Medication adherence and costs of medical care among patients with Parkinson's disease: an observational study using electronic medical records

BACKGROUND

Adherence to antiparkinsonian drugs (APDs) is critical for patients with Parkinson's disease (PD), for which medication is the main therapeutic strategy. Previous studies have focused on specific disorders in a single system when assessing clinical factors affecting adherence to PD treatment, and no international comparative data are available on the medical costs for Chinese patients with PD. The present study aimed to evaluate medication adherence and its associated factors among Chinese patients with PD using a systematic approach and to explore the impact of adequate medication adherence on direct medical costs.

METHODS

A retrospective analysis was conducted using the electronic medical records of patients with PD from a medical center in China. Patients with a minimum of two APD prescriptions from January 1, 2016 to August 15, 2018 were included. Medication possession ratio (MPR) and proportion of days covered were used to measure APD adherence. Multiple linear regression analysis was used to identify factors affecting APD adherence. Gamma regression analysis was used to explore the impact of APD adherence on direct medical costs.

RESULTS

In total, 1,712 patients were included in the study, and the mean MPR was 0.68 (± 0.25). Increased number of APDs and all medications, and higher daily levodopa-equivalent doses resulted in higher MPR (mean difference [MD] = 0.04 [0.03-0.05]; MD = 0.02 [0.01-0.03]; MD = 0.03 [0.01-0.04], respectively); combined digestive system diseases, epilepsy, or older age resulted in lower MPR (MD = -0.06 [-0.09 to -0.03]; MD = -0.07 [-0.14 to -0.01]; MD = -0.02 [-0.03 to -0.01], respectively). Higher APD adherence resulted in higher direct medical costs, including APD and other outpatient costs. For a 0.3 increase in MPR, the two costs increased by $34.42 ($25.43-$43.41) and $14.63 ($4.86-$24.39) per year, respectively.

CONCLUSIONS

APD adherence rate among Chinese patients with PD was moderate and related primarily to age, comorbidities, and healthcare costs. The factors should be considered when prescribing APDs.

Incidence of tuberculosis disease in individuals diagnosed with tuberculosis infection after screening: A population-based cohort study in South Korea

OBJECTIVES

Limited evidence exists regarding the impact of adherence to diverse tuberculosis (TB) preventive therapy (TPT) regimens on TB risk in individuals with TB infections (TBIs). This study aimed to examine the association between adherence to three TPT regimens and TB incidence.

METHODS

This population-based retrospective cohort study used South Korean national health insurance data to identify individuals who were newly diagnosed with TBI between 2015 and 2020. TB incidence was compared among the different TPT regimens used. Treatment adherence was evaluated using the medication possession ratio (MPR).

RESULTS

The study involved 220,483 individuals with TBI, with half undergoing TPT. Over a mean 3.17-year follow-up, 2,430 cases of active TB were observed. TPT was associated with a 14% reduction in TB incidence risk in the entire study population with varying levels of TB risk. Non-adherence (MPR <80%) rates were 36% for 9 months of treatment with isoniazid, 22% for 4 months of treatment with rifampicin, and 18% for 3 months of treatment with isoniazid and rifampicin. Non-adherence to TPT did not lead to a decrease in the risk of TB incidence, whereas adherence to TPT (MPR ≥80%) reduced the risk of TB incidence by up to 72%.

CONCLUSIONS

This study reveals increased adherence with shorter TPT regimens in a national TBI cohort, emphasizing the pivotal role of medication adherence in preventing TB.

Medication adherence in patients with type 2 diabetes after disability onset: a difference-in-differences analysis using nationwide data

BACKGROUND

Effectively managing the coexistence of both diabetes and disability necessitates substantial effort. Whether disability onset affects adherence to type 2 diabetes medication remains unclear. This study investigated whether disability onset reduces such adherence and whether any reduction varies by disability type.

METHODS

This study used the National Disability Registry and National Health Insurance Research Database from Taiwan to identify patients with type 2 diabetes who subsequently developed a disability from 2013 to 2020; these patients were matched with patients with type 2 diabetes without disability onset during the study period. Type 2 diabetes medication adherence was measured using the medication possession ratio (MPR). A difference-in-differences analysis was performed to determine the effect of disability onset on the MPR.

RESULTS

The difference-in-differences analysis revealed that disability onset caused a reduction of 5.76% in the 1-year MPR (P < 0.001) and 13.21% in the 2-year MPR (P < 0.001). Among all disability types, organ disabilities, multiple disabilities, rare diseases, and a persistent vegetative state exhibited the largest reductions in 2-year MPR.

CONCLUSIONS

Policies aimed at improving medication adherence in individuals with disabilities should consider not only the specific disability type but also the distinct challenges and barriers these patients encounter in maintaining medication adherence.

A Retrospective Comparison of HIV Pre-exposure Prophylaxis (PrEP) Outcomes Between a Pharmacist-led Telehealth Clinic and In-person Clinic in a Veteran Population

Pre-exposure prophylaxis (PrEP) reduces human immunodeficiency virus (HIV) transmission through sexual contact by at least 90% when taken as prescribed. This retrospective cohort study evaluated differences in adherence to PrEP medication and monitoring between the physician- and nurse practitioner (NP)-led in-person setting and the pharmacist-led telehealth setting among patients followed by the infectious diseases clinic at the VA Eastern Colorado Health Care System from July 2012 to February 2021. The primary outcomes were PrEP tablets filled per person-year, serum creatinine (SCr) tests per person-year, and HIV screens per person-year. Secondary outcomes included sexually transmitted infection (STI) screens per person-year and patients lost to follow-up.149 patients were included in the study, with 167 person-years in the in-person cohort and 153 person-years in the telehealth cohort. Adherence to PrEP medications and monitoring was similar between in-person and telehealth clinics. PrEP tablets filled per person-year was 324 in the in-person cohort and 321 in the telehealth cohort (RR = 0.99; 95% CI, 0.98-1.00). SCr screens per person-year was 3.51 in the in-person cohort and 3.37 in the telehealth cohort (RR = 0.96; 95% CI, 0.85-1.07). HIV screens per person-year was 3.55 in the in-person cohort and 3.38 in the telehealth cohort (RR = 0.95; 95% CI, 0.85-1.07). There were no new HIV infections. Additionally, patients were less likely to be lost to follow-up when followed via telehealth (11.9% vs. 30.0%), Χ2 (1, N = 149) = 6.85, p = 0.009. These findings indicate that pharmacist-driven delivery of PrEP via telehealth can be used to increase access to PrEP without sacrificing quality of care.

