Bisphosphonates and atrial fibrillation: Bayesian meta-analyses of randomized controlled trials and observational studies

The Effect of Digital Mental Health Literacy Interventions on Mental Health: Systematic Review and Meta-Analysis

BACKGROUND

Accelerated by technological advancements and the recent global pandemic, there is burgeoning interest in digital mental health literacy (DMHL) interventions that can positively affect mental health. However, existing work remains inconclusive regarding the effectiveness of DMHL interventions.

OBJECTIVE

This systematic review and meta-analysis investigated the components and modes of DMHL interventions, their moderating factors, and their long-term impacts on mental health literacy and mental health.

METHODS

We used a random-effects model to conduct meta-analyses and meta-regressions on moderating effects of DMHL interventions on mental health.

RESULTS

Using 144 interventions with 206 effect sizes, we found a moderate effect of DMHL interventions in enhancing distal mental health outcomes (standardized mean difference=0.42, 95% CI -0.10 to 0.73; P<.001) and a large effect in increasing proximal mental health literacy outcomes (standardized mean difference=0.65, 95% CI 0.59-0.74; P<.001). Uptake of DMHL interventions was comparable with that of control conditions, and uptake of DMHL interventions did not moderate the effects on both proximal mental health literacy outcomes and distal mental health outcomes. DMHL interventions were as effective as face-to-face interventions and did not differ by platform type or dosage. DMHL plus interventions (DMHL psychoeducation coupled with other active treatment) produced large effects in bolstering mental health, were more effective than DMHL only interventions (self-help DMHL psychoeducation), and were comparable with non-DMHL interventions (treatment as usual). DMHL interventions demonstrated positive effects on mental health that were sustained over follow-up assessments and were most effective in enhancing the mental health of emerging and older adults.

CONCLUSIONS

For theory building, our review and meta-analysis found that DMHL interventions are as effective as face-to-face interventions. DMHL interventions confer optimal effects on mental health when DMHL psychoeducation is combined with informal, nonprofessional active treatment components such as skills training and peer support, which demonstrate comparable effectiveness with that of treatment as usual (client-professional interactions and therapies). These effects, which did not differ by platform type or dosage, were sustained over time. Additionally, most DMHL interventions are found in Western cultural contexts, especially in high-income countries (Global North) such as Australia, the United States, and the United Kingdom, and limited research is conducted in low-income countries in Asia and in South American and African countries. Most of the DMHL studies did not report information on the racial or ethnic makeup of the samples. Future work on DMHL interventions that target racial or ethnic minority groups, particularly the design, adoption, and evaluation of the effects of culturally adaptive DMHL interventions on uptake and mental health functioning, is needed. Such evidence can drive the adoption and implementation of DMHL interventions at scale, which represents a key foundation for practice-changing impact in the provision of mental health resources for individuals and the community.

TRIAL REGISTRATION

PROSPERO International Prospective Register of Systematic Reviews CRD42023363995; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023363995.

Cardiovascular safety of zoledronic acid in the treatment of primary osteoporosis: A meta-analysis and systematic review

PURPOSE

Osteoporosis is intimately linked to cardiovascular disease and it has been uncertain that zoledronic acid is not correlated with cardiovascular disease. We intended to assess the cardiovascular safety of zoledronic acid in the treatment of primary osteoporosis.

METHODS

We included only randomized controlled trials (RCTs) of patients with osteoporosis receiving zoledronic acid or a placebo. We systematically searched PubMed, Embase, Web of Science, Cochrane CENTRAL, Scopus, the Chinese National Knowledge Infrastructure, ClinicalTrials.gov, and ICTRP from the time of database creation to April 5, 2023. Two investigators extracted data independently on study characteristics, outcomes of interest, and risk of bias based on PRISMA guidelines.

RESULTS

As of April 5, 2023, our search identified 32,361 records, and after excluding these records, 9 RCTs were included in the meta-analysis. The overall risk ratio for cardiovascular events with zoledronic acid for primary osteoporosis compared with placebo was 1.15 (95 % CI 1.05-1.26, I2=12 %, P = 0.002), while the risk of major adverse cardiovascular events with zoledronic acid (RR 1.03, 95 % CI 0. 89-1.18, I2=21 %, P = 0.71) was not significant, possibly due to atrial fibrillation (RR 1.21, 95 % CI 0.99-1.47, I2=0 %, P = 0.06) versus the increased relative risk of arrhythmia (RR 1.30, 95 % CI 1.11-1.52, I2=34 %, P = 0.001). Overall, the cardiovascular risk of zoledronic acid for the treatment of primary osteoporosis was not significant; however, the relative risk of elevated atrial fibrillation and arrhythmias remains to be further studied.

CONCLUSIONS

In women with primary osteoporosis, zoledronic acid may increase the risk of atrial fibrillation (P = 0.06) and arrhythmias (P = 0.001) compared with placebo, independent of the risk of major adverse cardiovascular events, angina, and heart failure. However, the sample size of men with primary osteoporosis is small, and the cardiovascular risk of zoledronic acid in men with osteoporosis is uncertain.

Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials: a meta-epidemiological study

BACKGROUND

Researchers and decision-makers often use evidence from randomised controlled trials (RCTs) to determine the efficacy or effectiveness of a treatment or intervention. Studies with observational designs are often used to measure the effectiveness of an intervention in 'real world' scenarios. Numerous study designs and their modifications (including both randomised and observational designs) are used for comparative effectiveness research in an attempt to give an unbiased estimate of whether one treatment is more effective or safer than another for a particular population. An up-to-date systematic analysis is needed to identify differences in effect estimates from RCTs and observational studies. This updated review summarises the results of methodological reviews that compared the effect estimates of observational studies with RCTs from evidence syntheses that addressed the same health research question.

OBJECTIVES

To assess and compare synthesised effect estimates by study type, contrasting RCTs with observational studies. To explore factors that might explain differences in synthesised effect estimates from RCTs versus observational studies (e.g. heterogeneity, type of observational study design, type of intervention, and use of propensity score adjustment). To identify gaps in the existing research comparing effect estimates across different study types.

SEARCH METHODS

We searched MEDLINE, the Cochrane Database of Systematic Reviews, Web of Science databases, and Epistemonikos to May 2022. We checked references, conducted citation searches, and contacted review authors to identify additional reviews.

SELECTION CRITERIA

We included systematic methodological reviews that compared quantitative effect estimates measuring the efficacy or effectiveness of interventions tested in RCTs versus in observational studies. The included reviews compared RCTs to observational studies (including retrospective and prospective cohort, case-control and cross-sectional designs). Reviews were not eligible if they compared RCTs with studies that had used some form of concurrent allocation.

