Unions and productivity growth: a meta-analytic review

The impact of unions on productivity growth has received extensive
attention from researchers in industrial relations and economics. Despite
a voluminous literature, controversy continues regarding the effect of unions on productivity growth. In this paper, meta-analysis and metaregression
analysis is used to quantify the association between unions and productivity growth and to accomplish a quantitative assessment of the empirical literature. The results indicate that the overall association between unions and productivity growth is negative, especially for the U.S. The search for moderator variables revealed that most of the variation in the published results is artificial and can be attributed to specification differences.

What do unions do to productivity? A meta-analysis

The impact of unions on productivity is explored using meta-analysis and meta-regression analysis. It is shown that most of the variation in published results is due to specification differences between studies. After controlling for differences between studies, a negative association between unions and productivity is established for the United Kingdom, whereas a positive association is established for the United States in general and for U.S. manufacturing.

The impact of U.S. unions on productivity : a bootstrap meta-analysis

Resampling methods are used to calculate confidence limits in a metaanalysis of the association between unions and productivity for the population of U.S. studies. The available evidence points to a positive and statistically significant association between unions and productivity in the U.S. manufacturing and education sectors, of around 10% and 7%, respectively

Aid effectiveness on accumulation: a meta study

The AEL (aid effectiveness literature) studies the macroeconomic effects of development aid using cross-country or panel data econometrics. It contains 97 papers of which 43 study whether development aid leads to increasing accumulation. The aggregate results of the 43 studies are that aid increases investment with about 25% of the aid, while most of the remaining 75% of the effect is crowded out by a fall in savings. However, these aggregate results are so variable that it is dubious if accumulation rises.

The effects of unions on labour productivity: a meta-analytic review

The impact of unions on productivity has been an important area of debate in
industrial relations and economics. The theoretical and empirical literature has produced conflicting results. In this paper, meta-analysis is used to quantify the association between unions and productivity and reach a quantitative assessment of the empirical literature. The results suggest that the union-productivity association is not invariant, and is country, industry and time specific.

Critical factors for electronic commerce success in small business : a meta study

Small to medium-sized enterprises (SMEs) contribute significantly to the national economies and to the employment levels of different countries and represent a viable source for inventions and innovations. The recent emergence of electronic commerce in the early nineties could provide different opportunities to the small business sector to overcome its inadequacies. However, in view of the electronic commerce/business (EC) literature in organisations in general and in SMEs specifically, it was observed that EC research is scarce. Therefore, this research attempts, by reviewing relevant EC literature, to develop deeper understanding about the factors influencing EC success in SMEs. The researcher found the following issues significantly influence EC success in SMEs: e-Value, e-Cost, e-Transformation, e-Product, e-Nvolvement, e-Nnovativeness, e-Competition, external e-Support, and e-Pressure. These factors are of importance to researchers, SMEs, professionals including educational institutions and policymakers in driving SMEs and EC forward.

Factors affecting e-commerce adoption by SMEs : a meta-analysis

There have been a myriad of research studies concerning SME e-Commerce adoption. However, the findings of these studies with regard to adoption factors have often been fragmented and contradictory. This paper analyses the previous research and synthesises the findings into a cohesive model of factors affecting SME adoption of e-Commerce. Eight meta-factors were identified: (1) perceived relative advantage; (2) perceived compatibility; (3) perceived complexity; (4) pressures from trading partners; (5) pressures from competitors; (6) external change agents; (7) knowledge and expertise about e-Commerce; and (8) management attitudes towards e-Commerce. These meta-factors were further grouped into three contexts: technological, environmental and organisational.

A preliminary meta-analysis of SME ebusiness journal publications: current trends and future research opportunities moving beyond adoption factor studies

Previous meta-analyses of SME-eBusiness journal research focuses on analysing adoption factors, pre-2000 articles and a small number of journals. This paper departs from this research by analysing 100 articles published between 2003 and 2006 in 41 journals on the basis of the research approaches employed, countries and eBusiness technologies studied, and research objectives focused upon. The paper presents preliminary insights into current major research trends based on this analysis, such as the predominant focus on adoption factor by many studies. It also identifies future research opportunities, and proposes a research agenda which aims to progress SME-eBusiness research beyond adoption factor studies by outlining research objectives to help SMEs overcome barriers and exploit drivers.

Fruit and vegetable consumption and stroke : meta-analysis of cohort studies

Background
Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of stroke in most epidemiological studies, although the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of stroke in a meta-analysis of cohort studies.

Methods
We searched MEDLINE, EMBASE, the Cochrane Library, and bibliographies of retrieved articles. Studies were included if they reported relative risks and corresponding 95% CIs of stroke with respect to frequency of fruit and vegetable intake.

Findings
Eight studies, consisting of nine independent cohorts, met the inclusion criteria. These groups included 257 551 individuals (4917 stroke events) with an average follow-up of 13 years. Compared with individuals who had less than three servings of fruit and vegetables per day, the pooled relative risk of stroke was 0·89 (95% CI 0·83–0·97) for those with three to five servings per day, and 0·74 (0·69–0·79) for those with more than five servings per day. Subgroup analyses showed that fruit and vegetables had a significant protective effect on both ischaemic and haemorrhagic stroke.

Interpretation
Increased fruit and vegetable intake in the range commonly consumed is associated with a reduced risk of stroke. Our results provide strong support for the recommendations to consume more than five servings of fruit and vegetables per day, which is likely to cause a major reduction in strokes.

Systematic review and meta-analysis of evidence for increasing numbers of drugs in antiretroviral combination therapy

Objective: To assess the evidence for the effectiveness of increasing numbers of drugs in antiretroviral combination therapy.