The real-world adherence of the first-line anti-osteoporosis medications in Taiwan: Visualize the gap between reality and expectations

BACKGROUND

Adherence to anti-osteoporosis medications (AOMs) is crucial. National Health Insurance (NHI) in Taiwan has its own rules of reimbursement rule for AOMs. The midterm adherence remained inconclusive. Here we investigated the adherence according to the initially used AOMs, for three consecutive years.

METHODS

The nationwide cohort study from 2008 to 2018, based on Taiwan's National Health Insurance Research Database, included 336,229 patients. Their adherence, indicated by medication possession ratio (MPR), to the initial AOMs was investigated yearly for three consecutive years. The overall MPRs (OMPR), including the switched AOMs, were also calculated in the first year. The Sankey diagram further visualized the patient flows toward different adherence according to the initial AOMs.

RESULTS

The OMPR in the first year improved if the patients used AOMs with longer dosing intervals. 100%, 68.9%, 40.7%, and 34.0% of the patients started the treatment with zoledronate, denosumab, alendronate, and raloxifene, respectively, had OMPR ≥75% in the first year. In the 3rd year, only 20.89%, 24.13%, and 12.83% of the patients continuously treated with zoledronate, denosumab, and alendronate, respectively, had MPR ≥75%. From the Sankey diagram, we also observed that patients who had poor adherence at one year were inclined to have poor adherence or discontinue antiosteoporosis treatment in the next year.

CONCLUSION

The initial AOMs and the observed adherence may provide clues for optimizing patient treatment. The real-world adherence in Taiwan was far from satisfactory in our study.

Prescription characteristics associated with drug overdose risk among adults prescribed benzodiazepines: a cohort study

BACKGROUND

Drug overdose (OD) deaths in the U.S. continue to rise. After opioids, benzodiazepines (BZD) are the medication most commonly involved in prescription overdoses, yet OD risk factors among those prescribed BZD are not well understood. Our objective was to examine characteristics of BZD, opioid, and other psychotropic prescriptions associated with increased drug OD risk following a BZD prescription.

METHODS

We completed a retrospective cohort study using a 20% sample of Medicare beneficiaries with prescription drug coverage. We identified patients with a BZD prescription ("index") claim between 1 April 2016 and 31 December 2017. In the 6 months pre-index, those without and with BZD claims comprised incident and continuing cohorts, which were split by age (incident < 65 [n = 105,737], 65 + [n = 385,951]; continuing < 65 [n =  240,358], 65 + [n = 508,230]). Exposures of interest were: average daily dose and days prescribed of the index BZD; baseline BZD medication possession ratio (MPR) for the continuing cohort; co-prescribed opioids and psychotropics. Our primary outcome was a treated drug OD event (including accidental, intentional, undetermined, or adverse effect) within 30 days of the index BZD, examined using Cox proportional hazards.

RESULTS

Among incident and continuing BZD cohorts, 0.78% and 0.56% experienced an OD event. Compared to 14-30 days, a < 14-day fill corresponded to higher OD risk in incident (< 65 adjusted hazard ratio [aHR] 1.16 [95% CI 1.03-1.31]; 65 + : aHR 1.21 [CI 1.13-1.30]) and continuing (< 65: aHR 1.33 [CI 1.15-1.53]; 65 + : aHR 1.43 [CI 1.30-1.57]) cohorts. Among continuing users, lower baseline exposure (i.e., MPR < 0.5) was associated with increased OD risk for those < 65 (aHR 1.20 [CI 1.06-1.36]); 65 + (aHR 1.12 [CI 1.01-1.24]). Along with opioids, concurrent antipsychotic use and antiepileptic use were associated with elevated risk of OD in all 4 cohorts (e.g., aHRs for the continuing 65 + cohort: opioid, 1.73 [CI 1.58-1.90]; antipsychotic, 1.33 [CI 1.18-1.50]; antiepileptic, 1.18 [1.08-1.30]).

CONCLUSIONS

In both the incident and continuing cohorts, patients dispensed fewer days' supply were at increased OD risk; those in the continuing cohort with more limited baseline BZD exposure were also at elevated risk. Concurrent medication exposures including opioids, antipsychotics, and antiepileptics were associated with short-term elevated OD risk.

Adherence to Treatment with Oral Nucleoside/Nucleotide Analogs in Patients with Chronic Hepatitis B

Objectives

Adherence to antiviral treatment is important for treatment success and prevention of resistance. It was aimed to determine treatment adherence to nucleoside/nucleotide analogs and factors influencing on adherence.

Methods

The study included 168 patients who received oral nucleoside/nucleotide analog with diagnosis of chronic hepatitis for at least 1 year. Data regarding demographic characteristics and missed drug were collected using a survey, while list of medication within prior year were extracted from pharmacy registry and Medication Possession Rate (MPR) was calculated.

Results

There were 60 women (35.7%) and 108 men (64.3%) in the study. Mean age was calculated as 43.61±10.35 years. It was found that 29.2% of patients were non-adherent based on MPR (MPR<0.90). It was observed that adherence was improved on middle age. Treatment adherence was found to be higher in patients receiving medication due to disorders other than hepatitis B. It was found that there was no significant difference in adherence according to age, gender, occupation status, marital status, smoking or alcohol consumption habits, type of antiviral treatment, time and mode of drug intake, and biopsy finding at time of drug prescription. The most common cause was identified as forgetfulness for missed drug. Other common causes were inoccupation and alteration in daily routine.

