then synthesized and recommendations were derived based on consideration of the relative strengths of the evidence. The resulting practice parameters were organized into 3 types of recommendations: Practice Standards, Practice Guidelines, and Practice Options. Conclusions: Overall, support exists for the effectiveness of several forms of cognitive rehabilitation for persons with stroke and TBI. Specific recommendations can be made for remediation of language and perception after left and right hemisphere stroke, respectively, and for the remediation of attention, memory, functional communication, and executive functioning after TBI. These recommendations may help to establish parameters of effective treatment, which should be of assistance to practicing clinicians. © 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Recruiting adolescents into qualitative tobacco research studies: experiences and lessons learned.

An increasing barrier to the development and implementation of effective youth smoking prevention and cessation programs involves recruiting adolescents into research studies. Even for non-intervention studies, issues of consent, confidentiality, and motivation to participate are important considerations. In 1996, 11 Prevention Research Center sites across the country conducted qualitative research using focus groups to explore ethnic differences in smoking among adolescents. The diversity in strategies used to interest, motivate, and retain potential focus group subjects provided a rich data set for information about effective strategies and challenges to recruitment. This article presents an overview of recruitment methods used in a multi-site qualitative study on adolescent tobacco use, reports on successful and less successful strategies, and provides recommendations for future recruitment.

The impact of Rhinanthus spp. on sward productivity and composition: Implications for the restoration of species-rich grasslands

The impact of parasitic angiosperms of the genus Rhinanthus on grassland productivity and floristic composition was monitored at five sites in Britain and N. Italy. A combination of non-intervention and perturbation studies were used to detect differences in the yield and community composition of swards in the presence and absence of Rhinanthus spp. Productivity was found to be consistently lower in areas where Rhinanthus was present. The degree of suppression ranged between 8 and 73%, and was found to be positively correlated with site productivity. Community composition differed significantly between parasite infected and uninfected regions of the sward, the most notable differences being a decline in the proportion of grasses, and a concomitant increase in the proportion of dicotyledons, in the presence of the parasite. The results are discussed in relation to the use of Rhinanthus spp. as management tools for the restoration of species-rich grasslands. The practicalities associated with this option are considered.