DATA COLLECTION AND ANALYSIS

Using results from observational studies as the reference group, we examined the relative summary effect estimates (risk ratios (RRs), odds ratios (ORs), hazard ratios (HRs), mean differences (MDs), and standardised mean differences (SMDs)) to evaluate whether there was a relatively larger or smaller effect in the ratio of odds ratios (ROR) or ratio of risk ratios (RRR), ratio of hazard ratios (RHR), and difference in (standardised) mean differences (D(S)MD). If an included review did not provide an estimate comparing results from RCTs with observational studies, we generated one by pooling the estimates for observational studies and RCTs, respectively. Across all reviews, we synthesised these ratios to produce a pooled ratio of ratios comparing effect estimates from RCTs with those from observational studies. In overviews of reviews, we estimated the ROR or RRR for each overview using observational studies as the reference category. We appraised the risk of bias in the included reviews (using nine criteria in total). To receive an overall low risk of bias rating, an included review needed: explicit criteria for study selection, a complete sample of studies, and to have controlled for study methodological differences and study heterogeneity. We assessed reviews/overviews not meeting these four criteria as having an overall high risk of bias. We assessed the certainty of the evidence, consisting of multiple evidence syntheses, with the GRADE approach.

MAIN RESULTS

We included 39 systematic reviews and eight overviews of reviews, for a total of 47. Thirty-four of these contributed data to our primary analysis. Based on the available data, we found that the reviews/overviews included 2869 RCTs involving 3,882,115 participants, and 3924 observational studies with 19,499,970 participants. We rated 11 reviews/overviews as having an overall low risk of bias, and 36 as having an unclear or high risk of bias. Our main concerns with the included reviews/overviews were that some did not assess the quality of their included studies, and some failed to account appropriately for differences between study designs - for example, they conducted aggregate analyses of all observational studies rather than separate analyses of cohort and case-control studies. When pooling RORs and RRRs, the ratio of ratios indicated no difference or a very small difference between the effect estimates from RCTs versus from observational studies (ratio of ratios 1.08, 95% confidence interval (CI) 1.01 to 1.15). We rated the certainty of the evidence as low. Twenty-three of 34 reviews reported effect estimates of RCTs and observational studies that were on average in agreement. In a number of subgroup analyses, small differences in the effect estimates were detected: - pharmaceutical interventions only (ratio of ratios 1.12, 95% CI 1.04 to 1.21); - RCTs and observational studies with substantial or high heterogeneity; that is, I2 ≥ 50% (ratio of ratios 1.11, 95% CI 1.04 to 1.18); - no use (ratio of ratios 1.07, 95% CI 1.03 to 1.11) or unclear use (ratio of ratios 1.13, 95% CI 1.03 to 1.25) of propensity score adjustment in observational studies; and - observational studies without further specification of the study design (ratio of ratios 1.06, 95% CI 0.96 to 1.18). We detected no clear difference in other subgroup analyses.

AUTHORS' CONCLUSIONS

We found no difference or a very small difference between effect estimates from RCTs and observational studies. These findings are largely consistent with findings from recently published research. Factors other than study design need to be considered when exploring reasons for a lack of agreement between results of RCTs and observational studies, such as differences in the population, intervention, comparator, and outcomes investigated in the respective studies. Our results underscore that it is important for review authors to consider not only study design, but the level of heterogeneity in meta-analyses of RCTs or observational studies. A better understanding is needed of how these factors might yield estimates reflective of true effectiveness.

Antiosteoporosis medications and cardiovascular disease: a population-based nationwide nested case-control study

Purpose: Patients with osteoporosis are at an increased risk of cardiovascular disease (CVD). Several antiosteoporosis medications have been demonstrated with the benefit of preventing osteoporosis. Our aim is to assess the CVD risks associated with antiosteoporosis medications using the National Health Insurance Research Database in Taiwan between 2000 and 2016. Methods: Among 41,102 patients of 40+ years old with newly diagnosed osteoporosis, 69.1% (N = 28,387) of patients were included in the user cohort of antiosteoporosis medicines, of whom 13, 472 developed CVD by the end of 2016, while 14,915 did not. Using the nested case-control analysis in the user cohort (88.0% women and 77.4% elderly), we applied conditional logistic regression to estimate odds ratios (ORs) of eight types of CVD for the users of denosumab, bisphosphonate, teriparatide, and hormone replacement therapy (HRT). Results: The adjusted ORs of overall CVDs were 0.13 (95% CI: 0.12-0.15) for denosumab users, 0.52 (95% CI: 0.45-0.61) for teriparatide users, and 0.80 (95% CI: 0.76-0.85) for bisphosphonate users. The HRT users were at higher odds of coronary artery and peripheral artery diseases, heart failure, pulmonary embolism, and deep vein thrombosis. Conclusion: Denosumab, teriparatide, and bisphosphonate may have more protective effects against CVD than hormone therapy. Physicians may take subsequent cardiovascular risks into account when choosing an adequate antiosteoporosis medication for patients with osteoporosis.

Methods for the inclusion of real-world evidence in network meta-analysis

Background

Network Meta-Analysis (NMA) is a key component of submissions to reimbursement agencies world-wide, especially when there is limited direct head-to-head evidence for multiple technologies from randomised controlled trials (RCTs). Many NMAs include only data from RCTs. However, real-world evidence (RWE) is also becoming widely recognised as a valuable source of clinical data. This study aims to investigate methods for the inclusion of RWE in NMA and its impact on the level of uncertainty around the effectiveness estimates, with particular interest in effectiveness of fingolimod.

Methods

A range of methods for inclusion of RWE in evidence synthesis were investigated by applying them to an illustrative example in relapsing remitting multiple sclerosis (RRMS). A literature search to identify RCTs and RWE evaluating treatments in RRMS was conducted. To assess the impact of inclusion of RWE on the effectiveness estimates, Bayesian hierarchical and adapted power prior models were applied. The effect of the inclusion of RWE was investigated by varying the degree of down weighting of this part of evidence by the use of a power prior.

Results

Whilst the inclusion of the RWE led to an increase in the level of uncertainty surrounding effect estimates in this example, this depended on the method of inclusion adopted for the RWE. ‘Power prior’ NMA model resulted in stable effect estimates for fingolimod yet increasing the width of the credible intervals with increasing weight given to RWE data. The hierarchical NMA models were effective in allowing for heterogeneity between study designs, however, this also increased the level of uncertainty.

Conclusion

The ‘power prior’ method for the inclusion of RWE in NMAs indicates that the degree to which RWE is taken into account can have a significant impact on the overall level of uncertainty. The hierarchical modelling approach further allowed for accommodating differences between study types. Consequently, further work investigating both empirical evidence for biases associated with individual RWE studies and methods of elicitation from experts on the extent of such biases is warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01399-3.

Classifying information-sharing methods

BACKGROUND

Sparse relative effectiveness evidence is a frequent problem in Health Technology Assessment (HTA). Where evidence directly pertaining to the decision problem is sparse, it may be feasible to expand the evidence-base to include studies that relate to the decision problem only indirectly: for instance, when there is no evidence on a comparator, evidence on other treatments of the same molecular class could be used; similarly, a decision on children may borrow-strength from evidence on adults. Usually, in HTA, such indirect evidence is either included by ignoring any differences ('lumping') or not included at all ('splitting'). However, a range of more sophisticated methods exists, primarily in the biostatistics literature. The objective of this study is to identify and classify the breadth of the available information-sharing methods.