Conclusion

In our study, the treatment adherence determined by MPR was 70.8%. This rate was lower than those reported for chronic hepatitis B in the literature. It is important to monitor and encourage treatment adherence in patients with chronic hepatitis B by clinicians.

Lipid-lowering drug adherence and combination therapy effects on gastrointestinal cancer in patients with dyslipidemia without diabetes: a retrospective cohort study in South Korea

BACKGROUND

In aging populations, the number of people with high cholesterol levels is increasing. Appropriate management of high cholesterol levels with drugs such as statins may prevent secondary diseases. Despite many studies on the effects of statins on various types of cancer, the effectiveness of lipid-lowering therapy in preventing cancer remains controversial. This study aimed to evaluate its long-term effect on developing gastrointestinal (GI) cancer in patients with dyslipidemia.

METHODS

This study used the National Health Insurance Sampling (NHIS) cohort data (2002-2015), which included patients with dyslipidemia without diabetes, and measured patients' adherence to lipid-lowering therapy using the medication possession ratio. We used the Cox proportional hazard ratio (HR) to identify the association between the continuity of lipid-lowering therapy and the risk of GI cancer. We also evaluated the association between a combination of lipid-lowering drugs and a reduced risk of GI cancer.

RESULTS

A total of 49,351 patients were diagnosed with dyslipidemia, of which 579 were diagnosed with GI cancer. Patients with higher adherence to lipid-lowering therapy had a significantly reduced risk of GI cancer compared to patients without drugs, and high adherence was associated with a reduced incidence of all types of GI cancer. Specifically, the combination of statins and ezetimibe or fibrates appears to reduce GI cancer risk effectively. Overall, the continuity of lipid-lowering therapy had a protective effect on GI cancer in middle-aged and elderly patients with dyslipidemia compared to non-users.

CONCLUSIONS

Our findings suggest that the continuity of lipid-lowering therapy is vital in patients with dyslipidemia. In addition, for individuals vulnerable to GI cancer, combination therapy may be associated with more effective protection against GI cancer. Healthcare providers need patient education and monitoring to improve drug adherence in patients with dyslipidemia.

Cost analysis of acute care resource utilization among individuals with sickle cell disease in a middle-income country

BACKGROUND

The costs associated with the treatment of sickle cell disease (SCD) are understudied in low and middle-income countries (LMIC). We evaluated the cost of treating SCD-related acute complications and the potential cost-savings of hydroxyurea in a specialized hematology center in Brazil.

METHODS

The costs (US dollars) of emergency department (ED) and hospitalizations from SCD-related complications between 01.01.2018 and 06.30.2018 were ascertained using absorption and micro-costing approaches. The reasons for acute hospital visits were grouped as: 1) vaso-occlusive (VOC) pain, 2) infection, 3) anemia exacerbation, and 4) chronic organ damage complications. Hydroxyurea adherence was estimated by medication possession ratio (MPR) during the study period.

RESULTS

In total, 1144 patients, median age 17 years (range 0-70), 903 (78.9%) with HbSS/HbSβ0-thalassemia, 441 (38.5%) prescribed hydroxyurea, visited the ED, of whom 381 (33%) were admitted. VOC accounted for 64% of all ED visits and 60% of all admissions. Anemia exacerbation was the most expensive reason for ED visit ($321.87/visit), while chronic organ damage carried the highest admission cost ($2176.40/visit). Compared with other genotypes, individuals with HbSS/HbSβ0-thalassemia were admitted more often (79% versus 21%, p < 0.0001), and their admission costs were higher ($1677.18 versus $1224.47/visit, p = 0.0001). Antibiotics and analgesics accounted for 43% and 42% of the total ED costs, respectively, while housing accounted for 46% of the total admission costs. Costs of ED visits not resulting in admissions were lower among HbSS/HbSβ0-thalassemia individuals with hydroxyurea MPR ≥65% compared with visits by patients with MPR <65% ($98.16/visit versus $182.46/visit, p = 0.0007). No difference in admission costs were observed relative to hydroxyurea use.

DISCUSSION

In a LMIC hematology-specialized center, VOCs accounted for most acute visits from patients with SCD, but costs were highest due to anemia exacerbation. Analgesics, antibiotics, and housing drove most expenses. Hydroxyurea may reduce ED costs among individuals with HbSS/HbSβ0-thalassemia but is dependent on adherence level.

Survival impact of adherence to tyrosine kinase inhibitor in chronic myeloid leukemia

BACKGROUND/AIMS

Adherence to tyrosine kinase inhibitors (TKIs) has become a critical aspect of care in chronic myeloid leukemia (CML). We aimed to examine the association of TKI adherence with overall survival (OS) outcomes in Korean patients diagnosed with CML and treated with TKIs using data from the National Health Information Database.

METHODS

This study included 2,870 CML patients diagnosed between 2005 and 2013. Drug adherence was evaluated according to the medication possession ratio (MPR) and classified as high adherence (i.e., MPR ≥ 0.95 [upper 50%]), moderate adherence (i.e., MPR ≥ 0.68 and < 0.95 [middle 25%]), and low adherence (i.e., MPR < 0.68 [lower 25%]).

RESULTS

The median MPR was 0.95 (range, 0 to 4.67). Male sex (p = 0.003), age < 70 years (p < 0.001), high income (≥ 30%, p < 0.001), and maintaining frontline TKI (< 0.001) were associated with better adherence. Adherence to dasatinib was the lowest (vs. imatinib or nilotinib, p < 0.001). Compared with high MPR patients, those with moderate MPR (hazard ratio [HR], 4.90; 95% confidence interval [CI], 3.87 to 6.19; p < 0.001) and low MPR (HR, 11.6; 95% CI, 9.35 to 14.42; p < 0.001) had poorer OS.

CONCLUSION

Adherence to TKI treatment is an important factor predicting survival outcomes in Korean CML patients. Male sex, age < 70 years, high income, and maintaining frontline TKI are associated with high adherence to TKI. Thus, those without these characteristics should be closely monitored for treatment adherence.

