Cost effectiveness of an adherence-improving programme in hypertensive patients

Long-term changes in carotid intima-media thickness according to baseline blood pressure level: J-STARS Echo study

BACKGROUND AND AIMS

We aimed to investigate long-term changes in carotid intima-media thickness (IMT) based on baseline blood pressure (BP) levels in non-cardioembolic stroke patients.

METHODS

Patients aged 45-80 years with dyslipidemia who were not on statins before enrollment and had experienced a non-cardioembolic stroke were assigned to either the pravastatin group or the control group in a randomized trial. Patients were classified into three groups according to BP levels: normal BP (N-group: systolic BP [sBP] <140 mmHg and diastolic BP [dBP] <90 mmHg), highly elevated BP (G2 group: sBP ≥160 mmHg or dBP ≥100 mmHg), and mildly elevated BP (G1 group: the remaining patients). Mixed effect models were used to examine differences in slope of mean carotid IMT increases annually over the 5-year observation period among three groups, and for two groups divided based on whether they were above or below certain BP cut-off levels set at every 1 mmHg, ranging between 139 and 161 mmHg for sBP, and 89-101 mmHg for dBP.

RESULTS

Of 792 patients, baseline mean carotid IMT in the G1-group (0.908 ± 0.152 mm) and G2-group (0.905 ± 0.145 mm) was significantly higher than the N-group (0.870 ± 0.153 mm) (P < 0.01, for both respectively). Although there was no significant difference in the increase among three groups (P = 0.091), the increase in patients above sBP 154, 159 and 160 mmHg or dBP 101 mmHg at baseline was higher than others (P < 0.05 for all).

CONCLUSIONS

High baseline BP correlated with a high baseline carotid IMT and its subsequent 5-year increase in non-cardioembolic stroke patients.

CLINICAL TRIAL REGISTRATION

http://www.

CLINICALTRIALS

gov.

UNIQUE IDENTIFIER

NCT00361530.

The effect of combining therapeutic drug monitoring of antihypertensive drugs with personalised feedback on adherence and resistant hypertension: the (RHYME-RCT) trial protocol of a multi-centre randomised controlled trial

BACKGROUND

Adherence to antihypertensive drugs (AHDs) is important for adequate blood pressure control. Not taking these drugs as prescribed is one of the main underlying causes for resistant hypertension (RH), which in turn leads to an increased risk of cardiovascular events, stroke and kidney damage. Therefore, correct identification of patients that are non-adherent to AHDs is crucial to improve clinical outcome. For this goal, therapeutic drug monitoring is the most reliable method. The primary objective of this trial is to investigate whether monitoring of drug concentrations with a dried blood spot (DBS) sampling method combined with personalised feedback leads to a decrease in prevalence of RH after 12 months due to an increase in adherence. Secondary objectives include the difference over time in the number of required AHDs as well as the defined daily dose (DDD). Lastly, the cost-utility of SoC versus the intervention in RH is determined.

METHODS

This is a multi-centre single-blinded randomised controlled trial (RHYME-RCT). First, at an eligibility visit, DBS sampling, to monitor drug concentrations in blood, and a 24-h ambulatory blood pressure measurement (24-h ABPM) are performed simultaneously. Patients with a daytime systolic blood pressure (SBP) > 135 and/or diastolic blood pressure (DBP) > 85 mmHg are randomised to SoC or intervention + SoC. The intervention is performed by the treating physician and includes information on drug concentrations and a comprehensive personalised feedback conversation with the use of a communication tool. The follow-up period is one year with visits at 3, 6 and 12 months randomisation and includes 24-h ABPM and DBS sampling.

DISCUSSION

This will be the first trial that focusses specifically on patients with RH without taking into account suspicion of non-adherence and it combines monitoring of AHD concentrations to identify non-adherence to AHDs with a comprehensive feedback to improve non-adherence. Furthermore, if this trial shows positive outcomes for the intervention it can be directly implemented in clinical practice, which would be a great improvement in the treatment of RH.

