Primary non-adherence in general practice: a Danish register study

Initiation and Single Dispensing in Cardiovascular and Insulin Medications: Prevalence and Explanatory Factors

BACKGROUND

Adherence problems have negative effects on health, but there is little information on the magnitude of non-initiation and single dispensing.

OBJECTIVE

The aim of this study was to estimate the prevalence of non-initiation and single dispensation and identify associated predictive factors for the main treatments prescribed in Primary Care (PC) for cardiovascular disease (CVD) and diabetes.

METHODS

Cohort study with real-world data. Patients who received a first prescription (2013-2014) for insulins, platelet aggregation inhibitors, angiotensin-converting enzyme inhibitors (ACEI) or statins in Catalan PC were included. The prevalence of non-initiation and single dispensation was calculated. Factors that explained these behaviours were explored.

RESULTS

At three months, between 5.7% (ACEI) and 9.1% (antiplatelets) of patients did not initiate their treatment and between 10.6% (statins) and 18.4% (ACEI) filled a single prescription. Body mass index, previous CVD, place of origin and having a substitute prescriber, among others, influenced the risk of non-initiation and single dispensation.

CONCLUSIONS

The prevalence of non-initiation and single dispensation of CVD medications and insulin prescribed in PC in is high. Patient and health-system factors, such as place of origin and type of prescriber, should be taken into consideration when prescribing new medications for CVD and diabetes.

Use of Antidepressants and Risk of Cutaneous Melanoma: A Prospective Registry-Based Case-Control Study

Purpose

Melanoma is the cancer with the most rapidly rising incidence rate in Norway. Although exposure to ultraviolet radiation (UVR) is the major environmental risk factor, other factors may also contribute. Antidepressants have cancer inhibiting and promoting side effects, and their prescription rates have increased in parallel with melanoma incidence. Thus, we aimed to prospectively examine the association between use of antidepressants and melanoma by using nation-wide data from the Cancer Registry of Norway, the National Registry, the Norwegian Prescription Database and the Medical Birth Registry of Norway.

Patient and Methods

All cases aged 18–85 with a primary cutaneous invasive melanoma diagnosed during 2007–2015 (n=12,099) were matched to population controls 1:10 (n=118,467) by sex and year of birth using risk-set sampling. We obtained information on prescribed antidepressants and other potentially confounding drug use (2004–2015). Conditional logistic regression was used to estimate adjusted rate ratios (RRs) and 95% confidence intervals (CIs) for the association between overall and class-specific use of antidepressants and incident melanoma.

Results

Compared with ≤1 prescription, ≥8 prescriptions of antidepressants overall were negatively associated with melanoma (RR 0.81 CI 0.75–0.87). Class-specific analyses showed decreased RRs for selective serotonin reuptake inhibitors (RR 0.82 CI 0.73–0.93) and mixed antidepressants (RR 0.77 CI 0.69–0.86). The negative association was found for both sexes, age ≥50 years, residential regions with medium and highest ambient UVR exposure, all histological subtypes, trunk, upper and lower limb sites and local disease.

Conclusion

Use of antidepressants was associated with decreased risk of melanoma. There are at least two possible explanations for our results; cancer-inhibiting actions induced by the drug and less UVR exposure among the most frequent users of antidepressants.

No Evidence of Off-label Use of Olodaterol and Indacaterol in Denmark, France, and the Netherlands: A Drug Utilization Study

To characterize the use of olodaterol and indacaterol in clinical practice and to quantify the off-label use in asthma. Drug utilization study of new users of olodaterol or indacaterol between 2014 and 2017 in the PHARMO Database Network in the Netherlands, the Danish population registers, and the IMS Real-World Evidence Longitudinal Patient Database panels in France. On-label use was defined as use among adults with a recorded diagnosis of COPD. Off-label use was defined as use among adults with a recorded diagnosis of asthma without a recorded diagnosis of COPD or as use among patients aged ≤18 years. Potential off-label use was defined as no recorded diagnosis of either COPD or asthma. The study included 4,158 new users of olodaterol and 9,966 new users of indacaterol. Prevalence of off-label use ranged from 3.5% for both drugs to 12.4% for olodaterol and 11.9% for indacaterol. Prevalence of on-label use ranged from 47.8% to 77.7% for olodaterol and from 28.7% to 70.1% for indacaterol. The remaining new users of olodaterol and indacaterol were classified as potential off-label users, with prevalence ranging from 17.3% to 48.6% for olodaterol and from 20.5% to 66.6% for indacaterol. This study provides no evidence of a major concern in Europe for olodaterol or indacaterol for off-label use in asthma or for pediatric use.

Trends in antidepressant use among children and adolescents: a Scandinavian drug utilization study

OBJECTIVE

To compare antidepressant utilization in individuals aged 5-19 years from the Scandinavian countries.

METHODS

A population-based drug utilization study using publicly available data of antidepressant use from Denmark, Norway, and Sweden.

RESULTS

In the study period from 2007 to 2017, the proportion of antidepressant users increased markedly in Sweden (9.3-18.0/1000) compared to Norway (5.1-7.6/1000) and Denmark (9.3-7.5/1000). In 2017, the cumulated defined daily doses (DDD) of selective serotonin reuptake inhibitors were 5611/1000 inhabitants in Sweden, 2709/1000 in Denmark, and 1848/1000 in Norway. The use of 'other antidepressants' (ATC code N06AX) also increased in Sweden with a higher DDD in 2017 (497/1000) compared to Denmark (225/1000) and Norway (170/1000). The use of tricyclic antidepressants was generally low in 2017 with DDDs ranging between 30-42 per 1000. The proportion of antidepressant users was highest among 15- to 19-year-old individuals. Girls were more likely to receive treatment than boys, and the treated female/male ratios per 1000 were similar in Sweden (2.39), Denmark (2.44), and Norway (2.63).

CONCLUSION

Even in highly comparable healthcare systems like the Scandinavian countries', variation in antidepressant use is considerable. Swedish children and adolescents have a markedly higher and still increasing use of antidepressants compared to Danish and Norwegian peers.

Factors influencing harmonized health data collection, sharing and linkage in Denmark and Switzerland: A systematic review

INTRODUCTION

The digitalization of medicine has led to a considerable growth of heterogeneous health datasets, which could improve healthcare research if integrated into the clinical life cycle. This process requires, amongst other things, the harmonization of these datasets, which is a prerequisite to improve their quality, re-usability and interoperability. However, there is a wide range of factors that either hinder or favor the harmonized collection, sharing and linkage of health data.

OBJECTIVE

This systematic review aims to identify barriers and facilitators to health data harmonization-including data sharing and linkage-by a comparative analysis of studies from Denmark and Switzerland.

METHODS

Publications from PubMed, Web of Science, EMBASE and CINAHL involving cross-institutional or cross-border collection, sharing or linkage of health data from Denmark or Switzerland were searched to identify the reported barriers and facilitators to data harmonization.

RESULTS

Of the 345 projects included, 240 were single-country and 105 were multinational studies. Regarding national projects, a Swiss study reported on average more barriers and facilitators than a Danish study. Barriers and facilitators of a technical nature were most frequently reported.

CONCLUSION

This systematic review gathered evidence from Denmark and Switzerland on barriers and facilitators concerning data harmonization, sharing and linkage. Barriers and facilitators were strictly interrelated with the national context where projects were carried out. Structural changes, such as legislation implemented at the national level, were mirrored in the projects. This underlines the impact of national strategies in the field of health data. Our findings also suggest that more openness and clarity in the reporting of both barriers and facilitators to data harmonization constitute a key element to promote the successful management of new projects using health data and the implementation of proper policies in this field. Our study findings are thus meaningful beyond these two countries.

Evidence-Practice Gaps in Postdischarge Initiation With Oral Anticoagulants in Patients With Atrial Fibrillation

Background

Oral anticoagulant (OAC) therapy reduces the risk of stroke in people with atrial fibrillation (AF), and is considered best practice; however, there is little Australian evidence around the uptake of OACs in this population.

