Quantitative Review (quantitative + review)

Distribution by Scientific Domains

Selected Abstracts

Nutrition and Physical Activity Interventions to Reduce Cardiovascular Disease Risk in Health Care Settings: A Quantitative Review with a Focus on Women

Sara Wilcox Ph.D.
The authors conducted a quantitative literature review of the impact of 32 diet and physical activity (PA) interventions delivered in health care settings on cardiovascular disease risk factors. Intervention effects were relatively modest but statistically significant for PA, body mass index or weight, dietary fat, blood pressure, and total and low-density lipoprotein serum cholesterol. Intervention effects were generally larger for samples with a mean age >50 years and for studies with <6 months follow-up. Type of comparison group, type of intervention, and use of a behavior theory did not have a consistent impact on intervention effects. Few studies focused on persons of color, although the results from these studies are promising. [source]

Self-injurious behavior and the efficacy of naltrexone treatment: A quantitative synthesis

Frank J. Symons
Abstract People with mental retardation, autism, and related developmental disabilities who self-injure are treated with a wide array of behavioral techniques and psychotropic medications. Despite numerous reports documenting short-term and some long-term changes in self-injury associated with the opiate antagonist naltrexone hydrochloride, no quantitative review of its efficacy has been reported. We conducted a quantitative synthesis of the peer-reviewed published literature from 1983 to 2003 documenting the use of naltrexone for the treatment of self-injurious behavior (SIB). Individual-level results were analyzed given subject and study characteristics. A sample of 27 research articles involving 86 subjects with self-injury was reviewed. Eighty percent of subjects were reported to improve relative to baseline (i.e., SIB reduced) during naltrexone administration and 47% of subjects SIB was reduced by 50% or greater. In studies reporting dose levels in milligrams, males were more likely than females to respond. No significant relations were found between treatment outcomes and autism status or form of self-injury. Results are discussed with respect to future efficacy work related to study outcomes and the pharmacological treatment of self-injury. 2004 Wiley-Liss, Inc. MRDD Research Reviews 2004;10:193,200. [source]

Can circle hook use benefit billfishes?

Joseph E Serafy
Abstract We performed a quantitative review to evaluate circle hook use in recreational and commercial hook-and-line fisheries that interact with billfishes (Family: Istiophoridae). Specifically, we scrutinized the findings of 11 recent empirical studies that reported, on a species-specific basis, side-by-side measures of circle vs. J-hook fishing performance: catch, mortality, deep-hooking and bleeding rates. Of the 30 total comparisons extracted from the literature that satisfied our inclusion criteria, 13 indicated significant differences between hook types for the specific metric compared. No study reported significant billfish catch rate differences between hook types. However, when significant differences between hook types were found, higher mortality rates and higher rates of deep-hooking and bleeding were associated with J-hooks relative to circle hooks. We conclude that empirical evidence is sufficient to promote circle hook use in almost all hook-and-line fishery sectors that typically interact with istiophorids. However, billfish conservation benefits will only be realized if fishers use unmodified circle hooks, commit to releasing live fish and take other appropriate measures which maximize post-release survival. While there may be fishing modes where circle hook effects are negative, for billfish conservation, we recommend managers grant exceptions to circle hook use only when experimental results support such a practice. [source]

A quantitative review comparing the yield of switchgrass in monocultures and mixtures in relation to climate and management factors

