An upper and lower bound of the Medication Possession Ratio

Hydrochlorothiazide Use and Risk of Skin Cancer: A Population-Based Retrospective Cohort Study

PURPOSE

Hydrochlorothiazide (HCTZ) exposure has been linked to increased skin cancer in Caucasian (white) populations, especially squamous cell carcinoma (SCC), but not basal cell carcinoma (BCC). This study aimed to evaluate and compare skin cancer risks associated with HCTZ- and other antihypertensives use.

METHODS

This retrospective cohort study utilized Taiwan's National Health Insurance Research Database. We identified patients aged 20 years and older, newly receiving antihypertensive medications between 2004 and 2015. We calculated the medication possession ratio (MPR) for the first 2 years of treatment to determine patient eligibility and treatment classification, whereby only patients with MPR above 80% were included. These were subsequently categorized by the type of antihypertensives they received, namely HCTZ, other thiazide diuretics, non-thiazide diuretics or non-diuretic antihypertensives. Cox proportional hazards model was used to evaluate skin cancer risks, and these were then classified as SCC or BCC.

RESULTS

Our study included 41 086, 27 402, 19 613, and 856 782 patients receiving HCTZ, other thiazide diuretics, non-thiazide diuretics, and non-diuretic antihypertensives, respectively. We found BCC risks were similar when comparing HCTZ with other thiazides (adjusted hazard ratio: 0.84; 95% CI: 0.54-1.33), non-thiazide diuretics (0.93; 0.51-1.67), and non-diuretic antihypertensives (0.91; 0.66-1.26). We observed a higher SCC risk in the HCTZ group, compared to other thiazides (1.24; 0.74-2.08), non-thiazide diuretics (1.32; 0.70-2.51), and non-diuretic antihypertensives (1.23; 0.87-1.73), although the confidence intervals (CIs) were wide and crossed the null.

CONCLUSIONS

We concluded that skin cancer need not be of major concern to physicians when prescribing antihypertensives for an Asian population.

The effects of multifactorial pharmacist-led intervention protocol on medication optimisation and adherence among patients with type 2 diabetes: A randomised control trial

Background

Patient-related factors and limited medication adherence in patients with chronic diseases, are associated with poor clinical outcomes, long-term complications, and increased overall disease costs. Many methods have been tested with mixed results, and innovative approaches are needed to encourage patients to adhere to their prescribed drug regimens.

Methods

This randomised controlled trial examined a new multifactorial pharmacist-led intervention protocol (MPIP), including a medication therapy management (MTM) program with face-to-face counselling, patient-specific medication booklets, and a mobile application, from July 2021 to September 2022 in the Oud Al Touba diagnostic and screening ambulatory centre in 192 patients with type 2 diabetes in the United Arab Emirates. Medication adherence was assessed using the fixed medication possession ratio of medication refills and the medication adherence questionnaire.

Results

At 12 months follow-up, participants in the MPIP showed significant improvement in overall medication adherence with total (composite) medication possession ratio (MPRt) of mean (±SD) 0.95 (±0.09) compared to 0.92 (± 0.09) in the control group with mean difference of 0.03 (95%, CI 0.01-0.06), P =0.02. In addition, improvement trend was evident in the MPIP group for all medication regimens with P value <0.01. Comparable results were noticeable in adherence questionnaire scores at the end of the study, with 66 participants in the intervention group scored zero on the questionnaire, suggesting high adherence to medication compared to the control group (48 participants only). The MTM program performed 41 clinical interventions on drug-related problems, compared to six interventions in the control group, and the use of mobile application and medication booklet have increased to 45.7% compared to 21.4% before study exit.

Conclusions

The pharmacy intervention protocol effectively improved medication adherence and optimised medication regimens in diabetic patients with chronic medication regimens in an ambulatory healthcare centre.

Investigating adherence to tyrosine kinase inhibitors in renal cancer

INTRODUCTION

Tyrosine kinase inhibitors (TKIs) have been used as the first-line treatment for many patients with renal cell carcinoma (RCC), the seventh most common cancer in the United Kingdom. However, suboptimal adherence to TKIs can result in poor clinical prognosis. This study quantified RCC patients' adherence to TKIs and explored factors associated with suboptimal adherence.

METHOD

This retrospective cohort study was conducted at a specialist oncology tertiary hospital in Northwest England, using pharmacy dispensing records between November 2021 and March 2022. TKI prescriptions dispensed to patients with RCC were extracted to calculate the persistency gaps (≥7 or ≥14 days) and medication possession ratio (MPR). Multilevel regression analysis was conducted to associate MPR and persistency gaps with specific patient-related and TKI-related factors. This study did not require ethics approval.

RESULTS

Of the 2225 prescriptions dispensed to 109 patients, 469 (23.4%) and 274 (13.7%) persistency gaps of ≥7 and ≥14 days were identified. About 75% and 92% of patients had a persistency gap of ≥7 days within the first 90 days and 180 days. The length of time since the first TKI prescription (p < 0.001) and the use of sunitinib(p = 0.003) were significantly associated with the number of prescription gaps of ≥7 days. Moreover, the median MPR was 95.6% (interquartile range: 90.7%, 100.1%). Similarly, the length of time since the first TKI prescription was dispensed (p < 0.001) and the use of sunitinib (p = 0.034) were significantly associated with MPR.

DISCUSSION AND CONCLUSION

This single-centre study found that patients with RCC generally adhere to TKIs (MPR > 90%), but many patients experienced a persistency gap. The crucial window to mitigate TKI utilisation is within 180 days after the initial dispensing of TKIs. Further large-scale studies are required to comprehensively investigate other factors associated with adherence to TKIs and develop interventions to improve adherence and medication use problems.

Initiation of Bisphosphonates Prior to Total Joint Arthroplasty Does Not Lower Periprosthetic Fracture Risk

BACKGROUND

Many patients are diagnosed with osteoporosis shortly prior to scheduling total joint arthroplasty (TJA). The purpose of this study was to determine if initiation of bisphosphonates prior to TJA decreased the risks of periprosthetic fractures (PPFx).

METHODS

A national database was used to identify all patients diagnosed with osteoporosis prior to primary TJA. Patients who had osteoporosis without preoperative bisphosphonate use were designated as our control group. Patients on preoperative bisphosphonates were stratified based on duration and timing of bisphosphonate use: long-term preoperative users (initiation 3 to 5 years preoperatively), intermediate-term preoperative users (initiation 1 to 3 years preoperatively), and short-term preoperative users (initiation 0 to 1 year preoperatively). Rates of PPFx at 90-day and 2-year follow-up were compared between groups.

RESULTS

In patients undergoing primary total hip arthroplasty, there was no difference in PPFx rate between our control group and preoperative bisphosphonate users of all durations at 90-day (P = .12) and 2-year follow-up (P = .22). In patients undergoing primary total knee arthroplasty, there was no difference in PPFx rate between our control group and preoperative bisphosphonate users of all durations at 90-day (P = .76) and 2-year follow-up (P = .39).

CONCLUSIONS

In patients undergoing primary TJA, preoperative bisphosphonate users did not have a decreased PPFx rate compared to our control group at 90-day and 2-year follow-up. Our findings suggest that preoperative bisphosphonate use, regardless of the duration of treatment, does not confer protective benefits against PPFx in patients undergoing TJA.

LEVEL OF EVIDENCE

Prognostic Level III.

Improved Outcomes in Eosinophilic Esophagitis with Higher Medication Possession Ratio

Eosinophilic esophagitis (EoE) disease activity can be caused by treatment non-adherence. Medication possession ratio (MPR) is an established metric of medication adherence. A higher MPR correlates with better outcomes in several chronic diseases, but MPR has not been investigated with respect to EoE. A retrospective cohort study was performed using an established EoE registry for the years 2005 to 2020. Treatment periods were identified, MPRs were calculated, and medical records were assessed for histologic remission (<15 eos/hpf), dysphagia, food impaction, stricture occurrence, and esophageal dilation that corresponded to each treatment period. In total, 275 treatment periods were included for analysis. The MPR in the histologic remission treatment period group was 0.91 (IQR 0.63-1) vs. 0.63 (IQR 0.31-0.95) for the non-remission treatment period group (p < 0.001). The optimal MPR cut-point for histologic remission was 0.7 (Sen 0.66, Spec 0.62, AUC 0.63). With MPRs ≥ 0.7, there were significantly increased odds of histologic remission (odds ratio 3.05, 95% confidence interval 1.79-5.30) and significantly decreased odds of dysphagia (OR 0.27, 95% CI 0.15-0.45), food impaction (OR 0.26, 95% CI 0.11-0.55), stricture occurrence (OR 0.52 95% CI 0.29-0.92), and esophageal dilation (OR 0.29, 95% CI 0.15-0.54). Assessing MPR before repeating an esophagogastroduodenoscopy may decrease unnecessary procedures in the clinical management of eosinophilic esophagitis.

Risk of circulatory diseases associated with proton-pump inhibitors: a retrospective cohort study using electronic medical records in Thailand

Background

Proton-pump inhibitors (PPIs) are prescribed to treat gastric acid-related diseases, while they may also have potential risks to population health. Recent studies suggested that a potential mechanism explaining the association between PPIs and cardiovascular diseases (CVD) includes the inhibition of the nitrate-nitrite-nitric oxide (NO) pathway. However, previous observational studies showed controversial results of the association. In addition, the inhibition of the NO pathway due to PPIs use may lead to peripheral vascular diseases (PVD); however, none of the studies explore the PPI-PVD association. Therefore, this study aimed to evaluate the association of PPIs with circulatory diseases (CVD, ischemic strokes or IS, and PVD).