Assessment of Human Immunodeficiency Virus Care Continuum in Korea using the National Health Insurance System Data

Background

Antiretroviral therapy (ART) has been shown to significantly reduce the likelihood of transmission to other people as well as promoting the health of people living with Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) (PLH). The purpose of this study was to assess the HIV care continuum of PLH in Korea using the national health insurance system (NHIS) database.

Materials and Methods

From 2006 to 2015, ART prescription/laboratory test claim data and enlisted accompanying comorbidities were extracted from the NHIS database. Utilizing these data, proportion of PLH on ART among those who registered to Korea Disease Control and Prevention Agency (KDCA), HIV viral load testing, prescription trends of ART, medication possession ratio (MPR) of ART, and accompanying comorbidities were reviewed. Factors related with MPR <90% was also investigated among demographic factors, ART prescription, and accompanying comorbidities.

Results

During the observation period, the number of people receiving ART prescription increased from 2,076 in 2006 to 9,201 in 2015. Considering the number of PLHs reported by the KDCA, the proportion of PLHs who received ART prescription increased from 55.4% to 87.6% during the study period. The median value of ART MPR increased from 76.4% to 94.2% and the proportion of patients with MPR >90% increased from 54.3% to 78.2%. The most commonly accompanying comorbidities were dyslipidemia (55.7%), osteoporosis (16.3%), hypertension (15.7%) and diabetes (13.7%), respectively. The proportion of PLH with two or more comorbid conditions increased from 22.0% to 31.6%. Regarding the factors associated with suboptimal compliance, age less than 50 years old, under support of National Medical Aid, alcoholic liver disease, mental and behavioral disorders due to use of alcohol, and ART regimen of protease inhibitor and non-single table regimen integrase strand transfer inhibitor were related with MPR <90%.

Conclusion

The proportion of PLHs who received ART prescription and median MPR of ART increased during the study period. However, proportion of patients with MPR >90% was 78.2% in 2015 and there are still much room for improvement in the aspect of compliance.

Insufficient persistence to pharmacotherapy in Japanese patients with osteoporosis: an analysis of the National Database of Health Insurance Claims and Specific Health Checkups in Japan

In Japan, persistence and the 2-year MPR were inadequate in increasing fracture control efficacy despite a high adherence rate during the treatment period. Both factors were higher in females and those with polypharmacy but worsened with increasing age.

PURPOSE

Only a few large-scale studies have examined the care gap between the patients who need osteoporosis treatment and those who receive them in Japan. The aim of this study was to investigate the persistence and adherence to osteoporosis pharmacotherapy in Japan.

METHODS

Continuation (persistence) rates and adherence to osteoporosis pharmacotherapy were investigated using medical insurance data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, between April 2012 and March 2019.

RESULTS

The study included 528,806 male and 3,064,410 female patients. Persistence proportions were 56.6% in the first year and 46.3% in the second year. The medication possession ratio (MPR) from start to discontinuation of treatment (MPR_discon) was 94.5%, and 92.7% of patients had an MPR_discon ≥ 80%. The 2-year MPR (MPR₇₃₀) was 61.9%, and 49.6% of patients had an MPR₇₃₀ ≥ 80%. Both the persistence proportion and MPR₇₃₀ were higher in females than in males, whereas MPR_discon was higher in males. The persistence proportion and MPR₇₃₀ were highest in the 70-79 years age group, whereas MPR_discon improved with increasing age. The MPR_discon and MPR₇₃₀ were higher in the mixed-fracture and vertebral-fracture groups, respectively. The persistence proportion, MPR_discon, and MPR₇₃₀ were higher in patients with polypharmacy than in those without.

CONCLUSION

In Japan, persistence and the 2-year MPR were inadequate in increasing fracture control efficacy despite a high adherence rate during the treatment period. To bridge the care gap following osteoporosis pharmacotherapy, improvements are required for males, the elderly, and those without polypharmacy.

Self-reported vs. objectively assessed adherence to inhaled corticosteroids in asthma

BACKGROUND

Adherence to inhaled corticosteroids (ICS) in asthma is vital for disease control. However, obtaining reliable and clinically useful measures of adherence remains a major challenge. We investigated the association between patient-reported adherence and objectively measured adherence based on filled prescriptions with inhaled corticosteroids in adults with asthma.

METHODS

In total, 178 patients with asthma were asked to self-assess adherence during routine visits at a respiratory outpatient clinic. Self-assessment was performed using Foster score ("How many days in a 7-day week do you take your medication as prescribed?", with the answer divided by 7). Objective adherence was calculated as medication possession ratio (MPR). Bivariate and multivariable linear regression, adjusted for age, sex, FEV1, GINA treatment step, excessive use of SABA, and history of exacerbations were used for analyses.

RESULTS

Of the included patients, 87.6% reported a Foster score of 100%, while the mean ICS MPR was 54.0% (SD 25%). Complex regimens such as twice-daily dosing or dual inhaler-use were associated with lower adherence (p = 0.015 and p < 0.001, respectively). Foster score was predictive of ICS MPR, with an absolute 32% increase in MPR between patients reporting Foster scores of 0 and 100% (95% CI 13-50%, p < 0.001). Female sex predicted higher ICS MPR (p = 0.019). Previous asthma-related hospitalization(s) predicted lower ICS MPR (p = 0.039).

CONCLUSION

Although a weak association was found between Foster score and ICS MPR, findings do not support the use of Foster score, and by that self-reported adherence, as a reliable marker of controller adherence in asthma due to significant mismatch between patient-reported adherence and MPR. Future studies should address the complex interplay between patient-reported and objectively assessed adherence to controller medication in asthma.