TRIAL REGISTRATION

RHYME-RCT is registered in the Dutch Trial Register on 27/12/2017 (NTR6914) and can be found in the International Clinical Trials Registry Platform.

Osteoporotic Fractures among Selective Estrogen Receptor Modulator Users in South Korea: Analysis Using National Claims Database

Background

We evaluated (1) compliance with selective estrogen receptor modulator (SERM) use in postmenopausal women; and (2) the risk of osteoporotic fractures according to compliance and other patient characteristics.

Methods

National claims data of postmenopausal women from January 2013 to December 2014 were reviewed. Demographics, comorbidities, type of medical institution, and patient compliance were investigated. Compliance was measured according to medication possession ratio (MPR) and the patients were classified into compliant (MPR ≥80%) or non-compliant (MPR <80%) groups. Osteoporotic fractures were followed up for 2 years after prescription.

Results

Among 15,166 postmenopausal women, 4,130 were categorized as compliant. Osteoporotic fractures were confirmed in 669 patients. The hip fracture rate in the non-compliant group (0.39%) was marginally higher than that in the compliant group (0.36%; P=0.06). Compared to age 50 to 54 years, age 55 to 59 years showed protection against fractures (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.379–0.857; P=0.007), while those over 70 years showed a higher risk of fractures (HR, 2.035; 95% CI, 1.485–2.789; P<0.0001 for age 70–74 years; HR, 2.197; 94% CI, 1.588–3.041; P<0.0001 for age 75–79 years; and HR, 3.53; 95% CI, 2.493–4.999; P<0.0001 for age ≥80 years). Patients with mild (HR, 1.29; 95% CI, 1.088–1.530; P=0.0034) and moderate (HR, 1.286; 95% CI, 1.002–1.652; P=0.0486) comorbidities were associated with higher risks of fractures compared to those without comorbidities.

Conclusions

Among postmenopausal women with osteoporosis, only 27.2% complied with SERM therapy. A marginal difference in hip fracture rate was observed between the compliant and non-compliant groups. Older age and severe comorbidities were associated with higher risks of osteoporotic fractures.

Temporal variations in the severity of COVID-19 illness by race and ethnicity

Introduction

Early reports highlighted racial/ethnic disparities in the severity of COVID-19 seen across the USA; the extent to which these disparities have persisted over time remains unclear. Our research objective was to understand temporal trends in racial/ethnic variation in severity of COVID-19 illness presenting over time.

Methods

We conducted a retrospective cohort analysis using longitudinal data from Cedars-Sinai Medical Center, a high-volume health system in Southern California. We studied patients admitted to the hospital with COVID-19 illness from 4 March 2020 through 5 December 2020. Our primary outcome was COVID-19 severity of illness among hospitalised patients, assessed by racial/ethnic group status. We defined overall illness severity as an ordinal outcome: hospitalisation but no intensive care unit (ICU) admission; admission to the ICU but no intubation; and intubation or death.

Results

A total of 1584 patients with COVID-19 with available demographic and clinical data were included. Hispanic/Latinx compared with non-Hispanic white patients had higher odds of experiencing more severe illness among hospitalised patients (OR 2.28, 95% CI 1.62 to 3.22) and this disparity persisted over time. During the initial 2 months of the pandemic, non-Hispanic blacks were more likely to suffer severe illness than non-Hispanic whites (OR 2.02, 95% CI 1.07 to 3.78); this disparity improved by May, only to return later in the pandemic.

Conclusion

In our patient sample, the severity of observed COVID-19 illness declined steadily over time, but these clinical improvements were not seen evenly across racial/ethnic groups; greater illness severity continues to be experienced among Hispanic/Latinx patients.