Methods and Results

We used linked hospital admissions, pharmaceutical dispensing claims, medical services, and mortality data for people in Australia's 2 most populous states (July 2010 to June 2015). Among OAC‐naïve people hospitalized with AF, we estimated initiation of OAC therapy within 30 days of discharge, and persistence with therapy in the first year. We analyzed both outcomes using multivariable Cox regression. In 71 184 people with AF (median age 78 years, 49% female), 22.7% initiated OAC therapy. Initiation was lowest in July to December 2011 (17.0%) and highest in July to December 2014 (30.1%) after subsidy of the direct OACs. In adjusted analyses, initiation was most likely in people with a CHA₂DS₂‐VA score ≥7 (versus 0) (hazard ratio=6.25, 95% CI 5.08–7.69), and a history of venous thromboembolism (hazard ratio=2.65, 95% CI 2.49–2.83). Of the people who initiated OAC therapy, 39.9% discontinued within 1 year; a lower risk of discontinuation was associated with a CHA₂DS₂‐VA score ≥7 (versus 0) (hazard ratio=0.22, 95% CI 0.14–0.35), or initiation on a direct OAC (versus warfarin) (hazard ratio=0.55, 95% CI 0.50–0.60).

Conclusions

We found that OAC therapy was severely underutilized in people hospitalized with AF, even among high‐risk individuals. Reasons for this underuse, whether patient, prescriber, or hospital related, should be identified and addressed to reduce stroke‐related morbidity and mortality in people with AF.

Effect of the market withdrawal of dextropropoxyphene on use of other prescribed analgesics

Background and aims Dextropropoxyphene (DXP) is a synthetic opioid that was prescribed worldwide for mild to moderate pain. It was withdrawn from the European market in 2009. In this study we aim to investigate the effect of the market withdrawal of dextropropoxyphene in Norway on overall use of opioids and other analgesics at an individual level. Methods Data were collected from the nationwide Norwegian Prescription Database (NorPD). It covers all prescription of drugs from 01 January 2004 from Norwegian pharmacies dispensed to individuals outside institutions. The study period was divided in two 2-year periods from 01 September 2008 to 31 August 2010, and from the market withdrawal of DXP on 01 September 2010 to 31 August 2012. We included every individual that filled at least one prescription of dextropropoxyphene in the first 2-year period in our study population. In this study dextropropoxyphene, codeine and tramadol are defined as "weak opioids", and all other opioids are termed "strong opioids". Results Nine thousand one hundred and seventy-one individuals were included in our study population. Four thousand two hundred and ninety filled a prescription of DXP only once and were classified as "single users", 2,990 were users with prescriptions of up to 200 defined daily doses (DDD) over the first 2-year period, or "sporadic users", and 1,886 were classified high users with over 200 DDDs over a 2-year period. After the market withdrawal 8,392 continued to be prescribed analgesics or benzodiazepines. In the single user group, the proportion of users of weak opioids decreased from 69.5% to 57.6%, whereas the proportion of users of strong opioids was unchanged. Among the sporadic user group, the proportion of users of weak opioids went from 69.7% to 71.0%, the proportion using tramadol from 39.1% to 43.9%, and the users of strong opioids from 25.8% to 31.3%. In the high user group, there was an increase in the number of users of strong opioids from 37.8% to 51.4%. The amount of strong opioids prescribed in the high user group increased from a mean of 262.5 DDD to a mean of 398.3 DDD in the following 2 years. The amount of tramadol increased in all groups and was 3 times as high in the high user group after market withdrawal of DXP. Conclusions Our study showed that the withdrawal of DXP lead to an increase in prescription of other analgesics. The proportion of users increased in all three groups and so did the prescribed amount of other analgesics. Both the proportion of users of other opioids and the amount prescribed increased considerably. However, 1 in 10 earlier users of DXP stopped using prescribed analgesics altogether in the following 2 years. The increase in use among earlier high users of DXP was most striking. Implications This study documents markedly increased prescriptions of other opioids after withdrawal of dextropropoxyphene due to its high risk of serious complications. However, consequences of the increased use of opioids among earlier high users of DXP such as changes in risk of poisonings, accidental deaths and suicides remain to be investigated.

Behavioral economic insights to improve medication adherence in adults with chronic conditions: a scoping review protocol

OBJECTIVE

The objective of this review is to map the evidence on the use of behavioral economic insights to improve medication adherence in adults with chronic conditions.

INTRODUCTION

Medication non-adherence is a barrier to effectively managing chronic conditions, leading to poorer patient outcomes and placing an additional financial burden on healthcare systems. As the population ages and the prevalence of chronic disease increases, new ways to influence patient behavior are needed. Approaches that use insights from behavioral economics may help improve medication adherence, thus reducing morbidity, mortality and financial costs of unmanaged chronic diseases.

INCLUSION CRITERIA

Eligible studies will include adults taking medication for a chronic condition. All interventions relevant to high-income settings using insights from behavioral economics to improve medication adherence in adults will be considered. Contexts may include, but are not limited to, primary health care, corporate wellness programs and health insurance schemes. Any study design published in English will be considered. Studies in facilities where medication is administered to patients will be excluded.

METHODS

PubMed, Embase, Scopus, PsycINFO, EconLit and CINAHL will be searched from database inception to present. Gray literature will be searched using Google Scholar, OpenGrey and the Grey Literature Report. One reviewer will review titles, and then two reviewers will independently review abstracts to identify eligible studies. One reviewer will extract data on study characteristics, study design and study outcomes. A second reviewer will validate 25% of the extracted information. The results of the data extraction will be presented in a table, and a narrative summary will be presented.

The comparative effectiveness of fourth-line drugs in resistant hypertension: An application in electronic health record data

PURPOSE

To examine the utility of electronic health records from a routine care setting in assessing comparative effectiveness of fourth-line anti-hypertensive drugs to treat resistant hypertension.

METHODS

We conducted a cohort study using the Clinical Practice Research Datalink: a repository of electronic health records from UK primary care. We identified patients newly prescribed fourth-line anti-hypertensive drugs (aldosterone antagonist , beta-blocker, or alpha-blocker). Using propensity score-adjusted Cox proportional hazards models, we compared the incidence of the primary outcome (composite of all-cause mortality, stroke, and myocardial infarction) between patients on different fourth-line drugs. AA was the reference drug in all comparisons. Secondary outcomes were individual components of the primary outcome, blood pressure changes, and heart failure. We used a negative control outcome, Herpes Zoster, to detect unmeasured confounding.

RESULTS

Overall, 8639 patients were included. In propensity score-adjusted analyses, the hazard ratio for the primary outcome was 0.81 (95% CI, 0.55-1.19) for beta-blockers and 0.68 (95% CI, 0.46-0.96) for alpha-blockers versus AA. Findings for individual cardiovascular outcomes trended in a more plausible direction, albeit imprecise. A trend for a protective effect for Herpes Zoster across both comparisons was seen.

CONCLUSIONS

A higher rate of all-cause death in the AA group was likely due to unmeasured confounding in our analysis of the composite primary outcome, supported by our negative outcome analysis. Results for cardiovascular outcomes were plausible, but imprecise due to small cohort sizes and a low number of observed outcomes.

Use of phthalate-containing prescription drugs and the risk of gastric cancer: a Danish nationwide case-control study

Background: Phthalates are used as excipients in some drug products, and up to a 50-fold increased urinary excretion of phthalate metabolites compared to non-users has been demonstrated in users of such products. In vitro studies have demonstrated that phthalates stimulate mechanisms involved in gastric cancer development. We therefore examined the association between cumulative phthalate exposure from drug products and the risk of gastric adenocarcinomas. Methods: Using the Danish Cancer Registry, we identified all patients with incident gastric adenocarcinoma from 2008 to 2015 (n = 1525). Cancer cases were matched to 10 controls. Linking information retrieved from nationwide Danish registries, we determined individual cumulative phthalate exposure to the ortho-phthalates diethyl phthalate (DEP), dibutyl phthalate (DBP) and enteric phthalate polymers from prescription drugs. The association between cumulative phthalate exposure and gastric adenocarcinoma was estimated using conditional logistic regression, adjusting for socioeconomical status and drugs or comorbidities known or suspected to modify the risk of gastric adenocarcinoma. Results: No association was seen for the risk of gastric adenocarcinomas among individuals with high cumulative exposure to ortho-phthalates (exceeding 500 mg) (OR_adj 1.22, 95% CI: 0.84-1.77). Likewise, no associations were observed individually for DEP (OR_adj 1.06 95% CI: 0.63-1.76) or DBP (OR_adj 1.32 95% CI: 0.78-2.23). Cumulative exposure to enteric phthalate polymers exceeding 10,000 mg, did not reveal an association with gastric adenocarcinoma (OR_adj 0.79, 95% CI: 0.54-1.16) and no association was seen for individual compounds. Additionally, no dose-response pattern was observed across exposure strata (p = .39, test for trend). Conclusion: We did not find an increased risk of gastric adenocarcinoma among Danish users of phthalate-containing drug products. Our study is limited by a low number of cases exposed to high cumulative doses of phthalates.