Methods

We conducted a retrospective hospital-based cohort study from Oct 2010 to Sep 2017 in Songkhla province, Thailand. PPIs and histamine 2-receptor antagonists (H2RAs) prescriptions were collected from electronic pharmacy records, while diagnostic outcomes were retrieved from electronic medical records at Songklanagarind hospital. Patients were followed up with an on-treatment approach. Cox proportional hazard models were applied to measure the association comparing PPIs vs H2RAs after 1:1 propensity-score-matching. Sub-group analysis, multi-bias E-values, and array-based sensitivity analysis for some covariates were used to assess the robustness of associations.

Results

A total of 3,928 new PPIs and 3,928 H2RAs users were included in the 1:1 propensity score-matched cohort. As compared with H2RAs, the association of PPIs with CVD, IS, and PVD, the hazard ratios were 1.76 95% CI = [1.40-2.20] for CVD, 3.53 95% CI = [2.21-5.64] for ischemic strokes, and 17.07 95% CI = [13.82-76.25] for PVD. The association between PPIs and each outcome was significant with medication persistent ratio of over 50%. In addition, the association between PPIs and circulatory diseases was robust to unmeasured confounders (i.e., smoking and alcohol).

Conclusion

PPIs were associated with circulatory diseases, particularly ischemic strokes in this hospital-based cohort study, whereas, the strength of associations was robust to unmeasured confounders.

Association of Thyroid Hormone Medication Adherence With Risk of Dementia

CONTEXT

Recent studies suggest that hypothyroidism is a risk factor for dementia. Based on existing literature, it is unclear if treatment or compliance to treatment is associated with decreased dementia risk in hypothyroidism patients.

OBJECTIVE

To determine the association between thyroid hormone medication adherence and risk of dementia.

METHODS

A population-based cohort study following patients with newly diagnosed hypothyroidism until incidence of dementia, death, or December 31, 2020, whichever came earliest. The study comprised 41 554 older adults age 50 and above with newly diagnosed hypothyroidism between 2004 and 2008 who underwent health screening. Risk of dementia was evaluated using multivariable-adjusted Cox proportional hazards regression.

RESULTS

Among 5188 men (12.5%) and 36 366 (87.5%) women, 2120 cases of incident dementia were identified. After stratification of the participants according to the interquartile range of the medication possession ratio (MPR), the fourth quartile (highest adherence) showed a 14% lower risk of overall dementia compared with the first quartile (lowest adherence) (adjusted hazard ratio 0.86; 95% CI 0.76-0.97). No consistent association was observed between thyroid hormone medication adherence and vascular dementia. After a dichotomous stratification of the MPR, higher MPR (≥0.8) showed a lower risk of Alzheimer disease (adjusted hazard ratio 0.91; 95% CI 0.84-0.99) than lower MPR (<0.8).

CONCLUSION

Better adherence to thyroid hormone medication may be beneficial in preventing incident dementia, especially Alzheimer disease, in older adults with newly diagnosed hypothyroidism. Along with the resolution of hypothyroid symptoms and the reduction of cardiovascular risk factors, the reduction of dementia risk may be another potential benefit of thyroid hormone medication.

Chronic Atopic Dermatitis with Eosinophilia Improved by Daesiho-Tang: A Case Report

Purpose

This study is to report a case of chronic atopic dermatitis (AD) with eosinophilia, which did not respond to conventional therapy and was improved by Daesiho-tang (DSHT).

Patients and Methods

The patient visited our clinic with symptoms of atopic dermatitis including skin lesions and pruritus. Based on her symptoms, DSHT was prescribed. At each visit, the Scoring Atopic Dermatitis (SCORAD), Dermatology Life Quality Index (DLQI), and accompanying systemic symptoms (ASS) were measured. Multiple Allergen Simultaneous Test (MAST) was initially performed for 108 allergens and analyzed by Western blotting using an Alternate Scoring Method (ASM) according to the specific IgE concentration. Also, peripheral blood laboratory (Lab) tests were performed three times during the patient's visit.

Results

After taking DSHT, the total SCORAD score improved from 62.9 to 23.5, while the patient's ASS also improved. The DLQI score improved from 19 to 5. The total number of eosinophils in the peripheral blood, which showed a mild increase, recovered from 17.2% (0.98 x103/μL) to 4.5% (0.24 x103/μL). The total IgE slightly decreased, while AST and ALT were also restored to normal ranges.

Conclusion

Based on this case, DSHT is considered a potential alternative treatment for AD.

Osteoporosis medication adherence tools: a systematic review

Poor adherence reduces the effectiveness of osteoporosis treatment, resulting in lower bone mineral density and subsequently higher fracture rates. Reliable and practical tools are needed to measure medication adherence. The aim of this systematic review was to find osteoporosis medication adherence measurement tools and assess their applicability. Osteoporosis adherence measurement tools and all their related keywords in PubMed, Embase, Web of Science, and Scopus databases were searched on 4 December, 2022. After excluding duplicates in the Endnote software, two researchers independently investigated the remaining articles and included all those that used a method for measuring adherence to osteoporosis pharmacotherapy. Articles that did not specify the medications evaluated or if the primary focus was not adherence excluded. Two common measures of adherence, i.e., compliance and persistence were included. Four separate tables were designed, one for direct methods, one for formulas, one for questionnaires, and one for electronic methods of measuring adherence to treatment. Quality assessment was performed for selected articles by the Newcastle-Ottawa Quality Assessment Scale (NOS). A total of 3821 articles were found, of which 178 articles met the inclusion and exclusion criteria. In general, five types of methods were observed to measure medication adherence of osteoporosis, including direct methods (n = 4), pharmacy records (n = 17), questionnaires (n = 13), electronic methods (n = 1), and tablet counting (n = 1). The most commonly used adherence measurement tool, based on pharmacy records, was medication possession ratio (MPR). Among questionnaires, Morisky Medication Adherence Scale was mostly used. Our findings show what tools have been used to measure medication adherence in osteoporosis patients. Among these tools, direct methods and electronic methods are the most accurate methods. However, due to their high cost, they are practically not used in measuring osteoporosis medication adherence. Questionnaires are the most popular among them and are mostly used in osteoporosis.

Comparing the effectiveness and safety of dual antiplatelet with ticagrelor or clopidogrel in elderly Asian patients with acute myocardial infraction

Background

Current guidelines recommend potent P2Y12 inhibitors for patients after acute coronary syndrome. However, the data on the efficacy and safety of potent P2Y12 inhibitors in elderly Asian populations was limited. We aimed to investigate the major adverse cardiovascular events (MACE), bleeding events, and net adverse clinical events (NACE) with ticagrelor and clopidogrel in Taiwanese patients aged 65 and older after acute myocardial infarction (AMI).

Methods

This retrospective population-based cohort study was conducted using data from the National Health Insurance Research Database. The AMI patients aged ≥65 years who underwent percutaneous coronary intervention (PCI) and survived after 1 month were included. The patients were separated into 2 cohorts depending on the type of dual antiplatelet therapy (DAPT) they received: ticagrelor plus aspirin (T + A) or clopidogrel plus aspirin (C + A). We used inverse probability of treatment weighting to balance the difference between these 2 study groups. The outcome included all-cause mortality, MACE (cardiovascular death, nonfatal ischemic stroke, and nonfatal myocardial infarction), intracerebral hemorrhage, major bleeding, and NACE which is composed of cardiovascular death, ischemic and hemorrhagic events. The follow-up period was up to 12 months.

Results

From 2013 to 2017, a total of 14,715 patients who met the eligibility criteria were separated into 2 groups: 5,051 for T + A and 9,664 for C + A. Compared to patients with C + A, patients who received T + A had a lower risk of cardiovascular death and all-cause death, with an adjusted HR of 0.57 [95% confidence interval (CI), 0.38–0.85, p = 0.006] and 0.58 (95% CI 0.45–0.74, p &lt; 0.001), respectively. No differences were found in MACE, intracranial and major bleeding between the 2 groups. In addition, the patients with T + A had a lower risk of NACE with an adjusted HR of 0.86 (95% CI 0.74–1.00, p = 0.045)

Conclusion

Among elderly AMI patients receiving DAPT after successful PCI, ticagrelor was a more favorable P2Y12 inhibitor than clopidogrel because of lowering the risk of death and NACE without increasing the risk of severe bleeding. Ticagrelor is an effective and safe P2Y12 inhibitor in Asian elderly survivors after PCI.