Adherence in Hypertension

The global epidemic of hypertension is largely uncontrolled and hypertension remains the leading cause of noncommunicable disease deaths worldwide. Suboptimal adherence, which includes failure to initiate pharmacotherapy, to take medications as often as prescribed, and to persist on therapy long-term, is a well-recognized factor contributing to the poor control of blood pressure in hypertension. Several categories of factors including demographic, socioeconomic, concomitant medical-behavioral conditions, therapy-related, healthcare team and system-related factors, and patient factors are associated with nonadherence. Understanding the categories of factors contributing to nonadherence is useful in managing nonadherence. In patients at high risk for major adverse cardiovascular outcomes, electronic and biochemical monitoring are useful for detecting nonadherence and for improving adherence. Increasing the availability and affordability of these more precise measures of adherence represent a future opportunity to realize more of the proven benefits of evidence-based medications. In the absence of new antihypertensive drugs, it is important that healthcare providers focus their attention on how to do better with the drugs they have. This is the reason why recent guidelines have emphasize the important need to address drug adherence as a major issue in hypertension management.

The Cost-Effectiveness of an Intervention Program to Enhance Adherence to Antihypertensive Medication in Comparison With Usual Care in Community Pharmacies

Introduction: Hypertension is considered an important public health issue. Inadequate disease management and non-adherence to antihypertensive medication may result in suboptimal clinical outcomes thereby imposing a financial burden on society. This study evaluates the cost-effectiveness of a patient-tailored, pharmacist-led intervention program aimed to enhance adherence to antihypertensive medication in comparison with usual care. Materials and Methods: An economic evaluation was conducted alongside a pragmatic randomized controlled trial with 9-months follow-up among 170 patients using antihypertensive medication. Effect outcomes included self-reported adherence (MARS-5), beliefs about medicines (BMQ Concern and Necessity scales) and quality-adjusted life-years (QALYs). Costs were measured from a societal perspective. Missing cost and effect data were imputed using multiple imputation. Bootstrapping was used to estimate uncertainty around the cost-differences and the incremental cost-effectiveness ratios. Cost-effectiveness planes and acceptability curves were estimated. Results: There were no significant differences in costs or effects between the intervention program and usual care. The probability of cost-effectiveness of the intervention in comparison with usual care was 0.27 at a willingness-to-pay value of 0 €/unit of effect gained. At a willingness-to-pay value of 20,000 €/unit of effect gained, the probability of cost-effectiveness was 0.70, 0.27, 0.64, 0.87, and 0.36 for the continuous MARS-5 score, dichotomized MARS-5 score, BMQ Concern scale, BMQ Necessity scale and QALYs, respectively. Discussion: In patients with hypertension, the patient-tailored, pharmacist-led intervention program to enhance medication adherence was not considered cost-effective as compared to usual care with regard to self-reported medication adherence, beliefs about medicines and QALYs.

Reducing Care Utilisation through Self-management Interventions (RECURSIVE): a systematic review and meta-analysis

Background

A critical part of future service delivery will involve improving the degree to which people become engaged in ‘self-management’. Providing better support for self-management has the potential to make a significant contribution to NHS efficiency, as well as providing benefits in patient health and quality of care.

Objective

To determine which models of self-management support are associated with significant reductions in health services utilisation (including hospital use) without compromising outcomes, among patients with long-term conditions.

Data sources

Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health, EconLit (the American Economic Association’s electronic bibliography), EMBASE, Health Economics Evaluations Database, MEDLINE (the US National Library of Medicine’s database), MEDLINE In-Process & Other Non-Indexed Citations, NHS Economic Evaluation Database (NHS EED) and PsycINFO (the behavioural science and mental health database), as well as the reference lists of published reviews of self-management support.

Methods

We included patients with long-term conditions in all health-care settings and self-management support interventions with varying levels of additional professional support and input from multidisciplinary teams. Main outcome measures were quantitative measures of service utilisation (including hospital use) and quality of life (QoL). We presented the results for each condition group using a permutation plot, plotting the effect of interventions on utilisation and outcomes simultaneously and placing them in quadrants of the cost-effectiveness plane depending on the pattern of outcomes. We also conducted conventional meta-analyses of outcomes.