Prevalence of and factors associated with primary medication non-adherence in chronic disease: A systematic review and meta-analysis

BACKGROUND

Primary medication non-adherence (PMN), defined as failure to obtain newly prescribed medications, results in adverse clinical and economic outcomes. We aimed to (a) assess the prevalence of PMN in six common chronic diseases: asthma and/ or chronic obstructive pulmonary disease, depression, diabetes mellitus, hyperlipidaemia, hypertension and osteoporosis; (b) identify and categorise factors associated with PMN; (c) explore characteristics that contributed to heterogeneity between studies.

METHODS

We performed a systematic search in MEDLINE, Embase, Cochrane Library, CINAHL and PsycINFO. Studies published in English between January 2008 and August 2018 assessing PMN in subjects aged ≥18 years were included. We used the Cochrane risk of bias tool, Newcastle-Ottawa Scale and National Heart, Lung and Blood Institute Quality Assessment Tool to assess the quality of randomised controlled trials, cohort and cross-sectional studies, respectively. Findings were reported using the PRISMA checklist. PMN rates were pooled using a random effects model. We summarised factors associated with PMN descriptively. Subgroup analysis was performed to explore sources of heterogeneity.

RESULTS

We screened 3083 articles and included 33 (5 randomised controlled trials, 26 cohort and 2 cross-sectional studies, n = 539 156), of which 31 (n = 519 971) were used in meta-analysis. The pooled PMN rate was 17% (95% CI: 15%-20%). Pooled PMN rates were highest in osteoporosis (25%, 95% CI: 7%-44%) and hyperlipidaemia (25%, 95% CI: 18%-32%) and lowest in diabetes mellitus (10%, 95% CI: 7%-12%). Factors commonly associated with PMN include younger age, number of concurrent medications, practitioner specialty and higher co-payment. Type of chronic disease, age, study setting and PMN definition contributed to heterogeneity between studies (all P < 0.001).

CONCLUSION

Primary medication non-adherence is common among patients with chronic diseases and more needs to be done to address this issue in order to improve patient outcomes. Future PMN studies could benefit from greater standardisation to enhance comparability.

Antidepressant use in Denmark, Germany, Spain, and Sweden between 2009 and 2014: Incidence and comorbidities of antidepressant initiators

BACKGROUND

We aimed to describe patterns of use and characteristics of 10 commonly used antidepressants for the period 2009-2014 in Denmark, Germany, Spain, and Sweden.

METHODS

Adult initiators from 2009 to 2014 of each study antidepressant were identified in four countries using five data sources: the Danish National registers, GePaRD (Germany), EpiChron (Aragon, Spain), SIDIAP (Catalonia, Spain), and the Swedish National Registers. The study included 10 study antidepressants: citalopram, escitalopram, fluoxetine, paroxetine, sertraline, duloxetine, venlafaxine, amitriptyline, mirtazapine, and agomelatine.

RESULTS

Citalopram was the most prescribed study antidepressant, followed by mirtazapine. Paroxetine and agomelatine were the least prescribed antidepressants. Mirtazapine was widely used among older antidepressant initiators with higher percentages of comorbidities at baseline, and fluoxetine was used among young patients. Citalopram and amitriptyline had the lowest percentage of multiple antidepressant use in the 12 months prior to the current treatment episode, while agomelatine, duloxetine, and venlafaxine had the highest percentage of multiple antidepressant use in the year prior to the current treatment episode.

LIMITATIONS

The most important limitations are exposure information based on filled prescriptions, focus on antidepressant initiators only, lack of information on the indication, and heterogeneity of the type of data across data sources.

CONCLUSIONS

Results of this study including 4.8 million study antidepressant initiators of study antidepressants suggest that citalopram and mirtazapine are the most commonly prescribed antidepressants. Agomelatine and paroxetine were the least used antidepressants in the participating populations. Mirtazapine was the antidepressant most commonly prescribed among older antidepressant initiators with high percentage of comorbidities at baseline, whereas fluoxetine was commonly used among young patients.

Prevalence of patients treated with anti-diabetic medicine in Greenland and Denmark. A cross-sectional register study

Diabetes mellitus is a large and growing worldwide health issue. Prior to this publication, a direct comparison of the prevalence of persons treated with anti-diabetic medicine in Greenland and Denmark has not been found. Therefore, the aim of this study is to estimate and compare the age- and gender-specific prevalence of patients treated with anti-diabetic medicine comparing Greenland and Denmark. The study was performed as a cross-sectional register study using data from population and medical registers in Greenland and Denmark. A total of 784 Greenlandic and 215,580 Danish patients treated with anti-diabetic medicine were included. The prevalence of patients aged 20-79 years treated with anti-diabetic medicine in Greenland was 2.6% (95% CI 2.4-2.8), much lower (p < 0.001) compared to Denmark with 5.2% (95% CI 5.2-5.2). The difference was less pronounced after excluding those treated with insulin and women below 45 years treated with metformin. In conclusion, this study showed a lower prevalence of patients treated with anti-diabetic medicine in Greenland than Denmark. The main reason may be a much higher prevalence of undiagnosed diabetes in Greenland, particularly among the middle-aged. Differences in awareness of diabetes and access to continued primary healthcare may be contributing factors.

Discontinuation of therapy among COPD patients who experience an improvement in exacerbation status

PURPOSE

A subset of patients with chronic obstructive pulmonary disease (COPD) experience a decrease in exacerbation frequency, leading to a diminished need for treatment with inhaled corticosteroids (ICS). We investigated prescribing and discontinuation patterns of long-acting bronchodilators and ICS in COPD patients according to exacerbation frequency.

METHODS

Using the nationwide Danish health registries, we conducted a drug utilization study among patients who had at least two exacerbations or one hospitalization due to an exacerbation during 2011-2012. This study population was stratified according to consistency of exacerbation occurrence after 12, 24, 36, and 48 months of follow-up and the groups were described according to use of ICS, long-acting β₂-agonists (LABA), and long-acting anticholinergics (LAMA), and combinations thereof.

RESULTS

We identified 29,010 COPD exacerbators during 2011-2012. Upon inclusion, 70% received ICS-containing regimens, in combination with LABA (23%) or both LABA and LAMA (41%). The proportion of prevalent users of ICS-containing regimens decreased to 56% during follow-up among exacerbation-free individuals, while it increased to 86% in individuals who experienced at least one exacerbation annually. Persistence to ICS-containing regimens was 58% after 4 years in individuals without exacerbations compared to 74% among those with annual exacerbations. Similar patterns were observed for triple therapy which was the most extensively used drug combination regardless of consistency of exacerbation occurrence.

CONCLUSIONS

The extensive use of ICS and the relatively high persistence to ICS-containing regimens in individuals who had a decrease in exacerbation occurrence highlight a need for the development and implementation of de-escalation strategies in clinical practice.

Exposure to phthalate-containing prescription drugs and the risk of colorectal adenocarcinoma: A Danish nationwide case-control study

PURPOSE

Some drug products contain phthalates as excipients, and in vitro studies have demonstrated that phthalates interfere with cellular mechanisms involved in colorectal cancer development. We therefore examined the association between cumulative phthalate exposure from drug products and risk of colorectal adenocarcinomas.

METHODS

We used the Danish Cancer Registry to identify all patients with incident colorectal adenocarcinoma from 2008 to 2015 (n = 25 814). Each cancer case was matched to ten population controls. Linking information from Danish registers, we quantified cumulative phthalate exposure to the ortho-phthalates diethyl phthalate (DEP) and dibutyl phthalate (DBP) as well as enteric phthalate polymers from orally administered drugs. The association between cumulative phthalate exposure and colorectal cancer was estimated using conditional logistic regression.

RESULTS

Cumulative exposure to ortho-phthalates exceeding 500 mg was associated with lower odds of colorectal cancer diagnosis (OR_adj  = 0.89; 95% CI, 0.81-0.96). Similar associations were observed for all DEP exposure exceeding 500 mg. Subgroup analysis excluding NSAID users, demonstrated that ortho-phthalate exposure was positively associated with colorectal cancer (OR_adj  = 1.26; 95% CI, 1.05-1.51).