Medication adherence with fixed-dose versus free-equivalent combination therapies: Systematic review and meta-analysis

Objective: We conducted a large-scale meta-analysis and subgroup analysis to compare the effect of fixed-dose combination (FDC) therapy with that of free-equivalent combination (FEC) therapy on medication adherence. Methods: Studies published in Web of Science, PubMed, Cochrane Library, ScienceDirect, and Embase up to May 2022 were identified according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary assessed outcomes were the medication possession ratio (MPR) and proportion of days covered (PDC). We investigated the probability of being adherent to the prescribed treatment (MPR or PDC ≥80%) or the average estimate of these two parameters. Studies reporting such results were included in this meta-analysis. The summary measures were reported as the risk ratio (RR) and the weighted mean difference (MD) with 95% of confidence interval (CI) using the random-effects model of DerSimonian and Laird. The quality of the cohort studies was assessed using the Newcastle-Ottawa scale. Results: Of the 1,814 screened studies, 61 met the predefined inclusion criteria. The meta-analysis of the results showed that compared to FEC, FDC significantly improved the medication compliance of patients by 1.29 times (95% CI:1.23-1.35, p < 0.00001). I² of 99% represent high heterogeneity across studies. The mean difference in medication adherence between FDC and FEC was 0.10 (95% CI: 0.06-0.14, p < 0.00001) with an I² estimate of 100%. Subgroup analyses were performed for studies that reported adherence outcomes according to disease type, period of evaluation and compliance indicators. A sensitivity analysis was conducted to exclude the results of low-quality studies, as well as studies in which there was ambiguity in the method of calculating the estimator. Conclusion: Analysis of the assessed parameters for the intention-to-treat and subgroup populations suggests that FDC can improve adherence to treatment and its advantages over FEC may increase over time. Further research is needed to better understand how medical conditions affect the impact of reduced pill burden on adherence, particularly in diseases other than cardiovascular disease and type 2 diabetes mellitus.

[Effect of a Family Pharmacist System on Medication Adherence of Patients with Dyslipidemia during a COVID-19 Epidemic]

The pharmacy pharmacist's function as a family pharmacist is expected to improve adherence to medication in patients suffering from chronic diseases, including dyslipidemia. This is true even in infectious disease epidemics. In this study, using anonymously processed receipt data from 700 insurance pharmacies in our group, we evaluated medication adherence in patients taking statin drugs before, during the first and second years of coronavirus disease 2019 (COVID-19) epidemic in terms of medication persistence and medication possession, and compared the results between the family pharmacist group (FP group) and non-family pharmacist group (NoFP group). The odds ratios of good medication adherence (medication persistence and medication possession) rates for the FP group relative to the NoFP group were 1.446 [95% confidence interval (CI): 1.210-1.727] in the pre-epidemic period, 1.428 (1.192-1.710) in the first year of the epidemic, and 1.270 (1.113-1.450) in the second year of the epidemic. The FP group was significantly higher in all time periods. Therefore, it is suggested that the family pharmacist function improves adherence to statins not only before but also during the COVID-19 epidemic.

Estimates of Chronic Kidney Diseases Associated with Proton-Pump Inhibitors Using a Retrospective Hospital-Based Cohort in Thailand

PURPOSE

Potential adverse outcomes of Proton pump inhibitors (PPIs) have increasingly been reported. The potential risks to PPIs include hypomagnesemia and chronic kidney disease (CKD). Unlike a real-world electronic medical record (RW-EMR) with active-comparator design, claim databases and special population cohort with non-user design, using in previous studies, resulted in a wide range of strength of association with indication bias. This study aimed to measure the total effect of association between PPIs use and CKD incidence using Thai RW-EMR.

PATIENTS AND METHODS

A retrospective hospital-based cohort was applied into this study. Electronic medical records and administrative data of out- and inpatient were retrieved from October 1st, 2010 to September 30th, 2017. On-treatment with grace period as well as propensity score matching was used in data analysis. Cox proportional hazard models were applied to evaluate the PPIs-CKD association.

RESULTS

Of all 63,595 participants, a total of 59,477 new PPIs and 4118 Histamine 2-receptor antagonist (H2RA) users were eligible for follow-up. As compared with H2RA, the PPI users were non-elderly and more likely being female. The association of PPIs with CKD was statistically significant (adjusted hazard ratio [HR] = 3.753, 95% CI = 2.385-5.905). The HR were not statistically different by concomitant use PPIs with NSAIDs and by medication possession ratio levels.

CONCLUSION

The association between PPIs and CKD incidence was statistically significant in this hospital-based cohort. However, self-treatment with over-the-counter PPIs, as well as, smoking, drinking alcohol and body mass index could not be fully retrieved, affecting the estimation of treatment effect.

Predictors of adherence and the role of primary non-adherence in antihormonal treatment of breast cancer

BACKGROUND

Antihormonal treatment for hormone receptor (HR) positive breast cancer has highly beneficial effects on both recurrence rates and survival. We investigate adherence and persistence in this group of patients.

METHODS

The study population comprised 1192 patients with HR-positive breast cancer who were prescribed adjuvant antihormonal treatment from 2004 to 2013. Adherence was defined as a medical possession ratio (MPR) of ≥80.

RESULTS

Of the 1192 included patients, 903 (75.8%) were adherent and 289 (24.2%) were non-adherent. Primary non-adherence was seen in 101 (8.5%) patients. The extremes of age (< 40 and ≥ 80 years) were associated with poor adherence. Patients with metastasis to axillary lymph nodes and those who received radiotherapy and/or chemotherapy were more likely to be adherent. Better adherence was also shown for those who switched medication at 2 years after diagnosis. Primary non-adherence seems to be associated with cancers with a good prognosis.

CONCLUSION

Adherence to antihormonal therapy for breast cancer is suboptimal. Primary non-adherence occurs among patients with a relatively good prognosis. Non-adherent patients tend to terminate their antihormonal therapy in the initial part of the treatment period. Targeted interventions to improve adherence should be focused on the first part of the treatment period.

Hydroxychloroquine and immunosuppressant adherence patterns and their association with subsequent hospitalization rates among children with systemic lupus erythematosus

OBJECTIVES

Using a representative sample of children with systemic lupus erythematosus (SLE) in the United States, we characterized prescription claim-based hydroxychloroquine and immunosuppressant adherence estimates and evaluated their concurrent and predictive validity.

METHODS

We identified children ages 5-18 with SLE in the Truven Health MarketScan® Commercial and Medicaid claims databases (2013-2018). Among new users of hydroxychloroquine and immunosuppressant medications, we calculated proportion of days covered (PDC) over 365 days to estimate adherence by user group (mycophenolate, azathioprine, methotrexate, and any immunosuppressant use). Agreement between adherence estimates was evaluated with intraclass correlation coefficients (ICC) and kappa statistics. Separate negative binomial regression models were used to estimate associations between (a) hydroxychloroquine, (b) immunosuppressant, or (c) concurrent immunosuppressant/hydroxychloroquine non-adherence and subsequent hospitalizations, adjusted for baseline demographics, disease severity, and healthcare utilization.

RESULTS

Among 423 new hydroxychloroquine/immunosuppressant users, 63% were Medicaid recipients. Sufficient adherence (PDC≥80%) ranged from 33 to 45% for immunosuppressants vs. 51-52% for hydroxychloroquine. Agreement between hydroxychloroquine and immunosuppressant adherence was modest overall, but better for mycophenolate (ICC 0.55) than methotrexate (0.27). Hydroxychloroquine non-adherence was associated with a 2.9-fold higher incidence of subsequent hospitalizations (95% CI [1.2-7.1]), whereas immunosuppressant and concurrent non-adherence were associated with 5.9 [2.4-14.6] and 5.6-fold [2.0-15.5] increased incidence, respectively. Use of concurrent adherence improved upon estimation of hospitalization risk compared to hydroxychloroquine adherence, but not immunosuppressant adherence alone.

CONCLUSIONS

Hydroxychloroquine adherence is an imperfect proxy for adherence to other lupus medications among children with SLE, and therefore assessing immunosuppressant adherence concurrently adds value to hydroxychloroquine adherence assessments. Prescription claims-based immunosuppressant adherence measures are predictive of acute care utilization and may inform population management strategies.

Can clinician champions reduce potentially inappropriate medications in people living with dementia? Study protocol for a cluster randomized trial

BACKGROUND

For people living with dementia (PLWD) the overuse of potentially inappropriate medications (PIMs) remains a persistent problem. De-prescribing trials in the elderly have mixed results. Clinician champions may be uniquely suited to lead efforts to address this challenge. Here we describe the study protocol for a 24-month embedded pragmatic cluster-randomized clinical trial within two accountable care organizations (ACOs) of such a clinician champion intervention. The specific aims are to (1) assess the effectiveness of a clinician champion on de-implementing PIMs in PLWD, (2) determine if the intervention is associated with a reduction in emergency department (ED) visits and hospitalizations attributed to a fall, and (3) examine five implementation outcomes: appropriateness, feasibility, fidelity, penetration, and equity.

METHODS/DESIGN

Two ACOs agreed to participate: United States Medical Management (USMM) and Oschner Health System. The unit of randomization will be the primary care clinic. A clinician champion will be recruited from each of the intervention clinics to participate in a 6-month training program and then work with clinicians and staff in their clinic for 12 months to reduce the use of PIMs in their PLWD population. For aims 1 and 2, Medicare claims data will be used to assess outcomes. The outcome for aim #1 will be medication possession rates per quarter, for the three therapeutic classes of PIMs among patients with dementia in intervention clinics versus control clinics. For aim #2, we will assess the incidence of falls using a previously validated algorithm. For both aims 1 and 2, we will construct hierarchical models with time period observations nested within patient using generalized estimating equations (GEE) with robust standard errors. The key variable of interest will be the treatment indicator assigned based on practice. For aim #3, we will conduct qualitative thematic analysis of documentation by the clinician champions in their project workbooks to evaluate the five implementation outcomes.

