Revisiting the medication possession ratio threshold for adherence in lipid management

The hypoglycemic effects of Juglans regia L. internal septum in type 2 diabetic patients: A double-blind, randomized, placebo-controlled clinical trial

Introduction

The internal septum of J.regia is traditionally used to control diabetes, and its effectiveness has been shown in animal studies. Accordingly, human clinical trials are needed to confirm its effectiveness on hemoglobin A1c (HbA1c), fasting blood sugar (FBS), blood insulin level, and insulin resistance as a complementary for better control of type 2 diabetes.

Methods

This study was a randomized, double-blinded, controlled trial. The lyophilized powder of extract of the internal septum of J.regia was used to fill the capsules. Sixty type 2 diabetic patients were randomly divided into two groups. 500 mg capsules three times daily before meal was added to their routine drug regimen, and HbA1c, FBS, and blood insulin level were checked at the baseline and after three months.

Results

Sixty patients completed the study. The mean(±SD) age of patients was 49.1(10.2) and 50.9(12.7) years in the placebo and J.regia groups, respectively. We observed that J.regia internal septum increases the level of HbA1c by about 0.02 units, but this effect was not significant (MD=0.02,95%CI=-0.36 to 0.40, P=0.93). Regarding the impact of capsules on insulin level, it seems that J.regia-containing capsules can raise insulin level by one unit. However, it was not significant (MD=1.01,95%CI=-0.86 to 2.88, P=0.28). As for FBS, it can cause a decrease of four units, but this effect is also not significant (MD=-3.98,95%CI=-18.33 to 10.37, P=0.58).

Conclusion

Based on our study, the internal septum of J.regia has no significant effect on HbA1c, FBS, and insulin resistance. Moreover, no specific adverse reaction was observed in any of the patients.

Long-Term Nonoperative Management is Associated With Lower Mean 9-Year Follow-Up Survival Compared to Total Knee Arthroplasty in Knee Osteoarthritis Patients-Survival Analysis of a Nationwide South Korean Cohort

BACKGROUND

Total knee arthroplasty (TKA) and medications are both considered as a treatment for knee osteoarthritis. However, the impact of the TKA on long-term survival remains controversial. This study aimed to compare 9-year follow-up survival between a TKA group with a nonoperative medication group.

METHODS

From 2007 to 2009, knee osteoarthritis patients were divided into TKA (N = 2,228) and nonoperative medication (N = 76,430) groups, and followed for up to 9 years. The hazard ratio (HR) and subdistribution HR (SHR) were derived from Cox proportional hazards regressions and Fine and Gray analyses, respectively.

RESULTS

The TKA group had a significantly lower adjusted mortality rate (adjusted HR , 0.78, 95% confidence interval [CI], 0.68-0.9) than the nonoperative medication group. Dose-response relationship between medication possession ratio and mortalities for overall (adjusted HR , 1.02; 95% CI, 1.01-1.04) and cardiovascular (CV) death (adjusted SHR, 1.03; 95% CI, 1.01-1.05) was also found. Also, there were significant interactions that indicate stronger protective survival effects of the TKA in several covariates: age >75 years (P = .04 for overall; P = .009 for CV), hypertension (P = .006 for overall), and ischemic heart disease (P = .009 for CV).

CONCLUSIONS

This study suggests that TKA patients had better mean 9-year follow-up survival than the nonoperative medication group after adjusting for baseline differences. For overall death, including CV death, adjusted mortality rates were higher in the medication group and showed a dose-response relationship. Specifically, the protective effect of the TKA for overall or CV deaths was found to be higher for age >75, hypertension, or ischemic heart disease patients.

LEVEL OF EVIDENCE

III.

What is the Statin Possession Ratio Cut-Off Which Identifies Those at Increased Risk Following Acute Coronary Syndrome (ANZACS-QI 68)?

AIMS

More optimal dispensing of statins is associated with greater cholesterol lowering; however, it is not known whether this translates to improved outcomes following acute coronary syndrome (ACS). The aim of this study was to assess the association between various levels of statin adherence and outcomes following ACS.

METHODS

Patients hospitalised with ACS who underwent coronary angiography between 2014-2018 were identified from the All New Zealand ACS Quality Improvement (ANZACS-QI) registry. Medication possession ratio (MPR) was used to assess statin adherence and calculated over 1 year post-discharge using linked pharmaceutical dispensing datasets. Optimal, adequate and suboptimal adherence was defined as an MPR of ≥1.0, 0.8-0.99 and 0-0.79, respectively. A combined outcome of all-cause mortality and rehospitalisation for atherosclerotic disease was identified from 1 year post-discharge through September 2021. Cox proportional hazard models were used to adjust for confounding variables.

RESULTS

Of the 30,452 patients, 68% had optimal adherence, 15% adequate adherence and 16% had suboptimal adherence to statins. Mean follow-up was 3.6 years. Those with suboptimal adherence had a higher adjusted risk of the combined outcome compared with those with optimal adherence (HR 1.18, 95% CI 1.11-1.26). There was no significant difference in adjusted outcome between those with optimal and adequate adherence (HR 0.99, 95% CI 0.92-1.06).

CONCLUSIONS

Suboptimal statin adherence following ACS is associated with an increased risk of mortality and rehospitalisation. An MPR cut-off of 0.8 seems reasonable to identify those at higher risk of cardiovascular events that could benefit the most from interventions to improve statin adherence and is appropriate as a target for quality improvement programs.

Impact of the First SARS-CoV-2 Lockdown on Adherence to Biological Treatment in Patients with Immune-Mediated Inflammatory Diseases in the Netherlands

PURPOSE

During the SARS-CoV-2 pandemic, national and international societies have recommended continuing biological agents in patients with immune-mediated inflammatory diseases (IMID) in the absence of SARS-CoV-2 symptoms. However, adherence to biological treatment might decrease, because these recommendations contradict patients' beliefs. Especially an increased concern about side effects could have influenced the adherence to biological treatment during the first lockdown. The primary objective was to investigate the impact of the first SARS-CoV-2 lockdown on adherence to biological treatment in IMID patients.

PATIENTS AND METHODS

In this prospective cohort study, IMID patients who received a biological agent before and during the first SARS-CoV-2 lockdown (March 2020- June 2020) were included. Patients were excluded if they did not complete the medication adherence report scale-5 (MARS-5) questionnaire at ≥1 visit before the lockdown and ≥1 visit during the lockdown. Adherence to biological treatment was measured with the MARS-5 and Medication Possession Ratio (MPR).

RESULTS

We included 157 IMID patients. The percentage of adherent patients, defined as MARS-5 score >21, was significantly lower during the lockdown compared to the period before the lockdown (88.5% vs 84.1%, p<0.001). Additionally, the overall percentage of adherent patients during the lockdown based on the MPR ≥90% was significantly lower compared to adherence based upon the MARS-5 (65.1% vs 84.1%, p<0.001).