CONCLUSION

We found an apparent overall protective effect of cumulative phthalate exposure from drug excipients for colorectal adenocarcinoma. Omitting NSAID users reversed the signal and suggested a slightly increased risk associated with high cumulative ortho-phthalate exposure.

Cardiovascular, antidepressant and immunosuppressive drug use in relation to risk of cutaneous melanoma: a protocol for a prospective case-control study

INTRODUCTION

The incidence of cutaneous melanoma (hereafter melanoma) has increased dramatically among fair-skinned populations worldwide. In Norway, melanoma is the most rapidly growing type of cancer, with a 47% increase among women and 57% among men in 2000-2016. Intermittent ultraviolet exposure early in life and phenotypic characteristics like a fair complexion, freckles and nevi are established risk factors, yet the aetiology of melanoma is multifactorial. Certain prescription drugs may have carcinogenic side effects on the risk of melanoma. Some cardiovascular, antidepressant and immunosuppressive drugs can influence certain biological processes that modulate photosensitivity and immunoregulation. We aim to study whether these drugs are related to melanoma risk.

METHODS AND ANALYSIS

A population-based matched case-control study will be conducted using nation-wide registry data. Cases will consist of all first primary, histologically verified melanoma cases diagnosed between 2007 and 2015 identified in the Cancer Registry of Norway (14 000 cases). Ten melanoma-free controls per case (on date of case melanoma diagnosis) will be matched based on sex and year of birth from the National Registry of Norway. For the period 2004-2015, and by using the unique personal identification numbers assigned to all Norwegian citizens, the case-control data set will be linked to the Norwegian Prescription Database for information on drugs dispensed prior to the melanoma diagnosis, and to the Medical Birth Registry of Norway for data regarding the number of child births. Conditional logistic regression will be used to estimate associations between drug use and melanoma risk, taking potential confounding factors into account.

ETHICS AND DISSEMINATION

The project is approved by the Regional Committee for Medical Research Ethics in Norway and by the Norwegian Data Protection Authority. The study is funded by the Southeastern Norway Regional Health Authority. Results will be published in peer-reviewed journals and disseminated further through scientific conferences, news media and relevant patient interest groups.

In utero exposure to antiepileptic drugs is associated with learning disabilities among offspring

OBJECTIVES

In utero exposure to antiepileptic drugs has previously been associated with adverse outcome among offspring, but evidence on longer term milestone development remains limited. We investigated the association between in utero exposure to antiepileptic drugs and learning disabilities in the first year of compulsory education among offspring and assessed which antiepileptic drugs carried the highest risk.

METHODS

This population-based case-cohort study used Danish nationwide register data from 2005 to 2008. Cases were offspring exposed to antiepileptic drugs in utero, and controls were unexposed offspring of mothers previously redeeming antiepileptic drug prescriptions. Offspring were followed from birth until the first year of compulsory education from 2011 to 2015. Learning disabilities were defined as mental retardation, specific developmental disorders, autism spectrum disorders, emotional/behavioural disorders or having special educational needs. Logistic regression was used to compute ORs with 95% CIs adjusted for potential confounding.

RESULTS

Of 117 475 incident singleton births, 636 cases and 434 controls were included (median age: 6.1 years, males: 55.7%). Learning disabilities were identified among 7.1% cases compared with 3.7% for controls. During any trimester, the adjusted OR of the association between in utero exposure to antiepileptic drugs and learning disabilities was 2.20 (95% CI 1.16 to 4.17). Among cases not exposed to polytherapy (n=556), in utero exposure to lamotrigine compared with another antiepileptic drug was associated with the lowest adjusted risk (OR 0.42, 95% CI 0.19 to 0.92), and valproate carried a higher risk (OR 4.67, 95% CI 1.73 to 12.59).

CONCLUSION

In utero exposure to antiepileptic drugs was significantly associated with learning disabilities among offspring. Lamotrigine should preferentially be considered over, for example, valproate if clinically feasible.

Use of topical ocular antibiotics in young children: a Scandinavian drug utilization study

PURPOSE

Acute infectious conjunctivitis is a common disease. While usually self-limiting, children often receive treatment to be accepted back into nursery, day care or school. We aimed to describe trends in the utilization of topical ocular antibiotics in young children aged 0-4 years in Denmark, Norway and Sweden.

METHODS

Using individual-level data from the Danish National Prescription Registry (2000-2015), we provided detailed descriptions of treatment patterns at the individual level, stratified by age (0-1 years, 2-4 years) and antibiotic substance. Aggregate-level data for Danish, Norwegian and Swedish children (0-4 years) were obtained from publicly available data sources (2000-2016).

RESULTS

We identified 107 581 Danish children aged 0-4 years receiving 271 980 treatment episodes. The incidence rate was relatively stable between 2000 and 2010 (on average, 637 and 283/1000 person-years for 0- to 1- and 2- to 4-year-olds, respectively), after which it dropped by 37% until 2015. In the aggregated data, a markedly higher use was seen in Denmark (211/1000 children in 2016) compared with Sweden (42) and Norway (151). The decrease from 2010 onwards was observed in all three countries. Chloramphenicol and fusidic acid were the most commonly used topical ocular antibiotics across Scandinavia. Tobramycin was rarely used in Norway and Sweden (≤1/1000 children in 2016) compared with Denmark (24/1000 children).

CONCLUSION

Considerable variation is seen in the utilization of topical ocular antibiotics among children in Scandinavia, with Denmark having the highest use. Across the Scandinavian countries, however, a decline was noted from 2010 onwards.

Switching Between Antibiotics Among Danish Children 0-4 Years of Age: A Nationwide Drug Utilization Study

BACKGROUND

In Denmark, the use of amoxicillin is widespread among children, despite phenoxymethylpenicillin being recommended as first-line therapy. The reason for this apparent discrepancy is not fully understood. We aimed at evaluating prescribing patterns of antibiotics among Danish children 0-4 years of age, with emphasis on incidence of treatment episodes, choice of initial antibiotic treatment and switching patterns between different types of antibiotics.

METHODS

We identified all children ≤4 years of age who filled a prescription of antibiotics from 2000 to 2015 according to the nationwide Danish National Prescription Registry. We estimated the incidence rate of episodes treated with antibiotics and the choice of initial antibiotic treatment over time. Further, we assessed the cumulative risk of switching within 0-3 days after initiating therapy.

RESULTS

We identified 3,481,684 antibiotic treatment episodes issued to 0- to 4-year-olds from 2000 to 2015. The incidence rate was stable until 2011 both among children 0-1 years of age (approximately 880/1000) and among children 2-4 years of age (approximately 610/1000), after which it dropped. Phenoxymethylpenicillin and, increasingly, amoxicillin were most frequently used as initial treatments (39% vs. 44%). Few switched from amoxicillin (1%) or phenoxymethylpenicillin (4.7%) within the first 3 days. Of those who switched from phenoxymethylpenicillin, 64% received amoxicillin as second-line treatment.

CONCLUSIONS

The incidence of episodes treated with antibiotics among Danish children 0-4 years of age has decreased considerably since 2011. In contrast to guideline recommendations, amoxicillin is the most frequently used initial treatment. Early switching between antibiotics is uncommon. Initiatives should address the extensive use of amoxicillin.

Statin use and mortality among endometrial cancer patients: a Danish nationwide cohort study

Statin use has been linked to improved prognosis of some cancer types, however, for endometrial cancer, the results are equivocal. We therefore examined the effect of statin use on endometrial cancer mortality. From the Danish Cancer Registry, we identified all women in Denmark aged 30-84 years with primary endometrial cancer during 2000-2012. Data on drug use, mortality outcomes and potential confounders were retrieved from nationwide registries. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for endometrial cancer-specific and other-cause mortality associated with statin use. Among 6,694 endometrial cancer patients, 753 died from endometrial cancer and 765 from other causes during a median follow-up of 4.5 year (interquartile range: 1.9-8.1). We observed an inverse association between time-varying postdiagnosis statin use (≥2 prescriptions) and endometrial cancer mortality (HR: 0.61, 95% CI: 0.48-0.77) compared to non-use (<2 prescriptions). The associations did not differ substantially by intensity or cumulative amount of statin use. In secondary analyses including prediagnosis statin use, we observed reduced mortality among both continuing (pre- and postdiagnosis) users (HR 0.70, 95% CI 0.53-0.92) and new (postdiagnosis only) users (HR 0.43, 95% CI 0.29-0.65) compared to "never users." In sensitivity analyses with fixed exposure periods after the endometrial cancer diagnosis, the inverse association was more pronounced more than 5 years after the diagnosis. Our findings suggest that statin use may be associated with improved survival in endometrial cancer patients.