DISCUSSION

This embedded pragmatic trial will add to our existing knowledge regarding the effectiveness of a clinician champion strategy to de-prescribe potentially inappropriate medication among patients with dementia as well as its appropriateness, feasibility, fidelity, penetration, and equity.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05359679 , Registered May 4, 2022.

A systematic review of adherence to anticoagulation regimens in pediatric patients

Thromboembolic disease rates are increasing in pediatric patients. Anticoagulation is prescribed for treatment and prevention of thromboembolic disease. While nonadherence to anticoagulation regimens predicts poor health outcomes in adults, data in anticoagulated pediatric patients are limited. We systematically reviewed the rates, outcomes, and predictors of anticoagulation nonadherence in the pediatric population. Out of a total of 3581 unique articles identified for review, 17 studies met inclusion criteria. These studies primarily evaluated patients with cardiac disease treated with vitamin K antagonists. Overall nonadherence rates varied from 3% to 42%, based upon population, definition of adherence, and measurement strategy. Patient age, goal international normalized ratio (INR), and number of concurrent potentially interacting medications correlated with nonadherence. Data examining the relationship between nonadherence and health outcomes were included in only two studies. Limitations of current literature, as well as critical knowledge gaps that require future study, are discussed.

Consumers' self-reported adherence to directions for non-prescription medicines and the role of risk perception

BACKGROUND

Non-prescription medicines (NPMs), while relatively safe, are responsible for a small but significant proportion of medication misadventure and inappropriate use may lead to avoidable healthcare cost. Some consumers vary their use of NPMs from the directions provided on packaging or advice from healthcare professionals. Consumers may use NPMs at lower doses or less frequently than directed because of the risk of side effects.

PURPOSE

This study aimed to develop and validate a self-report measure for the extent to which consumers' follow directions (FDs) for NPMs. Secondly, it aimed to explore the relationship between risk perception towards NPMs and following directions.

METHODS

A cross-sectional study was administered online to participants who belong to an Australian agency which conducts consumer research. Participants were Australian adults who had used NPMs within the last month. Items for the FD-NPM scale were developed and validated. Exploratory factor analysis and confirmatory factor analysis were used to validate the FD-NPM scale. Structural equation modelling (SEM) was employed to explore the relationships between risk perception, covariates, and FDs.

RESULTS

There were 403 participants recruited. Less than 20% "always" or "often" self-reported following directions for dose, frequency, or duration of use. Factor analyses confirmed that there are two moderately positively correlated dimensions of FD-NPM (r = 0.46), which were named underuse and overuse. That is, consumers who self-reported underuse of non-prescription medicines were also more likely to self-report overuse. Consumers with high-risk perception towards NPMs, those who were younger and those who were more educated had a greater tendency to not follow directions.

CONCLUSION

A new self-report measure, the FD-NPM scale was developed and validated. That people who perceives NPMs to be harmful, tend to underuse and more concerningly, overuse them, is of great interest to clinicians and policymakers who are required to manage risk communications.

Clinical Data Cohort Quality Improvement: The Case of the Medication Data in The University of Minnesota's Clinical Data Repository

Clinical and translational research centers (CTRCs) have emerged as key centers for electronic medical record related research through integrated data repositories (IDRs) and the 'secondary use' of clinical data. Researchers accessing and pre-processing ever increasing amounts of electronic medical records for data mining tasks have a growing need for best practice approaches for clinical data quality assessment and improvement. This project focused on a large data extract for 7 statin medication prescriptions for patients with cardiovascular disease. After the initial data extraction, we proceeded to analyze the data for completeness, correctness, currency, and percentage populated using established data quality frameworks. Assessment of the said data was performed through medication possession ratios, medication discontinuation reasons, and drug dosages. When we compared distributions of data elements such as drug dosage before and after changes were introduced by our pre-processing protocols, only a minimal noticeable difference was found as the clinical data cohort quality assessment and pre-processing were completed without substantially altering the original data structure. Our study demonstrated practical steps for clinical data cohort quality improvement using medication data and illustrates a best practice approach in clinical data cohort quality improvement for any data mining tasks.

Comparison of Approaches for Measuring Adherence and Persistence to Oral Oncologic Therapies in Patients Diagnosed with Metastatic Renal Cell Carcinoma

BACKGROUND

Adherence and persistence studies face several methodologic difficulties, including short-term mortality. We compared approaches to quantify adherence and persistence to first line (1L) oral targeted therapy (TT) in patients diagnosed with metastatic renal cell carcinoma (mRCC).

METHODS

Patients with mRCC ages 66 years or more who initiated TTs within 4 months of diagnosis were identified in the Surveillance, Epidemiology, and End Results Medicare-linked database (2007-2015). Adherence [proportion of days covered (PDC) >80%] was calculated using (i) PDC with a fixed 6-month denominator including then excluding patients who died within the 6 months and (ii) PDC with a denominator measuring time on treatment. Risk of nonpersistence was obtained by censoring death or treating death as a competing risk using cumulative incidence functions.

RESULTS

Among 485 patients with mRCC initiating a 1L oral TT (sunitinib, 64%; pazopanib, 25%; other, 11%), 40% died within 6 months. Adherence was higher after restricting to patients who survived (60%) compared with including those patients and assigning zero days covered after death (47%). Risk of nonpersistence was higher when censoring patients at death, 0.91 [95% confidence interval (CI), 0.88-0.94], compared with treating death as a competing risk, 0.75 (95% CI, 0.71-0.79).

CONCLUSIONS

Different approaches to handling death resulted in different adherence and persistence estimates in the metastatic setting. Future studies should explicitly report the proportion of patient deaths over time and explore appropriate methods to account for death as competing risk.

IMPACT

Use of several approaches can provide a more comprehensive picture of medication-taking behavior in the metastatic setting where death is a major competing risk.

The Impact of the COVID-19 Outbreak on Patients' Adherence to PCSK9 Inhibitors Therapy

PCSK9 inhibitors (PCSK9i) are monoclonal antibodies that have been shown to be effective in reducing both LDL cholesterol (LDL-C) values and major cardiovascular events in patients at high cardiovascular risk. Adherence to PCSK9i is critical for the success of the treatment. The aim of the present study is to evaluate patients' adherence to PCSK9i during the COVID-19 pandemic. Patients referred to the Cardiac Diagnostic Unit of the University of Campania "Luigi Vanvitelli" Naples, taking PCSK9i, and who missed the cardiological follow-up visit during the first national COVID-19 lockdown (9 March-17 May 2020), were included. Each patient underwent medical teleconsultation to collect current clinical conditions, adherence to drug treatments, and lipid profile laboratory tests. Among 151 eligible patients, 20 were excluded for missing or untraceable telephone numbers and one for refusing to join the interview. The selected study population consisted of 130 patients (64 ± 9 years, 68% males), of whom 11 (8.5%) reported a temporary interruption of the PCSK-9 therapy for a mean period of 65 ± 1.5 days. The non-adherent patients showed a marked increase in LDL-C than in the pre-pandemic period (90.8 ± 6.0 vs. 54.4 ± 7.7 mg/dL, p < 0.0001), and 82% of patients moved out of the LDL-C therapeutic range. The non-adherent group was more likely to have a very high cardiovascular risk compared to the adherent group (81.8 vs. 33.6%, p < 0.001). Causes of interruption included drug prescription failure (63.6%) due to temporary interruption of the non-urgent outpatient visits and failure in drug withdrawal (36.4%) due to patients' fear of becoming infected during the pandemic. The COVID-19 lockdown caused a remarkable lack of adherence to PCSK9i therapy, risking negative implications for the health status of patients at high cardiovascular risk. Facilitating patients' access to PCSK9i and enhancing telemedicine seem to be effective strategies to ensure the continuity of care and appropriate management of these patients.

Delta T, a Useful Indicator for Pharmacy Dispensing Data to Monitor Medication Adherence

INTRODUCTION

Calculating patients' medication availability from dispensing or refill data is a common method to estimate adherence. The most often used measures, such as the medication possession ratio (MPR), average medication supplies over an arbitrary period. Averaging masks the variability of refill behavior over time.

GOAL

To derive a new absolute adherence estimate from dispensing data.

METHOD

Dispensing histories of patients with 19 refills of direct oral anticoagulants (DOAC) between 1 January 2008 and 31 December 2017 were extracted from 39 community pharmacies in Switzerland. The difference between the calculated and effective refill day (ΔT) was determined for each refill event. We graphed ΔT and its dichotomized version (dΔT) against the MPR, calculated mean ΔT and mean dΔT per refill, and applied cluster analysis.

RESULTS

We characterized 2204 refill events from 116 DOAC patients. MPR was high (0.975 ± 0.129) and showed a positive correlation with mean ΔT. Refills occurred on average 17.8 ± 27.9 days "too early", with a mean of 75.8 ± 20.2 refills being "on time". Four refill behavior patterns were identified including constant gaps within or at the end of the observation period, which were critical.

CONCLUSION

We introduce a new absolute adherence estimate ΔT that characterizes every refill event and shows that the refill behavior of DOAC patients is dynamic.