Design: Systematic review, meta-analysis, and meta-regression of fully reported randomised controlled trials. All studies included compared quadruple versus triple therapy, triple versus double therapy, double versus monotherapy, or monotherapy versus placebo or no treatment.

Participants: Patients with any stage of HIV infection who had not received antiretroviral therapy.

Main outcome measures: Changes in disease progression or death (clinical outcomes); CD4 count and plasma viral load (surrogate markers).
Search strategy: Six electronic databases, including Medline, Embase, and the Cochrane Library, searched up to February 2001.

Results: 54 randomised controlled trials, most of good quality, with 66 comparison groups were included in the analysis. For both the clinical outcomes and surrogate markers, combinations with up to and including three (triple therapy) were progressively and significantly more effective. The odds ratio for disease progression or death for triple therapy compared with double therapy was 0.6 (95% confidence interval 0.5 to 0.8). Heterogeneity in effect sizes was present in many outcomes but was largely related to the drugs used and trial quality.

Conclusions: Evidence from randomised controlled trials supports the use of triple therapy. Research is needed on the effectiveness of quadruple therapies and the relative effectiveness of specific combinations of drugs.

Use of calcium or calcuim in combination with vitamin D supplementation to prevent fractures and bone loss in people aged 50 years and older: a meta-analysis

Background:  Whether calcium supplementation can reduce osteoporotic fractures is uncertain. We did a meta-analysis to include all the randomised trials in which calcium, or calcium in combination with vitamin D, was used to prevent fracture and osteoporotic bone loss.

Methods:  We identified 29 randomised trials (n=63 897) using electronic databases, supplemented by a hand-search of reference lists, review articles, and conference abstracts. All randomised trials that recruited people aged 50 years or older were eligible. The main outcomes were fractures of all types and percentage change of bone-mineral density from baseline. Data were pooled by use of a random-effect model.

Findings:  In trials that reported fracture as an outcome (17 trials, n=52 625), treatment was associated with a 12% risk reduction in fractures of all types (risk ratio 0·88, 95% CI 0·83–0·95; p=0·0004). In trials that reported bone-mineral density as an outcome (23 trials, n=41 419), the treatment was associated with a reduced rate of bone loss of 0·54% (0·35–0·73; p<0·0001) at the hip and 1·19% (0·76–1·61%; p<0·0001) in the spine. The fracture risk reduction was significantly greater (24%) in trials in which the compliance rate was high (p<0·0001). The treatment effect was better with calcium doses of 1200 mg or more than with doses less than 1200 mg (0·80 vs 0·94; p=0·006), and with vitamin D doses of 800 IU or more than with doses less than 800 IU (0·84 vs 0·87; p=0·03).

Interpretation:  Evidence supports the use of calcium, or calcium in combination with vitamin D supplementation, in the preventive treatment of osteoporosis in people aged 50 years or older. For best therapeutic effect, we recommend minimum doses of 1200 mg of calcium, and 800 IU of vitamin D (for combined calcium plus vitamin D supplementation).

Increased consumption of fruit and vegetables is related to a reduced risk of coronary heart disease: meta-analysis of cohort studies

Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of coronary heart disease (CHD) in many epidemiological studies, however, the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of CHD by carrying out a meta-analysis of cohort studies. Studies were included if they reported relative risks (RRs) and corresponding 95% confidence interval (CI) of CHD with respect to frequency of fruit and vegetable intake. Twelve studies, consisting of 13 independent cohorts, met the inclusion criteria. There were 278 459 individuals (9143 CHD events) with a median follow-up of 11 years. Compared with individuals who had less than 3 servings/day of fruit and vegetables, the pooled RR of CHD was 0.93 (95% CI: 0.86–1.00, P=0.06) for those with 3–5 servings/day and 0.83 (0.77–0.89, P<0.0001) for those with more than 5 servings/day. Subgroup analyses showed that both fruits and vegetables had a significant protective effect on CHD. Our meta-analysis of prospective cohort studies demonstrates that increased consumption of fruit and vegetables from less than 3 to more than 5 servings/day is related to a 17% reduction in CHD risk, whereas increased intake to 3–5 servings/day is associated with a smaller and borderline significant reduction in CHD risk. These results provide strong support for the recommendations to consume more than 5 servings/day of fruit and vegetables.

Women exposed to intimate partner violence : expectations and experiences when they encounter health care professionals : a meta-analysis of qualitative studies

Background The appropriate response of health care professionals to intimate partner violence is still a matter of debate. This article reports a meta-analysis of qualitative studies that answers 2 questions: (1) How do women with histories of intimate partner violence perceive the responses of health care professionals? and (2) How do women with histories of intimate partner violence want their health care providers to respond to disclosures of abuse?

Methods Multiple databases were searched from their start to July 1, 2004. Searches were complemented with citation tracking and contact with researchers. Inclusion criteria included a qualitative design, women 15 years or older with experience of intimate partner violence, and English language. Two reviewers independently applied criteria and extracted data. Findings from the primary studies were combined using a qualitative meta-analysis.

Results Twenty-nine articles reporting 25 studies (847 participants) were included. The emerging constructs were largely consistent across studies and did not vary by study quality. We ordered constructs by the temporal structure of consultations with health care professionals: before the abuse is discussed, at disclosure, and the immediate and further responses of the health care professional. Key constructs included a wish from women for responses from health care professionals that were nonjudgmental, nondirective, and individually tailored, with an appreciation of the complexity of partner violence. Repeated inquiry about partner violence was seen as appropriate by women who were at later stages of an abusive relationship.

Conclusion Women’s perceptions of appropriate and inappropriate responses partly depended on the context of the consultation, their own readiness to address the issue, and the nature of the relationship between the woman and the health care professional.