Does medication adherence itself confer fracture protection? An investigation of the healthy adherer effect in observational data

Impact of Medication Adherence on Bone Mineral Density and Fracture Risk in Patients With Osteoporosis: A Systematic Review

Osteoporosis is a chronic, prevalent disease marked by decreased bone mass and changes in bone anatomy associated with significant morbidity. The management of osteoporosis necessitates long-term therapy for which patient adherence is of vital importance. In the present review, we aim to collect all potential evidence from relevant studies that reported the impact of medication adherence on bone mineral density and fracture risk in patients with osteoporosis. We have conducted both electronic and manual search strategies within the potential databases and included articles and reviews to find relevant studies. We have assessed the effects of osteoporotic medication adherence on fracture rates and bone mineral density. The study participants were divided into two groups, adherent and non-adherent. Studies from the year 2010-2023 were included. Final inclusion consisted of 14 studies that showed variation in adherence rates with only three studies reporting optimal adherence followed by two studies with nearly half adherent population while the rest of the studies reported low medication adherence. The highest adherence rate reported was 82% while the lowest was 8%. Among the included studies the fracture rates varied significantly. Decreased rates of fracture were observed in the adherent population however two of the included studies were contrary to these findings. Additionally, only three studies discussed the effect of adherence on bone mineral density. Lack of medication adherence is linked to an increased risk of fracture, and low bone mineral density, further associated with more severe complications as per the evidence from the literature. However, variation in the fracture rates as observed in our findings advocates the need for further research for the generalizability of results.

Refracture risk and all-cause mortality after vertebral fragility fractures: Anti-osteoporotic medications matter

BACKGROUND

Osteoporotic vertebral fractures may predict the future occurrence of fractures and increase mortality. Treating underlying osteoporosis may prevent second fractures. However, whether anti-osteoporotic treatment can reduce the mortality rate is not clear. The aim of this population study was to identify the degree of decreased mortality following the use of anti-osteoporotic medication after vertebral fractures.

METHODS

We identified patients who had newly diagnosed osteoporosis and vertebral fractures from 2009 to 2019 using the Taiwan National Health Insurance Research Database (NHIRD). We used national death registration data to determine the overall mortality rate.

RESULTS

There were 59,926 patients with osteoporotic vertebral fractures included in this study. After excluding patients with short-term mortality, patients who had previously received anti-osteoporotic medications had a lower refracture rate as well as a lower mortality risk (hazard ratio (HR): 0.84, 95% confidence interval (CI): 0.81-0.88). Patients receiving treatment for more than 3 years had a much lower mortality risk (HR: 0.53, 95% CI: 0.50-0.57). Patients who used oral bisphosphonates (alendronate and risedronate, HR: 0.95, 95% CI: 0.90-1.00), intravenous zoledronic acid (HR: 0.83, 95% CI: 0.74-0.93), and subcutaneous denosumab injections (HR: 0.71, 95% CI: 0.65-0.77) had lower mortality rates than patients without further treatment after vertebral fractures.

CONCLUSION

In addition to fracture prevention, anti-osteoporotic treatments for patients with vertebral fractures were associated with a reduction in mortality. A longer duration of treatment and the use of long-acting drugs was also associated with lower mortality.

Adherence patterns in naïve and prevalent use of infliximab and its biosimilar

Introduction

Although short-term clinical trials have demonstrated that switching from infliximab (INF) bio-originator to its biosimilar is safe with no significant loss of efficacy, there are limited real-world data comparing their patterns of use and adherence.

Methods

Using 2015–2018 IBM Marketscan data, we established 4 cohorts of patients with at least one administration or pharmacy claim for INF bio-originator or biosimilar in 2017, including INF naïve biosimilar users, INF prevalent biosimilar users, INF naïve bio-originator users, and INF prevalent bio-originator users, defined according to their prior use of INF from 2015 to their first INF administration in 2017. The proportion of days covered (PDC) was calculated for patients with at least 6, 12, or 18 months of follow-up time. Factors associated with optimal adherence (PDC > 80%) were evaluated using log-binomial models.

