Bisphosphonates and osteoporotic fractures: a cross-design synthesis of results among compliant/persistent postmenopausal women in clinical practice versus randomized controlled trials

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.

Cost-Effectiveness of Sequential Denosumab/Zoledronic Acid Compared With Zoledronic Acid Monotherapy for Postmenopausal Osteoporotic Women in China

Objective: The primary purpose of this study was to estimate the cost-effectiveness of sequential denosumab/zoledronic acid versus zoledronic acid monotherapy for postmenopausal osteoporotic women in China.

Methods: We updated and utilized a previously validated Markov microsimulation model to obtain the cost-effectiveness of two strategies for treating postmenopausal osteoporotic women. We compared the incremental cost-effectiveness ratios (ICERs) (US dollars [$] per quality-adjusted life year [QALY]) of sequential denosumab/zoledronic acid (i.e., biannual subcutaneous denosumab for 3 years followed by annual intravenous zoledronic acid for 3 years) with zoledronic acid monotherapy for 3 years in Chinese women with postmenopausal osteoporosis at ages 65, 70, 75, and 80 from the health care payer perspective. Our study’s willingness-to-pay (WTP) threshold was set to three times the value of China’s per capita GDP in 2020 ($31,512).

Results: The ICERs of sequential denosumab/zoledronic acid versus zoledronic acid monotherapy were $59,389/QALY, $23,821/QALY, $22,710/QALY, and $14,027/QALY at age 65, 70, 75, and 80 years, respectively. One-way sensitivity analyses showed that the most impactful parameter was the persistence rate of the medications. If the persistence rate of denosumab or zoledronic acid was increased by 10%, sequential denosumab/zoledronic acid would be cost-effective at age 65. In probabilistic sensitivity analyses, the probabilities of sequential denosumab/zoledronic being cost-effective compared to zoledronic acid monotherapy were approximately 29.3%, 68.7%, 86.1%, and 99.4% for ages 65, 70, 75, and 80 years, respectively, at the WTP threshold of $31,512/QALY.

Conclusion: Among Chinese postmenopausal osteoporosis women over 70 years old, sequential denosumab/zoledronic acid was cost-effective compared with zoledronic acid monotherapy at the pre-determined WTP threshold.

The Male Athlete Triad-A Consensus Statement From the Female and Male Athlete Triad Coalition Part II: Diagnosis, Treatment, and Return-To-Play

ABSTRACT

The Male Athlete Triad is a medical syndrome most common in adolescent and young adult male athletes in sports that emphasize a lean physique, especially endurance and weight-class athletes. The 3 interrelated conditions of the Male Athlete Triad occur on spectrums of energy deficiency/low energy availability (EA), suppression of the hypothalamic-pituitary-gonadal axis, and impaired bone health, ranging from optimal health to clinically relevant outcomes of energy deficiency/low EA with or without disordered eating or eating disorder, functional hypogonadotropic hypogonadism, and osteoporosis or low bone mineral density with or without bone stress injury (BSI). Because of the importance of bone mass acquisition and health concerns in adolescence, screening is recommended during this time period in the at-risk male athlete. Diagnosis of the Male Athlete Triad is best accomplished by a multidisciplinary medical team. Clearance and return-to-play guidelines are recommended to optimize prevention and treatment. Evidence-based risk assessment protocols for the male athlete at risk for the Male Athlete Triad have been shown to be predictive for BSI and impaired bone health and should be encouraged. Improving energetic status through optimal fueling is the mainstay of treatment. A Roundtable on the Male Athlete Triad was convened by the Female and Male Athlete Triad Coalition in conjunction with the 64th Annual Meeting of the American College of Sports Medicine in Denver, Colorado, in May of 2017. In this second article, the latest clinical research to support current models of screening, diagnosis, and management for at-risk male athlete is reviewed with evidence-based recommendations.

Meta-analysis for the efficacy of bisphosphonates on hip fracture prevention

The aim of this study was to investigate the effect of bisphosphonates on preventing osteoporotic hip fracture in patients with or without prior major osteoporotic fracture. Randomized controlled trials (RCTs) and observational studies (OSs) based on electronic health records were used to assess bisphosphonate efficacy and were searched using PubMed, Scopus, and the Cochrane Library databases. Eight RCT studies and 14 OSs were extracted from the studies and quantitatively combined by random-effects meta-analysis. The odds ratio (OR) for all hip fractures in RCTs of 0.66, with a 95% confidence interval (CI) of 0.55-0.79, was lower than that in the OSs (OR 0.83; CI 0.74-0.94). The OR in patients with prior fracture was significantly reduced by bisphosphonates in both RCTs and OSs. Conversely, significant fracture reduction was not apparent in patients without prior fracture. A moderate relationship between prior major fracture rates and OR in hip fractures was defined. In patients with an average age of over 80 years, similar results were confirmed. In this meta-analysis, the efficacy of bisphosphonates was significant in patients with prior major fracture, recommending to prescribe for such patients. Their effect in patients without prior fracture, in contrast, remains unclear.

How Would You Manage This Patient With Osteoporosis?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Osteoporosis is a skeletal disorder characterized by reduced bone strength that increases the risk for fracture. Approximately 10 million men and women in the United States have osteoporosis, and more than 2 million osteoporosis-related fractures occur annually. In 2016, the American Association of Clinical Endocrinologists issued the "Clinical Practice Guideline for the Diagnosis and Treatment of Postmenopausal Osteoporosis," and in 2017, the American College of Physicians issued the guideline "Treatment of Low Bone Density or Osteoporosis to Prevent Fracture in Men and Women." Both guidelines agree that patients diagnosed with osteoporosis should be treated with an antiresorptive agent, such as alendronate, that has been shown to reduce hip and vertebral fractures. However, there is no consensus on how long patients with osteoporosis should be treated and whether bone density should be monitored during and after the treatment period. In this Beyond the Guidelines, 2 experts discuss management of osteoporosis in general and for a specific patient, the role of bone density monitoring during and after a 5-year course of alendronate, and treatment recommendations for a patient whose bone density decreases during or after a 5-year course of alendronate.