Adherence to oral anticancer chemotherapies and estimation of the economic burden associated with unused medicines

Background The list of oral and expensive chemotherapy agents has lengthened over the last few years and has created unique medication adherence concerns. In a real-life setting, patients often do not take their medications as prescribed. This pattern is associated with poor outcomes and increased health care costs. Objectives To estimate the adherence to oral anticancer chemotherapies and to determine the economic burden of unused medicines due to patients' death. Setting Alsace (France). Method This retrospective study was carried out by using ERASME, an Insurance Healthcare database. Main outcome measures Adherence was calculated using medication possession ratio and economic impact using prescription refill data. Results 10,734 patients were treated with oral anticancer medicines (cytotoxic agents, hormonal and targeted therapies). Averaged adherence of 0.86 was observed although it varied significantly between subclasses (cytotoxic agents: 0.69 ± 0.14, hormonal therapy: 0.91 ± 0.17 and targeted therapy: 0.79 ± 0.17). 1631 patients died during the study period. The expenses related to unused chemotherapies amounted to €152,175. Conclusions Our data showed that overall adherence to oral anticancer medicines was above the acceptable limit of adherence of 80% with a marked graduation in values between cytotoxic agents, hormonal and targeted therapies. These statistical significant differences in medication possession ratio could be related to the intrinsic toxicity of the three subclasses of molecules, their tolerance and adverse effects. To limit the cost associated with unused medicines, interventions such as dispensing expensive oral anticancer chemotherapies per unit over shorter periods and not only on monthly intervals could be implement.

Alendronate medication possession ratio and the risk of second hip fracture: an 11-year population-based cohort study in Taiwan

Alendronate is effective in preventing second hip fracture in osteoporotic patients. However, no consensus exists on the duration that is effective in preventing a second hip fracture. Our study demonstrated that risk can be reduced when the prescription is ≥ 6 months for the year following the index hip fracture.

INTRODUCTION

Alendronate is effective in preventing second hip fracture in osteoporotic patients. However, no consensus exists on the accurate medication possession ratio (MPR) that is effective in preventing a second hip fracture. Our objective was to compare the risk of second hip fracture in patients treated with different MPR of alendronate.

METHODS

In this population-based cohort study, data from National Health Insurance Research Database of Taiwan were analyzed. Patients 50 years and older who had an index hip fracture and were not receiving any osteoporotic medications before their fracture during 2000-2010 were included. The cohort consisted of 88,320 patients who were new alendronate users (n = 9278) and non-users (n = 79,042). Those without alendronate were matched 4:1 as the control group. Patients were subdivided into those with no medication, MPR < 25%, MPR 25-50%, MPR 50-75%, and MPR 75-100%. Cox proportional hazard models were used to calculate the adjusted hazard ratios for different MPRs of alendronate.

RESULTS

After matching, 38,675 patients were included in this study; 20,363 (52.7%) were women, and 30,940 (80%) patients were without medication of alendronate. During follow-up on December 31, 2012, 2392 patients had a second hip fracture, for an incidence of 1449/100,000 person-years. Patients with alendronate MPR 50-75% had a lower risk of a second hip fracture compared to non-users (hazard ratio 0.66). When the MPR increased to 75-100%, the hazard ratio decreased to 0.61.

CONCLUSIONS

In this population-based cohort study, risk of a second hip fracture can be reduced when the alendronate MPR is ≥ 50% for the year following the index hip fracture. As the MPR increases, the risk of a second hip fracture decreases.

Adherence in chronic hepatitis B: associations between medication possession ratio and adverse viral outcomes

Background

Antiviral therapy for chronic hepatitis B (CHB) is effective and can substantially reduce the risk of progressive liver disease and hepatocellular carcinoma but is often administered for an indefinite duration. Adherence has been shown in clinical trials to maximize the benefit of therapy and prevent the development of resistance, however the optimal threshold for predicting clinical outcomes has not been identified. The aim of this study was to analyse adherence using the medication possession ration (MPR) and its relation to virological outcomes in a large multi-centre hospital outpatient population, and guide development of an evidence-based threshold for optimal adherence.

Methods

Pharmacy and pathology records of patients dispensed CHB antiviral therapy from 4 major hospitals in Melbourne between 2010 and 2013 were extracted and analysed to determine their MPR and identify instances of unfavourable viral outcomes. Viral outcomes were classified categorically, with unfavourable outcomes including HBV DNA remaining detectable after 2 years treatment or experiencing viral breakthrough. The association between MPR and unfavourable outcomes was assessed according to various thresholds using ROC analysis and time-to-event regression.

Results

Six hundred forty-two individuals were included in the analysis. Median age was 46.6 years, 68% were male, 77% were born in Asia, and the median time on treatment was 27.5 months. The majority had favourable viral outcomes (91.06%), with most having undetectable HBV DNA at the end of the study period. The most common unfavourable outcome was a rise of < 1 log in HBV DNA (6.54% of the total), while 2.49% of participants experienced viral breakthrough. Adherence was linearly associated with favourable outcomes, with increasing risk of virological breakthrough as MPR fell. Decreasing the value of MPR, at which a cut-point was taken, was associated with a progressively larger reduction in the rate of unfavourable event; from a 60% reduction under a cut-point of 1.00 to a 79% reduction when the MPR cut-point was set at 0.8.

Conclusion

Lower adherence as measured using the MPR was strongly associated with unfavourable therapeutic outcomes, including virological failure. Optimising adherence is therefore important for preventing viral rebound and potential complications such as antiviral resistance. The evidence of dose-response highlights the need for nuanced interventions.

Assessing Oral Medication Adherence and Identifying Predictors of Low Adherence in Chinese Inflammatory Bowel Disease Patients

BACKGROUND

Poor medication adherence in inflammatory bowel disease (IBD) had a negative impact on disease outcomes. In this study, we aimed to determine predictors of low adherence in the Chinese IBD populations and also aimed to compare a self-reported scale to a pharmacy refill index in assessing adherence of 5-ASA and azathioprine taken by Chinese IBD patients.

PATIENTS AND METHODS

Adult patients with IBD who had been taking 5-ASA or azathioprine for at least 3 months were recruited from hospital outpatient clinics. The MPR was calculated from previous six-month pharmacy refill data and the self-reported Morisky Medication Adherence Scale (MMAS-8) was issued through QR code questionnaires. Intentional and unintentional adherence scores were calculated according to specific items. Non-adherence was defined as MMAS-8 scores <6 or MPR < 0.8.