METHODS

Forwards and backwards citation-mining techniques were used on a set of seminal papers on the topic of information-sharing. Papers were included if they specified (network) meta-analytic methods for combining information from distinct populations, interventions, outcomes or study-designs.

RESULTS

Overall, 89 papers were included. A plethora of evidence synthesis methods have been used for information-sharing. Most papers (n=79) described methods that shared information on relative treatment effects. Amongst these, there was a strong emphasis on methods for information-sharing across multiple outcomes (n=42) and treatments (n=25), with fewer papers focusing on study-designs (n=23) or populations (n=8). We categorise and discuss the methods under four 'core' relationships of information-sharing: functional, exchangeability-based, prior-based and multivariate relationships, and explain the assumptions made within each of these core approaches.

CONCLUSIONS

This study highlights the range of information-sharing methods available. These methods often impose more moderate assumptions than lumping or splitting. Hence, the degree of information-sharing that they impose could potentially be considered more appropriate. Our identification of four 'core' methods of information-sharing allows for an improved understanding of the assumptions underpinning the different methods. Further research is required to understand how the methods differ in terms of the strength of sharing they impose and the implications of this for health care decisions.

Association Between Cigarette Smoking and Systemic Lupus Erythematosus: An Updated Multivariate Bayesian Metaanalysis

OBJECTIVE

The association between cigarette smoking and the risk of systemic lupus erythematosus (SLE) remains a matter for debate. Additionally, the effect of the change of smokers' demographics on the risk of development of SLE over time has not been formally addressed. We aimed to examine the association between cigarette smoking and the risk of SLE by performing an updated metaanalysis.

METHODS

A literature search using keywords including "lupus," "smoking," "cigarette," "environmental," "autoimmune," and "connective tissue disease" was performed in computerized databases to identify studies addressing the relationship between cigarette smoking and SLE occurrence. A Bayesian metaanalysis was conducted by computing the log-OR between current and never smokers, and between former and never smokers. The average log-OR (subsequently converted to OR) and their corresponding 95% credible intervals (CrI) were calculated. The effect of publication time, sex, and age of patients with SLE on the effect sizes was examined by multivariate metaregression.

RESULTS

Data aggregation of 12 eligible studies comprising 3234 individuals who developed SLE and 288,336 control subjects revealed a significant association between SLE occurrence and current smoking status (OR 1.54, 95% CrI 1.06-2.25), while only a non-significant trend was demonstrated between SLE occurrence and former smoking status (OR 1.39, 95% CrI 0.95-2.08). Publication time, sex, and the mean age of patients with SLE did not explain the heterogeneity of the effect sizes.

CONCLUSION

Current smoking status is associated with risk of SLE. Sex and age of patients with SLE had no significant effect on the risk of SLE over time.

[The effect of bisphosphonate therapy on reducing the risk of cardiovascular complications associated with chronic heart failure, type 2 diabetes and osteoporosis in postmenopausal women]

AIM

To study the effectiveness of oral alendronate and ibandronate bisphosphonates for the prevention of cardiovascular complications in postmenopausal women with type 2 diabetes mellitus (DM) and osteoporosis during a 12-month prospective observation.

MATERIALS AND METHODS

The study included 86 women with osteoporosis, chronic heart failure (CHF) and type 2 diabetes: the 1st group (n=52) included patients who received basic therapy for heart failure; the 2nd group (n=34) included patients who, in addition to the basic therapy of heart failure, were prescribed alendronic and ibandronic acid preparations for the treatment of osteoporosis. In order to identify the possibility of associating the studied factors with the nature of the course of heart failure, the patients were divided according to the results of a one - year follow - up into two subgroups: subgroup A (n=49) - patients with a favorable course of the disease and subgroup B (n=37) - patients with an unfavorable course of pathology.

RESULTS AND DISCUSSION

After 12 months, a significant decrease in the levels of cerebral natriuretic peptide precursor (NT-proBNP), tumor necrosis factor-α, and interleukin-1β was found in the group of women treated with bisphosphonates compared to baseline. Significant associations of NT-proBNP levels (p=0.02) and the studied cytokines (p=0.01) with an unfavorable course of heart failure were revealed. A significant association of bisphosphonate therapy with a favorable course of heart failure (p=0.01) was also revealed. The probability of developing adverse cardiovascular events during the year in the treatment of heart failure with basic therapy drugs with additional therapy of osteoporosis with bisphosphonates is significantly (p=0.0025) lower than the treatment of patients with heart failure with only basic therapy and not taking bisphosphonates for the treatment of osteoporosis.

CONCLUSION

In postmenopausal women with associated cardiovascular pathology (CHF, type 2 diabetes and osteoporosis), prophylactic therapy with oral alendronate and ibandronate oral bisphosphonates is effective, reduces the risk of progression of heart failure, inhibits inflammatory mediators, positively affects the combined endpoints of comorbid cardiovascular pathology.

Bisphosphonates and cardiovascular risk in elderly patients with previous cardiovascular disease: a population-based nested case-control study in Italy

Background:

In a globally aging population, chronic conditions with a high impact on healthcare costs and quality of life, such as osteoporosis and associated fractures, are a matter of concern. For osteoporosis, several drug treatments are available, but evidence on adverse cardiovascular and cerebrovascular (CCV) events, and in particular the risk of atrial fibrillation (AF), related to anti-osteoporotic drug use is inconclusive. The objective of this study was to evaluate the association between the use of bisphosphonates (BPs), strontium ranelate (SR), and other anti-osteoporosis drugs and the risk of AF and CCV events in a large cohort of patients affected by CCV diseases.

Methods:

Based on a cohort of patients aged 65 years and over, discharged from the hospitals of five large Italian areas after a CCV event between 2008 and 2011, two nested case-control studies were conducted. Cases were patients with a subsequent hospital admission for AF or CCV; four controls for each case were randomly selected and matched by age group, sex and follow-up time. A total of three exposure measures were tested: ever use, adherence and recency of use. In the conditional logistic regression models, patients not treated with any anti-osteoporotic medication were considered as the reference category.

Results:

The initial cohort accounted for 657,246 patients. Neither BPs nor SR use was associated with an increased risk of AF regardless of the adherence and recency of use. Overall BP and SR use was associated with a slightly increased risk of CCV; however, results reversed when considering higher adherence: odds ratio (OR) 0.81, 95% confidence interval (CI) 0.71–0.92 for BPs and OR 0.71, 95% CI 0.52–0.97 for SR.

Conclusions:

BPs do not increase cardiovascular risk and can be prescribed to elderly patients for osteoporosis treatment. However, patients with pre-existing cerebrovascular/cardiovascular conditions should be carefully monitored.

The effects of zoledronic acid on ECG: a prospective study on patients with bone metastatic cancer

INTRODUCTION

There are controversial results in the risk of atrial fibrillation as well as arrhythmogenic potential of bis-phosphonates.