CONCLUSION

This study showed that the first SARS-CoV-2 lockdown negatively impacts adherence to biological treatment in IMID patients. Therefore, treating physicians should be aware of this problem to minimize the potential harmful effects of non-adherence.

Association Between Antidepressant Use and Adherence to Anti-hyperglycemic Medications in Adults With Type 2 Diabetes and Depression: A Retrospective Cohort Study

OBJECTIVES

Depression is a known risk factor for poor medication adherence, but it is unclear whether depression treatment affects adherence rates. In this study, we examined the association between pharmacologic treatment of a new depressive episode and subsequent adherence to oral anti-hyperglycemic medications.

METHODS

In this retrospective cohort study we used administrative health data to follow adult new metformin users in Alberta, Canada, between 2008 and 2018. Depressive episodes starting ≥1 year after metformin initiation were identified and individuals starting antidepressant treatment within the first 90 days were compared with those who did not. The proportion of days covered (PDC) with oral anti-hyperglycemic medications in the subsequent year (days 91 to 455) was used to estimate adherence. The association between antidepressant treatment and poor adherence (PDC<0.8) was examined using multivariate logistic regression models.

RESULTS

A new depressive episode occurred in 6,201 people, with a mean age of 56.0 (standard deviation [SD], 15.4) years. Of this cohort, 3,303 (53.2%) were women. Mean PDC was 0.55 (SD, 0.41); 924 (57.0%) of 1,621 people who started antidepressant treatment and 2,709 (59.2%) of 4,580 controls had poor adherence (p=0.13). After adjusting for baseline comorbidities and other characteristics, antidepressant treatment was associated with a lower likelihood of poor adherence (adjusted odds ratio, 0.85; 95% confidence interval, 0.75 to 0.96; p=0.007).

CONCLUSIONS

Although overall adherence to anti-hyperglycemic medications was low after onset of a depressive episode, antidepressant treatment was associated with a lower likelihood of poor adherence.

Clinical efficacy of mebeverine for persistent nocturnal enuresis after orthotopic W-neobladder

OBJECTIVES

To investigate the efficacy of mebeverine for nocturnal incontinence in male patients with an ileal orthotopic bladder substitute (OBS).

PATIENTS AND METHODS

A randomised controlled trial was carried out for adult male patients who were nocturnal incontinent. Patients were allocated to receive mebeverine 200 mg or placebo once a day in the evening for 3 months. The primary outcome was to compare the continence status between groups, assessed by the urinary domain of the Bladder Cancer Index (BCI) and pad usage. The secondary outcomes were to assess the safety of mebeverine.

RESULTS

There were 55 patients in the placebo group and 58 in mebeverine group who completed the follow-up. The median (interquartile range) interval between OBS surgery and starting treatment was 9 (4-13) years in the placebo group and 9 (6-13) years in the mebeverine group. The mean (SD) 3-month urinary domain score of the BCI was 70.8 (5.6) and 86.4 (14.2) in the placebo and mebeverine groups, respectively (P < 0.001). At 3 months, 54 (98.2%) and 26 (44.8%) patients required the use of a night-time pad in the placebo and mebeverine groups, respectively. Mebeverine reduced the risk of pad use by 53.4% (95% confidence interval 40.1-66.6; P < 0.001). Constipation occurred in one (2.1%) and three (5.8%) patients in the placebo and mebeverine groups, respectively; abdominal distention occurred in two (3.8%) of the patients in the mebeverine group (P = 0.25).

CONCLUSION

Mebeverine decreases night-time pad use and improves the quality of life in male patients with an ileal OBS and is associated with minimal adverse events.

Health-related quality of life and its predictors among adults living with HIV/AIDS and receiving antiretroviral therapy in Pakistan

BACKGROUND

Health-related quality of life (HRQoL) is considered to be the fourth 90 of UNAIDS 90-90-90 target to monitor the effects of combination antiretroviral therapy (ART). ART has significantly increased the life expectancy of people living with HIV/AIDS (PLWHA). However, the impact of chronic infection on HRQoL remains unclear, while factors influencing the HRQoL may vary from one country to another. The current study aimed to assess HRQoL and its associated factors among PLWHA receiving ART in Pakistan.

METHODS

A cross-sectional descriptive study was conducted among PLWHA attending an ART centre of a tertiary care hospital in Islamabad, Pakistan. HRQoL was assessed using a validated Urdu version of EuroQol 5 dimensions 3 level (EQ-5D-3L) and its Visual Analogue Scale (EQ-VAS).

RESULTS

Of the 602 patients included in the analyses, 59.5% (n = 358) reported no impairment in self-care, while 63.1% (n = 380) were extremely anxious/depressed. The overall mean EQ-5D utility score and visual analogue scale (EQ-VAS) score were 0.388 (SD: 0.41) and 66.20 (SD: 17.22), respectively. Multivariate linear regression analysis revealed that the factors significantly associated with HRQoL were: female gender; age  > 50 years; having primary and secondary education;  > 1 year since HIV diagnosis; HIV serostatus AIDS-converted; higher CD 4 T lymphocytes count; detectable viral load; and increased time to ART.

CONCLUSIONS

The current findings have shown that PLWHA in Pakistan adherent to ART had a good overall HRQoL, though with significantly higher depression. Some of the factors identified are amenable to institution-based interventions while mitigating depression to enhance the HRQoL of PLWHA in Pakistan. The HRQoL determined in this study could be useful for future economic evaluation studies for ART and in designing future interventions.

Statin adherence is lower in primary than secondary prevention: A national follow-up study of new users

BACKGROUND

Maintaining adherence to statins reduces the risk of an initial cardiovascular disease (CVD) event in high-risk individuals (primary prevention) and additional CVD events following the first event (secondary prevention). The effectiveness of statin therapy is limited by the level of adherence maintained by the patient. We undertook a nationwide study to compare adherence and discontinuation in primary and secondary prevention patients.

METHODS

Dispensing data from New Zealand community pharmacies were used to identify patients who received their first statin dispensing between 2006 and 2011. The Medication Possession Ratio (MPR) and proportion who discontinued statin medication was calculated for the year following first statin dispensing for patients with a minimum of two dispensings. Adherence was defined as an MPR ≥ 0.8. Previous CVD was identified using hospital discharge records. Multivariable logistic regression was used to control for demographic and statin characteristics.

RESULTS

Between 2006 and 2011 289,666 new statin users were identified with 238,855 (82.5%) receiving the statin for primary prevention compared to 50,811 (17.5%) who received it for secondary prevention. The secondary prevention group was 1.55 (95% CI 1.51-1.59) times as likely to be adherent and 0.67 (95% CI 0.65-0.69) times as likely to discontinue statin treatment than the primary prevention group. An early gap in statin coverage increased the odds of discontinuing statin treatment.