RESULTS

The response rate in the IBD patients was as high as 97%. 5-ASA non-adherence rate assessed by MPR was 30% and 37% by MMAS-8, and azathioprine non-adherence rate assessed was 33% by both MPR and MMAS-8. In a linear regression analysis, MPR value was significantly correlated with MMAS-8 score in 5-ASA group (r=0.4, p=0.003), and significantly correlated with unintentional adherence score (r=0.47, p<0.001). No significant correlation was observed between MPR value and MMAS-8 score in azathioprine group. Multivariate analysis demonstrated that age (OR: 1.08; 95% CI: 1.02-1.13; P=0.0015) and previous abdominal surgery (OR: 3.18; 95% CI: 2.09-4.27; P=0.04) were associated with high medication adherence. While patients who had small intestine lesion (OR: 0.09; 95% CI: 0.01-0.17; P=0.006) were associated with low adherence.

CONCLUSION

Predictors of low adherence were young age, lesions on small intestine, whereas previous abdominal surgery was a protective factor. This study also demonstrated that the MMAS-8 scale was a valid instrument for assessing 5-ASA adherence in IBD patients. Unintentional non-adherence was significantly related to the total non-adherence, which would allow to use the tool to seek ways for adherence improvement.

Long-term adherence to GnRH agonists in men with prostate cancer. A nation-wide population-based study in prostate cancer data base Sweden

Aim: Gonadotropin-releasing hormone (GnRH) agonists are used to treat men with prostate cancer (PCa). To date, no study has fully assessed patterns of adherence to GnRH agonists. We investigated patterns of adherence to GnRH agonists using data from Prostate Cancer data Base Sweden (PCBaSe).Methods: PCBaSe links the National Prostate Cancer Register (NPCR) Sweden to other healthcare registers and demographic databases. Men on primary or secondary GnRH agonists between 2006-2013 entered the study 45 days after GnRH agonists' initiation (run-in period) and exited at 3 years. Medication possession ratio quantified adherents (≥80%). Multivariable logistic regression models included age, injection interval, PCa risk categories, Charlson Comorbidity Index, prior PCa treatment, civil status and year of GnRH initiation. Odds ratios (OR) and 95% confidence intervals (CI) expressed odds of adherence.Results: Men on primary GnRH agonists (n = 8,105) were more adherent with increasing age (75-84 years compared to ≤65 years OR: 1.49; 95% CI: 1.23-1.81), longer injection intervals (365 days compared to 90 days OR: 3.29; 95% CI: 2.52-4.30) and higher PCa risk categories at diagnosis (distant metastasis compared to low risk PCa OR: 3.56; 95% CI: 2.54-5.00). Men on secondary GnRH agonists (n = 4,738) were more adherent with increasing age (≥85 years compared to ≤65 years OR: 1.65; 95% CI: 1.23-2.22) and prior PCa treatment (anti-androgens compared to deferred treatment OR: 1.50; 95% CI: 1.23-1.82), (radiotherapy compared to deferred treatment OR: 1.35; 95% CI: 1.11-1.64).Conclusions: Longer injection intervals could be addressed in the clinical setting to improve adherence.

Effects of First Diagnosed Diabetes Mellitus on Medical Visits and Medication Adherence in Korea

BACKGROUND

The National Health Insurance Service (NHIS) conducted a screening test to detect chronic diseases such as hypertension and diabetes in Korea. This study evaluated the effects of health screening for DM on pharmacological treatment.

METHODS

The data from qualification and the General Health Screening in 2012, the insurance claims of medical institutions from Jan 2009 to Dec 2014, and the diabetic case management program extracted from the NHIS administrative system were used. Total 16068 subjects were included. Visiting rate to medical institution, medication possession ratio and the rate of medication adherence of study subjects were used as the indices.

RESULTS

The visiting rates to medical institutions were 39.7%. The percentage who received a prescription for a diabetes mellitus medication from a doctor was 80.9%, the medication possession ratio was 70.8%, and the rate of medication adherence was 57.8%.

CONCLUSION

The visiting rate, medication possession ratio and rate of medication adherence for DM medication were not high. In order to increase the visiting rate, medication possession ratio and rate of medication adherence, NHIS should support environment in which medical institutions and DM patients can do the role of each part.

Characteristics of adherence to methadone maintenance treatment over a 15-year period among homeless adults experiencing mental illness

BACKGROUND

Methadone maintenance treatment (MMT) has important protective effects related to reduced illicit opioid use, infectious disease transmission, and overdose mortality. Adherence to MMT has not been examined among homeless people. We measured MMT adherence and reported relevant characteristics among homeless adults experiencing mental illness in Vancouver, British Columbia, Canada.

MATERIAL AND METHODS

Homeless adults living with mental illness who had received MMT prior to the baseline interview of the Vancouver At Home study (n = 78) were included in analyses. The medication possession ratio (MPR) was used to estimate MMT adherence from retrospective administrative pharmacy and public health insurance data collected across 15 years. Independent sample t tests and one-way ANOVA were used to test for significant differences in MMT MPR by participant characteristics.

RESULTS

Mean MMT MPR was 0.47. A large proportion of participants reported blood-borne infectious disease, three or more chronic physical health conditions, and substance use. Being single and never married was associated with significantly lower MMT MPR (0.40 vs. 0.55, p = 0.036), while living with schizophrenia, bipolar disorder, or a mood disorder with psychotic features was associated with significantly higher MMT MPR (0.54 vs. 0.37, p = 0.022). Daily drug use (excluding alcohol) was associated with significantly lower MMT MPR (0.39 vs. 0.54, p = 0.051).

CONCLUSIONS

The level of adherence to MMT was very low among homeless adults experiencing mental illness. Efforts are needed to improve adherence to MMT as a means of reducing illicit substance use, preventing overdose deaths, and attenuating infectious disease transmission.

Medical visits, antihypertensive prescriptions and medication adherence among newly diagnosed hypertensive patients in Korea

Objectives

The objective of this study was to assess the antihypertensive medication adherence in patients who were newly diagnosed with hypertension in Korea.