Results

We found 184 studies that met the inclusion criteria and provided data for analysis. The most common categories of long-term conditions included in the studies were cardiovascular (29%), respiratory (24%) and mental health (16%). Of the interventions, 5% were categorised as ‘pure self-management’ (without additional professional support), 20% as ‘supported self-management’ (< 2 hours’ support), 47% as ‘intensive self-management’ (> 2 hours’ support) and 28% as ‘case management’ (> 2 hours’ support including input from a multidisciplinary team). We analysed data across categories of long-term conditions and also analysed comparing self-management support (pure, supported, intense) with case management. Only a minority of self-management support studies reported reductions in health-care utilisation in association with decrements in health. Self-management support was associated with small but significant improvements in QoL. Evidence for significant reductions in utilisation following self-management support interventions were strongest for interventions in respiratory and cardiovascular disorders. Caution should be exercised in the interpretation of the results, as we found evidence that studies at higher risk of bias were more likely to report benefits on some outcomes. Data on hospital use outcomes were also consistent with the possibility of small-study bias.

Limitations

Self-management support is a complex area in which to undertake literature searches. Our analyses were limited by poor reporting of outcomes in the included studies, especially concerning health-care utilisation and costs.

Conclusions

Very few self-management support interventions achieve reductions in utilisation while compromising patient outcomes. Evidence for significant reductions in utilisation were strongest for respiratory disorders and cardiac disorders. Research priorities relate to better reporting of the content of self-management support, exploration of the impact of multimorbidity and assessment of factors influencing the wider implementation of self-management support.

Study registration

This study is registered as PROSPERO CRD42012002694.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Cost effectiveness of medication adherence-enhancing interventions: a systematic review of trial-based economic evaluations

BACKGROUND

In light of the pressure to reduce unnecessary healthcare expenditure in the current economic climate, a systematic review that assesses evidence of cost effectiveness of adherence-enhancing interventions would be timely.

OBJECTIVE

Our objective was to examine the cost effectiveness of adherence-enhancing interventions compared with care as usual in randomised controlled trials, and to assess the methodological quality of economic evaluations.

METHODS

MEDLINE, PsycInfo, EconLit and the Centre for Reviews and Dissemination databases were searched for randomised controlled trials reporting full economic evaluations of adherence-enhancing interventions (published up to June 2013). Information was collected on study characteristics, cost effectiveness of treatment alternatives, and methodological quality.

RESULTS

A total of 14 randomised controlled trials were included. The quality of economic evaluations and the risk of bias varied considerably between trials. Four studies showed incremental cost-effectiveness ratios (ICERs) below the willingness-to-pay threshold. Few studies seemed to evaluate interventions that successfully changed adherence.

CONCLUSIONS

Only 14 randomised controlled trials examined the cost effectiveness of adherence interventions. Despite that some studies showe favourable ICERs, the overall quality of studies was modest and the economic perspectives applied were frequently narrow. To demonstrate that adherence interventions can be cost effective, we recommend that proven-effective adherence programmes are subjected to comprehensive economic evaluations.

The effect of a reminder diary on risk factors in patients with chronic hypertension attending a clinic at a hospital in Johannesburg, South Africa

Background

Poor adherence to lifestyle interventions and medication-taking is problematic, and there is some evidence that a diary may be useful in facilitating patients’ adherence to lifestyle modification in chronic disease.

Objectives

To compare changes in blood pressure, waist–hip ratio, body mass index, blood levels and exercise capacity between two experimental groups and one control group (CG) after a six month intervention, and at a further three month follow up.

Method

This was a longitudinal randomised control trial. All three groups underwent usual treatment. In addition, Experimental group one (EG1) received the diary as well as a once-a-month telephone call and Experimental group two (EG2) received only a once-a-month telephone call. Changes in measurements were established using an ANCOVA. The significance of the study was set at p = 0.05.