GCB BIOENERGY, Issue 1 2010
Abstract Switchgrass (Panicum virgatum L.), a US Department of Energy model species, is widely considered for US biomass energy production. While previous studies have demonstrated the effect of climate and management factors on biomass yield and chemical characteristics of switchgrass monocultures, information is lacking on the yield of switchgrass grown in combination with other species for biomass energy. Therefore, the objective of this quantitative review is to compare the effect of climate and management factors on the yield of switchgrass monocultures, as well as on mixtures of switchgrass, and other species. We examined all peer-reviewed articles describing productivity of switchgrass and extracted dry matter yields, stand age, nitrogen fertilization (N), temperature (growing degree days), and precipitation/irrigation. Switchgrass yield was greater when grown in monocultures (10.9 t ha,1, n=324) than when grown in mixtures (4.4 t ha,1, n=85); yield in monocultures was also greater than the total yield of all species in the mixtures (6.9 t ha,1, n=90). The presence of legume species in mixtures increased switchgrass yield from 3.1 t ha,1 (n=65) to 8.9 t ha,1 (n=20). Total yield of switchgrass-dominated mixtures with legumes reached 9.9 t ha,1 (n=25), which was not significantly different from the monoculture yield. The results demonstrated the potential of switchgrass for use as a biomass energy crop in both monocultures and mixtures across a wide geographic range. Monocultures, but not mixtures, showed a significant positive response to N and precipitation. The response to N for monocultures was consistent for newly established (stand age <3 years) and mature stands (stand age ,3 years) and for lowland and upland ecotypes. In conclusion, these results suggest that fertilization with N will increase yield in monocultures, but not mixtures. For monocultures, N treatment need not be changed based on ecotype and stand age; and for mixtures, legumes should be included as an alternative N source. [source]

The neuropsychology of ecstasy (MDMA) use: a quantitative review

Konstantine K. Zakzanis
Abstract A growing number of empirical studies have found varying neuropsychological impairments associated with use of 3,4-methylenedioxymethamphetamine (MDMA) use. We set out to determine to what extent neuropsychological abilities are impaired in MDMA users. To do so, meta-analytical methods were used to determine the magnitude of neuropsychological impairment in MDMA users across pre-specified cognitive domains. We found that cognitive impairment secondary to recreational drug use may result in what might be described as small-to-medium effects across all cognitive domains with learning and memory being most impaired. We also found that total lifetime ingestion of MDMA appears to be negatively associated with performance on tasks ranging from attention and concentration to learning and memory. Implications and limitations of these findings are discussed. Copyright 2007 John Wiley & Sons, Ltd. [source]

Effectiveness of exercise programmes on shoulder mobility and lymphoedema after axillary lymph node dissection for breast cancer: systematic review

Dorothy N.S. Chan
chan d.n.s., lui l.y.y. & so w.k.w. (2010) Effectiveness of exercise programmes on shoulder mobility and lymphoedema after axillary lymph node dissection for breast cancer: systematic review. Journal of Advanced Nursing,66(9), 1902,1914. Abstract Aim., This article is a report of a review of the effectiveness of exercise programmes on shoulder mobility and lymphoedema in postoperative patients with breast cancer having axillary lymph node dissection, as revealed by randomized controlled trials. Background., Breast cancer is the most common malignancy in women. After surgery, the most common postoperative complications are reduced range of motion in the shoulder, muscle weakness in the upper extremities, lymphoedema, pain and numbness. To reduce these impairments, shoulder exercises are usually prescribed. However, conflicting results regarding the effect and timing of such exercises have been reported. Data sources., Studies were retrieved from a systematic search of published works over the period 2000,2009 indexed in the Cumulative Index to Nursing and Allied Health Literature, Ovid Medline, the British Nursing Index, Proquest, Science Direct, Pubmed, Scopus and the Cochrane Library, using the combined search terms ,breast cancer', ,breast cancer surgery', ,exercise', ,lymphoedema', ,shoulder mobility' and ,randomized controlled trials'. Methods., A quantitative review of effectiveness was carried out. Studies were critically appraised by three independent reviewers, and categorized according to levels of evidence defined by the Joanna Briggs Institute. Results., Six studies were included in the review. Early rather than delayed onset of training did not affect the incidence of postoperative lymphoedema, but early introduction of exercises was valuable in avoiding deterioration in range of shoulder motion. Conclusion., Further studies are required to investigate the optimal time for starting arm exercises after this surgery. Nurses have an important role in educating and encouraging patients to practise these exercises to speed up recovery. [source]