METHOD

37 patients and 40 healthy controls were evaluated prospectively with regard to the cardiac side effects related to the use of zoledronic acid (ZA) and its effects on electrocardiography (ECG) parameters.

RESULT

As the basal ECG results of the patients diagnosed with cancer compared with the control group, it was determined that QT maximum was significantly lower, QT minimum was significantly higher. However; it was determined that QT disp, P max, P min, and P disp values were not significantly different. There was no statistically significant difference in P max, P min, P disp, QT max, QT min, QT disp values of the ECG parameters measured from cancer patients, before and 60 minutes after ZA therapy.

CONCLUSION

There were no significant alterations in ECG in the acute period, indicated that ZA had no arrhythmia potential in the early period in patients with no underlying cardiac disease. However: patients receiving ZA should be monitored more closely because of the risk of arrhythmia which may ensue due to hypocalcemia, hypomagnesemia, or other chemotherapeutics.

Bisphosphonates and risk of cardiovascular events: a meta-analysis

Background and Objectives

Some evidence suggests that bisphosphonates may reduce atherosclerosis, while concerns have been raised about atrial fibrillation. We conducted a meta-analysis to determine the effects of bisphosphonates on total adverse cardiovascular (CV) events, atrial fibrillation, myocardial infarction (MI), stroke, and CV death in adults with or at risk for low bone mass.

Methods

A systematic search of MEDLINE and EMBASE through July 2014 identified 58 randomized controlled trials with longer than 6 months in duration that reported CV events. Absolute risks and the Mantel-Haenszel fixed-effects odds ratios (ORs) and 95% confidence intervals (CIs) of total CV events, atrial fibrillation, MI, stroke, and CV death were estimated. Subgroup analyses by follow-up duration, population characteristics, bisphosphonate types, and route were performed.

Results

Absolute risks over 25–36 months in bisphosphonate-treated versus control patients were 6.5% versus 6.2% for total CV events; 1.4% versus 1.5% for atrial fibrillation; 1.0% versus 1.2% for MI; 1.6% versus 1.9% for stroke; and 1.5% versus 1.4% for CV death. Bisphosphonate treatment up to 36 months did not have any significant effects on total CV events (14 trials; ORs [95% CI]: 0.98 [0.84–1.14]; I² = 0.0%), atrial fibrillation (41 trials; 1.08 [0.92–1.25]; I² = 0.0%), MI (10 trials; 0.96 [0.69–1.34]; I² = 0.0%), stroke (10 trials; 0.99 [0.82–1.19]; I² = 5.8%), and CV death (14 trials; 0.88 [0.72–1.07]; I² = 0.0%) with little between-study heterogeneity. The risk of atrial fibrillation appears to be modestly elevated for zoledronic acid (6 trials; 1.24 [0.96–1.61]; I² = 0.0%), not for oral bisphosphonates (26 trials; 1.02 [0.83–1.24]; I² = 0.0%). The CV effects did not vary by subgroups or study quality.

Conclusions

Bisphosphonates do not have beneficial or harmful effects on atherosclerotic CV events, but zoledronic acid may modestly increase the risk of atrial fibrillation. Given the large reduction in fractures with bisphosphonates, changes in osteoporosis treatment decision due to CV risk are not justified.

New strategies for osteoporosis patients previously managed with strontium ranelate

The aim of this article is to describe potential alternatives to patients no longer eligible for management with strontium ranelate for osteoporosis according to the recommendations by the European Medicines Agency. A systematic search of Pubmed was done for papers on fracture efficacy of various treatments for osteoporosis, and potential harms especially in terms of cardiovascular events and stroke. The results showed that drugs more efficacious in terms of relative risk reduction of fractures than strontium ranelate were alendronate, risedronate, zoledronate, and denosumab. Raloxifene, as for strontium, may be associated with an increased risk of deep venous thromboembolism and fatal stroke. In terms of cardiovascular events special attention may be given to calcium supplements. Thus, patients at risk of stroke and ischemic cardiac events such as acute myocardial infarction should not use strontium ranelate. Ideally more efficacious drugs in terms of fracture reduction should be used such as alendronate, risedronate, zoledronate or denosumab. Raloxifene may pose a special problem as this too may be associated with an increased risk of fatal strokes. Other less-potent drugs in terms of fracture reduction should only be used if no alternatives are available (ibandronate, pamidronate, clodronate). Parathyroid hormone or analogs may be used for a limited time interval in specially selected patients and needs to be followed up with antiresorptive treatment to prevent loss of the bone gained. However, it should be remembered that no head-to-head comparison studies exist.

Environmental factors, toxicants and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an immune-complex-mediated multi-systemic autoimmune condition of multifactorial etiology, which mainly affects young women. It is currently believed that the onset of SLE and lupus flares are triggered by various environmental factors in genetically susceptible individuals. Various environmental agents and toxicants, such as cigarette smoke, alcohol, occupationally- and non-occupationally-related chemicals, ultraviolet light, infections, sex hormones and certain medications and vaccines, have been implicated to induce SLE onset or flares in a number case series, case-control and population-based cohort studies and very few randomized controlled trials. Here, we will describe some of these recognized environmental lupus triggering and perpetuating factors and explain how these factors potentially bias the immune system towards autoimmunity through their interactions with genetic and epigenetic alterations. Further in-depth exploration of how potentially important environmental factors mechanistically interact with the immune system and the genome, which trigger the onset of SLE and lupus flares, will certainly be one of the plausible steps to prevent the onset and to decelerate the progress of the disease.

Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials

BACKGROUND

Researchers and organizations often use evidence from randomized controlled trials (RCTs) to determine the efficacy of a treatment or intervention under ideal conditions. Studies of observational designs are often used to measure the effectiveness of an intervention in 'real world' scenarios. Numerous study designs and modifications of existing designs, including both randomized and observational, are used for comparative effectiveness research in an attempt to give an unbiased estimate of whether one treatment is more effective or safer than another for a particular population.A systematic analysis of study design features, risk of bias, parameter interpretation, and effect size for all types of randomized and non-experimental observational studies is needed to identify specific differences in design types and potential biases. This review summarizes the results of methodological reviews that compare the outcomes of observational studies with randomized trials addressing the same question, as well as methodological reviews that compare the outcomes of different types of observational studies.

OBJECTIVES

To assess the impact of study design (including RCTs versus observational study designs) on the effect measures estimated.To explore methodological variables that might explain any differences identified.To identify gaps in the existing research comparing study designs.

SEARCH METHODS

We searched seven electronic databases, from January 1990 to December 2013.Along with MeSH terms and relevant keywords, we used the sensitivity-specificity balanced version of a validated strategy to identify reviews in PubMed, augmented with one term ("review" in article titles) so that it better targeted narrative reviews. No language restrictions were applied.