Results

The added intervention of the diary had no direct effect on blood pressure change greater than that achieved by the appropriate medication. All three groups showed a clinically significant drop in both systolic and diastolic blood pressure to accepted norms. There were marginal differences in EG1 for waist–hip ratios (p = 0.06) at six months. There were significant low density lipoprotein (LDL) reductions in both EG1 and EG2 at nine months compared with the CG (p = 0.02) Walking distances improved minimally in both EG1 and EG2.

Conclusion

The diary and telephone interventions showed some positive trends toward improvements in risk factors of patients with chronic hypertension.

Cost-effectiveness of a hypertension control intervention in three community health centers in China

BACKGROUND

Hypertension and associated chronic diseases impose enormous and growing health and economic burdens worldwide. The objective of this study was to investigate the cost-effectiveness (CE) of a hypertension control program in China.

METHODS

We collected information on program costs and health outcomes in three community health centers over a 1-year period. The participants were 4902 people with hypertension (systolic blood pressure [SBP] ≥140 mm Hg and/or diastolic blood pressure [DBP] ≥90 mm Hg, or on hypertension medication) aged 18 years and older. The SBP and DBP changes in the populations were estimated from a random sample of 818 participants by conducting face-to-face interviews and physical examinations. We derived CE measures based on the costs and effects on health outcomes.

FINDINGS

The total cost of implementing the intervention was Renminbi (RMB) 240 772 yuan (US$35 252), or 49 yuan (US$7.17) per participant in 2009. On average, SBP decreased from 143 to 131 mm Hg (P < .001) and DBP decreased from 84 to 78 mm Hg (P < .001), the SBP decreases ranged from 7.6 to 17.8 mm Hg and DBP decreases ranged from 3.9 to 8.3 mm Hg. CE ratios ranged from RMB 3.6 to 5.0 yuan (US$0.53-US$0.73) per person per mm Hg SBP decrease, and from RMB 6.3 to 9.7 yuan (US$0.92-US$1.42) per person per mm Hg DBP decrease.

INTERPRETATION

Per capita costs varied widely across the communities, as did changes in SBP and DBP, but CE was similar. The findings suggest (a) a positive correlation between per capita costs and program effectiveness, (b) differences in intervention levels, and (c) differences in health status. CE results could be helpful to policy makers in making resource allocation decisions.

Secondary analysis of electronically monitored medication adherence data for a cohort of hypertensive African-Americans

BACKGROUND

Electronic monitoring devices (EMDs) are regarded as the "gold standard" for assessing medication adherence in research. Although EMD data provide rich longitudinal information, they are typically not used to their maximum potential. Instead, EMD data are usually combined into summary measures, which lack sufficient detail for describing complex medication-taking patterns. This paper uses recently developed methods for analyzing EMD data that capitalize more fully on their richness.

METHODS

Recently developed adaptive statistical modeling methods were used to analyze EMD data collected with medication event monitoring system (MEMS™) caps in a clinical trial testing the effects of motivational interviewing on adherence to antihypertensive medications in a cohort of hypertensive African-Americans followed for 12 months in primary care practices. This was a secondary analysis of EMD data for 141 of the 190 patients from this study for whom MEMS data were available.

RESULTS

Nonlinear adherence patterns for 141 patients were generated, clustered into seven adherence types, categorized into acceptable (for example, high or improving) versus unacceptable (for example, low or deteriorating) adherence, and related to adherence self-efficacy and blood pressure. Mean adherence self-efficacy was higher across all time points for patients with acceptable adherence in the intervention group than for other patients. By 12 months, there was a greater drop in mean post-baseline blood pressure for patients in the intervention group, with higher baseline blood pressure values than those in the usual care group.

CONCLUSION

Adaptive statistical modeling methods can provide novel insights into patients' medication-taking behavior, which can inform development of innovative approaches for tailored interventions to improve medication adherence.