A cross-system synthesis of consumer and nutrient resource control on producer biomass

Daniel S. Gruner
Abstract Nutrient availability and herbivory control the biomass of primary producer communities to varying degrees across ecosystems. Ecological theory, individual experiments in many different systems, and system-specific quantitative reviews have suggested that (i) bottom,up control is pervasive but top,down control is more influential in aquatic habitats relative to terrestrial systems and (ii) bottom,up and top,down forces are interdependent, with statistical interactions that synergize or dampen relative influences on producer biomass. We used simple dynamic models to review ecological mechanisms that generate independent vs. interactive responses of community-level biomass. We calibrated these mechanistic predictions with the metrics of factorial meta-analysis and tested their prevalence across freshwater, marine and terrestrial ecosystems with a comprehensive meta-analysis of 191 factorial manipulations of herbivores and nutrients. Our analysis showed that producer community biomass increased with fertilization across all systems, although increases were greatest in freshwater habitats. Herbivore removal generally increased producer biomass in both freshwater and marine systems, but effects were inconsistent on land. With the exception of marine temperate rocky reef systems that showed positive synergism of nutrient enrichment and herbivore removal, experimental studies showed limited support for statistical interactions between nutrient and herbivory treatments on producer biomass. Top,down control of herbivores, compensatory behaviour of multiple herbivore guilds, spatial and temporal heterogeneity of interactions, and herbivore-mediated nutrient recycling may lower the probability of consistent interactive effects on producer biomass. Continuing studies should expand the temporal and spatial scales of experiments, particularly in understudied terrestrial systems; broaden factorial designs to manipulate independently multiple producer resources (e.g. nitrogen, phosphorus, light), multiple herbivore taxa or guilds (e.g. vertebrates and invertebrates) and multiple trophic levels; and , in addition to measuring producer biomass , assess the responses of species diversity, community composition and nutrient status. [source]

Variable reporting and quantitative reviews: a comparison of three meta-analytical techniques

Marc J. Lajeunesse
Abstract Variable reporting of results can influence quantitative reviews by limiting the number of studies for analysis, and thereby influencing both the type of analysis and the scope of the review. We performed a Monte Carlo simulation to determine statistical errors for three meta-analytical approaches and related how such errors were affected by numbers of constituent studies. Hedges'd and effect sizes based on item response theory (IRT) had similarly improved error rates with increasing numbers of studies when there was no true effect, but IRT was conservative when there was a true effect. Log response ratio had low precision for detecting null effects as a result of overestimation of effect sizes, but high ability to detect true effects, largely irrespective of number of studies. Traditional meta-analysis based on Hedges'd are preferred; however, quantitative reviews should use various methods in concert to improve representation and inferences from summaries of published data. [source]


We conducted qualitative and quantitative reviews of the medical literature to develop an understanding of the linkages between nonspecific lower back pain (LBP) and employee absenteeism, and the efficacy of lower back pain interventions (LBPI) in reducing absenteeism. First, we offered a general time-based framework to clarify the causal flows between LBP and absence. Second, we inspected LBPIs designed to ameliorate LBP, which should, in turn, lead to reduced absence-taking. Third, we conducted a meta-analysis of 45 effect sizes involving 12,214 people, to examine the relationships between both LBP and LBPIs and absenteeism. Consistent with a presumption in the medical literature, we found support for the idea that chronic LBP has a positive overall relationship with absence-taking. The relationship was stronger for absence frequency measures than time lost measures. In addition, we found that increasing aggregation time (i.e., increases in the periods over which absence is observed) enhances the size of the chronic LBP-absence connection. Further, evidence showed that LBPIs were effective overall in reducing absenteeism. Finally, when there was a temporal mismatch between the form of LBP (acute vs. chronic) and the absenteeism aggregation period in LBPI studies, effect sizes were significantly smaller. We concluded with a discussion of these results, methodological limitations, and suggestions for future research that blends medical with organizational approaches to the etiology of absence. [source]