CONCLUSION

Adherence to statin medication is higher in secondary prevention than primary prevention. Within each group, a range of demographic and treatment factors further influences adherence.

Association of Self-Reported Medication Adherence with Potentially Inappropriate Medications in Elderly Patients: A Cross-Sectional Pilot Study

BACKGROUND

Polypharmacy (PP) and potentially inappropriate medications (PIMs) cause problematic drug-related issues in elderly patients; however, little is known about the association between medication adherence and PP and PIMs. This study evaluated the association of self-reported medication adherence with PP and PIMs in elderly patients.

METHODS

A cross-sectional pilot study was conducted using data collected from electronic medical records of 142 self-administering patients aged ≥65 years, excluding emergency hospitalization cases. Self-reported medication adherence was assessed using the visual analogue scale (VAS).

RESULTS

Of the 142 patients, 91 (64.1%) had PP and 80 (56.3%) used at least one PIM. In univariate analysis, patients with a VAS score of 100% had a significantly higher number of female patients and ≥1 PIM use compared to other patients. We found no association between the VAS score and PP. In multivariable analysis, the use of PIMs was significantly associated with a VAS score of 100% (odds ratio = 2.32; 95% confidence interval = 1.16-4.72; p = 0.017).

CONCLUSIONS

Use of PIMs by elderly patients is significantly associated with self-reported medication adherence. Pharmacists should pay more attention to prescribed medications of self-administering elderly patients in order to improve their prescribing quality.

Long-Acting Injectable Statins-Is It Time for a Paradigm Shift?

In recent years, advances in pharmaceutical processing technologies have resulted in development of medicines that provide therapeutic pharmacokinetic exposure for a period ranging from weeks to months following a single parenteral administration. Benefits for adherence, dose and patient satisfaction have been witnessed across a range of indications from contraception to schizophrenia, with a range of long-acting medicines also in development for infectious diseases such as HIV. Existing drugs that have successfully been formulated as long-acting injectable formulations have long pharmacokinetic half-lives, low target plasma exposures, and low aqueous solubility. Of the statins that are clinically used currently, atorvastatin, rosuvastatin, and pitavastatin may have compatibility with this approach. The case for development of long-acting injectable statins is set out within this manuscript for this important class of life-saving drugs. An overview of some of the potential development and implementation challenges is also presented.

Systematic review of the predictors of statin adherence for the primary prevention of cardiovascular disease

INTRODUCTION

Previous research has shown that statin adherence for the primary prevention of CVD is lower compared to secondary prevention populations. Therefore the aim of this systematic review was to review predictors of statin adherence for the primary prevention of CVD.

METHODS

A systematic search of papers published between Jan 1984 and May 2017 was conducted in PubMed, PsycINFO, EMbase and CINAHL databases. A study was eligible for inclusion if; 1) it was a study of the general population or of patients with familial hypercholesterolemia, hypertension, diabetes or arthritis; 2) statins were prescribed; 3) adherence was defined and measured as the extent to which patients followed their statin regimen during the period of prescription, and 4) it was an original trial or observational study (excluding case reports). A study was subsequently excluded if 1) results were not presented separately for primary prevention; 2) it was a trial of an intervention (for example patient education). Papers were reviewed by two researchers and consensus agreed with a third. A quality assessment (QA) tool was used to formally assess each included article. To evaluate the effect of predictors, data were quantitatively and qualitatively synthesised.

RESULTS

In total 19 studies met the inclusion criteria and nine were evaluated as high quality using the QA tool. The proportion of patients classed as "adherent" ranged from 17.8% to 79.2%. Potential predictors of statin adherence included traditional risk factors for CVD such as age, being male, diabetes and hypertension. Income associated with adherence more strongly in men than women, and highly educated men were more likely and highly educated women less likely to be adherent. Alcohol misuse and high BMI associated with non-adherence. There was no association between polypharmacy and statin adherence. The evidence base for the effect of other lifestyle factors and health beliefs on statin adherence was limited.

CONCLUSION

Current evidence suggests that patients with more traditional risk factors for CVD are more likely to be adherent to statins. The implications for future research are discussed.

Is There a Threshold for Medication Adherence? Lessons Learnt From Electronic Monitoring of Drug Adherence

Medication adherence is a well-recognized problem in the management of patients with chronic diseases needing a long-term pharmacotherapy. While fighting against non-adherence, an important question frequently arises, i.e., how much adherence is enough to obtain the full treatment benefits? Most studies having attempted to answer this question have used large pharmacy records and health care databases to quantify the percentage of days covered by the prescribed treatment and hence deduce a threshold below which there appears to be fewer benefits from therapy. In the present paper, the use of data obtained using electronic monitoring of adherence is discussed as another means to assess adherence thresholds with a particular emphasis on hypertension. The data show that even with the use of electronic monitoring of adherence, which provides a comprehensive dosing history, it is extremely difficult to define an adherence threshold in hypertension. This is due to many factors that need to be taken into account, including not only the pattern of patients’ adherence and their clinical and environmental characteristics, but also the pharmacological characteristics of the prescribed drugs, the severity of the disease and many others. To determine adherence cut-offs more precisely, specific protocols should be designed to answer the question in various clinical conditions. These protocols should be conducted in well-defined patients’ groups, they should use the most reliable methods to measure adherence providing if possible a detailed dosing history perhaps combined with drugs levels in blood or urine. These studies should also choose the best methods to measure clinical endpoints, such as ambulatory blood pressure monitoring or home blood pressure in the case of hypertension. One important aspect is that datasets should be solid and large enough to be able to analyze adherence data as a continuous variable using newly developed mathematical models including new metrics catching the complexity of adherence. The rapid development of new technologies like devices, connectivity, and analytics, will probably provide new solutions to improve our ability to define valid and clinically useful adherence thresholds in various therapeutic areas.