Albumin in Burn Shock Resuscitation: A Meta-Analysis of Controlled Clinical Studies

Critical appraisal of outcomes after burn shock resuscitation with albumin has previously been restricted to small relatively old randomized trials, some with high risk of bias. Extensive recent data from nonrandomized studies assessing the use of albumin can potentially reduce bias and add precision. The objective of this meta-analysis was to determine the effect of burn shock resuscitation with albumin on mortality and morbidity in adult patients. Randomized and nonrandomized controlled clinical studies evaluating mortality and morbidity in adult patients receiving albumin for burn shock resuscitation were identified by multiple methods, including computer database searches and examination of journal contents and reference lists. Extracted data were quantitatively combined by random-effects meta-analysis. Four randomized and four nonrandomized studies with 688 total adult patients were included. Treatment effects did not differ significantly between the included randomized and nonrandomized studies. Albumin infusion during the first 24 hours showed no significant overall effect on mortality. However, significant statistical heterogeneity was present, which could be abolished by excluding two studies at high risk of bias. After those exclusions, albumin infusion was associated with reduced mortality. The pooled odds ratio was 0.34 with a 95% confidence interval of 0.19 to 0.58 (P < .001). Albumin administration was also accompanied by decreased occurrence of compartment syndrome (pooled odds ratio, 0.19; 95% confidence interval, 0.07–0.50; P < .001). This meta-analysis suggests that albumin can improve outcomes of burn shock resuscitation. However, the scope and quality of current evidence are limited, and additional trials are needed.

Effects of Aflibercept for Neovascular Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis of Observational Comparative Studies

Purposes

To compare the effects of aflibercept and other anti-vascular endothelial growth factor (anti-VEGF) medications on both functional and anatomical outcomes for treatment-naïve neovascular age-related macular degeneration (nAMD) in the real world.

Methods

A systematic review and meta-analysis of observational comparative studies.

Results

A total of 18 studies remained after literature selection and quality assessment of 1697 studies. The most common aflibercept treatment regimen was three monthly injections followed by pro re nata (PRN). Aflibercept and ranibizumab had similar effects in 2-year treatment. At 3, 6, 12, and 24 months, the differences in the logarithm of minimum angle of resolution (logMAR) decrease in aflibercept and ranibizumab groups were 0.00 (95% confidence interval [CI]: −0.03 to 0.02); 0.01 (95% CI: −0.02 to 0.05); −0.03 (95% CI: −0.07 to 0.01); and –0.06 (95% CI: −0.30 to 0.17), respectively; the differences in decrease of central retinal thickness (CRT) were 3.25 μm (95% CI: −15.03 to 21.53); 7.89 μm (95% CI: −31.91 to 47.69); 2.89 μm (95% CI: −18.33 to 24.11); and −2.42 μm (95% CI: −77.87 to 73.03), respectively. However, aflibercept was significantly more effective in patients with initial reduced visual acuity (logMAR >0.6 or <55 letters; P = 0.001). In the first year, treatment frequency was not significantly different for aflibercept and ranibizumab, but aflibercept required fewer injections than ranibizumab with PRN regimen (mean −0.90; 95% CI: −1.80 to 0.00).

Conclusions

Aflibercept has comparable effects with ranibizumab for treatment-naïve nAMD in the real world, and may be more effective for patients with initial lower visual acuity.

Examining the Effect of Medication Adherence on Risk of Subsequent Fracture Among Women with a Fragility Fracture in the U.S. Medicare Population

BACKGROUND

In the United States, osteoporosis affects approximately 10 million people, of whom 80% are women, and it contributes a significant clinical burden to the community. Poor adherence to osteoporosis medications adds to the overall burden of illness.

OBJECTIVE

To examine the association of osteoporosis medication adherence and the risk of a subsequent fracture among Medicare-enrolled women with a previous fragility fracture.

METHODS

This study was a retrospective observational analysis of U.S. administrative claims data among female Medicare beneficiaries who had a nontrauma closed fragility fracture between January 1, 2011, and December 31, 2011. Patients were required to have continuous medical and pharmacy enrollment 12 months pre- and postfracture date. In addition, patients were required to have an osteoporosis medication prescription for a bisphosphonate (alendronate, risedronate, pamidronate, etidronate, zoledronate, and tiludronate), calcitonin, denosumab, raloxifene, or teriparatide during the follow-up period. Adherence was calculated using cumulative medication possession ratio (MPR) from the treatment initiation date in 30-day increments. MPR was stratified into high adherence (MPR ≥ 80%), moderate adherence (50% ≤ MPR > 80%), and low adherence (MPR < 50%). Outcomes included first subsequent fracture after treatment initiation; patients were censored at treatment discontinuation, or end of the 12-month period posttreatment initiation. Covariates included demographics, comorbidities, osteoporosis medications, medications associated with falls, and health care utilization. Cox regression was used to model subsequent fractures with time-dependent cumulative MPR.

RESULTS

Of the 1,292,248 Medicare enrollees who had a fracture in 2011, a total of 103,852 (8.0%) women aged ≥ 65 years with a fragility fracture were identified. Overall, 27,736 (26.7%) patients were treated with osteoporosis medication within 12 months of the fragility fracture (mean time to treatment initiation was 85.0 ± 84.6 days). Over half of the patients were highly adherent (MPR ≥ 80%) to osteoporosis medications during the follow-up (n = 14,112; 50.9%). Almost a third of the patients had low adherence (MPR < 50%; n = 9,022, 32.5%), followed by patients with moderate adherence (50% ≤ MPR > 80%; n = 4,602, 16.6%). After adjusting for demographics and clinical characteristics, patients with low and moderate adherence to osteoporosis medications were 33% (hazard ratio [HR] = 1.33; 95% CI = 1.17-1.50, P < 0.001) and 19% (HR = 1.19; 95% CI = 1.02-1.38, P = 0.026) more likely to have a subsequent fracture, respectively, compared with patients with high adherence. Low adherence patients had a 32% and 34% increased risk for a hip/pelvis/femur fracture (HR = 1.32; 95% CI = 1.09-1.59, P = 0.005) and a clinical vertebral fracture (HR = 1.34; 95% CI = 1.09-1.63, P = 0.005), respectively, compared with high adherence patients.

CONCLUSIONS

Medicare-enrolled women with low and moderate adherence to osteoporosis medications had a higher risk of a subsequent fracture compared with high adherence patients. These results highlight the importance of improving osteoporosis medication adherence among women enrolled in Medicare.

DISCLOSURES

This study was funded by Eli Lilly. Xie, Keshishian, and Baser are employees of STATinMED Research, a paid consultant to Eli Lilly in connection with the study design, data analysis, and development of the manuscript for this study. Boytsov, Burge, Lombard, and Zhang are employees and stock owners of Eli Lilly. At the time of research, Krohn was an employee of Eli Lilly. Study concept and design were contributed by Burge and Lombard, along with the other authors. Xie, Baser, and Keshishian took the lead in data collection, assisted by the other authors. Data interpretation was performed by Krohn and Zhang, with assistance from the other authors. The manuscript was written by Keshishian and Boytsov, along with the other authors, and revised by Boytsov, Keshishian, and Burge, along with the other authors.