Results

We identified 96 INF naïve biosimilar users, 223 INF prevalent biosimilar users, 2,149 INF naïve bio-originator users, and 10,970 INF prevalent bio-originator users. At the end of 18 months of follow-up, 64% of INF prevalent bio-originators, 48% of INF naïve biosimilars, 41% of INF naïve bio-originators, and 36% of INF prevalent biosimilars had optimal adherence. Depression, previous hospitalization, and greater use of prior biologics were negatively associated with adherence, whereas IBD diagnoses (referent to RA) and age 55–64 (referent to < 35) were positively associated with high adherence.

Conclusion

INF prevalent users had higher adherence in our analyses than INF naïve users. However, further studies with larger sample size are needed to evaluate INF biosimilar users’ adherence.

The Impact of Various Anti-Osteoporosis Drugs on All-Cause Mortality After Hip Fractures: A Nationwide Population Study

Anti-osteoporosis treatment following hip fractures may reduce the overall mortality rate. However, the effects of different drugs on mortality is still unclear. This population-based cohort study aimed to identify the degree of reduced mortality after various anti-osteoporosis regimens following hip fracture surgery. We conducted this cohort study to identify patients with newly diagnosed osteoporosis and hip fractures from 2009 to 2017 using the Taiwan National Health Insurance Research Database (NHIRD). The subsequent use of anti-osteoporosis medication following hip fracture surgery was collected and analyzed. National death registration records were retrieved to determine mortality. A total of 45,226 new cases of osteoporotic hip fracture were identified. Compared with patients who did not receive further treatment, patients who had ever used oral bisphosphonates (alendronate and risedronate, hazard ratio [HR] 0.81; 95% confidence interval [CI], 0.78-0.84), ibandronate (HR 0.76; 95% CI, 0.67-0.86), zoledronic acid (HR 0.70; 95% CI, 0.64-0.76), and denosumab (HR 0.64; 95% CI, 0.60-0.68) showed lower all-cause mortality rates. Patients treated with bisphosphonates had a lower mortality risk than those treated with selective estrogen receptor modulators (HR 0.81; 95% CI, 0.75-0.87). Patients treated with zoledronic acid showed a lower mortality risk than those treated with oral bisphosphonates (HR 0.89; 95% CI, 0.82-0.97). However, patients receiving denosumab and zoledronic acid did not show a significant difference in mortality (HR 0.94; 95% CI, 0.85-1.03). Different anti-osteoporosis treatments for postsurgical patients were associated with different levels of decline in mortality. Generally, longer durations of drug use were associated with lower mortality. © 2022 American Society for Bone and Mineral Research (ASBMR).

Treatment of osteoporosis after hip fracture is associated with lower all-cause mortality: A nationwide population study

PURPOSE

Mortality after osteoporotic hip fractures is high. Postoperative care is as important as surgery itself to prevent a second fracture and improve outcomes, and the effect of anti-osteoporosis treatment after hip fractures on overall mortality is controversial. This nationwide population study aimed to determine whether anti-osteoporosis treatment might reduce overall mortality after hip fracture surgery.

METHODS

We conducted this cohort study using the National Health Insurance Research Database (NHIRD) of Taiwan to identify patients admitted for surgery due to hip fractures from 2008 to 2018. The subsequent use and duration of anti-osteoporotic medication and other parameters were analyzed, and national death registration records were retrieved to investigate mortality.

RESULTS

A total of 59,943 patients admitted for hip fracture surgery were identified. The 22,494 patients (37.5%) who received anti-osteoporotic medication showed a lower all-cause mortality rate compared with the 37,449 patients (62.5%) who did not receive further treatment (hazard ratio (HR): 0.69, 95% confidence interval (CI): 0.67-0.70, p < 0.0001). Patients who received anti-osteoporotic medication for more than 1, 2, and 3 years exhibited propotional reductions in all-cause mortality (HR & 95%CI: 0.57 (0.54-0.60), 0.42 (0.38-0.46), and 0.29 (0.26-0.33) respectively).

CONCLUSION

Anti-osteoporosis treatment was associated with lower all-cause mortality after hip fracture surgery. A longer duration of treatment was also associated with lower mortality. Postoperative treatment for osteoporosis is crucial for patients with hip fracture.

Duration of Bisphosphonate Drug Holidays and Associated Fracture Risk

BACKGROUND

Discontinuation of bisphosphonates (BP) or a "drug holiday" after several years of treatment is increasingly common. However, the association of drug holiday duration with future fracture risk is unclear.