Estimating Adherence Based on Prescription or Dispensation Information: Impact on Thresholds and Outcomes. A Real-World Study With Atrial Fibrillation Patients Treated With Oral Anticoagulants in Spain

Objective: To estimate drug exposure, Proportion of Days Covered (PDC) and percentage of patients with PDC ≥ 80% from a cohort of atrial fibrillation patients initiating oral anticoagulant (OAC) treatment. We employed three different approaches to estimate PDC, using either data from prescription and dispensing (PD cohort) or two common designs based on dispensing information only, requiring at least one (D1) or at least two (D2) refills for inclusion in the cohorts. Finally, we assessed the impact of adherence on health outcomes according to each method. Methods: Population-based retrospective cohort of all patients with Non Valvular Atrial Fibrillation (NVAF), who were newly prescribed acenocoumarol, apixaban, dabigatran or rivaroxaban from November 2011 to December 2015 in the region of Valencia (Spain). Patients were followed for 12 months to assess adherence using three different approaches (PD, D1 and D2 cohorts). To analyze the relationship between adherence (PDC ≥ 80) defined according to each method of calculation and health outcomes (death for any cause, stroke or bleeding) Cox regression models were used. For the identification of clinical events patients were followed from the end of the adherence assessment period to the end of the available follow-up period. Results: PD cohort included all patients with an OAC prescription (n = 38,802), D1 cohort excluded fully non-adherent patients (n = 265) and D2 cohort also excluded patients without two refills separated by 180 days (n = 2,614). PDC ≥ 80% ranged from 94% in the PD cohort to 75% in the D1 cohort. Drug exposure among adherent (PDC ≥ 80%) and non-adherent (PDC < 80%) patients was different between cohorts. In adjusted analysis, high adherence was associated with a reduced risk of death [Hazard Ratio (HR): from 0.82 to 0.86] and (except in the PD cohort) the risk for ischemic stroke (HR: from 0.61 to 0.64) without increasing the risk of bleeding. Conclusion: Common approaches to assess adherence using measures based on days' supply exclude groups of non-adherent patients and, also, misattribute periods of doctors' discontinuation to patient non-adherence, misestimating adherence overall. Physician-initiated discontinuation is a major contributor to reduced OAC exposure. When using the PDC80 threshold, very different groups of patients may be classified as adherent or non-adherent depending on the method used for the calculation of days' supply measures. High adherence and high exposure to OAC treatment in NVAF patients is associated with better health outcomes.

A Systematic Review of Medication Adherence Thresholds Dependent of Clinical Outcomes

Background: In pharmacotherapy, the achievement of a target clinical outcome requires a certain level of medication intake or adherence. Based on Haynes's early empirical definition of sufficient adherence to antihypertensive medications as taking ≥80% of medication, many researchers used this threshold to distinguish adherent from non-adherent patients. However, we propose that different diseases, medications and patient's characteristics influence the cut-off point of the adherence rate above which the clinical outcome is satisfactory (thereafter medication adherence threshold). Moreover, the assessment of adherence and clinical outcomes may differ greatly and should be taken into consideration. To our knowledge, very few studies have defined adherence rates linked to clinical outcomes. We aimed at investigating medication adherence thresholds in relation to clinical outcomes.

Method: We searched for studies that determined the relationship between adherence rates and clinical outcomes in the databases PubMed, Embase^Ⓡ and Web of Science™ until December 2017, limited to English-language. Our outcome measure was any threshold value of adherence. The inclusion criteria of the retrieved studies were (1) any measurement of medication adherence, (2) any assessment of clinical outcomes, and (3) any method to define medication adherence thresholds in relation to clinical outcomes. We excluded articles considered as a tutorial. Two authors (PB and IA) independently screened titles and abstracts for relevance, reviewed full-texts, and extracted items. The results of the included studies are presented qualitatively.

Result: We analyzed 6 articles that assessed clinical outcomes linked to adherence rates in 7 chronic disease states. Medication adherence was measured with Medication Possession Ratio (MPR, n = 3), Proportion of Days Covered (PDC, n = 1), both (n = 1), or Medication Event Monitoring System (MEMS). Clinical outcomes were event free episodes, hospitalization, cortisone use, reported symptoms and reduction of lipid levels. To find the relationship between the targeted clinical outcome and adherence rates, three studies applied logistic regression and three used survival analysis. Five studies defined adherence thresholds between 46 and 92%. One study confirmed the 80% threshold as valid to distinguish adherent from non-adherent patients.

Conclusion: The analyzed studies were highly heterogeneous, predominantly concerning methods of calculating adherence. We could not compare studies quantitatively, mostly because adherence rates could not be standardized. Therefore, we cannot reject or confirm the validity of the historical 80% threshold. Nevertheless, the 80% threshold was clearly questioned as a general standard.

The Adherence Rate Threshold is Drug Specific

Introduction

Patient adherence to a medication regimen is usually expressed as an adherence rate, defined as the proportion of prescribed doses actually taken. An adherence rate threshold, above which the therapeutic effect is maintained, is typically assigned an arbitrary value, commonly 0.8.

Objective

Here, we determined the value of the adherence rate threshold objectively in different drugs of the same class, using statins as an example.

Methods

We used pharmacokinetic/pharmacodynamic (PK/PD) modeling to predict serum levels of low-density lipoprotein cholesterol (LDL-C) in patients taking simvastatin 20 mg or atorvastatin 5 mg once daily for 30 days. LDL-C reduction was modeled for adherence rates of 1.0, 0.8, 0.6, 0.4, and 0.2. The results were expressed as the percentage of time spent at the LDL-C goal (< 70 mg/dL). The adherence rate threshold was defined as the minimum adherence rate that resulted in the same amount of time at goal as perfect adherence (i.e., a rate of 1.0).

Results

For simvastatin, an adherence rate of 0.8 resulted in a significant decrease in time at the LDL-C goal compared to perfect adherence (54.8% versus 85.1%; P < 0.001), and rates < 0.8 resulted in progressively less time at goal. For atorvastatin, the rates of 0.8 and 0.6 resulted in essentially the same amount of time at goal as perfect adherence (87.8% and 87.7%, respectively, versus 88.1%; P > 0.05 for both), with less time at goal only occurring at rates ≤ 0.4 (P < 0.001). Thus, the adherence rate thresholds are > 0.8 for simvastatin and between 0.4 and 0.6 for atorvastatin.

Conclusion

These results indicate that a value of 0.8 cannot be applied universally.

Relationship Between Adherence Rate Threshold and Drug 'Forgiveness'

The medication adherence rate (A) is the proportion of prescribed drug doses consumed within a given time period. It is often assumed that there is an adherence rate threshold (A _th) at or above which the therapeutic effect of the medication is maintained. Drug forgiveness (F) is the number of consecutive doses that can be missed while still maintaining a therapeutic effect. At a given value for A, the therapeutic effect of the drug will be continuously maintained if there is no possibility of >F missed doses. Hence, for a once-daily drug prescribed for N days, A _th and F are related by the formula, A _th = (N - F)/N. At adherence rates below A _th the probability of maintaining the therapeutic effect is equal to the probability of there being no instances of >F consecutive missed doses. Since F is a function of the duration of the drug effect (D) and D varies depending on the specific drug's pharmacokinetic/pharmacodynamic properties, there is no universal A _th applicable to all drugs.