Urban-rural differences in the uptake of new oral bisphosphonate formulations

We identified significantly slower uptake, and consistently lower proportions of new oral bisphosphonate formulations dispensed in rural regions compared to urban regions of Ontario. Further research examining regional differences in outcomes may provide insight as to whether urban-rural differences in prescribing translate into health disparities between regions.

PURPOSE

The aim of this study was to examine urban-rural differences in the uptake of new oral bisphosphonate formulations available on the Ontario drug formulary: alendronate + vitamin D3 (January 2007), monthly risedronate (June 2009), and risedronate delayed-release (February 2012).

METHODS

We plotted the monthly proportion of new formulation claims of all claims with the same drug molecule, from their formulary listing date until March 2014. Results were stratified by major urban, nonmajor urban, and rural regions as defined by the Rurality Index of Ontario. We compared the rate of uptake over the first year of formulary availability using linear regression, and compared proportions dispensed between regions using chi-squared tests.

RESULTS

We identified a regional gradient in uptake for alendronate + vitamin D3 and monthly risedronate; major urban regions had the fastest uptake, followed by nonmajor urban regions, and rural regions had the slowest uptake. Rural regions also had the slowest uptake of risedronate delayed-release; however, uptake in major urban and nonmajor urban regions were similar. Rural regions dispensed the lowest proportions for all new formulations 1 year after formulary availability: alendronate + vitamin D3 (32% major urban, 23% nonmajor urban, 12% rural), monthly risedronate (26% major urban, 21% nonmajor urban, 16% rural), and risedronate delayed-release (21% major urban, 22 % nonmajor urban, 13% rural). This pattern persisted throughout our study.

CONCLUSION

We identified significantly slower uptake and lower proportions of new formulations dispensed in rural regions compared to urban regions. Further research examining regional differences in outcomes may demonstrate whether urban-rural differences in prescribing translate into health disparities between regions.

Proportion of osteoporotic women remaining at risk for fracture despite adherence to oral bisphosphonates

BACKGROUND

Adherence to oral bisphosphonates is often low, but even adherent patients may remain at elevated fracture risk. The goal of this study was to estimate the proportion of bisphosphonate-adherent women remaining at high risk of fracture.

METHODS

A retrospective cohort of women aged 50years and older, adherent to oral bisphosphonates for at least two years was identified, and data were extracted from a multi-system health information exchange. Adherence was defined as having a dispensed medication possession ratio≥0.8. The primary outcome was clinical occurrence of: low trauma fracture (months 7-36), persistent T-score≤-2.5 (months 13-36), decrease in bone mineral density (BMD) at any skeletal site≥5%, or the composite of any one of these outcomes.

RESULTS

Of 7435 adherent women, 3110 had either pre- or post-adherent DXA data. In the full cohort, 7% had an incident osteoporotic fracture. In 601 women having both pre- and post-adherent DXA to evaluate BMD change, 6% had fractures, 22% had a post-treatment T-score≤-2.5, and 16% had BMD decrease by ≥5%. The composite outcomes occurred in 35%. Incident fracture was predicted by age, previous fracture, and a variety of co-morbidities, but not by race, glucocorticoid treatment or type of bisphosphonate.

CONCLUSION

Despite bisphosphonate adherence, 7% had incident osteoporotic fractures and 35% had either fracture, decreases in BMD, or persistent osteoporotic BMD, representing a substantial proportion of treated patients in clinical practices remaining at risk for future fractures. Further studies are required to determine the best achievable goals for osteoporosis therapy, and which patients would benefit from alternate therapies.

Early (1-year) Discontinuation of Different Anti-osteoporosis Medications Compared: A Population-Based Cohort Study

Although a number of reports suggest very low persistence with oral bisphosphonates, there is limited data on persistence with other anti-osteoporosis medications. We compare rates of early discontinuation (in the first year) with all available outpatient anti-osteoporosis drugs in Catalonia, Spain. We conducted a population-based retrospective cohort study using data from the SIDIAP database. SIDIAP contains computerized primary care records and pharmacy dispensing data for >80 % of the population of Catalonia (>5 million people). All SIDIAP participants starting an anti-osteoporosis drug between 1/1/2007 and 30/06/2011 (with 2 years wash-out) were included. We modelled persistence as the time between first prescription and therapy discontinuation (refill gap of at least 6 months) using Fine and Gray survival models with competing risk for death. We identified 127,722 patients who started any anti-osteoporosis drug in the study period. The most commonly prescribed drug was weekly alendronate (N = 55,399). 1-Year persistence ranges from 40 % with monthly risedronate to 7.7 % with daily risedronate, and discontinuation was very common [from 49.5 % (monthly risedronate) to 84.4 % (daily risedronate)] as was also switching in the first year of therapy [from 2.8 % (weekly alendronate) to 10 % (daily alendronate)]. Multivariable-adjusted models showed that only monthly risedronate had better one-year persistence than weekly alendronate and teriparatide equivalent, whilst all other therapies had worse persistence. Early discontinuation with available anti-osteoporosis oral drugs is very common. Monthly risedronate, weekly alendronate, and daily teriparatide are the drugs with the best persistence, whilst daily oral drugs have 40-60 % higher first-year discontinuation rates compared to weekly alendronate.

Albumin treatment regimen for type 1 hepatorenal syndrome: a dose-response meta-analysis

BACKGROUND

Recommended treatment for type 1 hepatorenal syndrome consists of albumin and vasoconstrictor. The optimal albumin dose remains poorly characterized. This meta-analysis aimed to determine the impact of albumin dose on treatment outcomes.

METHODS

Clinical studies of type 1 hepatorenal syndrome treatment with albumin and vasoconstrictor were sought. Search terms included: hepatorenal syndrome; albumin; vasoconstrictor; terlipressin; midodrine; octreotide; noradrenaline; and norepinephrine. A meta-analysis was performed of hepatorenal syndrome reversal and survival in relation to albumin dose.