OBJECTIVES

We evaluated the rate of fracture in relation to various lengths of drug holidays among women receiving long-term BP therapy.

RESEARCH DESIGN

Observational cohort study using US Medicare data 2006-2016. Incidence rates (IRs) and Cox proportional hazards models were used to evaluate the rate and adjusted hazard ratios (aHRs) controlling for potential confounders.

SUBJECTS

Women aged 65 years and above enrolled in fee-for-service Medicare who had been adherent (≥80%) to alendronate, risedronate, or zoledronate for ≥3 years.

MEASURES

Hip, humerus, distal forearm, and clinical vertebral fracture.

RESULTS

Among 81,427 eligible women observed for a median (interquartile range) of 4.0 (2.5, 5.3) years, 28% of women underwent a drug holiday. In the alendronate cohort (73% overall), the IR of hip fracture among women who discontinued BP for >2 years was 13.2 per 1000 person-years. Risk was increased (aHR=1.3, 1.1-1.4) versus continuing therapy (IR=8.8, referent). Rates were elevated for humerus fracture with discontinuation >2 years (aHR=1.3, 1.1-1.66) and for clinical vertebral fracture with discontinuation >2 years (aHR=1.2, 1.1-1.4). Results were similar for risedronate, zoledronate, and ibandronate for hip and clinical vertebral fracture.

CONCLUSION

Discontinuing alendronate beyond 2 years was associated with increased risk of hip, humerus, and clinical vertebral fractures.

Hip fracture risk and safety with alendronate treatment in the oldest-old

BACKGROUND

There is high evidence for secondary prevention of fractures, including hip fracture, with alendronate treatment, but alendronate's efficacy to prevent hip fractures in the oldest-old (≥80 years old), the population with the highest fracture risk, has not been studied.

OBJECTIVE

To investigate whether alendronate treatment amongst the oldest-old with prior fracture was related to decreased hip fracture rate and sustained safety.

METHODS

Using a national database of men and women undergoing a fall risk assessment at a Swedish healthcare facility, we identified 90 795 patients who were 80 years or older and had a prior fracture. Propensity score matching (four to one) was then used to identify 7844 controls to 1961 alendronate-treated patients. The risk of incident hip fracture was investigated with Cox models and the interaction between age and treatment was investigated using an interaction term.

RESULTS

The case and control groups were well balanced in regard to age, sex, anthropometrics and comorbidity. Alendronate treatment was associated with a decreased risk of hip fracture in crude (hazard ratio (HR) 0.62 (0.49-0.79), P < 0.001) and multivariable models (HR 0.66 (0.51-0.86), P < 0.01). Alendronate was related to reduced mortality risk (HR 0.88 (0.82-0.95) but increased risk of mild upper gastrointestinal symptoms (UGI) (HR 1.58 (1.12-2.24). The alendronate association did not change with age for hip fractures or mild UGI.

CONCLUSION

In old patients with prior fracture, alendronate treatment reduces the risk of hip fracture with sustained safety, indicating that this treatment should be considered in these high-risk patients.

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.

Association Between Alendronate Use and Hip Fracture Risk in Older Patients Using Oral Prednisolone

IMPORTANCE

Oral glucocorticoid treatment increases fracture risk, and evidence is lacking regarding the efficacy of alendronate to protect against hip fracture in older patients using glucocorticoids.

OBJECTIVE

To investigate whether alendronate treatment in older patients using oral prednisolone is associated with decreased hip fracture risk and adverse effects.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study using a national database (N = 433 195) of patients aged 65 years or older undergoing a health evaluation (baseline) at Swedish health care facilities; 1802 patients who were prescribed alendronate after at least 3 months of oral prednisolone treatment (≥5 mg/d) were identified. Propensity score matching was used to select 1802 patients without alendronate use from 6076 patients taking prednisolone with the same dose and treatment time criteria. Follow-up occurred between January 2008 and December 2014.

EXPOSURES

Alendronate vs no alendronate use; no patients had previously taken alendronate at the time of prednisolone initiation.

MAIN OUTCOMES AND MEASURES

The primary outcome was incident hip fracture.