SELECTION CRITERIA

We examined systematic reviews that were designed as methodological reviews to compare quantitative effect size estimates measuring efficacy or effectiveness of interventions tested in trials with those tested in observational studies. Comparisons included RCTs versus observational studies (including retrospective cohorts, prospective cohorts, case-control designs, and cross-sectional designs). Reviews were not eligible if they compared randomized trials with other studies that had used some form of concurrent allocation.

DATA COLLECTION AND ANALYSIS

In general, outcome measures included relative risks or rate ratios (RR), odds ratios (OR), hazard ratios (HR). Using results from observational studies as the reference group, we examined the published estimates to see whether there was a relative larger or smaller effect in the ratio of odds ratios (ROR).Within each identified review, if an estimate comparing results from observational studies with RCTs was not provided, we pooled the estimates for observational studies and RCTs. Then, we estimated the ratio of ratios (risk ratio or odds ratio) for each identified review using observational studies as the reference category. Across all reviews, we synthesized these ratios to get a pooled ROR comparing results from RCTs with results from observational studies.

MAIN RESULTS

Our initial search yielded 4406 unique references. Fifteen reviews met our inclusion criteria; 14 of which were included in the quantitative analysis.The included reviews analyzed data from 1583 meta-analyses that covered 228 different medical conditions. The mean number of included studies per paper was 178 (range 19 to 530).Eleven (73%) reviews had low risk of bias for explicit criteria for study selection, nine (60%) were low risk of bias for investigators' agreement for study selection, five (33%) included a complete sample of studies, seven (47%) assessed the risk of bias of their included studies,Seven (47%) reviews controlled for methodological differences between studies,Eight (53%) reviews controlled for heterogeneity among studies, nine (60%) analyzed similar outcome measures, and four (27%) were judged to be at low risk of reporting bias.Our primary quantitative analysis, including 14 reviews, showed that the pooled ROR comparing effects from RCTs with effects from observational studies was 1.08 (95% confidence interval (CI) 0.96 to 1.22). Of 14 reviews included in this analysis, 11 (79%) found no significant difference between observational studies and RCTs. One review suggested observational studies had larger effects of interest, and two reviews suggested observational studies had smaller effects of interest.Similar to the effect across all included reviews, effects from reviews comparing RCTs with cohort studies had a pooled ROR of 1.04 (95% CI 0.89 to 1.21), with substantial heterogeneity (I(2) = 68%). Three reviews compared effects of RCTs and case-control designs (pooled ROR: 1.11 (95% CI 0.91 to 1.35)).No significant difference in point estimates across heterogeneity, pharmacological intervention, or propensity score adjustment subgroups were noted. No reviews had compared RCTs with observational studies that used two of the most common causal inference methods, instrumental variables and marginal structural models.

AUTHORS' CONCLUSIONS

Our results across all reviews (pooled ROR 1.08) are very similar to results reported by similarly conducted reviews. As such, we have reached similar conclusions; on average, there is little evidence for significant effect estimate differences between observational studies and RCTs, regardless of specific observational study design, heterogeneity, or inclusion of studies of pharmacological interventions. Factors other than study design per se need to be considered when exploring reasons for a lack of agreement between results of RCTs and observational studies. Our results underscore that it is important for review authors to consider not only study design, but the level of heterogeneity in meta-analyses of RCTs or observational studies. A better understanding of how these factors influence study effects might yield estimates reflective of true effectiveness.

Meta-analysis of the association of HLA-DRB1 with rheumatoid arthritis in Chinese populations

Background

Individual studies have reported different results regarding the association of HLA alleles with RA in Chinese populations. This study was performed to systematically summarize results on the association of HLA-DRB1 with rheumatoid arthritis (RA) in China.

Methods

We examined the case–control studies concerned about the relationship between HLA-DRB1and RA and differences of clinical and laboratory parameters between the HLA-DR4 (DR4)+ and DR4- in RA patients in Chinese populations. Odds ratios (ORs) and weighted mean difference (WMD) with corresponding 95% confidence intervals (CI) was used to describe the relationship.

Results

22 studies with 1690 cases and 1793 controls were included. Chinese populations with RA had significantly higher frequencies of HLA-DRB1*04, *0401, *0404, *0405 and *0410 than controls (ORDRB1*04 =4.19, 95% CI =3.44–5.11, p<0.00001; ORDRB1*0401 =2.53, 95% CI =1.54–4.16, p=0.0003; ORDRB1*0404 =2.28, 95% CI =1.28–4.06, p=0.005; ORDRB1*0405=3.71, 95% CI =2.52–5.45, p<0.00001; ORDRB1*0410 =2.99, 95% CI =1.25–7.14, p=0.01respectively). As to laboratory parameters, Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Rheumatoid factor (RF), Anti-cyclic citrullinated peptide antibodies (Anti-CCP ) in patients with DR4+ were higher than patients with DR4- (WMD=0.26, 95% CI =0.15–0.37, p<0.00001; WMD = 0.26, 95% CI =0.12–0.41, p=0.0005; WMD = 0.44, 95% CI =0.23–0.65, p<0.00001; WMD = 0.58, 95% CI =0.24–0.91, p=0.0007 respectively). As to clinical features, there was no difference in duration of morning stiffness, number of swollen joints, number of joint tenderness, X-ray phases and joint function between the DR4+ and DR4- in RA patients.

Conclusions

It was found that HLA-DRB1*04, *0401, *0404, *0405 and *0410 are risk factors for RA in Chinese populations. ESR, CRP, RF, Anti-CCP are different between the DR4+ and DR4- in RA patients in Chinese populations, while there’s no difference for indexes of clinical features.

Safety issues with bisphosphonate therapy for osteoporosis

Randomized controlled trials have demonstrated the efficacy of bisphosphonates (BP) in improving BMD and reducing fracture risk. Various safety issues that were not noted in clinical trials have, however, now emerged with post-marketing surveillance and increasing clinical experience. The risk of atypical femoral fracture could increase with long-term use of BP, although absolute risk is very small, particularly when balanced against benefits. A drug holiday should be considered after 5 years of treatment for patients at low risk of fracture, although there is no official recommendation regarding this to guide clinicians. Osteonecrosis of the jaw from low-dose BP used for osteoporosis is very rare, and mainly a complication with high-dose i.v. BP used in oncology. The risk of atrial fibrillation too is negligible, and a definite link cannot be established between BP and oesophageal cancer. BP should be avoided in patients with severe renal impairment and during pregnancy and lactation because of limited safety data. Further epidemiological and clinical data are required to establish safety of BP in long-term users (>5 years) and provide evidence-based management.

Drug-induced atrial fibrillation

Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with severe consequences, including symptoms, haemodynamic instability, increased cardiovascular mortality and stroke. While other arrhythmias such as torsades de pointes and sinus bradycardia are more typically thought of as drug induced, AF may also be precipitated by drug therapy, although ascribing causality to drug-associated AF is more difficult than with other drug-induced arrhythmias. Drug-induced AF is more likely to occur in patients with risk factors and co-morbidities that commonly co-exist with AF, such as advanced age, alcohol consumption, family history of AF, hypertension, thyroid dysfunction, sleep apnoea and heart disease. New-onset AF has been associated with cardiovascular drugs such as adenosine, dobutamine and milrinone. In addition, medications such as corticosteroids, ondansetron and antineoplastic agents such as paclitaxel, mitoxantrone and doxorubicin have been reported to induce AF. Whether bisphosphonate drugs are associated with new-onset AF remains controversial and requires further study. The potential contribution of specific drug therapy should be considered when patients present with new-onset AF.