RESULTS

Nineteen clinical studies with 574 total patients were included, comprising 8 randomized controlled trials, 8 prospective studies and 3 retrospective studies. The pooled percentage of patients achieving hepatorenal syndrome reversal was 49.5% (95% confidence interval, 40.0-59.1%). Increments of 100 g in cumulative albumin dose were accompanied by significantly increased survival (hazard ratio, 1.15; 95% confidence interval, 1.02-1.31; p = 0.023). A non-significant increase of similar magnitude in hepatorenal syndrome reversal was also observed (odds ratio, 1.15; 95% confidence interval, 0.97-1.37; p = 0.10). Expected survival rates at 30 days among patients receiving cumulative albumin doses of 200, 400 and 600 g were 43.2% (95% confidence interval, 36.4-51.3%), 51.4% (95% confidence interval, 46.3-57.1%) and 59.0% (95% confidence interval, 51.9-67.2), respectively. Neither survival nor hepatorenal syndrome reversal was significantly affected by vasoconstrictor dose or type, treatment duration, age, baseline serum creatinine, bilirubin or albumin, baseline mean arterial pressure, or study design, size or time period.

CONCLUSIONS

This meta-analysis suggests a dose-response relationship between infused albumin and survival in patients with type 1 hepatorenal syndrome. The meta-analysis provides the best current evidence on the potential role of albumin dose selection in improving outcomes of treatment for type 1 HRS and furnishes guidance for the design of future dose-ranging studies.

Improving adherence to and persistence with oral therapy of osteoporosis

Osteoporosis treatment has low adherence and persistence. This study evaluated if greater patient involvement could improve them. At 12 months, only 114 out of 344 participants were "fully adherent and persistent" (all drug doses taken throughout the study). Only frequency of drug administration had a significant influence on adherence.

INTRODUCTION

Osteoporosis affects millions of individuals worldwide. There are now several effective drugs, but adherence to and persistence with treatment are low. This 12-month multicenter, prospective, randomized study evaluated the efficacy of two different methods aimed at improving adherence and persistence through greater patient involvement, compared with standard clinical practice.

METHODS

Three hundred thirty-four post-menopausal women, receiving an oral prescription for osteoporosis for the first time, were recruited and randomized into three groups: group 1 (controls, managed according to standard clinical practice) and groups 2 and 3 (managed with greater patient and caregiver involvement and special reinforcements: group 2, instructed to use several different "reminders"; group 3, same "reminders" as group 2, plus regular phone calls from and meetings at the referring Center). All enrolled women had two visits (baseline and 12 months).

RESULTS

Of 334 enrolled women, 247 (74%) started the prescribed therapy. Of those who started, 219 (88.7%) persisted in therapy for at least 10 months. At final evaluation, only 114 women were considered as "fully adherent and persistent" (all doses taken throughout the 12 months). There were no significant differences regarding "full adherence" among the three randomized groups. The frequency of drug administration had a significant influence: weekly administration had a >5-fold higher adherence and monthly administration an 8-fold higher adherence (p < 0.0001) than daily administration.

CONCLUSIONS

The special effort of devising and providing additional reminders did not prove effective. Additional interventions during the follow-up, including costly interventions such as phone calls and educational meetings, did not provide significant advantages.

Considerations regarding adherence of anti-osteoporosis therapy

Osteoporosis remains a challenging disease to treat due to a number of barriers including patient adherence to therapies. One of the most recent advances has been the development of the Fracture Risk Assessment Tool, which is helpful in conveying fracture risk to patients and providing treatment guidance to clinicians. The decision to use an anti-osteoporosis therapy must be tailored to the patient's specific clinical scenario. The bisphosphonates are first-line agents in the treatment of osteoporosis and are efficacious in substantially reducing fracture risk between 25% and 70% on average depending on fracture site. Compliance with oral bisphosphonate pills can be poor, resulting in a significant deterrent to the proper management of osteoporosis. Non-pill forms of bisphosphonate and nonbisphosphonate therapy are available for the treatment of osteoporosis and may increase compliance. Among these is Binosto, a new formulation of weekly effervescent alendronate, as well as intravenous bisphosphonates, teriparatide, and subcutaneously administered denosumab, which are all costly medications and are unlikely to become the mainstay of treatment over the oral bisphosphonate pills. Having a detailed conversation between the patient and physician is essential to the development of a tailored treatment plan that will decrease fracture risk.

Using multiple types of studies in systematic reviews of health care interventions--a systematic review

BACKGROUND

A systematic review may evaluate different aspects of a health care intervention. To accommodate the evaluation of various research questions, the inclusion of more than one study design may be necessary. One aim of this study is to find and describe articles on methodological issues concerning the incorporation of multiple types of study designs in systematic reviews on health care interventions. Another aim is to evaluate methods studies that have assessed whether reported effects differ by study types.

METHODS AND FINDINGS

We searched PubMed, the Cochrane Database of Systematic Reviews, and the Cochrane Methodology Register on 31 March 2012 and identified 42 articles that reported on the integration of single or multiple study designs in systematic reviews. We summarized the contents of the articles qualitatively and assessed theoretical and empirical evidence. We found that many examples of reviews incorporating multiple types of studies exist and that every study design can serve a specific purpose. The clinical questions of a systematic review determine the types of design that are necessary or sufficient to provide the best possible answers. In a second independent search, we identified 49 studies, 31 systematic reviews and 18 trials that compared the effect sizes between randomized and nonrandomized controlled trials, which were statistically different in 35%, and not different in 53%. Twelve percent of studies reported both, different and non-different effect sizes.

CONCLUSIONS

Different study designs addressing the same question yielded varying results, with differences in about half of all examples. The risk of presenting uncertain results without knowing for sure the direction and magnitude of the effect holds true for both nonrandomized and randomized controlled trials. The integration of multiple study designs in systematic reviews is required if patients should be informed on the many facets of patient relevant issues of health care interventions.

Adherence to raloxifene therapy: assessment methods and relationship with efficacy

Response to therapy depends on patient compliance but accurate assessment is difficult and adequate levels of adherence are uncertain. Adherence to raloxifene treatment may be assessed more accurately by electronic monitoring than by counting returned tablets. The level of adherence is positively associated with the degree of bone response.

INTRODUCTION

Adherence to study medication is usually estimated by counting returned tablets. This method relies on subjects' honesty and may be inaccurate. We aimed to assess adherence more accurately, and examine its effect on measures of bone response, by using electronic monitoring.