Factors associated with pharmacological and psychotherapy treatments adherence in patients with borderline personality disorder

BACKGROUND

Borderline personality disorder is a major mental illness characterized by sustained relationship instability, impulsive behavior, and intense affects. Adherence is a complex behavior, from minor refusals to abandonment of treatment, which can be affected by various factors. Therefore, the present study aimed to investigate the factors affecting pharmacological and psychotherapy adherence, patients' attitude toward medication, and assessing medication and treatment adherence in patients with borderline personality disorder referred to an outpatient referral clinic in Tehran, Iran.

METHODS

The study was a cross-sectional study. The files of patients with borderline personality disorder referred to the outpatient clinic of the Tehran Psychiatric Institute were reviewed as the first step. Data were collected using the Drug Attitude Inventory-10 (DAI-10) questionnaire and a questionnaire to determine the attitude of patients toward pharmacological and psychotherapy treatment as well as therapeutic adherence. After collecting data, patients' therapeutic adherence was divided into poor, partial, and good compliance.

RESULTS

Ninety-four patients were involved in the study, and fifty-four were women. Findings of DAI showed that 54 (57.4%) participants had negative attitudes toward medication, while 38 (40.4%) participants showed a negative attitude toward psychotherapy treatment. Additionally, the percentage of patients with good psychotherapy adherence (44.7%) was higher than that of patients with good medication adherence (31.9%). The most common reasons for discontinuation of treatment were medication side effects (53.1%), dissatisfaction with the therapist (40.3%), and then fear of medication dependence (40%). Patients with higher education levels and a positive history of hospitalization in a psychiatric ward had better adherence to psychotherapy (P < 0.05).

CONCLUSION

Results of the current study show that attitude toward psychotherapy is more favorable than pharmacotherapy among patients with BPD. The rationale may be that medications are mainly prescribed for comorbid conditions and do not have substantial effects on the BPD symptoms, resulting in low medication adherence.

Associations Between Antidepressant Use and Advanced Diabetes Outcomes in Patients with Depression and Diabetes Mellitus

CONTEXT

Comorbid depression in patients with diabetes deteriorates the prognosis. Antidepressants might attenuate the adverse effects of depression; however, they are associated with cardiometabolic adverse effects.

OBJECTIVE

This study aimed to explore the association between antidepressant treatment and advanced diabetic complications and mortality among patients with depression and diabetes mellitus.

METHODS

We conducted a nationwide retrospective cohort study of 36 276 patients with depression and newly treated diabetes mellitus using Taiwan's universal health insurance database. Antidepressant treatment patterns within a 6-month window were classified into none, poor, partial, and regular use, and we accounted for time-dependent variables in the Cox proportional hazards regression analysis with adjustment for time-dependent comorbidity and concomitant use of medications. Different classes of antidepressants were compared. Macro- and microvascular complications, as well as all-cause mortality, were the main outcomes. Benzodiazepines were chosen as negative control exposure.

RESULTS

Compared with poor use of antidepressants, regular use was associated with a 0.92-fold decreased risk of macrovascular complications and a 0.86-fold decreased risk of all-cause mortality but not associated with microvascular complications. Regular use of selective serotonin reuptake inhibitors was associated with a 0.83- and 0.75-fold decreased risk of macrovascular complications and all-cause mortality, respectively. Regular use of tricyclic or tetracyclic antidepressants was associated with a 0.78-fold decreased risk of all-cause mortality. Regular use of benzodiazepine showed no association with diabetic outcomes.

CONCLUSION

Regular antidepressant use was associated with lower risk of advanced diabetic complications compared with poor adherence. Clinicians should emphasize antidepressant treatment adherence among patients with depression and diabetes mellitus.

Measuring Medication Adherence in a Population-Based Asthma Administrative Pharmacy Database: A Systematic Review and Meta-Analysis

Background

Limited studies have systematically reviewed the literature to identify and compare the various database methods and optimal thresholds for measuring medication adherence specific to adolescents and adults with asthma. In the present study, we aim to identify the methods and optimal thresholds for measuring medication adherence in population-based pharmacy databases.

Methods

We searched PubMed, Embase, International Pharmaceutical Abstracts (IPA), Web of Science, Google Scholar, and grey literature from January 1, 1998, to March 16, 2021. Two independent reviewers screened the studies, extracted the data, and assessed the quality of the studies. A quantitative knowledge synthesis was employed.

Results

Thirty-eight (38) retrospective cohort studies were eligible. This review identified 20 methods for measuring medication adherence in adolescent and adult asthma administrative health records. Two measures namely the medication possession ratio (MPR) and proportion of days covered (PDC) were commonly reported in 87% of the literature included in this study. From the meta-analysis, asthma patients who achieved adherence threshold of "0.75-1.00" [OR: 0.56, 95% CI: 0.41 to 0.77] and ">0.5" [OR: 0.71, 95% CI: 0.54 to 0.94] were less likely to experience asthma exacerbation.

Conclusion

Despite their limitations, the PDC and the MPR still remain the most common measures for assessing adherence in asthma pharmacy claim databases. The evidence synthesis showed that an adherence threshold of at least 0.75 is optimal for classifying adherent and non-adherent asthma patients.

Obese, non-eosinophilic asthma: frequent exacerbators in a real-world setting

OBJECTIVE

In the UK, asthma deaths are at their highest level this century. Increased recognition of at-risk patients is needed. This study phenotyped frequent asthma exacerbators and used machine learning to predict frequent exacerbators.

METHODS

Patients admitted to a district general hospital with an asthma exacerbation between 1st March 2018 and 1st March 2020 were included. Patients were organized into two groups: "Infrequent Exacerbators" (1 admission in the previous 12 months) and "Frequent Exacerbators" (≥2 admissions in the previous 12 months). Patient data were retrospectively collected from hospital and primary care records. Machine learning models were used to predict frequent exacerbators.

RESULTS

200 patients admitted for asthma exacerbations were randomly selected (73% female; mean age 47.8 years). Peripheral eosinophilia was uncommon in either group (21% vs 19%). More frequent exacerbators were being treated with high-dose ICS than infrequent exacerbators (46.5% vs 23.2%; P < 0.001), and frequent exacerbators used more SABA inhalers (10.9 vs 7.40; P = 0.01) in the year preceding the current admission. BMI was raised in both groups (34.2 vs 30.9). Logistic regression was the most accurate machine learning model for predicting frequent exacerbators (AUC = 0.80).

CONCLUSIONS

Patients admitted for asthma are predominately female, obese and non-eosinophilic. Patients who require multiple admissions per year have poorer asthma control at baseline. Machine learning algorithms can predict frequent exacerbators using clinical data available in primary care. Instead of simply increasing the dose of corticosteroids, multidisciplinary management targeting Th2-low inflammation should be considered for these patients.

Accurate Medication Adherence Measurement Using Administrative Data for Frequently Hospitalized Patients

Background: Pharmacy administrative claims data remain an accessible and efficient source to measure medication adherence for frequently hospitalized patient populations that are systematically excluded from the landmark drug trials. Published pharmacotherapy studies use medication possession ratio (MPR) and proportion of days covered (PDC) to calculate medication adherence and usually fail to incorporate hospitalization and prescription overlap/gap from claims data. To make the cacophony of adherence measures clearer, this study created a refined hospital-adjusted algorithm to capture pharmacotherapy adherence among patients with end-stage renal disease (ESRD). Methods: The United States Renal Data System (USRDS) registry of ESRD was used to determine prescription-filling patterns of those receiving new prescriptions for oral P2Y12 inhibitors (P2Y12-I) between 2011 and 2015. P2Y12-I-naïve patients were followed until death, kidney transplantation, discontinuing medications, or loss to follow-up. After flagging/censoring key variables, the algorithm adjusted for hospital length of stay (LOS) and medication overlap. Hospital-adjusted medication adherence (HA-PDC) was calculated and compared with traditional MPR and PDC methods. Analyses were performed with SAS software. Results: Hospitalization occurred for 78% of the cohort (N = 46 514). The median LOS was 12 (interquartile range [IQR] = 2-34) days. MPR and PDC were 61% (IQR = 29%-94%) and 59% (IQR = 31%-93%), respectively. After applying adjustments for overlapping coverage days and hospital stays independently, HA-PDC adherence values changed in 41% and 52.7% of the cohort, respectively. When adjustments for overlap and hospital stay were made concurrently, HA-PDC adherence values changed in 68% of the cohort by 5.8% (HA-PDC median = 0.68, IQR = 0.31-0.93). HA-PDC declined over time (3M-6M-9M-12M). Nearly 48% of the cohort had a ≥30 days refill gap in the first 3 months, and this increased over time (P < .0001). Conclusions: Refill gaps should be investigated carefully to capture accurate pharmacotherapy adherence. HA-PDC measures increased adherence substantially when adjustments for hospital stay and medication refill overlaps are made. Furthermore, if hospitalizations were ignored for medications that are included in Medicare quality measures, such as Medicare STAR program, the apparent reduction in adherence might be associated with lower quality and health plan reimbursement.

Using a learning health system to understand the mismatch between medicines supply and actual medicines use among adults with cystic fibrosis

BACKGROUND

Studies in separate cohorts suggest possible discrepancies between inhaled medicines supplied (median 50-60%) and medicines used (median 30-40%). We performed the first study that directly compares CF medicine supply against use to identify the cost of excess medicines supply.

METHODS

This cross-sectional study included participants from 12 UK adult centres with ≥1 year of continuous adherence data from data-logging nebulisers. Medicine supply was measured as medication possession ratio (MPR) for a 1-year period from the first suitable supply date. Medicine use was measured as electronic data capture (EDC) adherence over the same period. The cost of excess medicines was calculated as whole excess box(es) supplied after accounting for the discrepancy between EDC adherence and MPR with 20% contingency.