Adverse drug reactions to osteoporosis treatments

Treatments for postmenopausal osteoporosis are generally safe, but are linked to some rare serious adverse drug reactions, for which causality is not always certain. The bisphosphonates are associated with gastrointestinal effects, acute phase reactions, and musculoskeletal pain, and, more rarely, cases of atrial fibrillation, subtrochanteric fracture, osteonecrosis of the jaw, cutaneous hypersensitivity reactions and renal impairment. It is too soon for pharmacovigilance data on denosumab, but it has been associated with cutaneous effects and possibly osteonecrosis of the jaw (to date, only in metastatic cancer). The selective estrogen receptor modulators may induce hot flushes and leg cramps, and--more rarely--venous thromboembolism and stroke. Strontium ranelate is associated with headache, nausea and diarrhea, and, more rarely, cutaneous hypersensitivity reactions and venous thromboembolism, while teriparatide and parathyroid hormone(1-84) are associated with headache, nausea, dizziness and limb pain. The management of osteoporosis should entail weighing the probability of adverse reactions against the benefits of therapy--that is, reduction of fracture risk.

Long-term treatment of osteoporosis in postmenopausal women: a review from the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and the International Osteoporosis Foundation (IOF)

INTRODUCTION

Postmenopausal osteoporosis is a chronic disease requiring treatment that balances long-term fracture efficacy against risk.

METHODS

We reviewed the efficacy and safety of calcium and vitamin D, the selective estrogen receptor modulators (SERMs), the bisphosphonates, denosumab, and strontium ranelate in studies of 3 years or longer.

RESULTS

Six trials lasted for 5 years, and seven went beyond that. The evidence beyond 5 years is generally weak, mainly due to methodological issues (open-label design, small samples, or absence of placebo control). Although calcium and vitamin D appear to be beneficial, the data are insufficient to evaluate benefits and risk beyond 3 years. The fracture efficacy of SERMs beyond 5 years is not known, though increases in bone mineral density (BMD) appear to be maintained. The SERMs have good long-term safety, including protective effects against breast cancer. The bisphosphonates have established fracture efficacy to 3 years, and 4 or 5 years with alendronate and risedronate. The evidence beyond 5 years indicates sustained increases in BMD. The safety of the bisphosphonates does not appear to be modified with time, with the possible exceptions of atypical subtrochanteric fracture and other events of unknown frequency. Denosumab has been tested up to 5 years, with continued increased in BMD and no reported safety issues. There is evidence for fracture efficacy of strontium ranelate, and sustained increases in BMD over 10 years. Strontium ranelate has good long-term safety.

CONCLUSION

Robust long-term studies are relatively rare for the osteoporosis treatments, and generally show maintenance of BMD and, for some agents, an additional reduction in fracture incidence.

Alendronate and atrial fibrillation: a meta-analysis of randomized placebo-controlled clinical trials

In this meta-analysis of all Merck-conducted, placebo-controlled clinical trials of alendronate, the occurrence of AF was uncommon, with most studies reporting two or fewer events. Across all studies, no clear association between overall bisphosphonate exposure and the rate of serious or non-serious AF was observed.

INTRODUCTION

To explore the incidence of atrial fibrillation (AF) and other cardiovascular endpoints in clinical trials of alendronate.

METHODS

All double-blind, placebo-controlled studies of alendronate 5, 10, or 20 mg daily, 35 mg once-weekly, 35 mg twice-weekly, and 70 mg once-weekly of at least 3 months duration conducted by Merck were included in this meta-analysis. The primary method of analysis was exact Poisson regression. Estimated relative risk (RR) of alendronate versus placebo and the associated 95% confidence interval was derived from a model that included number of episodes with factors for treatment group and study and an offset parameter for number of person-years on study.

RESULTS

Of 41 studies considered, 32 met all criteria for inclusion in the analysis (participants-9,518 alendronate, 7,773 placebo). Estimated RR for all AF events was 1.16 (95% CI = 0.87, 1.55; p = 0.33). Most trials had two or fewer AF events. The RR of AF classified as a serious adverse event was 1.25 (95% CI = 0.82, 1.93; p = 0.33), but became 0.97 (95% CI = 0.51, 1.85) when the clinical fracture cohort of the Fracture Intervention Trial was excluded, indicating that results were driven by events in that study. Estimated RRs for other cardiovascular endpoints were less than 1.

CONCLUSIONS

The incidence of atrial fibrillation was low in Merck clinical trials of alendronate and was not significantly increased in any single trial nor in the meta-analysis. Based on this analysis, alendronate use does not appear to be associated with an increased risk of atrial fibrillation.

Predictors of incident atrial fibrillation and influence of medications: a retrospective case-control study

BACKGROUND

Atrial fibrillation (AF) is a common condition, associated with raised mortality and risk of major morbidity, and is predicted to increase due to an aging population.

AIM

To update earlier research of AF predictors using UK data.

DESIGN AND SETTING

Case-control analysis of adults aged 18 years and older with a diagnosis of AF in practices registered with the General Practice Research Database (GPRD) in the UK.

METHOD

Using the GPRD, a case.control analysis was performed using logistic regression to compare 55,412 incident AF cases to 216,400 controls, for medical history and prior use of drugs. The association between time since start of diagnosis or drug use and AF risk was summarised using Spline regression.

RESULTS

The following were confirmed as risk factors for AF: heart failure (risk ratio [RR] 2.91 [95% CI = 2.59 to 3.27]); ischaemic heart disease (IHD) (RR 2.00 [95% CI = 1.78 to 2.24]); hypertension (RR 2.60 [95% CI = 2.32 to 2.92]); hyperthyroidism (RR 1.56 [95% CI = 1.39 to 1.75]); being a heavy drinker (RR 1.43 [95% CI = 1.27 to 1.60]); cerebrovascular accident (RR 1.48 [95% CI = 1.32 to 1.66]); and obesity (body mass index ≥30 kg/m(2) RR 1.29 [95% CI = 1.15 to 1.45]). Current use of oral glucocorticoids (RR 1.62 [95% CI = 1.44 to 1.82]) and of beta-2 agonists (RR 1.30 [95% CI = 1.16 to 1.46]) were identified as significant risk factors, and statins (RR 0.82 [95% CI = 0.73 to 0.92]) as a significant protective factor. No effect was found for current use of bisphosphonates (RR 0.95 [95% CI = 0.85 to 1.07]), renin.angiotensin.aldosterone system (RAAS) agents (RR 1.04 [95% CI = 0.93 to 1.17]), or xanthine derivatives (RR 1.09 [95% CI = 0.97 to 1.22]). Spline regression analysis found the effect of heart failure, IHD, use of oral glucocorticoids, and use of statins on the likelihood of developing AF was sustained over a number of years.