Effect of a medication-taking behavior feedback theory-based intervention on outcomes in patients with heart failure

BACKGROUND

Medication nonadherence contributes to hospitalization and mortality, yet there have been few interventions tested that improve adherence and reduce hospitalization and mortality in heart failure (HF). Our objective was to determine whether an education intervention improved medication adherence and cardiac event-free survival.

METHODS AND RESULTS

A randomized controlled trial was conducted on 82 HF patients. The intervention was based on the theory of planned behavior (TPB) and included feedback of medication-taking behavior using the Medication Event Monitoring System (MEMS). Patients were assigned to one of three groups: 1) theory-based education plus MEMS feedback; 2) theory-based education only; or 3) usual care (control). Cardiac events were collected for 9 months. Patients in both intervention groups were more adherent over follow-up compared with the control group. In Cox regression, patients in either intervention group had a longer event-free survival compared with those in the control group before and after controlling age, marital status, financial status, ejection fraction, New York Heart Association functional class, angiotensin-converting enzyme inhibitor use, and presence or absence of a significant other during the intervention (P < .05).

CONCLUSIONS

Use of an intervention based on the TPB improves medication adherence and outcomes in patients with HF and therefore offers promise as a clinically applicable intervention to help patients with HF to adhere to their prescribed regimen.

An attempt to improve antipsychotic medication adherence by feedback of medication possession ratio scores to prescribers

Poor medication adherence is well documented for patients with severe and persistent mental illness. The State of Missouri implemented an early alert system to notify caregivers when patients fail to refill essential prescriptions in a timely manner and as an educational resource for providers on best practices for improving treatment adherence. Missouri Medicaid patients who were prescribed at least 1 of 9 orally-administered antipsychotic medications and who had at least 1 medication possession ratio (MPR) score below 0.8 were included in the adherence intervention group. Their prescribing clinicians and case managers were messaged electronically 2 times per week at the point that failure to refill the targeted prescription was identified. Notification occurred when the prescription had lapsed at 7 days, 30 days, and 45 days, and occurred in real time. In addition, MPR scores were provided monthly for the most recent 6-month period. Change in MPR scores was measured for the intervention group and for a matched control group. Trends in MPR scores were analyzed for both groups pre, during, and post intervention. In both the intervention and postintervention periods, there was a significant difference in the MPR scores between the two groups. The intervention group had a significantly greater increase in MPR score between preintervention and intervention periods. After the conclusion of the intervention, the MPR score decreased somewhat but was still higher than during the preintervention period. Results suggest that clinicians and patients need specific data about adherence in order to address the issue.

The modeled lifetime cost-effectiveness of published adherence-improving interventions for antihypertensive and lipid-lowering medications

OBJECTIVE

 We sought to compare the cost-effectiveness of different interventions that have been shown to improve adherence with antihypertensive and lipid-lowering therapy, by combining a burden of nonadherence model framework with literature-based data on adherence-improving interventions.

METHODS

  MEDLINE was reviewed for studies that evaluated ≥1 adherence intervention compared with a control, used an adherence measure other than self-report, and followed patients for ≥6 months. Effectiveness was assessed as Relative Improvement, ratio of adherence with an intervention versus control. Costs, standardized to 12 months and adjusted to 2007 US$, and effectiveness estimates for each intervention were entered into a previously published model designed to measure the burden of nonadherence with antihypertensive and lipid-lowering medications, in a hypertensive population. Outputs included direct medical costs and incremental costs per quality-adjusted life-year (QALY) gained.

RESULTS

 After screening, 23 eligible adherence-improving interventions were identified from 18 studies. Relative Improvement ranged from 1.13 to 3.60. After eliminating more costly/less effective interventions, two remained. Self-monitoring, reminders, and educational materials incurred total health-care costs of $17,520, and compared with no adherence intervention, had an incremental cost-effectiveness ratio (ICER) of $4984 per QALY gained. Pharmacist/nurse management incurred total health-care costs of $17,896, and versus self-monitoring, reminders, and education had an ICER of $6358 per QALY gained.