RESULTS

Among 275 participants, 133 (48.4%) were females and mean age was 30 years (95% CI 29-31 years). Median EDC adherence was 57% (IQR 23-86%), median MPR was 74% (IQR 46-96%) and the discrepancy between measures was median 14% (IQR 2-29%). Even with 20% contingency, mean potential cost of excess medicines was £1,124 (95% CI £855-1,394), ranging from £183 (95% CI £29-338) for EDC adherence ≥80% to £2,017 (95% CI £1,507-2,526) for EDC adherence <50%.

CONCLUSIONS

This study provides a conservative estimate of excess inhaled medicines supply cost among adults with CF in the UK. The excess supply cost was highest among those with lowest EDC adherence, highlighting the importance of adherence support and supplying medicine according to actual use. MPR provides information about medicine supply but over-estimates actual medicine use.

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.

Comparative Effectiveness and Safety of Different Types of Inhaled Long-Acting β2-Agonist Plus Inhaled Long-Acting Muscarinic Antagonist vs Inhaled Long-Acting β2-Agonist Plus Inhaled Corticosteroid Fixed-Dose Combinations in COPD A Propensity Score-Inverse Probability of Treatment Weighting Cohort Study

BACKGROUND

Despite multiple available fixed-dose combinations (FDCs) of inhaled long-acting β₂-agonists (LABAs) plus long-acting muscarinic antagonists (LAMAs) and LABAs plus inhaled corticosteroids (ICS) for COPD, uncertainty remains regarding their comparative effects.

RESEARCH QUESTION

Can comparative effectiveness and safety of LABA plus LAMA (LABA/LAMA) and LABA plus ICS (LABA/ICS) FDCs vary by different individual components of the dual combinations in COPD?

STUDY DESIGN AND METHODS

We conducted a new user, propensity score-inverse probability of treatment weighting cohort study to compare the effectiveness and safety of two frequently used LABA/LAMA FDCs (indacaterol plus glycopyrronium [IND/GLY] and vilanterol plus umeclidinium [VI/UMEC]) vs three commonly prescribed LABA/ICS FDCs (salmeterol plus fluticasone propionate [SAL/FP], formoterol fumarate plus budesonide [FF/BUD], and formoterol fumarate plus beclomethasone dipropionate [FF/BDP]) using the Taiwanese nationwide health-care claims from 2014 through 2017. The primary effectiveness outcome was the annual moderate to severe exacerbation rate, and safety outcomes included risks of severe pneumonia and cardiovascular disease requiring hospitalization. Weighted generalized linear mixed models and Cox proportional hazard models were used to assess the effectiveness and safety outcomes, respectively.

RESULTS

Patients with COPD initiating IND/GLY and VI/UMEC showed an 11% (incidence rate ratio [IRR], 0.89; 95% CI, 0.80-0.98) and 20% (IRR, 0.80; 95% CI, 0.71-0.90) reduced annual rate of moderate to severe exacerbations, respectively, than those initiating SAL/FP, but showed a similar rate as those initiating FF/BUD or FF/BDP. Both LABA/LAMA FDCs, compared with SAL/FP and VI/UMEC vs FF/BDP, were associated with a 27% (hazard ratio [HR], 0.73; 95% CI, 0.59-0.90) to 42% (HR, 0.58; 95% CI, 0.48-0.70) reduced pneumonia risk. Cardiovascular risk was comparable in five groups. An intraclass difference existed in rates of moderate to severe COPD exacerbation and risks of pneumonia among LABA/ICS FDCs, but not between LABA/LAMA FDCs.

INTERPRETATION

Both LABA/LAMAs vs SAL/FP are associated with a lower exacerbation rate and pneumonia risk, but exhibit similar effectiveness and safety outcomes compared with FF/BDP or FF/BUD, suggesting that comparative effects may differ by individual components of the dual therapies in COPD.

Optimal cut-off points for adherence measure among patients with type 2 diabetes in primary care clinics: a retrospective analysis

Background

Medication adherence measures are often dichotomized to classify patients into those with good or poor adherence using a cut-off value ⩾80%, but this cut-off may not be universal across diseases or medication classes. This study aimed to examine the cut-off value that optimally distinguish good and poor adherence by using the medication possession ratio (MPR) and proportion of days covered (PDC) as adherence measures and glycated hemoglobin (HbA1c) as outcome measure among type 2 diabetes mellitus (T2DM) patients.

Method

We used pharmacy dispensing data of 1461 eligible T2DM patients from public primary care clinics in Malaysia treated with oral antidiabetic drugs between January 2018 and May 2019. Adherence rates were calculated during the period preceding the HbA1c measurement. Adherence cut-off values for the following conditions were compared: adherence measure (MPR versus PDC), assessment period (90-day versus 180-day), and HbA1c target (⩽7.0% versus ⩽8.0%).

Results

The optimal adherence cut-offs for MPR and PDC in predicting HbA1c ⩽7.0% ranged between 86.1% and 98.3% across the two assessment periods. In predicting HbA1c ⩽8.0%, the optimal adherence cut-offs ranged from 86.1% to 92.8%. The cut-off value was notably higher with PDC as the adherence measure, shorter assessment period, and a stricter HbA1c target (⩽7.0%) as outcome.

Conclusion

We found that optimal adherence cut-off appeared to be slightly higher than the conventional value of 80%. The adherence thresholds may vary depending on the length of assessment period and outcome definition but a reasonably wise cut-off to distinguish good versus poor medication adherence to be clinically meaningful should be at 90%.

Gender Differences in the Risk of Ischemic Heart Disease According to Healthcare Utilization and Medication Adherence among Newly Treated Korean Hypertensive Patients

We aimed to investigate gender differences in ischemic heart disease (IHD) according to healthcare utilization and medication adherence among newly treated Korean hypertensive adults. The National Sample Cohort version 2.0 of the National Health Insurance Service was used for analysis. Newly treated hypertensive patients ≥ 20 years and without IHD in 2002 were selected from a population that underwent health examination during 2003-2006. Of those patients, 11,942 men and 11,193 women were analyzed and followed up for 10 years. We determined the association between IHD and healthcare utilization and medication adherence using the Cox proportional hazards model. Hypertensive women patients had a lower risk of IHD than men patients (hazard ratio [HR] = 0.93, 95% confidence interval [CI] 0.88-1.00). The IHD risk was increased in patients who visited healthcare providers > 12 times/person-year (HR = 2.97, 95% CI 2.79-3.17), paid high out-of-pocket expense/person-year (HR = 1.55, 95% CI 1.41-1.69), and had medication nonadherence (HR = 1.67, 95% CI 1.58-1.77). However, the risk was decreased in patients who used both urban and rural areas (HR 0.75, 95% CI 0.67-0.84) and mixed types of providers (HR = 0.93, CI 0.88-0.99). The risk of IHD was significantly different between men and women only in the visiting frequency to healthcare providers (men, HR = 3.21, 95% CI 2.93-3.52; women, HR = 2.78, 95% CI 2.53-3.04, p for interaction = 0.0188). In summary, the risk of IHD was similar according to healthcare utilization and medication adherence between men and women, except visiting frequency to healthcare providers.

Extent of non-adherence and non-persistence in asthma patients: analysis of a large claims data set

OBJECTIVE

The objective of this study was to assess non-adherence (NA) and non-persistence (NP) to long-acting asthma medications in Germany by differentiating between measurement of NA in periods of therapy continuation and measurement of NP in therapy-naïve patients.

METHODS

We analyzed treatment adherence to long-acting asthma medication using German claims data for periods of treatment continuation based on the medication possession ratio (MPR) and the proportion of days covered. Persistence was assessed in treatment-naïve patients. Outcomes were observed from the date of the first to the last prescription within a 12-month period. Both NA and NP analyses considered prescription supply, using either defined daily dosages, or prescribed daily dosages derived from a medical chart review.

RESULTS

We identified 52,508 asthma patients (mean age: 40.1, 58.4% female) who received at least two long-acting asthma prescriptions within 12 months; 50,660 treatment-naïve patients were included in the NP analysis (mean age: 39.7, 58.8% female). The mean 12-month MPR was 38.5% (89.4% NA according to MPR ≤ 80%) and the average proportion of days covered was 40.4% (85.9% NA). Agent-specific MPR and NA rates varied between 31.8% (91.8% NA) and 56.2% (71.6% NA). The average weighted-MPR increased to 53.1% when using the prescribed daily dosage. Based on a > 90-day gap definition, 86.7% of patients were considered non-persistent after 12 months (>180: 72.3%). When using prescribed daily dosages, NP rates ranged from 66.7 to 78.5%.

CONCLUSION

High levels of treatment NA and NP indicate a substantial need to improve adherence and persistence to long-acting asthma medication in Germany.