RESULTS

Of the 3604 included patients, the mean age was 79.9 (SD, 7.5) years, and 2524 (70%) were women. After a median follow-up of 1.32 years (interquartile range, 0.57-2.34 years), there were 27 hip fractures in the alendronate group and 73 in the no-alendronate group, corresponding to incidence rates of 9.5 (95% CI, 6.5-13.9) and 27.2 (95% CI, 21.6-34.2) fractures per 1000 person-years, with an absolute rate difference of -17.6 (95% CI, -24.8 to -10.4). The use of alendronate was associated with a lower risk of hip fracture in a multivariable-adjusted Cox model (hazard ratio, 0.35; 95% CI, 0.22-0.54). Alendronate treatment was not associated with increased risk of mild upper gastrointestinal tract symptoms (alendronate vs no alendronate, 15.6 [95% CI, 11.6-21.0] vs 12.9 [95% CI, 9.3-18.0] per 1000 person-years; P = .40) or peptic ulcers (10.9 [95% CI, 7.7-15.5] vs 11.4 [95% CI, 8.0-16.2] per 1000 person-years; P = .86). There were no cases of incident drug-induced osteonecrosis and only 1 case of femoral shaft fracture in each group.

CONCLUSIONS AND RELEVANCE

Among older patients using medium to high doses of prednisolone, alendronate treatment was associated with a significantly lower risk of hip fracture over a median of 1.32 years. Although the findings are limited by the observational study design and the small number of events, these results support the use of alendronate in this patient group.

Hip and other fragility fracture incidence in real-world teriparatide-treated patients in the United States

This study demonstrates real-world effectiveness of teriparatide in reducing the risk of hip and other fragility fractures. Fracture incidence significantly decreased as adherence and persistence increased for any clinical, vertebral, nonvertebral, and hip fractures among patients who were observed for 2 years after teriparatide initiation.

INTRODUCTION

Examine the relationship of treatment adherence and persistence to teriparatide with hip and other fractures.

METHODS

Truven MarketScan Research Databases, 2004 through 2014, provided teriparatide users ≥18 years old with continuous coverage 12 months pre- and 24 months post-teriparatide prescription. Adherence (medication possession ratio, MPR) groups were defined as high (≥0.80), medium (0.50 ≤ MPR < 0.80), and low (<0.50). Persistence, allowing for ≤90-day gaps between prescriptions, was defined as 1-6, 7-12, 13-18, and 19-24 months. Fracture incidence was summarized and compared by using ANOVA and logistic regression models; the effects of adherence were examined with Cox proportional hazard models with time-dependent covariates for teriparatide exposure.

RESULTS

Among 14,284 teriparatide subjects, mean age was 68.4 years, 89.8% were female, and 29.6% had a fracture in the previous year; these characteristics were similar across MPR and persistence groups. The effects of adherence and persistence to teriparatide were statistically significant (P < .001) for all fracture types except wrist (P ≥ .125). By logistic regression, high vs low adherence was associated with reduced risk for any (OR = 0.67; P < .001); vertebral (OR = 0.64; P < .001); nonvertebral (OR = 0.71; P < .001); and hip fractures (OR = 0.52; P < .001) and longer (19-24 months) vs shorter persistence (1-6 months) was associated with reduced risk for any (OR = 0.63, P < .001); vertebral (OR = 0.56, P < .001); nonvertebral (OR = 0.69, P < .001); and hip fractures (OR = 0.48, P < .001). Cox models revealed a significantly reduced risk between high and low adherence for any (OR = 0.69, P < .001); vertebral (OR = 0.60, P < .001); nonvertebral (OR = 0.77, P < .001); and hip fractures (OR = 0.55, P < .001).

CONCLUSION

Fracture incidence significantly decreased as persistence and adherence to teriparatide increased.