Use of N-nitrosodimethylamine (NDMA) contaminated valsartan products and risk of cancer: Danish nationwide cohort study

OBJECTIVE

To perform an expedited assessment of cancer risk associated with exposure to N-nitrosodimethylamine (NDMA) through contaminated valsartan products.

DESIGN

Nationwide cohort study.

SETTING

Danish health registries on individual level prescription drug use, cancer occurrence, and hospital diagnoses.

PARTICIPANTS

5150 Danish patients with no history of cancer, aged 40 years or older, and using valsartan at 1 January 2012 or initiating use between 1 January 2012 and 30 June 2017. Participants were followed from one year after cohort entry (lag time period) until experiencing a cancer outcome, death, migration, or end of study period (30 June 2018). Each participant's exposure to NDMA (ever exposure and predefined categories of cumulative valsartan exposure) was mapped out as a time varying variable while also applying a one year lag.

MAIN OUTCOME MEASURES

Association between NDMA exposure and a primary composite endpoint comprising all cancers except non-melanoma skin cancer, estimated using Cox regression. In supplementary analyses, the risk of individual cancers was determined.

RESULTS

The final cohort comprised 5150 people followed for a median of 4.6 years. In total, 3625 cohort participants contributed 7344 person years classified as unexposed to NDMA, and 3450 participants contributed 11 920 person years classified as ever exposed to NDMA. With 104 cancer outcomes among NDMA unexposed participants and 198 among exposed participants, the adjusted hazard ratio for overall cancer was 1.09 (95% confidence interval 0.85 to 1.41), with no evidence of a dose-response relation (P=0.70). For single cancer outcomes, increases in risk were observed for colorectal cancer (hazard ratio 1.46, 95% confidence interval 0.79 to 2.73) and for uterine cancer (1.81, 0.55 to 5.90), although with wide confidence intervals that included the null.

CONCLUSIONS

The results do not imply a markedly increased short term overall risk of cancer in users of valsartan contaminated with NDMA. However, uncertainty persists about single cancer outcomes, and studies with longer follow-up are needed to assess long term cancer risk.

Reasons for Primary Medication Nonadherence: A Systematic Review and Metric Analysis

BACKGROUND

The behavior of medication nonadherence is distinguished into primary and secondary nonadherence. Primary nonadherence (PNA) is not as thoroughly studied as secondary nonadherence.

OBJECTIVE

To explore and synthesize contributing factors to PNA based on the existing body of literature.

METHODS

A search was performed on the PubMed, PsycINFO, CINAHL, and ScienceDirect databases to identify previously published scholarly articles that described the "factors," "reasons," "determinants" or "facilitators" of PNA. The alternate spelling of "nonadherence" was used as well. The effect that the articles had in the research community, as well as across social media, was also explored.

RESULTS

22 studies met the inclusion criteria for this review. The PNA factors that the studies identified were diverse, spanning economic, social, and medical dimensions. A multilevel classification method was applied to categorize the factors into 5 broad groups-patient, medication, health care provider, health care system, and socioeconomic factors. Patient factors were reported the most. Some groups overlapped and shared a dynamic causal relationship where one group influenced the outcome of the other.

CONCLUSIONS

Like all nonadherence behaviors, PNA is multifaceted with highly varied contributing factors that are closely associated with one another. Given the multidimensional nature of PNA, future intervention studies should focus on the dynamic relationship between these factor groups for more efficient outcomes.

DISCLOSURES

This research was supported by the National Research Foundation Singapore under its National Innovation Challenge on Active and Confident Ageing (Award No. MOH/NIC/CAHIG03/2016) and administered by the Singapore Ministry of Health's National Medical Research Council. This research was also supported by the National Research Foundation within the Prime Minister's Office of Singapore, under its Science of Research, Innovation and Enterprise Programme (SRIE Award No. NRF2014-NRF-SRIE001-019). The authors have no relevant conflicts of interest to disclose.

Cumulative exposure to phthalates from phthalate-containing drug products: a Danish population-wide study

AIMS

Up to 50-fold higher levels of urinary phthalate metabolites have been observed in users of phthalate-containing drug products compared with non-users. This is of concern, as phthalates are suspected endocrine disrupters and have been associated with cancer development. This study aims to quantify annual cumulated phthalate exposure from drug products among users of phthalate-containing oral medications in Denmark throughout the period of 2004-2016.

METHODS

We conducted a Danish nationwide cohort study using The Danish National Prescription Registry and an internal database held by The Danish Medicines Agency. These databases hold information on drug products; date of dispensing, and the type and quantity of excipients in drugs with Danish marketing permission. We present the number of users over time and their distribution of exposure to enteric phthalate polymers and ortho-phthalates.

RESULTS

The annual number of individuals exposed to phthalate-containing products declined during 2004-2016. The total number of individuals exposed to dibutyl phthalate declined from 21 499 in 2004 to 5400 in 2016. However, among those exposed, the median dibutyl phthalate exposure remained above European regulatory limit of exposure ranging between 380-1710 mg/year throughout the study period. Lithium-products constituted the majority of dibutyl phthalate exposure. Diethyl phthalate exposure, mainly caused by erythromycin, theophylline and diclofenac products, did not exceed the EMA regulatory limit.

CONCLUSION

While the number of individuals exposed to phthalates from oral medications during 2004-2016 declined, the use of phthalate-containing drugs is still considerable.

Development of a Strategic Tool for Shared Decision-Making in the Use of Antidepressants among Patients with Major Depressive Disorder: A Focus Group Study

Shared decision-making (SDM) has been recognized as an important tool in the mental health field and considered as a crucial component of patient-centered care. Therefore, the purpose of this study was to develop a strategic tool towards the promotion and implementation of SDM in the use of antidepressants among patients with major depressive disorder. Nineteen doctors and 11 major depressive disorder patients who are involved in psychiatric outpatient clinic appointments were purposively selected and recruited to participate in one of six focus groups in a large teaching hospital in Malaysia. Focus groups were transcribed verbatim and analyzed using a thematic approach to identify current views on providing information needed for SDM practice towards its implementation in near future. Patients&rsquo; and doctors&rsquo; views were organized into six major themes, which are; summary of treatment options, correct ways of taking medication, potential side effects of treatments related to patients, sharing of case study related to the treatment options, cost of treatment options, and input from pharmacist. The information may be included in the SDM tool which can be useful to inform further research efforts and developments that contribute towards the successful implementation of SDM into clinical practice.

Exposure to selective serotonin reuptake inhibitors in utero and early elementary school outcomes

OBJECTIVE

Data on special education in offspring exposed to selective serotonin reuptake inhibitors (SSRIs) in utero are lacking. We examined associations of in utero SSRI exposure with special education needs and delayed elementary school start.

METHODS

A population-based case-cohort study using Danish nationwide birth and prescription registry data from 2005 to 2008. Follow-up ends during 2011-2015 to capture special education needs during and delayed entry to the first elementary school year. Cases were in utero SSRI-exposed offspring. Cohort-controls were SSRI-unexposed offspring of mothers previously on SSRIs. We reported odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for relevant potential confounders.

RESULTS

Of 117 475 first-incident non-multiple pregnancy births, 3314 were SSRI-exposed, and 3536 were unexposed. Among SSRI-exposed offspring, 3.2% (n = 98) had special school needs vs. 2.4% (n = 77) in unexposed offspring, P-value=0.048. Correspondingly, 12.3% (n = 383) among SSRI-exposed children had delayed school entry vs. 9.4% (n = 308) in unexposed offspring, P-value < 0.001. Adjusted OR for the association with special school needs was 1.12 (95% CI 0.82-1.55; P-value = 0.48) and 1.38 (95% CI 0.90-2.13; P-value = 0.14) for exposure in all three trimesters. The corresponding adjusted ORs for delayed school entry were 1.17 (95% CI 0.99-1.38; P-value = 0.073) and 1.40 (95% CI 1.11-1.76; P-value = 0.004).

CONCLUSION

In utero SSRI exposure in all three trimesters was associated with delayed elementary school start but not special education needs.