Polypharmacy, Medication Possession, and Deprescribing of Potentially Non-Beneficial Drugs in Hospice Patients

Patients frequently have comorbidities that when combined with their primary diagnosis qualifies the patient for hospice. Consequently, patients are at risk for polypharmacy due to the number of medications prescribed to treat both the underlying conditions and the related symptoms. Polypharmacy is associated with negative consequences, including increased risk for adverse drug events, drug-drug and drug-disease interactions, reduced functional status and falls, multiple geriatric syndromes, medication nonadherence, and increased mortality. Polypharmacy also increases the complexity of medication management for caregivers and contributes to the cost of prescription drugs for hospices and patients. Deprescribing or removing nonbeneficial or ineffective medications can reduce polypharmacy in hospice. We study medication possession ratios and rates of deprescribing of commonly prescribed but potentially nonbeneficial classes of medication using a large hospice pharmacy database. Prevalence of some classes of potentially inappropriate medications is high. We report possession ratios for 10 frequently prescribed classes, and, because death and prescription termination are competing events, we calculate prescription termination rates using Cumulative Incidence Functions. Median duration of antifungal and antiviral medications is brief (5 and 7 days, respectively), while statins and diabetes medications have slow discontinuance rates (median termination durations of 93 and 197 days). Almost all patients with a proton pump inhibitor prescription have the drug for their entire hospice stay. Data from this study identify those drug classes that are commonly deprescribed slowly, suggesting drug classes and diagnoses that hospices may wish to focus on more closely, as they act to limit polypharmacy and reduce prescription costs.

Impact of Psychiatric Diagnosis and Treatment on Medication Adherence in Youth With Systemic Lupus Erythematosus

OBJECTIVE

Youth with systemic lupus erythematosus (SLE) experience high rates of psychiatric comorbidities, which may affect medication adherence. We undertook this study to examine the association between psychiatric disorders and hydroxychloroquine adherence and to determine whether psychiatric treatment modifies this association.

METHODS

We identified incident hydroxychloroquine users among youth with SLE (ages 10-24 years) using de-identified US commercial insurance claims in Optum Clinformatics Data Mart (2000-2016). Adherence was estimated using medication possession ratios (MPRs) over a 365-day time period. Multivariable linear regression models were used to estimate the effect of having any psychiatric disorder on MPRs, as well as the independent effects of depression, anxiety, adjustment, and other psychiatric disorders. We tested for interactions between psychiatric diagnoses and treatment with psychotropic medications or psychotherapy.

RESULTS

Among 873 subjects, 20% had a psychiatric diagnosis, most commonly depression. Only adjustment disorders were independently associated with decreased MPRs (β -0.12, P = 0.05). We observed significant crossover interactions, in which psychiatric disorders had opposite effects on adherence depending on the receipt of psychiatric treatment. Among youth with any psychiatric diagnosis, psychotropic medication use was associated with a 0.15 increase in the MPR compared with no psychotropic medication use (P = 0.02 for interaction). Among youth with depression or anxiety, psychotherapy was also associated with a higher MPR compared with no psychotherapy (P = 0.05 and P < 0.01 for interaction, respectively).

CONCLUSION

The impact of psychiatric disorders on medication adherence differed by whether youth had received psychiatric treatment. Improving recognition and treatment of psychiatric conditions may increase medication adherence in youth with SLE.

Patient-Centric Structural Determinants of Adherence Rates Among Asthma Populations: Exploring the Potential of Patient Activation and Encouragement Tool TRUSTR to Improve Adherence

BACKGROUND

Lack of adherence with prescribed medications among the asthma populations exacerbates health outcomes and increases social and economic costs.

OBJECTIVES

The proposed study aims to model patient-centric structural determinants of adherence rates among asthma patients and explore the potential of mobile health apps such as the TRUSTR platform to improve adherence using its power of monetary and non-monetary chatbotting and non-non-monetary nudges. Following specific hypotheses are tested: (1) Patient attributes, such as their age and monetary medical condition, have significant effect on their adherence with the prescribed treatment plans. (2) Behavioral nudging with rewards and engagement via mobile health apps will increase adherence rates.

METHODS

The patient population (N = 37 359) consists of commercially insured patients with asthma who have been identified from administrative claims in the HealthCore Integrated Research Database (HIRD) between April 1, 2018 and March 31, 2019. Two Structural Equation Models (SEMs) are estimated to quantify direct, indirect, and total effect sizes of age and medical condition on proportion of days covered (PDC) and medical possession ratio (MPR), mediated by patient medical and pharmacy visits. Fourteen additional SEMs were estimated to lateralize TRUSTR findings and conduct sensitivity analysis.

RESULTS

HIRD data reveal mean adherence rate of 59% (standard deviation (SD) 29%) for PDC and 58% for MPR (SD 36%). Key structural findings from SEMs derived from the HIRD dataset indicate that each additional year in the age of the patient has a positive total effect on the adherence rate. Patients with poor medical condition are likely to have lower adherence rate, but this direct effect is countered by mediating variables. Further, each additional reward and higher engagement with a mobile app is likely to have a positive total effect on increasing the adherence rate.

CONCLUSIONS

HIRD data reveal mean adherence rate of 59% (SD 29%), providing the evidence for the opportunity to increase adherence rate by around 40%. Statistical modeling results reveal structural determinants, such as the opportunity to nudge, are higher among younger patients, as they have higher probability of being non-adherent. Methodologically, lateralization approach demonstrates the potential to capture real-world evidence beyond clinical data and merge it with clinical data.

The challenge of long-term adherence: The role of bone turnover markers in monitoring bisphosphonate treatment of osteoporosis

Oral Bisphosphonates (BPs) are the mainstay of osteoporotic treatment, however long-term adherence remains a challenge, primarily owing to the chronic character of the disease and the regimen complexity. Poor compliance has been shown to have a clear link to fracture risk. The role of bone turnover markers (BTMs) as a tool to ascertain adherence and response to therapy is supported by their rapid response to treatment; a decrease in values is witnessed within days or weeks of commencing treatment. A greater reduction of serum CTX and NTX is evidenced with alendronate and ibandronate compared to risedronate. A change in bone formation BTMs appears to be related to vertebral fracture risk reduction, whereas no significant relationship is evident for hip and non-vertebral fractures. The utility of BTMs as an adjunct for monitoring withdrawal of treatment with oral BP has also been suggested. Finally, studies evaluating BTMs as an intervention, failed to demonstrate any effect on adherence. This review explores the challenge of long-term adherence with bisphosphonates and provides an analytic framework with respect to the role of BTMs in monitoring bisphosphonate treatment, adherence and the offset of treatment effect.

A study on the impact of poor medication adherence on health status and medical expense for diabetes mellitus patients in Taiwan: A longitudinal panel data analysis

Medication adherence plays an important role in disease management, especially for diabetes. The aim of this study was to examine the impacts of demographic characteristics on medication nonadherence and the impacts of nonadherence on both health status and medical expenses for diabetic patients in Taiwan.A total of 1 million diabetes mellitus patients were randomly selected from the National Health Insurance Research Database between January 1, 2000 and December 31, 2004. All records with missing values and those for participants under 18 years of age were then deleted. Because many patients had multiple clinical visit records, all records within the same calendar year were summarized into 1 single record for each person. This pre-processing resulted in 14,602 total patients with a combined 73,010 records over the course of 5 years. Generalized estimating equation models were then constructed to investigate the effects of demographic characteristics on medication nonadherence and the effects of nonadherence on patient health status and medical expenses. The demographic characteristics examined for each patient include gender, age, residential area, and socioeconomic status.Our analysis of how demographic variables impacted nonadherence revealed that elderly patients exhibited better overall medication adherence, but that male patients exhibited poorer medication adherence than female patients. Next, our analysis of how nonadherence impacted health status revealed that patients who exhibited medication nonadherence had poorer health status than patients with proper medication adherence. Finally, our analysis of how nonadherence impacted medical expenses revealed that patients who exhibited medication nonadherence incurred more medical expenses than those who exhibited proper medication adherence.This study's empirical results corroborate the general relationships expressed in the current literature regarding medication nonadherence. However, this study's results were statistically more reliable and revealed the precise impact on health status in terms of the Charlson comorbidity index and increased annual medical expenses. This indicates the need to improve patient attitudes toward medication adherence, which can have substantial effects both medically and economically.

Association of out-of-pocket costs on adherence to common neurologic medications

OBJECTIVE

To determine the association between out-of-pocket costs and medication adherence in 3 common neurologic diseases.

METHODS

Utilizing privately insured claims from 2001 to 2016, we identified patients with incident neuropathy, dementia, or Parkinson disease (PD). We selected patients who were prescribed medications with similar efficacy and tolerability, but differential out-of-pocket costs (neuropathy with gabapentinoids or mixed serotonin/norepinephrine reuptake inhibitors [SNRIs], dementia with cholinesterase inhibitors, PD with dopamine agonists). Medication adherence was defined as the number of days supplied in the first 6 months. Instrumental variable analysis was used to estimate the association of out-of-pocket costs and other patient factors on medication adherence.

RESULTS

We identified 52,249 patients with neuropathy on gabapentinoids, 5,246 patients with neuropathy on SNRIs, 19,820 patients with dementia on cholinesterase inhibitors, and 3,130 patients with PD on dopamine agonists. Increasing out-of-pocket costs by $50 was associated with significantly lower medication adherence for patients with neuropathy on gabapentinoids (adjusted incidence rate ratio [IRR] 0.91, 0.89-0.93) and dementia (adjusted IRR 0.88, 0.86-0.91). Increased out-of-pocket costs for patients with neuropathy on SNRIs (adjusted IRR 0.97, 0.88-1.08) and patients with PD (adjusted IRR 0.90, 0.81-1.00) were not significantly associated with medication adherence. Minority populations had lower adherence with gabapentinoids and cholinesterase inhibitors compared to white patients.