ACE inhibitors and the risk of fractures: a meta-analysis of observational studies

A meta-analysis was conducted to evaluate the effect of treatment with angiotensin-converting enzyme inhibitors on the risk of fractures. All the included articleswere retrieved from MEDLINE, EMBASE and the Cochrane Database. Trial eligibility and methodological quality were assessed before data extraction. Relative risk (RR) with corresponding 95% confidence intervals (95% CI) were used to assess the effect. Six case-control studies with11,387,668 participants met the inclusion criteria and were included in the meta-analysis. A small but significant risk effect on fractures was shown in the overall analysis of angiotensin-converting enzyme inhibitor users compared with nonusers (Pooled RR 1.27; 95% CI 1.01-1.60), although a relatively high heterogeneity was found across studies. In the stratified analysis, therewas no statistically significant association in the subgroups of hip fracture (Pooled RR 1.14; 95% CI 0.73-1.76) and the study quality (Pooled RR 1.13; 95% CI 0.89-1.44), while the over 65-year-old angiotensin-converting enzyme inhibitor users showed a stronger risk effect on fractures (Pooled RR 2.06; 95% CI 1.53-3.17). Moreover, age was found to be contributed a large part of the high heterogeneity across the included studies. This study demonstrated that the use of angiotensin-converting enzyme inhibitors might have a small but significant risk effect on fractures, especially for the over 65-year-old users. These results should be interpreted with caution as the relatively high heterogeneity across studies. Additional multiple observational studies and high quality data from randomized controlled trials are needed to confirm these findings.

Effects of antipsychotics, antidepressants and mood stabilizers on risk for physical diseases in people with schizophrenia, depression and bipolar disorder

People with severe mental illness have a considerably shorter lifespan than the general population. This excess mortality is mainly due to physical illness. Next to mental illness-related factors, unhealthy lifestyle, and disparities in health care access and utilization, psychotropic medications can contribute to the risk of physical morbidity and mortality. We systematically reviewed the effects of antipsychotics, antidepressants and mood stabilizers on physical health outcomes in people with schizophrenia, depression and bipolar disorder. Updating and expanding our prior systematic review published in this journal, we searched MEDLINE (November 2009 - November 2014), combining the MeSH terms of major physical disease categories (and/or relevant diseases within these categories) with schizophrenia, major depressive disorder and bipolar disorder, and the three major psychotropic classes which received regulatory approval for these disorders, i.e., antipsychotics, antidepressants and mood stabilizers. We gave precedence to results from (systematic) reviews and meta-analyses wherever possible. Antipsychotics, and to a more restricted degree antidepressants and mood stabilizers, are associated with an increased risk for several physical diseases, including obesity, dyslipidemia, diabetes mellitus, thyroid disorders, hyponatremia; cardiovascular, respiratory tract, gastrointestinal, haematological, musculoskeletal and renal diseases, as well as movement and seizure disorders. Higher dosages, polypharmacy, and treatment of vulnerable (e.g., old or young) individuals are associated with greater absolute (elderly) and relative (youth) risk for most of these physical diseases. To what degree medication-specific and patient-specific risk factors interact, and how adverse outcomes can be minimized, allowing patients to derive maximum benefits from these medications, requires adequate clinical attention and further research.

Osteoporotic fracture rate among women with at least 1 year of adherence to osteoporosis treatment

PURPOSE

In clinical trials, bisphosphonate therapy reduces but does not eliminate the risk of fracture. The objective of this retrospective observational study was to examine fracture rates among women who were adherent to bisphosphonate therapy for at least 1 year.

METHODS

We studied outcomes for women ≥50 years old who received their first osteoporosis therapy as an oral bisphosphonate during 2002-2008 and were enrolled in a large claims database for ≥3 consecutive years, including a baseline year before and 2 years after the index prescription (thus, the full study period was 2001-2010). Adherence during the first year of therapy was defined as a medication possession ratio (MPR) ≥80% (total number of days' supply/365 days × 100%).

RESULTS

Of the 62,446 women who met the eligibility criteria, 26,852 (43%) had an MPR ≥80% for osteoporosis therapy during year 1. In year 2, the fracture rate was 52/1000 patient-years. Fragility fractures were recorded for 1292 patients (4.8%) during the baseline year (before initiating therapy); for 1051 patients (3.9%) during year 1 (adherence year); and for 871 patients (3.2%) during year 2. Significant predictors of fracture in year 2 were older age, higher comorbidity score, comorbid inflammatory joint disease, and prior fragility fracture during the baseline year or first year of treatment. The primary limitation of these results is the scope of the claims database, which did not provide information on bone mineral density, supplemental use of calcium or vitamin D, or reasons for initiating oral bisphosphonates.

CONCLUSIONS

Despite being adherent to bisphosphonate treatment for 1 year, 3.2% of women experienced a fracture in the subsequent year. These results suggest an unmet need in patients with osteoporosis and an opportunity for newer therapies to help address this need.