Effect of copayment policies on initial medication non-adherence according to income: a population-based study

Objective

Copayment policies aim to reduce the burden of medication expenditure but may affect adherence and generate inequities in access to healthcare. The objective was to evaluate the impact of two copayment measures on initial medication non-adherence (IMNA) in several medication groups and by income level.

Design

A population-based study was conducted using real-world evidence.

Setting

Primary care in Catalonia (Spain) where two separate copayment measures (fixed copayment and coinsurance) were introduced between 2011 and 2013.

Participant

Every patient with a new prescription issued between 2011 and 2014 (3 million patients and 10 million prescriptions).

Outcomes

IMNA was estimated throughout dispensing and invoicing information. Changes in IMNA prevalence after the introduction of copayment policies (immediate level change and trend changes) were estimated through segmented logistic regression. The regression models were stratified by economic status and medication groups.

Results

Before changes to copayment policies, IMNA prevalence remained stable. The introduction of a fixed copayment was followed by a statistically significant increase in IMNA in poor population, low/middle-income pensioners and low-income non-pensioners (OR from 1.047 to 1.370). In high-income populations, there was a large statistically non-significant increase. IMNA decreased in the low-income population after suspension of the fixed copayment and the introduction of a coinsurance policy that granted this population free access to medications (OR=0.676). Penicillins were least affected while analgesics were affected to the greatest extent. IMNA to medications for chronic conditions increased in low/middle-income pensioners.

Conclusion

Even nominal charge fixed copayment may generate inequities in access to health services. An anticipation effect and expenses associated with IMNA may have generated short-term costs. A reduction in copayment can protect from non-adherence and have positive, long-term effects. Copayment scenarios could have considerable long-term consequences for health and costs due to increased IMNA in medication for chronic physical conditions.

Use of Dicloxacillin and Risk of Pregnancy among Users of Oral Contraceptives

The antibiotic dicloxacillin has been shown to induce drug-metabolizing CYP enzymes to a clinically relevant extent. In this study, we investigated whether the use of dicloxacillin confers an increased risk of unwanted pregnancy among oral contraceptive users. The study population comprised Danish women falling pregnant (1997-2015) during oral contraceptive use, defined as having filled a prescription for an oral contraceptive within 120 days both before and after the estimated date of conception. Data were analysed using a case-crossover approach. For each woman, we assessed the use of dicloxacillin preceding the date of conception and during 10 previous control periods and estimated the odds ratio for such unintended pregnancies associated with the use of dicloxacillin. Among 364 women using dicloxacillin prior to conception, 40 (11%) were exposed to dicloxacillin at the time of conception, yielding an odds ratio (OR) associating use of dicloxacillin to unintended pregnancy of 1.18 (95% CI 0.84-1.65). Supplementary and sensitivity analyses generally returned similar estimates, except for a slightly increased risk among users of progestogen-only oral contraceptives (OR 1.83, 95% CI 0.63-5.34). Analysis of other antibiotics as negative controls yielded results close to unity (ORs ranging from 0.83 to 1.13). In conclusion, our study found no evidence for an increased risk of oral contraceptive failure when using dicloxacillin. However, acknowledging study limitations, we suggest the use of supplementary barrier methods during treatment with dicloxacillin, until our findings are confirmed in further studies.

Research Priorities for Optimizing Geriatric Pharmacotherapy: An International Consensus

Medication management is becoming increasingly challenging for older people, and there is limited evidence to guide medication prescribing and administration for people with multimorbidity, frailty, or at the end of life. Currently, there is a lack of clear research priorities in the field of geriatric pharmacotherapy. To address this issue, international experts from 5 research groups in geriatric pharmacotherapy and pharmacoepidemiology research were invited to attend the inaugural Optimizing Geriatric Pharmacotherapy through Pharmacoepidemiology Network workshop. A modified nominal group technique was used to explore and consolidate the priorities for conducting research in this field. Eight research priorities were elucidated: quality of medication use; vulnerable patient groups; polypharmacy and multimorbidity; person-centered practice and research; deprescribing; methodological development; variability in medication use; and national and international comparative research. The research priorities are discussed in detail in this article with examples of current gaps and future actions presented. These priorities highlight areas for future research in geriatric pharmacotherapy to improve medication outcomes in older people.

Impact of initial medication non-adherence to SSRIs on medical visits and sick leaves

BACKGROUND

Initial medication non-adherence (IMNA) to antidepressants, which are commonly used to treat depression in primary care (PC), is around 6-12%. Although it is well known that post-initial non-adherence to antidepressants increases the cost of depression, the impact of IMNA on cost is unknown. The aim of this study is to assess the impact of IMNA to Selective Serotonin Reuptake Inhibitors (SSRI) on medical visits and sick leave in patients with depression treated in PC in Catalonia (Spain).

METHODS

This was a four-year retrospective register-based study (2011-2014). All PC patients of working age who received a new SSRI prescription and had a diagnosis of depression were included (N = 79,642). Treatment initiation, number of visits and days on sick leave were gathered from the database. We assessed the impact of IMNA on costs with ordered logistic regressions.

RESULTS

The 3-year incidence of IMNA was 15%. Initially non-adherent patients made a lesser number of GP visits (OR = 0.82; 95% CI = 0.79-0.84) but had more days on sick leave (OR = 1.25; 95% CI = 1.20-1.31). There were no differences in the number of specialist visits (OR = 1.04; 95% CI = 0.99-1.08).

LIMITATIONS

Differences between adherent and non-adherent patients could be explained by non-observed variables. GP recognition and documentation of depression might be inaccurate. Costs of unpaid work and use of hospital services were not considered.

CONCLUSIONS

Although IMNA decreases the use of medical PC services, it increases the number of days on sick leave. This could also indicate worse health status. These consequences are currently overlooked when considering post-initial medication non-adherence.

Primary nonadherence to chronic disease medications: a meta-analysis

BACKGROUND

Medication nonadherence is a global problem that requires urgent attention. Primary nonadherence occurs when a patient consults with a medical doctor, receives a referral for medical therapy but never fills the first dispensation for the prescription medication. Nonadherence to chronic disease medications costs the USA ~$290 billion (USD) every year in avoidable health care costs. In Canada, it is estimated that 5.4% of all hospitalizations are due to medication nonadherence.

OBJECTIVES

The objective of this study was to quantify the extent of primary nonadherence for four of the most common chronic disease medications. The second objective was to identify factors associated with primary nonadherence to chronic disease medications.

MATERIALS AND METHODS

We conducted an extensive systematic literature review of eight databases with a wide range of keywords. We identified relevant articles for primary nonadherence to antihypertensives, lipid-lowering agents, hypoglycemics, and antidepressants. After further screening and assessment of methodologic quality, relevant data were extracted and analyzed using a random-effects model.

RESULTS

Twenty-four articles were included for our meta-analysis after full review and assessment for risk of bias. The pooled primary nonadherence rate for the four chronic disease medications was 14.6% (95% CI: 13.1%-16.2%). Primary medication nonadherence was higher for lipid-lowering medications among the four chronic disease medications assessed (20.8%; 95% CI: 16.0%-25.6%). The rates in North America (17.0%; 95% CI: 14.4%-19.5%) were twice those from Europe (8.5%; 95% CI: 7.1%-9.9%). The absence of social support (20%; 95% CI: 14.4%-26.6%) was the most common sociodemographic variable associated with chronic disease medication primary nonadherence.

CONCLUSION

Evidence suggests that a considerable percentage of patients do not initially fill their medications for treatable chronic diseases or conditions. This represents a major health care problem that can be successfully addressed. Efforts should be directed toward proper medication counseling, patient social support, and clinical follow-up, especially when the indications for the prescribed medication aim to provide primary prevention.

Evidence-Based Therapy and Its Association With Workforce Detachment After First Hospitalization for Heart Failure

OBJECTIVES

This study investigated the association between the use of evidence-based medicine (EBM) for heart failure (HF) and risk of workforce detachment.

BACKGROUND

The ability to work can be a marker of functional capacity and quality of life.

METHODS

We examined a nationwide cohort of patients in the workforce 1 year after first hospitalization for HF. EBM was defined as treatment with β-blockers and renin angiotensin system inhibitors. The fraction of target dose (0 TO 1) for each drug was calculated. The sum of the fractions gave each patient a score between 0 and 2. Patients were stratified into 4 groups according to this score: group 4 score = 2 (target dose of both drugs); group 3 score <2 to >1; group 2 score ≤1 to >0.5; and group 1 score ≤0.5. The risk of subsequent workforce detachment was estimated in cause specific Cox regression models.