Methods

Study subjects were diagnosed with hypertension for the first time by the General Health Screening in 2012 and were 65,919. As indices, visiting rate to medical institution, the antihypertensive prescription rate, medication possession ratio and the rate of appropriate medication adherence were used. The qualification data, the General Health Screening data and the health insurance claims data were used.

Resutls

Visiting rate to medical institution within one-year was 42.3%. Gender, age, family history of hypertension, smoking status, drinking frequency, insurance type, BMI, hypertension status, blood glucose level and LDL-cholesterol level were significant variables for visiting a medical institution. Of the study subjects who visited a medical institution, the antihypertensive prescription rate was 89.1%. Medication possession ratio was 70.9% and the rate of appropriate medication adherence was 60.6%. Age, family history of hypertension, smoking status, BMI level, hypertension level, blood glucose level, status, and LDL-cholesterol level were significant variables for the antihypertensive prescription and gender, age, family history of hypertension, smoking status, BMI, hypertension status, and the time of the first visit to a medical institution were significant variables for appropriate medication adherence.

Conclusions

This study showed that the antihypertensive medication adherence in patients who were newly diagnosed with hypertension was not relatively high in Korea. National Health Insurance Service should support an environment in which medical institutions and those diagnosed with hypertension can fulfill their roles.

Short- and long-term use of medication for psychological distress after the diagnosis of cancer

PURPOSE

This study investigated the short- and long-term use of medication for psychological distress after the diagnosis of cancer.

METHODS

Longitudinal data from the Taiwan National Health Insurance database were used to follow 35,137 cancer patients for 2.5 years after being diagnosed in 2006 and 2007.

RESULTS

Among those patients who survived for at least 180 days, 20.9 % had used psychotropic medications; sedatives were the most frequently prescribed (14.3 %), followed by antidepressants (5.5 %), anxiolytics (3.6 %), and antipsychotics (2.7 %). Lung cancer, prostate cancer, and oral cancer showed a significant association with the regular use of medication in the first 180 days. Among patients who survived for at least 2.5 years, 4.8 % still used psychotropic medication on a regular basis. Lung cancer and prostate cancer were associated with such prolonged use.

CONCLUSIONS

This longitudinal study found that the type of cancer was significantly associated with the use of psychotropic drugs after the diagnosis was made. It provided information about the trajectory of that use and found that a small number of patients were still using those medications after 2.5 years.

Adherence to antipsychotic medication among homeless adults in Vancouver, Canada: a 15-year retrospective cohort study

PURPOSE

The purpose of this study was to investigate the level of adherence to antipsychotic prescription medication in a well-defined homeless cohort over a 15-year period. We hypothesized that adherence would be well below the recommended threshold for clinical effectiveness (80 %), and that it would be strongly associated with modifiable risk factors in the social environment in which homeless people live.

METHOD

Linked baseline data (including comprehensive population-level administrative prescription records) were examined in a subpopulation of participants from two pragmatic-randomized trials that investigated Housing First for homeless and mentally ill adults. Adherence to antipsychotic medication was operationalized using the medication possession ratio. Multivariable logistic regression was used to estimate effect sizes between socio-demographic, homelessness-related and illness factors, and medication possession ratio.

RESULTS

Among the 290 participants who met inclusion criteria for the current analysis, adherence to antipsychotic prescription was significantly associated with: history of psychiatric hospitalization; receipt of primary medical services; long-acting injectable antipsychotic formulations; and duration of homelessness. Mean medication possession ratio in the pre-randomization period was 0.41. Socio-demographic characteristics previously correlated with antipsychotic non-adherence were not significantly related to medication possession ratio.

CONCLUSIONS

This is the first study to quantify the very low level of adherence to antipsychotic medication among homeless people over an extended observation period of 15 years. Each of the four factors found to be significantly associated with adherence presents opportunities for intervention. Strategies to end homelessness for this population may represent the greatest opportunity to improve adherence to antipsychotic medication.

Rationale and design of mDOT-HuA study: a randomized trial to assess the effect of mobile-directly observed therapy on adherence to hydroxyurea in adults with sickle cell anemia in Tanzania

Background

Hydroxyurea (HU) has been demonstrated to be efficacious in reducing complications in individuals with sickle cell anemia (SCA) but poor adherence is a barrier. Directly Observed Therapy (DOT) has been shown to improve adherence in various chronic diseases but there is limited data in adults with SCA.

Methods and design

To examine the effect of mobile-directly observed therapy (mDOT) on adherence to HU (mDOT-HuA) in adults with SCA at Muhimbili National Hospital in Tanzania. The mDOT-HuA study is a single centre, prospective, randomized, open label clinical trial. One-hundred individuals with SCA with haemoglobin SS genotype, aged ≥18 years, living in Dar es Salaam, able and willing to record and submit videos electronically will be included. Participants will be divided into two treatment arms; 50 in the standard monitoring (SM) arm will receive mobile phones and fixed dose HU therapy with standard monitoring; 50 in the mDOT arm will receive mobile phones, fixed dose HU therapy with standard monitoring and a mobile directly observed web based medication adherence monitoring system. The primary outcome is the proportion of participants achieving ≥80 % HU adherence compared between the two arms as assessed through medication possession ratio at the end of 3 months of treatment. REDCap, an open source software application will be used to collect data using clinical research forms. The proportions of adherence in the two arms will be compared by Fisher’s exact test. Analysis of outcomes will have performed by both the intention-to treat and per-protocol methods.

Discussion

Should this study become sucessful, it will have the potential for the development of novel strategies for improving HU adherence in SCA.

Trial registration

ClinicalTrials.gov Identifier: NCT02844673, registered on 25^tht July 2016 (retrospectively registered).

Healthcare resource utilization associated with ivacaftor use in patients with cystic fibrosis

OBJECTIVE

Ivacaftor was approved in 2012 to treat patients with cystic fibrosis (CF) with specific CFTR gene mutations. The objective of this analysis was to analyze the impact of ivacaftor on health resource utilization through analysis of claims data.