Long-term persistence and switching patterns among women using osteoporosis therapies: 24- and 36-month results from POSSIBLE US™

Persistence with postmenopausal osteoporosis (PMO) medications is not well characterized beyond 12 months. Of 3,011 postmenopausal women treated in primary care, 36.8 % continued baseline PMO medication during 36 months of follow-up. Many factors were associated with nonpersistence, including newly initiating or switching therapy, and reporting moderate to severe side effects.

INTRODUCTION

Persistence with postmenopausal osteoporosis (PMO) medications is not well characterized beyond 12 months. We describe 24- and 36-month persistence using patient-reported data from women with different PMO treatment histories in the US primary care setting.

METHODS

Data from 3,011 participants of the Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBLE US™, 10/2005-12/2008) and Kaplan-Meier methods were used to estimate the probability of persisting (i.e., not discontinuing or switching PMO agents) with baseline PMO medication and hazard ratios for predictors of nonpersistence 24 and 36 months after study entry.

RESULTS

The probability of persisting with the baseline medication was 46.2 % (95 % confidence interval [CI] 44.2-48.1 %) during 24 months of follow-up and 36.8 % (95 % CI 34.7-38.9 %) during 36 months of follow-up. In adjusted analyses, newly initiating therapy or switching to a new agent, reporting moderate to severe side effects, having lower disease-specific quality of life scores, smoking, and residing in the South or West USA (all measured at study entry) were independent predictors of nonpersistence in both time periods. The majority of participants who discontinued therapy and had the opportunity to reinitiate (i.e., discontinued ≥4 months before the end of follow-up) restarted therapy (24 months 69 %; 36 months 75 %).

CONCLUSIONS

In this primary care cohort, a minority of women continued their baseline PMO therapy during a 24- to 36-month follow-up. Supporting patients during the initiation of a new therapy or if side effects occur may improve persistence and increase the therapeutic benefit of PMO medications.

Healthy adherer effect - the pitfall in the interpretation of the effect of medication adherence on health outcomes

RATIONALE, AIMS AND OBJECTIVES

Different designs of studies monitoring adherence may cause bias and subsequent unavailability to compare results. Healthy adherer effect (HAE) is a type of bias reflecting patient behaviour. It cannot be easily monitored in study population and can favourably affect health outcomes that may be incorrectly attributed to drug therapy. The aim of this paper was to assess the HAE impact on health outcomes of studies concerning medication adherence.

METHODS

Systematic review of literature from PubMed, EMBASE and Cochrane Register of Controlled Trials identified all randomized controlled or observational studies dealing with HAE. Included studies were analysed with respect to relationships between HAE, adherence to therapy and health outcomes.

RESULTS

Seven studies were identified - two randomized controlled and five cohort studies. Significant occurrence of HAE in relation to mortality was not observed while one study indicated the presence of HAE in relation to surrogate (bone mineral density). Cohort studies were mainly based on drug class effect, but HAE was not revealed. Factors associated with patient behaviour (e.g. smoking, regular preventive screening) were also not clearly associated with the occurrence of HAE, but their inclusion in design of cohort studies can help to detect health seeking behaviour.

CONCLUSION

Only a few studies concerning HAE were found, but they did not obtain any consistent conclusions. HAE impact was supposed particularly on treatment outcomes that may be easier affected by patient behaviour. However, researchers and clinicians should be still aware of HAE, interpret results carefully and verified them in further studies.

Cost-effectiveness of denosumab in the treatment of postmenopausal osteoporotic women

Denosumab is a novel biological agent for the treatment of osteoporosis in postmenopausal women with increased risk of fractures. With limited healthcare resources, economic evaluations are increasingly being used by decision-makers to optimize healthcare resource allocation. The cost-effectiveness of denosumab has been evaluated in various studies, and a systematic literature study was conducted up to April 2012 to identify all published research articles and research abstracts presented at various congresses. This article provides a systematic review of four articles and eight abstracts reporting on the cost-effectiveness of denosumab in the treatment of osteoporosis. In most economic evaluations, denosumab has been considered as a cost-effective treatment compared with first-line and second-line options (including generic alendronate) in the treatment of women with high risk of fractures.