CONCLUSIONS

Higher out-of-pocket costs were associated with lower medication adherence in 3 common neurologic conditions. When prescribing medications, physicians should consider these costs in order to increase adherence, especially as out-of-pocket costs continue to rise. Racial/ethnic disparities were also observed; therefore, minority populations should receive additional focus in future intervention efforts to improve adherence.

Methylphenidate Treatment Initiated During Childhood Is Continued in Adulthood in Half of the Study Population

Objectives: To estimate the number of patients who started methylphenidate during childhood and continued treatment beyond the age of 18 years and to study the determinants that may be associated with continuing treatment. Methods: Patients 17 years of age and younger who have received at least one prescription of methylphenidate were identified in the Integrated Primary Care Information database (1996-2017). Logistic regression analyses were performed to assess the association between potential determinants and continuation with methylphenidate treatment at the age of 18 years. Results: Fifty-three percent of all methylphenidate users (n = 1020) continued their treatment after the age of 18 years. Patients were more likely to continue treatment with methylphenidate if they started treatment at the age of 15-17 years compared with patients of 11 years and younger (adjusted odds ratio [OR]: 5.74, 95% confidence interval [CI]: 1.48-22.31), if they had a medication possession ratio (MPR) between 0.80 and 1.00 compared with a low MPR (adjusted OR: 2.18, 95% CI: 1.23-3.85) and if they lived in an area with a medium level of urbanization (adjusted OR: 1.98, 95% CI: 1.06-3.69). Furthermore, a relatively high number of patients had a MPR >1.0 (24.8%), of whom 91.3% started their treatment when they were between 15 and 17 years of age. Conclusions: Methylphenidate treatment initiated during childhood was continued in half of the study population when reaching the age of 18, where adolescents were more likely to continue treatment than young children. We also found that ∼25% of our study population had a MPR >1, mainly patients 15-17 years of age, which may suggest misuse or abuse of methylphenidate.

Adherence to immunomodulatory drugs in patients with multiple myeloma

Background

Immunomodulatory drugs (thalidomide, lenalidomide and pomalidomide; IMID) are widely used in the treatment of multiple myeloma patients. To date, few data are available on IMID adherence in multiple myeloma patients. The aim of our study was to evaluate IMID adherence and to compare two indirect methods to measure IMID adherence in multiple myeloma patients: a specific questionnaire and the medication possession ratio (MPR). Another aim was to explore this specific questionnaire for the assessment of IMID adherence in multiple myeloma patients.

Methods

All consecutive multiple myeloma patients, with at least two consecutive dispensations of thalidomide, lenalidomide or pomalidomide in our hospital were included in this prospective study. IMID adherence was measured using a specific questionnaire and the medication possession ratio. Relationship between the questionnaire scores and variables of interest was evaluated by multiple linear regression with a robust variance estimator.

Findings

Sixty-three patients were included in our study. The mean questionnaire score was 8.2±1.2 and the mean medication possession ratio value was 0.97±0.06. A total of 76% of patients were considered adherent according to the questionnaire (i.e. score ≥ 8), 94% according to the medication possession ratio (i.e. MPR ≥ 0.90), and 70% according to the questionnaire and the medication possession ratio. No statistically significant linear association was observed between the questionnaire score and any variables of interest including medication possession ratio. All Cronbach’s alpha were relatively low (range 0.0342–0.2443), showing a low correlation of the different questions with the questionnaire score.

Conclusions

Our study is the first prospective study evaluating IMID adherence in multiple myeloma patients in real life. The high adherence to IMIDs reported here, regardless of the drug, is encouraging considering the efficacy, toxicity and elevated cost of IMIDs. The specific questionnaire should be used with caution to evaluate IMID adherence.

Hospitalization risk in bipolar disorder patients treated with lurasidone versus other atypical antipsychotics

OBJECTIVE

This observational study compared the risk of hospitalization for patients with bipolar disorder when treated with lurasidone versus other oral atypical antipsychotics.

METHODS

This US commercial claims analysis (4 April 2010 through 24 September 2014) used the Optum Research Database to identify adult patients with bipolar disorder treated with oral atypical antipsychotics (N = 11,132). The first claim for an atypical antipsychotic defined the index date, with pre-index and post-index periods of 180 and 360 days, respectively. Every month of the post-index period was categorized as monotherapy treatment with lurasidone, aripiprazole, olanzapine, quetiapine, risperidone, ziprasidone, no/minimal treatment or other. Starting with the initial month of treatment, the risk of psychiatric or all-cause hospitalization in the subsequent month was examined based on treatment in the current month and pre-index covariates (age, gender, hospitalizations, emergency room visits, diagnoses for anxiety, alcohol abuse, substance abuse, hypertension, type 2 diabetes and obesity) and time-varying versions of the pre-index covariates using a marginal structural model.

RESULTS

After controlling for covariates, relative to lurasidone, the odds of psychiatric and all-cause hospitalization, respectively, were 2-3 times higher for olanzapine (odds ratio [OR] = 2.78, CI 1.09, 7.08, p = .032; OR = 3.20, CI 1.24, 8.26, p = .016), quetiapine (OR = 2.80, CI 1.13, 6.95, p = .026; OR = 3.23, CI 1.29, 8.11, p = .013), risperidone (OR = 2.50, CI 1.01, 6.21, p = .048; OR = 2.79, CI 1.11, 7.02, p = .029), aripiprazole (OR = 2.13, CI 0.87, 5.20, p = .097; OR = 2.57, CI 1.04, 6.37, p = .041) and ziprasidone (OR =2.31, CI 0.91, 5.85, p = .079; OR = 2.49, CI 0.97, 6.40, p = .058).

CONCLUSIONS

In this claims database analysis, lurasidone-treated patients with bipolar disorder had a significantly lower risk of psychiatric hospitalization compared to quetiapine, olanzapine and risperidone, but not aripiprazole or ziprasidone. Lurasidone-treated patients had a significantly lower risk of all-cause hospitalization compared to quetiapine, olanzapine, risperidone and aripiprazole, but not ziprasidone.

Cognition and drug adherence to oral hypoglycemic and antihypertensive agents in older adults

Background and objectives: Chronic disorders such as diabetes mellitus type II and hypertension have been associated with cognitive decline in older adults. It is unclear whether adherence to antihypertensive and oral hypoglycemic agents impact cognitive health. The objectives are to study the association between adherence to antihypertensive and oral hypoglycemic agents and cognitive status in community-living older adults. Methods: We used data from a large representative sample of older adults (N=2,286) covered under a public drug insurance plan in Quebec and participating in Quebec's health survey on older adults (ESA-study) with a Mini-Mental State Examination (MMSE) score ≥22 at baseline (T1) and examined one year later (T2). Participants with hypertension and diabetes mellitus type II were identified according to criteria used in the Canadian Chronic Disease Surveillance System. Antihypertensive and oral hypoglycemic prescriptions delivered were ascertained via Quebec's pharmaceutical database (RAMQ). Medication adherence was calculated using the medication possession ratio as a continuous variable in the year prior to and following baseline interview. Multivariate linear regressions were used to study the percentage change in MMSE scores between interviews (T1,T2) as a function of adherence to antihypertensive and oral hypoglycemic agents (before and after T1) controlling for potential confounders. Results: In participants with diabetes mellitus type II only, adherence to oral hypoglycemics was not associated with a change in MMSE scores. In participants with hypertension only, the change in MMSE scores was associated with adherence to antihypertensives (β 1.23; 95%CI: 0.29-2.17). In participants with comorbid hypertension and diabetes mellitus type II, the change in MMSE scores was associated with adherence to both antihypertensive and oral hypoglycemic agents (β 0.75; 95%CI: 0.01-1.48). Conclusions: Adherence to oral hypoglycemic agents and antihypertensive agents among older adults with hypertension and comorbid diabetes mellitus type II can have a preserving effect on cognitive health in older adults. Further research on the long-term impact on cognition is recommended.

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.

Sensitivity of the Medication Possession Ratio to Modelling Decisions in Large Claims Databases

OBJECTIVES

When preparing administrative medical and pharmacy claims data for analysis, decisions about data clean up and analytical approach need to be made. However, information about the effects of various modelling decisions on adherence measures such as the medication possession ratio (MPR) is limited. We address this gap with this study.

METHODS

We utilized cross-sectional administrative claims data for commercially insured members filling at least two prescriptions for drugs within five classes of hypertension medication between 2008 and 2010. We divided nine modelling decisions into three categories: data scrubbing, study design, and MPR definition/calculations. We defined the base-case settings with commonly used values, varied each modelling decision singly and in combination, and measured the effects on the MPR.

RESULTS

Claims data for 358,418 individuals were available for analysis. Two modelling decisions were found to be highly influential, each yielding a difference of over 25 percentage points from the base case: the decision of whether to use interval- or prescription-based study periods, and the decision of how to handle overlapping prescription claims. The effect of other decisions was smaller, with a difference of 1-9 percentage points from the base case.

CONCLUSIONS

Some of the decisions considered had a large impact on the MPR. Therefore, it is important for researchers to standardize approaches for study period length and overlapping prescription claims. We also conclude that transparent reporting of modelling decisions will facilitate the interpretation of results and comparisons across studies.