RESULTS

One year after first HF hospitalization, 10,185 patients were part of the workforce, and 7,561 (74%) were in treatment with at least 1 of the components of EBM. During a median follow-up of 727 days, 2,698 individuals (36%) became detached from the workforce. Patients receiving more EBM had a significantly lower risk of workforce detachment compared with those receiving less EBM (group 4 hazard ratio [HR]: 0.87; 95% confidence interval [CI]: 0.77 to 0.98; group 3 HR: 0.85; 95% CI: 0.77 to 0.94; and group 2 HR 0.92; 95% CI: 0.83 to 1.02), all compared to group 1.

CONCLUSIONS

Patients in the workforce 1 year after first HF hospitalization and treated with target or near-target doses of EBM were associated with a significantly lower risk of subsequent workforce detachment.

Trends for prevalence and incidence of resistant hypertension: population based cohort study in the UK 1995-2015

Objective To estimate the incidence and prevalence of resistant hypertension among a UK population treated for hypertension from 1995 to 2015.Design Cohort study.Setting Electronic health records from the UK Clinical Practice Research Datalink in primary care.Participants 1 317 290 users of antihypertensive drugs with a diagnosis of hypertension.Main outcome measures Resistant hypertension was defined as concurrent use of three antihypertensive drugs inclusive of a diuretic, uncontrolled hypertension (≥140/90 mm Hg), and adherence to the prescribed drug regimen, or concurrent use of four antihypertensive drugs inclusive of a diuretic and adherence to the prescribed drug regimen. To determine incidence, the numerator was new cases of resistant hypertension and the denominator was person years of those with treated hypertension and at risk of developing resistant hypertension. To determine prevalence, the numerator was total number of cases with resistant hypertension and the denominator was those with treated hypertension. Prevalence and incidence were age standardised to the 2015 hypertensive population.Results The age standardised incidence of resistant hypertension increased from 0.93 cases per 100 person years (95% confidence interval 0.87 to 1.00) in 1996 to a peak level of 2.07 cases per 100 person years (2.03 to 2.12) in 2004. Incidence then decreased to 0.42 cases per 100 person years (0.40 to 0.44) in 2015. Age standardised prevalence increased from 1.75% (95% confidence interval 1.66% to 1.83%) in 1995 to a peak of 7.76% (7.70% to 7.83%) in 2007. Prevalence then plateaued and subsequently declined to 6.46% (6.38% to 6.54%) in 2015. Compared with patients aged 65-69 years, those aged 80 or more years were more likely to have prevalent resistant hypertension throughout the study period.Conclusions Prevalent resistant hypertension has plateaued and decreased in recent years, consistent with a decrease in incidence from 2004 onwards. Despite this, resistant hypertension is common in the UK hypertensive population. Given the importance of hypertension as a modifiable risk factor for cardiovascular disease, reducing uncontrolled hypertension should remain a population health focus.

Impact of initial medication non-adherence on use of healthcare services and sick leave: a longitudinal study in a large primary care cohort in Spain

BACKGROUND

Initial medication non-adherence is highly prevalent in primary care but no previous studies have evaluated its impact on the use of healthcare services and/or days on sick leave.

AIM

To estimate the impact of initial medication non-adherence on the use of healthcare services, days of sick leave, and costs overall and in specific medication groups.

DESIGN AND SETTING

A 3-year longitudinal register-based study of all primary care patients (a cohort of 1.7 million) who were prescribed a new medication in Catalonia (Spain) in 2012.

METHOD

Thirteen of the most prescribed and/or costly medication subgroups were considered. All medication and medication subgroups (chronic, analgesics, and penicillin) were analysed. The number of healthcare services used and days on sick leave were considered. Multilevel multivariate linear regression was used. Three levels were included: patient, GP, and primary care centre.

RESULTS

Initially adherent patients made more use of medicines and some healthcare services than non-adherent and partially adherent patients. They had lower productivity losses, producing a net economic return, especially when drugs for acute diseases (such as penicillins) were considered. Initial medication non-adherence resulted in a higher economic burden to the system in the short term.

CONCLUSION

Initial medication non-adherence seems to have a short-term impact on productivity losses and costs. The clinical consequences and long-term economic consequences of initial medication non-adherence need to be assessed. Interventions to promote initial medication adherence in primary care may reduce costs and improve health outcomes.

Clinical indications for antibiotic use in Danish general practice: results from a nationwide electronic prescription database

OBJECTIVE

To assess the availability and applicability of clinical indications from electronic prescriptions on antibiotic use in Danish general practice.

DESIGN

Retrospective cohort register-based study including the Danish National Prescription Register.

SETTING

Population-based study of routine electronic antibiotic prescriptions from Danish general practice.

SUBJECTS

All 975,626 patients who redeemed an antibiotic prescription at outpatient pharmacies during the 1-year study period (July 2012 to June 2013).

MAIN OUTCOME MEASURES

Number of prescriptions per clinical indication. Number of antibiotic prescriptions per 1000 inhabitants by age and gender. Logistic regression analysis estimated the association between patient and provider factors and missing clinical indications on antibiotic prescriptions.

RESULTS

A total of 2.381.083 systemic antibiotic prescriptions were issued by Danish general practitioners in the study period. We identified three main clinical entities: urinary tract infections (n = 506.634), respiratory tract infections (n = 456.354) and unspecified infections (n = 416.354). Women were more exposed to antibiotics than men. Antibiotic use was high in children under 5 years and even higher in elderly people. In 32% of the issued prescriptions, the clinical indication was missing. This was mainly associated with antibiotic types. We found that a prescription for a urinary tract agent without a specific clinical indication was uncommon.

CONCLUSION

Clinical indications from electronic prescriptions are accessible and available to provide an overview of drug use, in casu antibiotic prescriptions, in Danish general practice. These clinical indications may be further explored in detail to assess rational drug use and congruence with guidelines, but validation and optimisation of the system is preferable.

Characterisation of antibiotic prescriptions for acute respiratory tract infections in Danish general practice: a retrospective registry based cohort study

Inappropriate use of antibiotics is contributing to the increasing rates of antimicrobial resistance. Several Danish guidelines on antibiotic prescribing for acute respiratory tract infections in general practice have been issued to promote rational prescribing of antibiotics, however it is unclear if these recommendations are followed. We aimed to characterise the pattern of antibiotic prescriptions for patients diagnosed with acute respiratory tract infections, by means of electronic prescriptions, labeled with clinical indications, from Danish general practice. Acute respiratory tract infections accounted for 456,532 antibiotic prescriptions issued between July 2012 and June 2013. Pneumonia was the most common indication with 178,354 prescriptions (39%), followed by acute tonsillitis (21%) and acute otitis media (19%). In total, penicillin V accounted for 58% of all prescriptions, followed by macrolides (18%) and amoxicillin (15%). The use of second-line agents increased with age for all indications, and comprised more than 40% of the prescriptions in patients aged >75 years. Women were more often prescribed antibiotics regardless of clinical indication. This is the first Danish study to characterise antibiotic prescription patterns for acute respiratory tract infections by data linkage of clinical indications. The findings confirm that penicillin V is the most commonly prescribed antibiotic agent for treatment of patients with an acute respiratory tract infection in Danish general practice. However, second-line agents like macrolides and amoxicillin with or without clavulanic acid are overused. Strategies to improve the quality of antibiotic prescribing especially for pneumonia, acute otitis media and acute rhinosinusitis are warranted.

Better adherence to guidelines for prescribing antibiotics for different respiratory tract infections are warranted in Danish general practice. The over-use of antibiotics, particularly so-called ‘second-line’ agents such as amoxicillin, increases resistance and may lead to a potentially catastrophic scenario where antibiotics are no longer effective. Exactly how widespread the over-use of antibiotics is for different infections, however, is not clear. Rune Aabenhus at the University of Copenhagen and co-workers analyzed primary care data regarding antibiotic prescriptions for acute respiratory tract infections including pneumonia and ear infections in Denmark. They found that penicillin V—the current recommended first-line drug in Scandinavian countries—accounted for 58 per cent of prescriptions, a figure which should be improved. Amoxicillin and macrolides were over-prescribed, particularly in elderly patients. The team also call for further analysis of prescriptions given by out-of-hours clinics.