CONCLUSION

These findings update the risk factors that are associated with AF, and confirm the protective properties of statins and the risks of beta-2 agonists in developing AF, but not the supposed protective qualities of glucocorticoids and RAAS agents.

Role of bisphosphonates in the management of postmenopausal osteoporosis: an update on recent safety anxieties

Following their introduction in the 1990s, bisphosphonates have become the mainstay of treatment in the management of postmenopausal osteoporosis, and their use continues to rise. Commonly noted adverse effects in clinical practice include gastrointestinal side-effects, acute phase reactions (predominately seen with intravenous preparations) cutaneous reactions and more rarely, ocular side-effects. However, recent reports of potentially serious adverse effects of bisphosphonate therapy, including atypical subtrochanteric and femoral shaft fractures, atrial fibrillation, oesophageal carcinoma and osteonecrosis of the jaw, have prompted concerns regarding the long-term safety of this class of drugs. This review summarizes the benefits and potential adverse effects of bisphosphonates used in the treatment of postmenopausal osteoporosis. Although evidence of a definitive casual relationship between bisphosphonate therapy and serious adverse effects is lacking, concern remains particularly in relation to atypical subtrochanteric and femoral shaft fractures. This has important consequences in terms of determining optimum duration of therapy and how best to target therapy at those most at risk. Recently, attention has focused on individual fracture risk assessment in order to optimize the risk-benefit ratio of treatment for individual patients. A review of the role of hormone replacement therapy in younger women with significant risk of osteoporotic fractures may be timely in these circumstances.

Antiresorptive therapies for osteoporosis: a clinical overview

Antiresorptive therapies are used to increase bone strength in individuals with osteoporosis and include five principal classes of agents: bisphosphonates, estrogens, selective estrogen receptor modulators (SERMs), calcitonin and monoclonal antibodies such as denosumab. However, no head-to-head studies have compared different antiresorptive agents using fracture as an end point. Bisphosphonates, which have proven antifracture efficacy and a good safety profile, are the most widely used first-line antiresorptive therapy and are recommended for patients with osteoporosis, a prior fragility fracture or osteopenia, as well as individuals with a high risk of fracture. Denosumab, which also has good antifracture efficacy, is another possible first-line therapy, although long-term safety data are lacking. However, no single antiresorptive therapy is currently appropriate for all patients or clearly superior to other therapies. Antiresorptive agents such as estrogens, SERMs (in postmenopausal women) and calcitonin are considered to be second-line agents that are appropriate in special circumstances. Clinicians should determine the most appropriate pharmacological therapy after a careful assessment of the risk:benefit profiles of these drugs in each patient. In addition, patients should receive a detailed explanation of the treatment goals, so that the therapeutic benefit can be maximized through good compliance and persistence.

Intravenous bisphosphonate therapy and atrial fibrillation/flutter risk in cancer patients: a nationwide cohort study

Background:

There is conflicting evidence regarding bisphosphonates and atrial fibrillation (AF) risk in osteoporosis patients. However, bisphosphonates are used in much higher doses in treatment of bone metastasis and hypercalcemia, but little is known about the AF risk in cancer patients.

Methods:

We conducted a nationwide population-based cohort study using Danish databases. All cancer patients exposed to intravenous bisphosphonates during 2000–2008 were matched with two non-exposed cancer patients by cancer type, distant metastasis presence at diagnosis, age, and gender. We used Cox proportional hazard regression to estimate hazards ratios (HRs) of AF/flutter adjusting for important confounding factors.

Results:

Of the 3981 cancer patients exposed to intravenous bisphosponates, 128 (3.2%) developed AF/flutter. This condition occurred in 192 (2.4%) of the 7906 non-exposed cancer patients, corresponding to an adjusted HR of 1.7 (95% CI: 1.2–2.4).

Conclusion:

Intravenous bisphosphonates may increase AF/flutter risk in cancer patients.

Adverse reactions and drug-drug interactions in the management of women with postmenopausal osteoporosis

The pharmacological management of disease should involve consideration of the balance between the beneficial effects of treatment on outcome and the probability of adverse effects. The aim of this review is to explore the risk of adverse drug reactions and drug-drug interactions with treatments for postmenopausal osteoporosis. We reviewed evidence for adverse reactions from regulatory documents, randomized controlled trials, pharmacovigilance surveys, and case series. Bisphosphonates are associated with gastrointestinal effects, musculoskeletal pain, and acute-phase reactions, as well as, very rarely, atrial fibrillation, atypical fracture, delayed fracture healing, osteonecrosis of the jaw, hypersensitivity reactions, and renal impairment. Cutaneous effects and osteonecrosis of the jaw are of concern for denosumab (both very rare), though there are no pharmacovigilance data for this agent yet. The selective estrogen receptor modulators are associated with hot flushes, leg cramps, and, very rarely, venous thromboembolism and stroke. Strontium ranelate has been linked to hypersensitivity reactions and venous thromboembolism (both very rare) and teriparatide with headache, nausea, dizziness, and limb pain. The solidity of the evidence base depends on the frequency of the reaction, and causality is not always easy to establish for the very rare adverse reactions. Drug-drug interactions are rare. Osteoporosis treatments are generally safe and well tolerated, though they are associated with a few very rare serious adverse reactions. While these are a cause for concern, the risk should be weighed against the benefits of treatment itself, i.e., the prevention of osteoporotic fracture.

Fracture prevention in postmenopausal women

INTRODUCTION

The lifetime risk of fracture in white women is 20% for the spine, 15% for the wrist, and 18% for the hip, with an exponential increase in risk beyond the age of 50 years.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of bisphosphonates to prevent fractures in postmenopausal women? What are the effects of pharmacological treatments other than bisphosphonates to prevent fractures in postmenopausal women? What are the effects of non-pharmacological treatments to prevent fractures in postmenopausal women? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 71 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: alendronate, calcitonin, calcium, calcium plus vitamin D, clodronate, denosumab, etidronate, exercise, hip protectors, hormone replacement therapy, ibandronate, multifactorial non-pharmacological interventions, pamidronate, parathyroid hormone, raloxifene, risedronate, strontium ranelate, vitamin D, vitamin D analogues, and zoledronate.