Comparison of adherence to generic multi-tablet regimens vs. brand multi-tablet and brand single-tablet regimens likely to incorporate generic antiretroviral drugs by breaking or not fixed-dose combinations in HIV-infected patients

Adherence to antiretroviral (ARV) is crucial to achieve viral load suppression in HIV-infected patients. This study aimed to compare adherence to generic multi-tablet regimens (MTR) vs. brand MTR likely to incorporate ARV drugs without breaking fixed-dose combinations (FDC) and brand single-tablet regimens (STR) likely to incorporate generics by breaking the FDC. Patients aged of 18 years or over exposed to one of the generic or the brand of lamivudine (3TC), zidovudine/lamivudine (AZT/TC), nevirapine (NVP), or efavirenz (EFV), or the brand STR of efavirenz/emtricitabine/tenofovir (EFV/FTC/TDF). Adherence was measured by medication possession ratio (MPR) using both defined daily dose (DDD) and daily number of tablet recommended for adults (DNT). Adherence to generic MTR vs. brand MTR and brand STR was compared using Kruskal-Wallis. The overall median adherence was 0.97 (IQR 0.13) by DNT method and 0.97 (0.14) by DDD method. Adherence in patients exposed to generic MTR (n = 165) vs. brand MTR (n = 481) and brand STR (n = 470) was comparable by DNT and DDD methods. In conclusion, adherence to generic MTR was high and comparable with adherence to brand MTR and to STR. Utilization of DDD instead DNT to measure the MPR led to small but nonsignificant difference that has no clinical impact.

Eye Drop Dispenser Type and Medication Possession Ratio in Patients With Glaucoma: Single-Use Containers Versus Multiple-Use Bottles

PURPOSE

To determine whether the consumption of topical glaucoma medication is influenced by the type of eye drop dispenser.

DESIGN

Retrospective cohort study.

METHODS

We examined 366 patients with open-angle glaucoma or ocular hypertension who were bilaterally treated with 0.0015% tafluprost or 2% dorzolamide/0.5% timolol fixed combination (DTFC). The patients were grouped by the type of dispenser and content of eye drops used: (1) tafluprost in bottles (T-Bottle group); (2) tafluprost in unit-dose pipettes (T-Unit group); (3) DTFC in bottles (C-Bottle group); and (4) DTFC in unit-dose pipettes (C-Unit group). We evaluated the medication possession ratio (MPR) among groups, and factors associated with over-consumption (MPR > 1.2) or under-consumption (MPR < 0.8) in multinomial logistic regression.

RESULTS

The mean MPR was 1.49 (range, 0.69-2.91) in the T-Bottle group, 0.91 (range, 0.32-1.27) in the T-Unit group, 1.25 (range, 0.51-2.60) in the C-Bottle group, and 0.96 (range, 0.36-1.60) in the C-Unit group. The Bottle groups demonstrated higher mean values and wider ranges of MPR compared to the Unit groups. The MPR interval at which the largest number of patients were found was 1.0-1.4 in the Bottle groups and 0.8-1.2 in the Unit groups. Bottle-type dispenser (odds ratio [OR] 64.02), tafluprost medication (OR 2.84), and older age (OR 1.03) were associated with over-consumption, whereas no factor was correlated with under-consumption.

CONCLUSIONS

The type of eye drop dispenser affects the consumption of glaucoma medication. Physicians should consider the type of eye drop dispenser when assessing glaucoma medication adherence.

Defining an Optimal Adherence Threshold for Patients Taking Subcutaneous Anti-TNFs for Inflammatory Bowel Diseases

OBJECTIVES

In patients with inflammatory bowel disease (IBD) using biological therapy, non-adherence leads to anti-drug antibody formation and reduced effectiveness. Little is known about the optimal level of adherence in IBD patients on biologic therapy. We aimed to identify the association between adherence and disease flare and determine an optimal level of adherence.

METHODS

We analyzed claims data for IBD patients prescribed adalimumab (ADA) and certolizumab (CZP) from the Truven Health MarketScan Commercial Claims and Encounters database from 2009 to 2013. Adherence was calculated using the medication possession ratio (MPR) from initiation until flare occurrence. A disease flare was defined as any hospitalization or new steroid prescription>90-days after drug initiation. The optimal MPR was determined using log-rank testing. The association between the optimal MPR and flare was assessed using multivariable Cox-Proportional hazards ratio.

RESULTS

There were 6,048 patients who were prescribed ADA (n=5,325) or CZP (n=723) for IBD. The average age was 41 years (±15) and 54% were female. The optimal MPR identified was 0.86 for ADA and 0.87 for CZP; 24% of the patients were below this level. Adjusting for age, gender, and concomitant medications at initiation, patients who were adherent above these levels had a 25% lower risk of flare for ADA (HR: 0.75, 95%CI: 0.67-0.83, P<0.01) and 41% lower risk for CZP (HR: 0.59, 95%CI: 0.46-0.76, P<0.01).

CONCLUSIONS

Patients who delay refills >2 days on average every 2 weeks of their subcutaneous biologics have significantly increased risk of flare. Further studies to improve adherence among those patients who consistently delay medication use are necessary.

Adherence and dosing interval of subcutaneous antitumour necrosis factor biologics among patients with inflammatory arthritis: analysis from a Canadian administrative database

OBJECTIVES

Subcutaneous tumour necrosis factor alpha TNFαinhibitors (SC-TNFis) such as golimumab (GLM), adalimumab (ADA), etanercept (ETA) and certolizumab pegol (CZP) have been used for many years for the treatment of inflammatory arthritis. Non-adherence to therapy is an important modifiable factor that may compromise patient outcomes. The aim of this analysis was to compare adherence and dosing interval of SC-TNFis in the treatment of people with inflammatory arthritis.

DESIGN

We used the IMS Brogan database combining both Canadian private and public drug plan databases of Ontario and Quebec. Target drugs included SC-TNFis for inflammatory arthritis. The index period was from 1 January 2010 to 30 June 2012 and patients were followed for 24 months through 30 June 2014. Inclusion criteria were adult patients newly prescribed a SC-TNFis with at least three prescriptions and retained on therapy at 24 months.Dosing regimens as per the product monographs were used to compare actual versus expected drug utilisation. The mean possession ratio was used as a marker for adherence. Patients who scored >80% were considered adherent. The average days between units was estimated by taking the total days on therapy and divided by the number of units the patient received.

RESULTS

4035 patients were included: 683 (16.9%), 1400 (34.7%), 1765 (43.7%) and 187 (4.6%) were treated with GLM, ADA, ETA and CZP, respectively. The proportion of adherent patients in the GLM cohort (n=595/683, 87%, p<0.0001) was greater compared with ADA (n=1044/1400, 75%), ETA (n=1285/1765, 73%) and CZP-treated patients (132/187, 71%). In addition, the number of patients receiving biological drug at a shorter dosing interval was similar between cohorts, and was 5%, 6%, 12% and 4% in GLM (≤26 days), ADA (≤12 days), ETA (≤6 days) and CZP-treated patients (≤12 days), respectively.