METHODS

Patients diagnosed with CF aged ≥6 years prescribed ivacaftor between January 1, 2012 and July 31, 2014 with ≥12 months of continuous insurance coverage prior to and following the prescription were identified. All-cause and CF-specific healthcare resource utilization during the pre- and post-prescription periods and ivacaftor adherence levels were studied.

RESULTS

The 79 identified patients had a mean age of 20.8 years, and 54% were female. The proportion of patients with inpatient admissions (all-cause and CF-related) was significantly higher in the pre index compared to post index period (p ≤ 0.05). Mean ivacaftor medication possession ratio was 0.8 (SD = 0.3), and 73% of patients had a medication possession ratio >0.80.

LIMITATIONS

Only a small number of patients met the inclusion criteria. Additionally, claims data may contain errors or inconsistencies and cannot be used to determine if medications were taken as prescribed.

CONCLUSIONS

Ivacaftor therapy was associated with significant reductions in hospitalizations along with high rates of adherence to treatment over 12 months.

Association between gastrointestinal events and compliance with osteoporosis therapy

PURPOSE

The aim of this study was to estimate the rate of gastrointestinal (GI) events, and association between GI events and compliance with osteoporosis therapy among osteoporotic women.

METHODS

A retrospective cohort study using a large administrative claims database in the United States from 2001 through 2010 was conducted. We studied women ≥ 55 years old who were continuously enrolled in a health plan for at least 2 years, a baseline year before and a follow-up year after the date of the first prescription of oral bisphosphonate as the first oral osteoporosis treatment. Compliance with osteoporosis therapy was measured using the medication possession ratio (MPR), with compliance defined as MPR ≥ 0.8. Multivariate logistic regression was used to assess the association between occurrence of GI events and compliance with osteoporosis therapy after controlling for demographic and clinical characteristics.

RESULTS

A sample consisting of 75,593 women taking at least one oral bisphosphonate with mean (SD) age of 64 (8) years was identified. A total of 21,142 (28%) patients experienced at least one GI event during the follow-up period. Only 31,306 (41%) patients were compliant with osteoporosis therapy. Patients who experienced GI events after initiation of oral bisphosphonates were 29% less likely to adhere to osteoporosis therapy as compared to patients who did not experience GI events (odds ratio [95% CI], 0.71 [0.69-0.74]; P < .001).

CONCLUSIONS

Less than half of the patients were compliant with osteoporosis therapy within one year after initiating oral bisphosphonates, and the likelihood of compliance was significantly lower by 29% among women with GI events.

An evaluation of the impact of memory and mood on antiepileptic drug adherence

RATIONALE

Antiepileptic drugs are the mainstay of treatment for patients with epilepsy. Adherence to the prescribed regimen is a major factor in achieving a reduced seizure burden, which can decrease morbidity and mortality. Patients with epilepsy oftentimes complain about difficulty with memory. Because little is known about the relationship between memory and mood and adherence, the purpose of this project was to determine the impact of the confounding factors of memory and mood on antiepileptic drug adherence in patients with epilepsy.

METHODS

One hundred adult patients with epilepsy were recruited from the outpatient neurology clinic for this cross-sectional study. Patients who met the inclusion criteria completed measures of subjective memory (subset of 6 memory questions from the QOLIE-89) and objective memory (Hopkins Verbal Learning Test - Revised), subjective adherence (Morisky scale) and objective adherence (medication possession ratio), and mood (Neurological Disorders Depression Inventory for Epilepsy). Refill records from each patient's community pharmacy were used to objectively assess adherence. Medication possession ratios were calculated based on the antiepileptic drug refill records over the previous 6months. Patients were considered adherent if their MPR was >80%.

RESULTS

Women made up the majority of the sample (n=59), and, on average, patients had been living with epilepsy for nearly 20years. Approximately 40% of the sample were on antiepileptic drug monotherapy; most patients (>70%) took their antiepileptic drugs twice daily, and the mean number of total medications was 4.25±2.98. Based on the objective measure of adherence, 35% of the patients were nonadherent. Patients self-reported better adherence than what was objectively measured. Only the retention metric of the objective memory measure differentiated adherent patients from nonadherent patients. Patients in the adherent group had significantly lower depression scores (indicating better mood) compared with those in the nonadherent group (p=0.04).

CONCLUSIONS

Objective memory measures were not robustly correlated with adherence. However, we observed that patients with higher depressed mood scores were more likely to be nonadherent. By targeting patients with epilepsy and comorbid depression, practitioners may identify patients at greatest risk of nonadherence and subsequent harm.

Adherence to denosumab in the treatment of osteoporosis and its utilization in the Czech Republic

OBJECTIVES

The objective was to analyze adherence and current trends in utilization and prescription practice patterns of the anti-RANKL monoclonal antibody denosumab in the treatment of postmenopausal osteoporosis (OP).

METHODS

The prescription-based database of the General Health Insurance Company of the Czech Republic that covers approximately 60% of the Czech population (6 million) was used as the data source. Medication possession ratio (MPR) and persistence were calculated for all patients (both OP medication-naïve and medication-experienced) with postmenopausal OP from the start of their therapy with denosumab 60 mg per ml subcutaneous injection within a period between September 2011, i.e. first denosumab availability, and May 2014. Clinical data such as fractures, co-morbidities and co-medication were not analyzed.

RESULTS

A total of 7904 women treated with denosumab were analyzed; 93.8% of patients were identified as compliant (MPR ≥0.8) while 6.2% were non-compliant (MPR < 0.8). Persistence (base case, i.e. refill gap ≤30 days) was 59.1% after 12 months and 34.8% after 24 months. By 2013, i.e. within 2 years, denosumab became the second most utilized and most costly drug after oral bisphosphonates.

CONCLUSIONS

Despite relatively high MPR and persistence rate observed in denosumab treatment, adherence enhancing strategies, focused on persistence in particular, are still needed. The uptake of denosumab has been rapid, its utilization keeps rising swiftly, and denosumab already represents a significant part of the osteoporosis therapy budget.