METHODS

Osteopenic women, ages 50 to 80, were prescribed daily raloxifene for 2 years. Electronic bottle caps (Medication Event Monitoring System (MEMS), Aardex) recorded the date and time on opening. Returned tablets were also counted. We measured bone mineral density (BMD) in duplicate at the spine and hip at baseline and 2 years. We also measured urinary N-terminal cross-linked telopeptide of type I collagen (NTX) at baseline, 1 and 2 years. We calculated the percentage changes in BMD and NTX from mean baseline to mean follow up measurements. Percentage adherence was assessed by both methods for 71 subjects that completed the study.

RESULTS

The two methods correlated significantly (p <0.001, Spearman's rho = 0.73) but the tablet count showed a higher median adherence than the MEMS caps (95.7 vs. 85.0%, p <0.001), with greater divergence at lower adherence levels. MEMS adherence in 65 subjects with complete data correlated with NTX response (p <0.01, rho = -0.33) but with BMD response only at the femoral neck. However, adherence in the lowest quartile was associated with poorer BMD response at all sites (p <0.05).

CONCLUSION

Tablet counts may give similar results overall but conceal substantial individual non-adherence. Monitoring caps may assess adherence more accurately than tablet counts and would be the preferred method in clinical trials. The degree of adherence is associated with both bone turnover and BMD responses to anti-resorptive therapy.

Comparison of orally administered bisphosphonate drugs in reducing the risk of hip fracture in older adults: a population-based cohort study

BACKGROUND

Orally administered bisphosphonate drugs (i.e., alendronate, etidronate, risedronate) can reduce the risk of vertebral fracture. However, only alendronate and risedronate have proven efficacy in reducing the risk of hip fracture. We sought to examine the comparative effectiveness of orally administered bisphosphonate drugs in reducing hip fractures among older adults.

METHODS

We identified new users of orally administered bisphosphonate drugs in British Columbia and Ontario between 2001 and 2008. We used province- and sex-specific propensity score-matching strategies to maximize comparability between exposure groups. We used Cox proportional hazards models to compare time-to-hip fracture within 1 year of treatment between exposures by sex in each province. Our secondary analyses considered hip fracture rates within 2 and 3 years' follow-up. We used alendronate as the reference for all comparisons and pooled provincial estimates using random effects variance-weighted meta-analysis.

RESULTS

We identified 321 755 patients who were eligible for inclusion in the study. We found little difference in fracture rates between men (pooled hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.74-1.14) or women (pooled HR 1.15, 95% CI 0.73-1.56) taking risedronate and those taking alendronate. We similarly identified little difference in fracture rates between women taking etidronate and those taking alendronate (pooled HR 1.00, 95% CI 0.82-1.18). However, we identified lower rates of hip fracture among men taking etidronate relative to alendronate (pooled HR 0.77, 95% CI 0.60-0.94). Results extended to 2 and 3 years' follow-up were similar. However, with 3 years' follow-up, rates of hip fracture were lower among women in British Columbia who had taken alendronate.

INTERPRETATION

We identified little overall difference between alendronate and risedronate in reducing the risk of hip fracture in men or women. Our finding that etidronate is associated with lower fracture risk among men is likely due to selection bias. The long-term comparative effects of orally administered bisphosphonate drugs warrant further study.

Meta-analysis: oral bisphosphonates and the risk of oesophageal cancer

BACKGROUND

Bisphoshonates, which are used in the treatment and prevention of osteoporosis, have recently been implicated in the development of oesophageal cancer; however, studies report conflicting data.

AIM

To conduct a meta-analysis of studies reporting on the association between bisphosphonates and oesophageal cancer to quantify the relationship.

METHODS

A search was conducted through Medline, PubMed, Embase and Current Contents Connect to 2 August 2012. We calculated pooled odds ratios and 95% CIs using a random effects model for the risk of oesophageal cancer associated with exposure to bisphosphonates, as well as for the different periods of exposure.

RESULTS

Seven studies, with 19 700 oesophageal cancer cases, met our inclusion criteria. We found a positive relationship between exposure to bisphosphonates and oesophageal cancer, with an odds ratio (OR) of 1.74 with a 95% CI of 1.19-2.55. Heterogeneity was observed (I(2 ) = 85%, P < 0.001). Publication bias was not present. An increased risk of oesophageal cancer was also found in the group exposed to bisphosphonates for a longer period of time, compared with the group who experienced a shorter period of exposure (OR 2.32; 95% CI 1.57-3.43 vs. OR 1.35; 95% CI 0.77-2.39). An increased risk was associated with exposure to Etidronate (OR 1.58; 95% CI 1.12-2.24), but not to Aledronate.

CONCLUSIONS

Exposure to bisphosphonates may be associated with an increased risk of oesophageal cancer. More studies are needed to confirm the relationship.

Quality of life and health status with zoledronic acid and generic alendronate--a secondary analysis of the Rapid Onset and Sustained Efficacy (ROSE) study in postmenopausal women with low bone mass

SUMMARY

The ROSE study compared annual infusion with zoledronic acid and weekly generic alendronate. No significant differences in quality of life or health status between treatment groups were observed. Adherence to alendronate during the study was high, with 80.9% of patients achieving adequate adherence.

INTRODUCTION

A secondary analysis to evaluate quality of life, health status, adherence to alendronate and therapy preference in postmenopausal women with low bone mass who received treatment with zoledronic acid or alendronate was conducted.

METHODS

Postmenopausal women with low bone mass were randomised 2:1 to receive an annual infusion of zoledronic acid or weekly oral generic alendronate in this open-label, multicentre study. Changes in quality of life and health status were assessed using questionnaires at baseline and month 12. Adherence to alendronate was assessed by the investigator and/or study personnel, and subjective therapy preference was assessed using a questionnaire at month 12.

RESULTS

Patients were randomised to zoledronic acid (n = 408) and alendronate (n = 191). Overall, there were no significant differences in quality of life between zoledronic acid and alendronate. However, improvements in quality of life with zoledronic acid versus alendronate could be detected by posthoc analysis in patients with previous fractures. There were no significant differences in health status between patients receiving zoledronic acid or alendronate. Adherence to alendronate during the study was high, with 80.9% of patients achieving adequate adherence. A total of 81% of patients who had received zoledronic acid indicated that they would prefer to continue with that treatment, and 43% of the patients who received oral alendronate would like to switch to zoledronic acid.

CONCLUSIONS

There were no significant differences in quality of life between patients receiving zoledronic acid or alendronate.

Bisphosphonate prescribing, persistence and cumulative exposure in Ontario, Canada

We studied new users of oral bisphosphonates and found that less than half persisted with therapy for 2 years, and interruptions in use were common. During a median observation period of 4.7 years, 10% of patients filled only a single prescription, 37% switched therapies and median cumulative exposure was 2.2 years.