CONCLUSIONS

 Of published interventions shown to improve adherence, reminders and educational materials, and a pharmacist/nurse management program, appear to be cost-effective and should be considered before other interventions. Understanding relative cost-effectiveness of adherence interventions may guide design and implementation of efficient adherence-improving programs.

The cost and effectiveness of adherence-improving interventions for antihypertensive and lipid-lowering drugs*

AIMS

Adherence to cardiovascular medications is poor. Accordingly, interventions have been proposed to improve adherence. However, as intervention-associated costs are rarely considered in full, we sought to review the effectiveness and costs associated with different adherence-improving interventions for cardiovascular disease therapies.

METHODS

We reviewed MEDLINE to update a prior review of interventions to improve adherence with antihypertensive and/or lipid-lowering therapy covering January 1972 to June 2002, to add studies published from July 2002 to October 2007. Eligible studies evaluated > or = 1 intervention compared with a control, used measures other than self-report, reported significant improvement in adherence and followed patients for > or = 6 months. Effectiveness was measured as relative improvement (RI), the ratio of adherence in the intervention group to the control group. Costs were calculated based on those reported in the analysis, if available or estimated based on resource use described. All costs were truncated to 6 months and adjusted to 2007 US$.

RESULTS

Of 755 new articles, five met all eligibility criteria. Combining with the prior review gave 23 interventions from 18 studies. RI in adherence ranged from 1.11 to 4.65. Six-month intervention costs ranged from $10 to $142 per patient. Reminders had the lowest effectiveness (RI: 1.11-1.14), but were least costly ($10/6 months). Case management was most effective (RI: 1.23-4.65), but the most costly ($90-$130/6 months).

CONCLUSIONS

Generally, we found a positive association between intervention costs and effectiveness. Therefore, consideration of intervention costs, along with the benefits afforded to adherence, may help guide the design and implementation of adherence-improving programs.

Systematic review and meta-analysis of real-world adherence to drug therapy for osteoporosis

OBJECTIVE

To quantify the adherence of patients to drug therapy for osteoporosis in real-world settings via a systematic review and meta-analysis of observational studies.

METHODS

The PubMed and Cochrane databases were searched for English-language observational studies published from January 1, 1990, to February 15, 2006, that assessed patient adherence to drug therapy for osteoporosis using the following medical subject headings and keywords: drug therapy, medication adherence, medication persistence, medication possession ratio, patient compliance, and osteoporosis. Studies were stratified into 3 groups: persistence (how long a patient continues therapy), compliance (how correctly, in terms of dose and frequency, a patient takes the medication), and adherence (a combination of persistence and compliance). A random-effects model was used to pool results from the selected studies.

RESULTS

Twenty-four studies were included in the meta-analysis. The pooled database-derived persistence rate was 52% (95% confidence interval [CI], 44%-59%) for treatment lasting 1 to 6 months, 50% (95% CI, 37%-63%) for treatment lasting 7 to 12 months, 42% (95% CI, 20%-68%) for treatment lasting 13 to 24 months, returning to 52% (95% CI, 45%-58%) for treatment lasting more than 24 months. Pooled adherence rates decreased from 53% (95% CI, 52%-54%) for treatment lasting 1 to 6 months to 43% for treatment lasting 7 to 12 months (95% CI, 38%-49%) or 13 to 24 months (43%; 95% CI, 32%-54%). The pooled refill compliance estimate was 68% (95% CI, 63%-72%) for treatment lasting 7 to 12 months and 68% (95% CI, 67%-69%) for treatment lasting 13 to 24 months. The pooled self-reported compliance rate was 62% (95% CI, 48%-75%) for treatment lasting 1 to 6 months and 66% (95% CI, 45%-81%) for treatment lasting 7 to 12 months.

CONCLUSION

One-third to half of patients do not take their medication as directed. Nonadherence occurs shortly after treatment initiation. Terms and definitions need to be standardized to permit comparability of technologies designed to improve patient adherence. Prospective trials are needed to assess the relationship between adherence and patient outcomes.