Odense Pharmacoepidemiological Database: A Review of Use and Content

The Odense University Pharmacoepidemiological Database (OPED) is a prescription database established in 1990 by the University of Southern Denmark, covering reimbursed prescriptions from the county of Funen in Denmark and the region of Southern Denmark (1.2 million inhabitants). It is still active and thereby has more than 25 years of continuous coverage. In this MiniReview, we review its history, content, quality, coverage, governance and some of its uses. OPED's data include the Danish Civil Registration Number (CPR), which enables unambiguous linkage with virtually all other health-related registers in Denmark. Among its research uses, we review record linkage studies of drug effects, advanced drug utilization studies, some examples of method development and use of OPED as sampling frame to recruit patients for field studies or clinical trials. With the advent of other, more comprehensive sources of prescription data in Denmark, OPED may still play a role as in certain data-intensive regional studies.

Initial medication non-adherence: prevalence and predictive factors in a cohort of 1.6 million primary care patients

AIMS

Adherence to medicines is vital in treating diseases. Initial medication non-adherence (IMNA) - defined as not obtaining a medication the first time it is prescribed - has been poorly explored. Previous studies show IMNA rates between 6 and 28% in primary care (PC). The aims of this study were to determine prevalence and predictive factors of IMNA in the most prescribed and expensive pharmacotherapeutic groups in the Catalan health system.

METHODS

This is a retrospective, register-based cohort study which linked the Catalan PC System (Spain) prescription and invoicing databases. Medication was considered non-initiated when it was not collected from the pharmacy by the end of the month following the one in which it was prescribed. IMNA prevalence was calculated using July 2013-June 2014 prescription data. Predictive factors related to patients, general practitioners and PC centres were identified through multilevel logistic regression analyses. Missing data were attributed using simple imputation.

RESULTS

Some 1.6 million patients with 2.9 million prescriptions were included in the study sample. Total IMNA prevalence was 17.6% of prescriptions. The highest IMNA rate was observed in anilides (22.6%) and the lowest in angiotensin-converting-enzyme (ACE) inhibitors (7.4%). Predictors of IMNA are younger age, American nationality, having a pain-related or mental disorder and being treated by a substitute/resident general practitioner in a resident-training centre.

CONCLUSIONS

The rate of IMNA is high when all medications are taken into account. Attempts to strengthen trust in resident general practitioners and improve motivation to initiate a needed medication in the general young and older immigrant population should be addressed in Catalan PC.

Utilization of Stimulants and Atomoxetine for Attention-Deficit/Hyperactivity Disorder among 5.4 Million Children Using Population-Based Longitudinal Data

Use of stimulants to treat attention-deficit/hyperactivity disorder (ADHD) has increased over the past two decades and varies substantially between countries. The objective of this multinational population-based study was to examine utilization of ADHD drugs (stimulants and atomoxetine) including comedication with other psychotropic drugs in the entire child population in the five Nordic countries. We included longitudinal data on dispensed ADHD drugs from five Nordic prescription registers during 2008-2012, which in 2012 comprised 48,296 individuals among 5.42 million inhabitants aged 0-17 years. Prevalence of filling ≥1 prescriptions of ADHD drugs among children aged 6-17 years increased during 2008-2012 from 5.9 to 11.2 and 19.4 to 31.0 per 1000 girls and boys, respectively. Prevalence by country showed that Iceland, Finland and Sweden had a steady increase during the study period, while in Norway the prevalence was quite stable and in Denmark it levelled off from 2010. Use in preschoolers (aged 0-5 years) was rare. Iceland had much higher prevalence and incidence than the other Nordic countries. The incidence of ADHD drug use increased during the study period, from 4.0 to 4.9 and from 1.5 to 2.3 per 1000 boys and girls, respectively. The increasing number of new users levelled off somewhat after 2010. Comedication with other psychotropic drugs was more common among girls (33.9%) than boys (27.0%) and was mainly melatonin, followed by antidepressants and antipsychotics. Overall prevalence of ADHD drug use increased among Nordic girls and boys aged 6-17 years, whereas the incidence increased slightly during 2008-2010 but levelled off through 2012. The substantial differences in ADHD drug use across the Nordic countries and high degree of comedication with other psychotropic drugs underscore the importance of close monitoring of treatment for ADHD among children.

Socioeconomic Inequalities in Statin Adherence Under Universal Coverage: Does Sex Matter?

BACKGROUND

Previous research shows that low socioeconomic position (SEP; especially low income) is associated with statin nonadherence. We investigated the relationship between SEP and statin adherence in a country with universal coverage using group-based trajectory modeling in addition to the proportion of days covered.

METHODS AND RESULTS

Using data from Finnish healthcare registers, we identified 116 846 individuals, aged 45 to 75 years, who initiated statin therapy for primary prevention of cardiovascular disease. We measured adherence as proportion of days covered over an 18-month period since initiation and identified different adherence patterns based on monthly adherence with group-based trajectory modeling. When adjusted for age, marital status, residential area, clinical characteristics, and copayment, low SEP was associated with statin nonadherence (proportion of days covered <80%) among men (eg, lowest versus highest income quintile: odds ratio, 1.41; 95% confidence interval, 1.32-1.50; basic versus higher-degree education: odds ratio, 1.18; 95% confidence interval, 1.13-1.24; unemployment versus employment: odds ratio, 1.17; 95% confidence interval, 1.10-1.25). Among women, the corresponding associations were different (P<0.001 for sex-by-income quintile, sex-by-education level, and sex-by-labor market status interactions) and mainly nonsignificant. Results based on adherence trajectories showed that men in low SEP were likely to belong to trajectories presenting a fast decline in adherence.

CONCLUSIONS

Low SEP was associated with overall and rapidly increasing statin nonadherence among men. Conversely, in women, associations between SEP and nonadherence were weak and inconsistent. Group-based trajectory modeling provided insight into the dynamics of statin adherence and its association with SEP.

Assessing adherence to inhaled corticosteroids in asthma patients using an integrated measure based on primary and secondary adherence

PURPOSE

There are very few studies on primary adherence (i.e., first filling of a prescription) to inhaled corticosteroids (ICS) in asthma patients; two have involved children. Moreover, adherence can be overestimated when considering only secondary adherence (i.e., following the medication recommendations for a defined period) and ignoring primary adherence. We aimed thus to evaluate the real-world primary and secondary adherence to ICS and to develop an integrated primary and secondary adherence (IPSA) measure.

METHODS

From two clinical databases of pediatric and adult asthma patients, we included 198 children and 206 adults with one ICS prescription recorded in their medical chart between 2010 and 2012 and follow-up data for ≥12 months. Adherence was estimated from written prescriptions and prescription claims data. Primary adherence was defined as filling the ICS prescription at a pharmacy within 12 months. Secondary adherence was defined as the proportion of days covered (PDC) in subjects who filled their prescription at least once. The IPSA was based on the PDC with a correction factor for primary adherence.

RESULTS

Primary adherence to ICS at 12 months was 89.4 % in children and 69.4 % in adults. Secondary adherence at 12 months in children was 33.9 %, and the IPSA was 30.3 %. These values were 52.8 and 36.6 %, respectively, in adults.

CONCLUSIONS

Primary adherence to ICS is low in adults and secondary adherence is poor in children and adults. Using the PDC as a unique measure of adherence led to significant overestimation in adults; IPSA leads to more valid estimates of adherence to ICS.

Defining and Measuring Primary Medication Nonadherence: Development of a Quality Measure

Poor medication adherence has been increasingly recognized as a major public health issue and a priority for health care reform. Primary medication nonadherence (PMN) is a subset of this broader subject and occurs when a new medication is prescribed for a patient, but the patient does not obtain the medication, or an appropriate alternative, within an acceptable period of time after it was prescribed. It is increasingly evident that the public health problem of PMN is widespread. However, the lack of standardized definitions and measures inhibits the ability to establish the true incidence of this problem or to track changes in PMN rates over time. Given the limitations of current measures, the Pharmacy Quality Alliance (PQA) convened an expert working group to set parameters for a new industry measure. That new measure, which links electronic prescribing and pharmacy dispensing databases and was developed and approved by the PQA, is described here. PMN literature from 1990 to June 2015 is also reviewed, and existing PMN measures are summarized.

DISCLOSURES

No funding was received for this article, and the authors declare no conflicts of interest. The views expressed in this article are those of the authors alone and do not necessarily reflect those of their respective employers. Adams has received grant support from Pfizer for adherence research. Adams and Stolpe were equally involved in all aspects of study design, data collection and interpretation, and manuscript preparation.