CONCLUSIONS

In this real-life administrative database, GLM had better adherence compared with other SC-TNFis.

The impact of incident depression on medication adherence in patients with type 2 diabetes

BACKGROUND

Depression has been correlated with suboptimal adherence to antidiabetic drugs (ADs). Most studies on this topic were cross-sectional; thus, the directionality of this relationship could not be established. The objective of this study was to measure the association between incident depression and AD nonadherence among newly treated patients with diabetes.

METHODS

We performed a population-based cohort study among new AD users using the Quebec public health insurance data. To avoid immortal time bias, we carried out depression diagnosis-time distribution matching by assigning a date of depression diagnosis to individuals without depression. Nonadherence (i.e.,<90% of days covered by≥1 AD) during the year following depression diagnosis (real or assigned date) was the outcome. Multivariate logistic regression analyses that adjusted for baseline adherence and other confounders were used to estimate the adjusted effect of depression on AD nonadherence.

RESULTS

Between 2000 and 2006, we identified 3,106 new AD users with a subsequent diagnosis of depression and 70,633 without depression, of which 52% and 49% became non-adherent to AD treatment, respectively. Among patients with depression, 52.0% were considered AD non-adherent in the year after depression diagnosis compared with 49.0% of matched patients without depression. Depression was associated with AD nonadherence after accounting for baseline adherence and other confounders with an adjusted odds ratio of 1.24 (95% confidence interval: 1.13-1.37).

CONCLUSIONS

The results suggest that depression is an independent risk factor for AD nonadherence. Patients with type 2 diabetes and depression might benefit from adherence-enhancing interventions.

Factors associated with antidiabetic medication non-adherence in patients with incident comorbid depression

AIM

To identify factors associated with antidiabetic drug (AD) non-adherence among patients with type 2 diabetes and depression.

STUDY DESIGN AND SETTINGS

We conducted a population-based retrospective cohort study among new AD users with a diagnosis of depression following AD initiation. We used public health insurance data from Quebec. The dependent variable was non-adherence (i.e., <90% of days covered by ≥1AD) in the year after a depression diagnosis. Different sociodemographic, clinical and medication-related variables were assessed as potential factors of non-adherence to AD treatment. We performed univariate and multivariate logistic regressions.

RESULTS

We identified 3106 new users of ADs with a diagnosis of depression between 2000 and 2006. Of these individuals, 52% were considered non-adherent to their ADs. Baseline non-adherence, younger age, the addition of another AD to the initial treatment, <4 drug claims, visits with several different physicians, high socioeconomic status, and a small number of diabetes complications were associated with AD non-adherence.

CONCLUSIONS

The factors identified in the present study may help clinicians recognize patients with type 2 diabetes and incident depression at increased risk for non-adherence. In these patients, close follow-up and targeted interventions could help improve adherence to AD treatment, improve glycemic control and reduce complications.

Prescribing patterns, adherence and LDL-cholesterol response of type 2 diabetes patients initiating statin on low-dose versus standard-dose treatment: a descriptive study

AIMS

The aim of this study was to describe and compare treatment modifications and discontinuation, adherence levels and response to treatment in patients with type 2 diabetes initiating on low-dose vs. standard-dose statin treatment.

METHODS

A 2-year follow-up cohort study was performed using data from the Groningen Initiative to Analyse Type 2 Diabetes Treatment (GIANTT) database in patients with type 2 diabetes initiating statin treatment between January 2007 and December 2012. First, we determined whether there were differences in treatment modifications and discontinuation after statin initiation between patients starting on a low-dose vs. standard-dose. Second, we looked at differences in adherence and LDL-cholesterol response after 2 years follow-up between these groups.

RESULTS

Around 22% of patients initiated statin treatment on a dose lower than recommended. More than half of them remained on a low dose during a 2-year follow-up period, whereas less than 15% received a dose increase. Of the patients initiating on standard-dose, also more than half remained on the same treatment during this period, whereas 8% received a dose decrease without subsequent increase. Over 25% of patients starting on low-dose or standard-dose treatment discontinued treatment, often within the first 180 days after initiation or after a first treatment change. Patients on low-dose treatment had lower adherence levels and were less likely to have adequate LDL-cholesterol response compared with patients on standard-dose after 2 years follow-up.

CONCLUSIONS

Current patterns of statin treatment in patients with type 2 diabetes are suboptimal, with discontinuation, inadequate adherence levels and lack of treatment intensification seen in those who had inadequate LDL-cholesterol response after 2 years of follow-up. Patients starting on low-dose had more treatment modifications, discontinuation and adherence problems as compared with those starting on standard-dose treatment, which calls for a closer look at the rationale of starting patients on low-dose statin treatment.

Effects of medication adherence on hospitalizations and healthcare costs in patients with schizophrenia in Thailand

Background:

This study was conducted to determine the impacts of medication adherence on hospitalization and direct healthcare cost in patients with schizophrenia in Thailand.

Methods:

A retrospective study was undertaken. Patients with schizophrenia aged 18–65 years who visited a University hospital and received antipsychotics from April 2011 to October 2011 were included. Propensity score–adjusted logistic regression was used to determine the impacts of medication adherence on schizophrenia-related and all-cause hospitalizations.

Results:

A total of 582 patients were included. Three out of 224 patients (1.3%) were hospitalized with schizophrenia in optimal adherence group, while 10 of 140 (7.1%) were hospitalized in under-adherence group, and 7 of 218 (3.2%) were hospitalized in over-adherence group. Based on propensity score–adjusted multivariate logistic regression, the adjusted odds ratio was 5.86 (95% confidence interval = 1.53–22.50) for schizophrenia-related hospitalization and 8.04 (95% confidence interval = 2.20–29.40) for all-cause hospitalization. The average annual direct healthcare costs in patients with optimal adherence, under-adherence, and over-adherence were US$371 ± US$836, US$386 ± US$734, and US$508 ± US$2168, respectively.

Conclusion:

An initiation of interventions to maintain optimal adherence in patients with schizophrenia would significantly impact the healthcare system.

The Medicines Advice Service Evaluation (MASE): a randomised controlled trial of a pharmacist-led telephone based intervention designed to improve medication adherence

AIM

To test the effectiveness of a tailored, pharmacist-led centralised advice service to improve adherence to patients on established medications.