INTRODUCTION

We sought to describe bisphosphonate prescribing, persistence and cumulative exposure among seniors in Ontario, Canada.

METHODS

We used Ontario Drug Benefit pharmacy claims to identify residents aged ≥ 66 years who initiated oral bisphosphonate therapy between April 1996 and March 2009. The first date of bisphosphonate dispensing was considered the index date. Persistence with therapy was defined as continuous treatment with no interruption exceeding 60 days. We examined persistence with therapy and the number of extended gaps (>60 days) between prescriptions over time periods ranging from 1 to 9 years. We also identified the proportion of patients filling only a single prescription and switching to a different bisphosphonate, and calculated the median days of exposure irrespective of gaps in therapy.

RESULTS

A total of 451,113 eligible new bisphosphonate users were identified: mean age = 75.6 years (SD = 6.9), 84% female, and median follow-up length = 4.7 years. Persistence with therapy declined from 63% at 1 year to 46% at 2 years and 12% at 9 years. Among those with at least 5 years of follow-up (n = 213,029), 61% had one or more extended gaps in bisphosphonate therapy. Overall, 10% of patients filled only a single prescription, 37% switched to a different bisphosphonate and the median exposure was 2.2 years.

CONCLUSION

Less than half of patients persisted with bisphosphonate therapy for 2 years and interruptions in therapy were common, with most patients experiencing two or more >60-day gaps in therapy. Interventions are needed to improve persistence with bisphosphonate therapy and reduce the frequency of gaps in treatment.

Osteoporosis telephonic intervention to improve medication regimen adherence: a large, pragmatic, randomized controlled trial

BACKGROUND

Multiple studies demonstrate poor adherence to medication regimens prescribed for chronic illnesses, including osteoporosis, but few interventions have been proven to enhance adherence. We examined the effectiveness of a telephone-based counseling program rooted in motivational interviewing to improve adherence to a medication regimen for osteoporosis.

METHODS

We conducted a 1-year randomized controlled clinical trial. Participants were recruited from a large pharmacy benefits program for Medicare beneficiaries. All potentially eligible individuals had been newly prescribed a medication for osteoporosis. Consenting participants were randomized to a program of telephone-based counseling (n = 1046) using a motivational interviewing framework or a control group (n = 1041) that received mailed educational materials. Medication regimen adherence was the primary outcome compared across treatment arms and was measured as the median (interquartile range) medication possession ratio, calculated as the ratio of days with filled prescriptions to total days of follow-up.

RESULTS

The groups were balanced at baseline, with a mean age of 78 years; 93.8% were female. In an intention-to-treat analysis, median adherence was 49% (interquartile range, 7%-88%) in the intervention arm and 41% (2%-86%) in the control arm (P = .07, Kruskal-Wallis test). There were no differences in self-reported fractures.

CONCLUSION

In this randomized controlled trial, we did not find a statistically significant improvement in adherence to an osteoporosis medication regimen using a telephonic motivational interviewing intervention.

Can B-domain deletion alter the immunogenicity of recombinant factor VIII? A meta-analysis of prospective clinical studies

BACKGROUND

As a result of the infrequency of inhibitors in previously treated patients (PTPs) with hemophilia A and the small size of available clinical studies, the immunogenicity of factor (F)VIII products has been difficult to assess.

OBJECTIVES

A meta-analysis of prospective clinical studies was conducted to test the hypothesis that de novo inhibitor incidence differs between PTPs receiving full-length recombinant FVIII (FL-rFVIII) and B-domain deleted recombinant FVIII (BDD-rFVIII).

METHODS

Prospective studies with data on inhibitors in PTPs receiving FL-rFVIII or BDD-rFVIII were sought using systematic methods including bibliographic database searches. Data were secured from published study reports and inquiries to investigators. Between-group differences in inhibitor incidence rates were evaluated using mixed effects Cox regression.

RESULTS

Twenty-nine studies with 3012 total PTPs were included. Patients were at risk of de novo inhibitor development for a median of 79 exposure days. A total of 35 de novo inhibitors were observed. The cumulative hazard for all de novo inhibitors was 1.25% with a 95% confidence interval (CI) of 0.63-1.88%. The corresponding rate for high-titer de novo inhibitors [> 5 Bethesda units (BU)] was 0.29% (CI, 0.01-0.57%). Exposure to BDD-rFVIII was associated with an increased risk of all de novo inhibitors (hazard ratio, 7.26; CI, 2.12-24.9; P = 0.0016) and of high-titer de novo inhibitors (hazard ratio, 10.8; CI, 2.17-53.7; P = 0.0037), compared with FL-rFVIII.

CONCLUSIONS

This meta-analysis of prospective clinical studies suggests that recombinant FVIII products may differ in immunogenicity.

Safety of long-term bisphosphonate therapy for the management of osteoporosis

Drugs in the bisphosphonate class are the most commonly prescribed therapeutic agents for the treatment of osteoporosis. Prospective, randomized, placebo-controlled clinical trials have demonstrated efficacy in reducing fracture risk, with favourable safety profiles, in women with postmenopausal osteoporosis. However, long-term use in clinical practice has been associated with reports of undesirable events not previously recognized. These have included gastrointestinal intolerance, osteonecrosis of the jaw, atypical femur fractures, oesophageal cancer, atrial fibrillation and chronic musculoskeletal pain. Physicians must be alert to newly recognized safety concerns, understand the level of evidence supporting them and be able to effectively communicate the balance of expected benefit and potential risk to patients. Usually, post-marketing adverse events are first presented as case reports or observational studies with variable levels of supporting evidence for plausibility, pathophysiology and causality. Widespread coverage in the news media, which can be alarming to patients and their physicians, may not present a balanced view of the proven benefits, the uncertain risks of therapy and the relative magnitude of these events. There may be confusion about the risks associated with bisphosphonate use for the treatment of osteoporosis versus treatment of other conditions, such as cancer, which typically involves a very different patient population and different doses or frequency of drug administration. Often reports of possible adverse events do not provide information on the number of patients exposed to the drug in proportion to the reported adverse event, or do not describe the incidence of the adverse event in a comparator population not exposed to the drug. Gastrointestinal intolerance with oral bisphosphonates, and hypocalcaemia, acute phase reactions and renal toxicity with intravenous bisphosphonates are characterized by biological plausibility and demonstration of causality. Safety concerns with uncertain biological plausibility and unproven causality include osteonecrosis of the jaw, atypical femur fractures, oesophageal cancer and ocular inflammation. Suspected concerns that are unlikely to be causally related include atrial fibrillation and hepatotoxicity. When making the decision to use a bisphosphonate for the treatment of osteoporosis, the balance between benefit and potential risks according to clinical circumstances of each patient should be considered.