Impact of bisphosphonates on the risk of atrial fibrillation

Osteoporosis is a major public health problem resulting in significant morbidity, mortality, and utilization of healthcare resources. Bisphosphonates are the most widely prescribed drugs for increasing bone mass and preventing osteoporosis-related fractures. Although these drugs have proven efficacy and are generally considered safe, a clinical trial of once-yearly zoledronic acid reported an unexpected increase in the risk of cardiac arrhythmias, primarily due to serious atrial fibrillation (AF). Subsequently, a post hoc analysis of another clinical trial reported a nonsignificant trend toward an increased risk of serious AF. Based on these concerns, the US FDA issued a cautionary advisory and is conducting an ongoing safety review. A major limitation of the clinical trials was the fact that none were designed or powered to evaluate arrhythmia endpoints. In search of more definitive answers, several observational studies using both population-based cohort and case-control designs have attempted to verify this association. However, only two studies, one cohort and one case-control study, have found a positive association, while six additional studies have reported negative findings. While most of the observational studies attempted to control for confounders, the chosen variables have varied considerably, and other key potential confounders such as smoking were not controlled for in any of the studies. Because the occurrence of AF events in the studies was relatively low, four meta-analyses have been conducted to increase sample size by using pooled data from multiple studies. Again, results have been inconsistent, with two of the analyses reporting a significant increase in serious AF and two finding no association. Additionally, no direct evidence has identified any underlying mechanism to explain an increased arrhythmia risk with bisphosphonate therapy. However, several possible mechanisms have been proposed, including an activated inflammatory state, altered electrolytes impacting cardiac conduction, and long-term atrial structural changes. Due to the widespread use of bisphosphonates in a population for whom the baseline risk of AF also increases with advancing age, further prospective assessment of this possible association is clearly warranted. If an association does exist between bisphosphonates and an increased risk for AF, several additional questions will need to be answered including impact of baseline risk, the time course for increased risk, relationship to drug dose, and whether or not this represents a drug-class adverse effect. Until definitive evidence is available, clinicians will continue to have to make clinical judgments based on the available and often inconsistent evidence to date. To provide further perspective on this possible association, we performed a systematic search of the PubMed database from 1966 to 30 June 2010, drug regulatory websites, and drug manufacturer websites. In this review we summarize the findings from clinical trials, observational studies, and meta-analyses evaluating the risk of AF following bisphosphonate exposure, and discuss possible mechanisms that could explain an increased risk.

Meta-analysis in medicine: an introduction

Meta-analysis, a complex statistical method which involves synthesis of data from relevant studies to devise an effect size or a conclusion, has increasingly been recognized and impacts on evidence-based medicine, especially in the field of health science. Thanks to the advent and unmet need of evidence-based medicine, since the first recordable publication of a meta-analysis in 1904 addressing the effectiveness of typhoid vaccine, both the number and quality of meta-analyses published relating to healthcare science have been on a steep rise. If properly conducted, based on answering relevant clinical questions, strict selection criteria of participating studies, appropriate analytical methods, and proper presentation of results, coupled with critical and faithful discussion on the strength and weakness of the analysis, meta-analysis will definitely be an invaluable tool for clinicians and researchers in understanding epidemiology, justifying and refining hypotheses of various diseases, for medical practitioners to implement sound management decisions based on evidence-based medicine, and ultimately, for policy-makers to formulate cost-efficient treatment strategies, guidelines and legislation. In this first paper of a mini-series, the current trend of meta-analysis publications in the medical literature, examples of important meta-analyses relevant to rheumatology and the pros and cons of meta-analysis, will be discussed. Important terminology related to meta-analysis, the systematic ways to critically appraise, and finally the preferred methodology of conducting meta-analysis will be covered in the subsequent three reviews of this mini-series.

Emerging drugs for the management of cancer treatment induced bone loss

AREAS COVERED IN THIS REVIEW

We focus our attention on data on the efficacy of currently available and emerging drugs for the management of cancer treatment induced bone loss (CTIBL) found in a PubMed research from 1997 till today.

IMPORTANCE OF THE FIELD

One of the most common and severe safety issues of the antihormonal therapy in both sexes is the CTIBL and the related fragility fractures. In postmenopausal women with estrogenic receptor positive breast cancer, the third-generation aromatase inhibitors (AIs) are the standard therapy. Observational retrospective studies have found that AIs treated patients had a high rate of bone loss and fracture risk (RR 1.3). Also in men with prostate cancer receiving androgen deprivation therapy, the increase in bone turnover and the consequent bone loss are very rapid and sustained significantly increasing the fracture risk.

WHAT THE READER WILL GAIN

The aim of our review is to provide the current evidences for the management of bone loss and fracture risk in this subpopulation.

TAKE HOME MESSAGE

The very high rate of bone loss and the high incidence of fractures indicate that cancer patients at risk of CTIBL need to be carefully monitored and stratified for fracture risk. Although there is a strong evidence of efficacy in prevention of bone loss and reduction of fracture risk for many drugs approved for postmenopausal osteoporosis (PMO) and male osteoporosis, for CTIBL there are actually no drugs approved for this indication.

Bisphosphonates and risk of atrial fibrillation: a meta-analysis

Introduction

Bisphosphonates are the most commonly used drugs for the prevention and treatment of osteoporosis. Although a recent FDA review of the results of clinical trials reported no clear link between bisphosphonates and serious or non-serious atrial fibrillation (AF), some epidemiologic studies have suggested an association between AF and bisphosphonates.

Methods

We conducted a meta-analysis of non-experimental studies to evaluate the risk of AF associated with bisphosphonates. Studies were identified by searching MEDLINE and EMBASE using a combination of the Medical Subject Headings and keywords. Our search was limited to English language articles. The pooled estimates of odds ratios (OR) as a measure of effect size were calculated using a random effects model.

Results

Seven eligible studies with 266,761 patients were identified: three cohort, three case-control, and one self-controlled case series. Bisphosphonate exposure was not associated with an increased risk of AF [pooled multivariate OR 1.04, 95% confidence interval (CI) 0.92-1.16] after adjusting for known risk factors. Moderate heterogeneity was noted (I-squared score = 62.8%). Stratified analyses by study design, cohort versus case-control studies, yielded similar results. Egger's and Begg's tests did not suggest an evidence of publication bias (P = 0.90, 1.00 respectively). No clear asymmetry was observed in the funnel plot analysis. Few studies compared risk between bisphosphonates or by dosing.

Conclusions

Our study did not find an association between bisphosphonate exposure and AF. This finding is consistent with the FDA's statement.

Atrial fibrillation and bisphosphonate therapy

Bisphosphonates are the most commonly used treatment for osteoporosis and have proven efficacy in the reduction of vertebral and nonvertebral fractures. Recently, concerns have been raised about a possible association between bisphosphonate therapy and atrial fibrillation (AF) following the report of a significant increase in risk of serious AF in women treated with zoledronic acid in the HORIZON study. Subsequent studies have produced conflicting results but have not excluded the possibility of such an association. Currently there is no direct evidence that bisphosphonates exert either acute or chronic effects on cardiac electrophysiology. Nevertheless, altered intracellular electrolyte homeostasis and proinflammatory, profibrotic, and antiangiogenic effects provide potential mechanisms by which atrial conduction could be affected in patients treated with bisphosphonates. In studies in which an increase in risk of AF has been identified, there is no evidence that this translates into increased mortality or increased risk of stroke, and the risk-benefit balance of bisphosphonate therapy in patients with osteoporosis and other forms of metabolic bone disease remains strongly positive.