METHODS

A parallel group randomised controlled trial was conducted. Patients prescribed at least one oral medication for type 2 diabetes and/or lipid regulation were eligible to participate. 677 patients of a mail-order pharmacy were recruited and randomised (340 intervention, 337 control). The intervention comprised two tailored telephone consultations with a pharmacist, 4-6 weeks apart, plus a written summary of the discussion and a medicines reminder chart. The primary outcome was self-reported adherence to medication at 6-month follow-up, collected via a postal questionnaire, analysed using generalised estimating equations. Secondary outcomes included prescription refill adherence, lipid and glycaemic control and patient satisfaction.

RESULTS

In intention-to-treat analysis 36/340 (10.6%) of the intervention group were non-adherent (<90% of medication taken in the past 7 days) at 6 months compared with 66/337 (19.6%) in the control group, yielding an unadjusted OR of 1.54 (95% CI 1.11 to 2.15, p=0.01). Analyses of dispensing data also showed that the odds of being classified as adherent (≥90%) were 60% greater for the intervention group compared with the control group (OR 1.60, 95% CI 1.14 to 2.24, p<0.01). In a subsample of patients who provided blood samples, glycaemic and lipid control did not differ significantly between groups (p=0.06 and p=0.24, respectively) but positive trends were observed. Ninety-two per cent of intervention group patients reported that they were satisfied with the service overall.

CONCLUSIONS

A telephone intervention, led by a pharmacist and tailored to the individuals' needs, can significantly improve medication adherence in patients with long-term conditions, using a mail-order pharmacy. Further work is needed to confirm a trend towards improved clinical outcome.

TRIAL REGISTRATION NUMBER

NCT01864239.

Racial Differences in Quality of Anticoagulation Therapy for Atrial Fibrillation (from the TREAT-AF Study)

The influence of race on quality of anticoagulation control is not well described. We examined the association between race, international normalized ratio (INR) monitoring intensity, and INR control in warfarin-treated patients with atrial fibrillation (AF). Using data from the Veterans Health Administration (VHA), we performed a retrospective cohort study of 184,161 patients with a new diagnosis of AF/flutter from 2004 to 2012 who received any VHA prescription within 90 days of diagnosis. The primary predictor was race, ascertained from multiple VHA and linked Medicare demographic files. The primary outcome was first-year and long-term time in therapeutic range (TTR) of INR 2.0 to 3.0. Secondary outcomes were INR monitoring intensity and warfarin persistence. Of the 116,021 patients who received warfarin in the cohort, INR monitoring intensity was similar across racial groups. However, TTR was lowest in blacks and highest in whites (first year 0.49 ± 0.23 vs 0.57 ± 0.21, p <0.001; long term 0.52 ± 0.20 vs 0.59 ± 0.18, p <0.001); 64% of whites and 49% of blacks had long-term TTR >55% (p <0.001). After adjusting for site and patient-level covariates, black race was associated with lower first-year and long-term TTRs (4.2% and 4.1% below the conditional mean, relative to whites; p <0.0001 for both). One-year warfarin persistence was slightly lower in blacks compared to whites (58% vs 60%, p <0.0001). In conclusion, in patients with AF anticoagulated with warfarin, differences in INR control are most evident among blacks, underscoring the need to determine if other types of intensive management or warfarin alternatives may be necessary to improve anticoagulation among vulnerable AF populations.

Adherence to standard-dose or low-dose statin treatment and low-density lipoprotein cholesterol response in type 2 diabetes patients

OBJECTIVE

To determine the association between adherence, dose and low-density lipoprotein (LDL) cholesterol response in patients with type 2 diabetes initiating statin treatment.

RESEARCH DESIGN AND METHODS

This cohort study was performed using data for 2007-2012 from the Groningen Initiative to Analyse Type 2 Diabetes Treatment (GIANTT) database. The association between adherence to a standard-dose statin and LDL cholesterol response was assessed using linear regression, adjusting for covariates. The effect of low-dose versus standard-dose was assessed in a propensity-score matched cohort. Adherence rates, defined as the proportion of days covered (PDC), were estimated between statin initiation and LDL outcome measurement.

MAIN OUTCOME MEASURE

LDL cholesterol level at follow-up.

RESULTS

The effect of adherence on LDL cholesterol response, measured in 2160 patients, was dependent on the baseline LDL cholesterol level. For patients with a baseline LDL cholesterol of 3.7 mmol/l and an adherence rate of 80%, a 40% reduction in LDL cholesterol was predicted. In the matched sample of 1144 patients, the treatment dose showed a difference in impact on the outcome for adherence rates higher than 50%. It was estimated that a patient with a baseline LDL cholesterol of 3.7 mmol/l will need an adherence rate of at least 76% on low-dose and 63% on standard-dose treatment to reach the LDL cholesterol target of 2.5 mmol/l.

LIMITATIONS

Adherence was measured as the PDC, which is known to overestimate actual adherence. Also, we were not able to adjust for lifestyle factors.

CONCLUSIONS

We determined the concurrent effect of treatment adherence and dose on LDL cholesterol outcomes. Given the adherence levels seen in clinical practice, diabetes patients initiating statin treatment are at high risk of not reaching the recommended cholesterol target, especially when they start on a low-dose statin.

Using machine learning to examine medication adherence thresholds and risk of hospitalization

BACKGROUND

Quality improvement efforts are frequently tied to patients achieving ≥80% medication adherence. However, there is little empirical evidence that this threshold optimally predicts important health outcomes.

OBJECTIVE

To apply machine learning to examine how adherence to oral hypoglycemic medications is associated with avoidance of hospitalizations, and to identify adherence thresholds for optimal discrimination of hospitalization risk.

METHODS

A retrospective cohort study of 33,130 non-dual-eligible Medicaid enrollees with type 2 diabetes. We randomly selected 90% of the cohort (training sample) to develop the prediction algorithm and used the remaining (testing sample) for validation. We applied random survival forests to identify predictors for hospitalization and fit survival trees to empirically derive adherence thresholds that best discriminate hospitalization risk, using the proportion of days covered (PDC).

OUTCOMES

Time to first all-cause and diabetes-related hospitalization.

RESULTS

The training and testing samples had similar characteristics (mean age, 48 y; 67% female; mean PDC=0.65). We identified 8 important predictors of all-cause hospitalizations (rank in order): prior hospitalizations/emergency department visit, number of prescriptions, diabetes complications, insulin use, PDC, number of prescribers, Elixhauser index, and eligibility category. The adherence thresholds most discriminating for risk of all-cause hospitalization varied from 46% to 94% according to patient health and medication complexity. PDC was not predictive of hospitalizations in the healthiest or most complex patient subgroups.

CONCLUSIONS

Adherence thresholds most discriminating of hospitalization risk were not uniformly 80%. Machine-learning approaches may be valuable to identify appropriate patient-specific adherence thresholds for measuring quality of care and targeting nonadherent patients for intervention.

Over-the-counter fish oil use in a county hospital: Medication use evaluation and efficacy analysis

BACKGROUND

Little is known about the use and effectiveness of over-the-counter (OTC) fish oil supplements for triglyceride (TG) lowering.