Clinical utility of denosumab for treatment of bone loss in men and women

While most older patients with osteoporosis are treated with antiresorptive bisphosphonates such as alendronate, risedronate, ibandronate, and zoledronic acid, such drugs have side effects, remain in bone for extended periods, and lead to poor adherence to chronic treatment. Denosumab is a humanized monoclonal antibody and antiresorptive agent that works by decreasing the activity of the receptor activator of nuclear factor kappa B ligand. In major trials in postmenopausal women, denosumab increased bone mineral density by dual energy x-ray absorptiometry in the spine, hip, and distal third of the radius and decreased vertebral, nonvertebral, and hip fractures. Denosumab is administered by subcutaneous injection every six months, suggesting that adherence may be improved with such therapy. In addition, pharmacokinetic studies measuring bone turnover markers imply that the antiresorptive effect diminishes more quickly over time. Whether these properties will lead to fewer long-term side effects needs to be proven. Denosumab has also been studied in men with prostate cancer treated with androgen deprivation therapy. These men, at high risk for fracture, also have increases in spine, hip, and forearm dual energy x-ray absorptiometry, as well as fewer morphologic vertebral fractures on x-ray. Denosumab is approved for postmenopausal women with osteoporosis in the US and Europe and for men on androgen deprivation therapy in Europe.

Overcoming problems with adherence to osteoporosis medication

Nonadherence to pharmacological treatment in osteoporosis is a well-recognized problem. As in other chronic diseases, adherence to osteoporosis treatment is poor, resulting in enormous burden on patients and healthcare resources. Most importantly, low adherence rates consistently result in increased rates of fractures. However, it seems that efforts to evaluate and improve rates of both compliance and persistence are increasing. The extension of dosing intervals may be an element, among others, allowing improvements in therapeutic adherence. Improved patient education, enhancing healthcare provider-patients interaction, taking into account patient's preferences and involving them in treatment decisions may improve adherence.

Adherence to osteoporosis drugs and fracture prevention: no evidence of healthy adherer bias in a frail cohort of seniors

We examined new users of osteoporosis drugs among seniors in Pennsylvania and found no evidence of healthy adherer bias on observed associations between adherence to treatment and non-vertebral fracture risk; we document fracture reduction with better adherence to bisphosphonates, yet no fracture reduction with better adherence to calcitonin or raloxifene.

INTRODUCTION

We examined the potential for "healthy adherer bias" when studying the effects of adherence to osteoporosis pharmacotherapy on fracture risk. Based on clinical trial evidence, bisphosphonates, calcitonin, and raloxifene reduce vertebral fracture risk; yet only bisphosphonates are documented to reduce non-vertebral fracture risk.

METHODS

This is a cohort study of older women in Pennsylvania who initiated osteoporosis drugs between 1995 and 2005. We included new users of bisphosphonates, calcitonin, and raloxifene. Adherence was categorized based on a measure of compliance as high [proportion of days covered (PDC) ≥ 80%], intermediate (50% < PDC < 80%), or low (PDC ≤ 50%) according to a 180-day ascertainment period. Non-vertebral fracture rates within 365 days after the ascertainment period were compared between adherence categories (reference = low) using Cox proportional hazard models and adjusting for fracture risk factors. Primary and secondary prevention cohorts were examined separately. Adherence to calcitonin and raloxifene were control analyses.

RESULTS

We found little difference in fracture rates between levels of adherence to calcitonin, bisphosphonates for primary prevention, or raloxifene for secondary prevention. We document lower fracture rates among high versus low adherent bisphosphonate users for secondary prevention (HR = 0.53, 95%CI = 0.38-0.74) and higher fracture rates among high versus low adherent raloxifene users for primary prevention (HR = 2.01, 95%CI = 1.04-3.87).

CONCLUSIONS

We document little evidence of healthy adherer bias when studying the association between better adherence to osteoporosis drugs and fracture risk reduction, with only better adherence to bisphosphonates reducing fracture risk. The higher fracture risk among highly adherent raloxifene users for primary prevention is likely due to residual confounding.

Monitoring pharmacological therapy for osteoporosis

Osteoporosis is a common disease characterized by low bone strength that increases the risk of fractures. The consequences of fractures include increases in morbidity, mortality, and healthcare costs. Randomized clinical trials have shown that pharmacological therapy can reduce the risk of fractures. In clinical practice, however, failure to achieve optimal therapeutic benefit is common for reasons that include taking medication incorrectly, stopping it prematurely, malabsorption, and the presence of unrecognized diseases or conditions with adverse skeletal effects. Monitoring for anti-fracture effectiveness in individual patients is limited by the absence of clinical tools to directly measure bone strength. It is therefore necessary to monitor therapy with biomarkers such as bone mineral density and bone turnover markers. This is a review of the utility of these tools in the care of individual patients.

Risk communication and shared decision making in the care of patients with osteoporosis

Health maintenance and disease management require vigilance in assessing risk, communicating risk, and balancing the expected benefits of therapeutic interventions with potential harms. The evaluation of skeletal health includes identification of clinical risk factors for fracture, bone density testing in appropriate patients, and the use of validated algorithms for estimating the probability of fracture. To reduce the burden of osteoporotic fractures, patients at risk for fracture must be identified and treated with effective agents that are taken regularly, correctly, and for a sufficient length of time to achieve the desired benefit. These goals may be enhanced by shared decision making, a process by which the clinician and the patient share all applicable information and negotiate a plan of treatment that is acceptable to both. As an educator and a partner in making treatment decisions, the clinician must be familiar with the medical evidence and able to discuss complex medical information in a manner that is understood by the patient, with appropriate consideration of the patient's expectations, beliefs, and concerns. After treatment is started, risk communication, patient education, and shared decision making should be continued in an effort to maintain good compliance and persistence with therapy. Further study is needed to identify and validate optimal risk communication tools for the care of patients with osteoporosis. Challenges to shared decision making include competition from other health care priorities for limited patient encounter time during office visits, poor reimbursement, insufficient knowledge of the medical evidence, inadequate communication skills, and cognitive/affective disorders limiting patient participation in making treatment decisions.