OBJECTIVES

To (1) perform a medication-use evaluation (MUE) and (2) assess the efficacy of OTC fish oil.

METHODS

Retrospective, observational cohort study using electronic medical records and the pharmacy database from Parkland Health and Hospital System in Dallas, Texas. Parkland is a tax-supported county institution that provides patients with single-brand OTC fish oil. Two separate analyses were conducted. Six hundred seventeen patients (prescribed fish oil between July 1, 2012, and August 31, 2012) were included in the MUE analysis and 235 patients (109 fish oil, 72 fenofibrate, and 54 gemfibrozil, prescribed between January 1, 2012, and July 31, 2013) were included in the efficacy analysis. The main outcome measure for the MUE was fish oil prescribing habits including dosages and patient adherence, as defined by medication possession ratio. The main outcome measure for the efficacy analysis was change in lipids measured using the last value before fish oil treatment and the first value after fish oil treatment.

RESULTS

MUE: 617 patients received prescriptions for OTC fish oil. Sixty-four percent were prescribed a total daily dose of 2000 mg. Only 25% of patients were adherent. Efficacy analysis: despite being prescribed suboptimal doses, fish oil reduced TGs by 29% (95% confidence interval, 34.3-22.7). Compared with fish oil therapy, fibrate therapy resulted in a greater TG reduction: 48.5% (55.1-41.0) with fenofibrate and 49.8% (57.6-40.5) with gemfibrozil (P < .0001, both medications compared with fish oil).

CONCLUSIONS

Health care providers prescribe suboptimal doses of fish oil, and adherence is poor. Even at low doses (2 g/d), though, fish oil lowers TGs by 29%.

Increased mortality associated with digoxin in contemporary patients with atrial fibrillation: findings from the TREAT-AF study

BACKGROUND

Despite endorsement of digoxin in clinical practice guidelines, there exist limited data on its safety in atrial fibrillation/flutter (AF).

OBJECTIVES

The goal of this study was to evaluate the association of digoxin with mortality in AF.

METHODS

Using complete data of the TREAT-AF (The Retrospective Evaluation and Assessment of Therapies in AF) study from the U.S. Department of Veterans Affairs (VA) healthcare system, we identified patients with newly diagnosed, nonvalvular AF seen within 90 days in an outpatient setting between VA fiscal years 2004 and 2008. We used multivariate and propensity-matched Cox proportional hazards to evaluate the association of digoxin use with death. Residual confounding was assessed by sensitivity analysis.

RESULTS

Of 122,465 patients with 353,168 person-years of follow-up (age 72.1 ± 10.3 years, 98.4% male), 28,679 (23.4%) patients received digoxin. Cumulative mortality rates were higher for digoxin-treated patients than for untreated patients (95 vs. 67 per 1,000 person-years; p < 0.001). Digoxin use was independently associated with mortality after multivariate adjustment (hazard ratio [HR]: 1.26, 95% confidence interval [CI]: 1.23 to 1.29, p < 0.001) and propensity matching (HR: 1.21, 95% CI: 1.17 to 1.25, p < 0.001), even after adjustment for drug adherence. The risk of death was not modified by age, sex, heart failure, kidney function, or concomitant use of beta-blockers, amiodarone, or warfarin.

CONCLUSIONS

Digoxin was associated with increased risk of death in patients with newly diagnosed AF, independent of drug adherence, kidney function, cardiovascular comorbidities, and concomitant therapies. These findings challenge current cardiovascular society recommendations on use of digoxin in AF.

Medication adherence and resistant hypertension

Non-adherence has been a major concern in the treatment of hypertension and is particularly important in understanding and intervening in patients who appear to have resistant hypertension. Relatively few studies have examined the role of non-adherence in resistant hypertension. This review will address issues related to measurement of adherence, adherence interventions and rates of non-adherence in general hypertensive populations and in patients classified as having resistant hypertension.

Cost-effectiveness of statins for primary prevention in patients newly diagnosed with type 2 diabetes in the Netherlands

BACKGROUND

Statins are lipid-lowering drugs that reduce the risk of cardiovascular events in patients with diabetes.

OBJECTIVES

The objective of this study was to determine whether statin treatment for primary prevention in newly diagnosed type 2 diabetes is cost-effective, taking nonadherence, baseline risk, and age into account.

METHODS

A cost-effectiveness analysis was performed by using a Markov model with a time horizon of 10 years. The baseline 10-year cardiovascular risk was estimated in a Dutch population of primary prevention patients with newly diagnosed diabetes from the Groningen Initiative to Analyse Type 2 Diabetes Treatment (GIANTT) database, using the United Kingdom Prospective Diabetes Study risk engine. Statin adherence was measured as pill days covered in the IADB.nl pharmacy research database. Cost-effectiveness was measured in costs per quality-adjusted life-year (QALY) from the health care payers' perspective.

RESULTS

For an average patient aged 60 years, the base case, statin treatment was highly cost-effective at €2245 per QALY. Favorable cost-effectiveness was robust in sensitivity analysis. Differences in age and 10-year cardiovascular risk showed large differences in cost-effectiveness from almost €100,000 per QALY to almost being cost saving. Treating all patients younger than 45 years at diabetes diagnosis was not cost-effective (weighted cost-effectiveness of almost €60,000 per QALY).

CONCLUSIONS

Despite the nonadherence levels observed in actual practice, statin treatment is cost-effective for primary prevention in patients newly diagnosed with type 2 diabetes. Because of large differences in cost-effectiveness according to different risk and age groups, the efficiency of the treatment could be increased by targeting patients with relatively higher cardiovascular risk and higher ages.

Relationship between buprenorphine adherence and health service utilization and costs among opioid dependent patients

Buprenorphine-medication assisted therapy (B-MAT) is an effective treatment for opioid dependence, but may be considered cost-prohibitive based on ingredient cost alone. The purpose of this study was to use medical and pharmacy claims data to estimate the healthcare service utilization and costs associated with B-MAT adherence among a sample of opioid dependent members. Members were placed into two adherence groups based on 1-year medication possession ratio (≥ 0.80 vs. <0.80). The B-MAT adherent group incurred significantly higher pharmacy charges (adjusted means; $6,156 vs. $3,581), but lower outpatient ($9,288 vs. $14,570), inpatient ($10,982 vs. $26,470), ER ($1,891 vs. $4,439), and total healthcare charges ($28,458 vs. $49,051; p<0.01) compared to non-adherent members. Adherence effects were confirmed in general linear models. Though B-MAT adherence requires increased pharmacy utilization, adherent individuals were shown to use fewer expensive health care services, resulting in overall reduced healthcare expenditure compared to non-adherent patients.