Measuring and improving adherence to osteoporosis pharmacotherapy

PURPOSE OF REVIEW

Osteoporosis is a major public health issue resulting in considerable fracture-related morbidity. Although effective treatment exists, adherence to osteoporosis pharmacotherapy is suboptimal and linked to reduced drug effectiveness. In this paper, we review methods of measuring and improving adherence to osteoporosis pharmacotherapy.

RECENT FINDINGS

Most patients will stop osteoporosis pharmacotherapy, yet the majority who discontinue will reinitiate treatment after an extended gap. The key to improving adherence to osteoporosis pharmacotherapy is to reduce the number and length of gaps in treatment. Multifaceted and individualized interventions may help to improve adherence. New strategies aimed at identifying patients likely to stop therapy may also facilitate the development of targeted interventions.

SUMMARY

Adherence to osteoporosis pharmacotherapy is suboptimal with short periods of persistence and lengthy gaps in therapy. Regular communication regarding the importance of continued therapy is critical. More research to help identify risk profiles of patients likely to become nonadherent, targeted multifaceted interventions to maximize adherence to therapy, and data to support when patients may safely consider a physician directed drug holiday is needed.

Bone mineral density and fracture rate in response to intravenous and oral bisphosphonates in adult osteogenesis imperfecta

The effect of bisphosphonate treatment on bone mineral density (BMD) and fracture rates was assessed in adults with osteogenesis imperfecta (OI). This observational nonrandomized study included 90 OI adults treated with intravenous pamidronate (n = 28), oral alendronate (n = 10), or oral residronate (n = 17) or not treated (n = 35). There were 63 type I, 15 type III, and 12 type IV OI patients. BMD results were observed for up to 161 months and an average of 52 months of treatment. For type I and grouped type III/IV patients, treatment with pamidronate showed an increasing rate in L1-L4 BMD from baseline (0.006 [P = 0.03] and 0.016 [P < 0.001] gm/cm(2)/year, respectively); oral bisphosphonate treatment showed a significant increasing rate in L1-L4 BMD (0.004 gm/cm(2)/year [P = 0.047]) for type I patients. Pamidronate-treated type III/IV and oral bisphosphonate-treated type I patients showed significant increases in total-hip BMD (0.006 [P = 0.003] and 0.011 [P = 0.046] gm/cm(2)/year, respectively). Bisphosphonate effect on fracture rate was assessed for 5-year periods before and after treatment in 51 treated and 22 nontreated individuals matched for age at which bisphosphonate was first administered to the treated group. Bisphosphonate treatment did not decrease fracture rate in type I OI patients. Fracture rate decreased in type III/IV patients following pamidronate but not following oral bisphosphonate treatment. These results underscore a need to consider whether bisphosphonate treatment is appropriate for all adults with OI.

Methods to examine the impact of compliance to osteoporosis pharmacotherapy on fracture risk: systematic review and recommendations

The objective of this study was to review the methods of prior studies that estimate the association between compliance to osteoporosis pharmacotherapy on fracture risk, and make recommendations to guide future research. We completed a systematic search of MEDLINE to identify all English language nonexperimental studies that examined the impact of adherence to osteoporosis pharmacotherapy on fracture risk. Studies that measured compliance were eligible and those that only examined persistence were excluded. We summarized the methodology of each study and make recommendations for future research. We identified 14 eligible articles: nine cohort and five nested case-control. Length of baseline (lookback) periods ranged between 3 months and 2 years, with nearly all studies (86%) restricting inclusion to treatment-naïve users. A threshold of 80% was most commonly used to define compliance (n = 10), with few studies providing a more thorough analysis through categorical (n = 3) or continuous (n = 1) measures. All nine cohort studies adjusted for age, sex, prior fracture, and at least one other comorbidity or drug; two cohort studies adjusted for a comorbidity score. Two of the five case-control studies clearly controlled for age, sex, drug exposure, event date and length of follow up. One study considered a theoretical sensitivity analysis to account for potential healthy adherer bias, yet all mentioned limitations related to possible residual confounding. We identify great variability in methods of prior studies that evaluate the impact of compliance to osteoporosis pharmacotherapy on fracture risk, and make recommendations to guide future research.

Bisphosphonates for the treatment of osteoporosis: insights for clinicians

Osteoporosis is a common skeletal disease characterized by a reduction in bone strength and increased risk of fractures. Osteoporotic fractures are associated with substantial morbidity, mortality, and high healthcare costs. Treatments for osteoporosis have been shown to increase bone strength and reduce fracture risk. The drugs most commonly used to treat osteoporosis are bisphosphonates: stable analogs of naturally occurring inorganic pyrophosphate. The bisphosphonates share a common chemical structure with side chain variations that convey differences in their pharmacological properties, such as affinity for bone mineral and inhibitory effect on osteoclastic bone resorption. The clinical profiles of bisphosphonates, such as time of onset and offset of effect, may differ according to these pharmacological properties. Bisphosphonates can be administered orally or intravenously with a wide range of doses and dosing intervals. Randomized placebo-controlled clinical trials have shown that bisphosphonates reduce fracture risk in postmenopausal women with osteoporosis and have a generally excellent safety record. Clinical challenges in using bisphosphonates to treat osteoporosis include appropriate selection of patients for initiating therapy, choosing which bisphosphonate to use, monitoring therapy to assure that medication is taken correctly and the desired effect is achieved, determining when drug discontinuation should be considered, and managing side effects, possible side effects, and fear of side effects. Strategies for treating patients with bisphosphonates should consider each of these issues.

Benefits and limitations of bone mineral density and bone turnover markers to monitor patients treated for osteoporosis

Medications are approved by regulatory agencies for treating osteoporosis when at least one randomized placebo-controlled clinical trial shows a reduction in vertebral fracture risk and the benefit-risk ratio is determined to be acceptable. Subjects who participate in registration trials are a generally homogeneous group carefully screened with strict entry criteria. Individual patients who are treated for osteoporosis in clinical practice commonly differ from subjects enrolled in these clinical trials according to confounding factors that include age, sex, comorbidities, compliance, and persistence. Because the goal of therapy is reduction of fracture risk, and this cannot be directly assessed in an individual patient, biomarkers are commonly used as surrogate end points for effectiveness. This article reviews the clinical use and abuse of the two biomarkers most commonly used to assess the effectiveness of therapy in clinical practice: bone mineral density testing and measurement of markers of bone turnover.