Use of proton pump inhibitors is associated with increased risk of out-of-hospital cardiac arrest in the general population: a nested case-control study

AIMS

Proton pump inhibitors (PPIs) impair cardiac repolarization, prolong the QT interval, and may potentially be pro-arrhythmic. However, the risk of out-of-hospital cardiac arrest (OHCA) is scarcely investigated. We studied whether past or current PPI use is associated with OHCA in the general population.

METHODS AND RESULTS

We conducted a nationwide nested case-control study with OHCA-cases of presumed cardiac causes and age/sex/OHCA-date-matched non-OHCA-controls from the general population. Exposure to PPI was categorized into three mutually exclusive groups of current-, past-, and non-use. Conditional logistic regression analyses with adjustments for risk factors of OHCA were used to calculate the odds ratio (OR) of OHCA comparing PPI use with non-users. We identified 46 578 OHCA cases and 232 890 matched non-OHCA controls (mean: 71 years, 68.8% men). PPI was used by 8769 OHCA-cases and 21 898 non-OHCA controls, and current use of PPI was associated with increased odds of OHCA compared with non-users [OR: 1.32 (95% CI: 1.28-1.37)], while past use conferred no increase in the odds of OHCA [OR: 1.01 (95% CI: 0.98-1.04)]. This increased odds of OHCA occurred in both sexes. Finally, the ORs remained elevated when we repeated the analyses in individuals without registered ischaemic heart disease [OR: 1.36 (95% CI: 1.31-1.41)], without heart failure [OR: 1.33 (95% CI: 1.29-1.38)], or without any cardiovascular comorbidities [OR: 1.84 (95% CI: 1.70-2.00)]. Also, the OR remained elevated when H2-antagonists served as the reference group [OR: 1.28 (95% CI: 1.11-1.47)].

CONCLUSION

PPI use is associated with an increased risk of OHCA in the general population. Considering the widespread use of PPIs, this study raises concerns and the need for awareness to balance the benefit and risk of treatment.

The use of opioids nine months after surgery for Crohn's disease - a nationwide cohort study

BACKGROUND

The risk of chronic opioid use after surgery for Crohn's disease (CD) is not known.

AIM

The aim of this study is to examine the chronic opioid use after surgery according to age at time of surgery and to opioid use prior to surgery.

METHODS

This nationwide cohort study included patients with a first surgery for CD (January 1, 1996 through 2021). We examined prescribed opioids 9 months after surgery and estimated adjusted odds ratios (OR) for chronic opioid use in elderly (≥60 years), adults (≥40 and <60 years), and young adults (≥18 and <40 years) according to opioid use prior to surgery. Chronic opioid use was defined as prescriptions in at least two of three consecutive quarters.

RESULTS

A total of 797 patients had surgery as elderly, 1603 as adults, and 2786 as young adults. Across all age groups, 18%-38% received opioid prescriptions throughout 9 months after surgery, if opioids were prescribed prior to surgery. If opioids were not prescribed prior to surgery, the corresponding proportions were 2%-5%. If patients were prescribed opioids (≥1) prior to surgery, the adjusted ORs (95% CIs) for their chronic use after surgery in elderly, adults, and young adults were 10.37 (6.77-15.88), 10.48 (7.74-14.19), and 6.55 (4.93-8.72), respectively.

CONCLUSION

Clinicians should be aware that in patients with a need for opioids before surgery, the surgery may not change the need for opioids. Future research should examine effective analgesic strategies that help minimise opioid use in this population.

Screening of dermatology drugs for aberrant use-patterns: An application of epidemiologic estimates and measures of inequality in drug use

AIMS

Dermatology treatments require adherence for safe and effective use. Real-world healthcare databases can reveal drug utilization patterns and uncover inappropriate or unexpected use. This study aimed to analyse dermatology drug utilization patterns using epidemiological and inequality measures, leveraging Danish nationwide registries. It also assessed the feasibility of this method for detecting aberrant drug use.

METHODS

We formed a 2019 cohort of all patients treated for skin conditions through Danish healthcare registries. We calculated prevalence, incidence rates and treatment duration for dermatological drugs. Inequality in drug utilization was assessed using Lorenz curves, Gini coefficients and other measures.

RESULTS

The study encompassed 1 021 255 patients using 94 dermatology drugs. Most usage aligned with 'expected clinical use', but we detected inequality, with some drugs having high Gini coefficients and disproportionate consumption by the top percentile of users. Notable findings included potential inappropriate antibiotic use, excessive topical corticosteroid use and unexpected drug use duration.

CONCLUSIONS

In Denmark, dermatology drugs are used primarily as anticipated, with minimal unexpected patterns. Specific follow-up is required to draw conclusions about inappropriate use. This approach demonstrates broad applicability for screening aberrant drug utilization.

Association Between First-time Neurologic Events and Metronidazole Treatment: A Case-time Control Study

PURPOSE

Metronidazole, a widely used antimicrobial medication, has been linked to neurologic adverse drug reactions. This study investigates the association between metronidazole use and first-time neurologic events.

METHODS

We conducted a case-time-control study using data from the Danish National Patient Register and the National Prescription Register in years 2013 to 2021. Patients with a first-time diagnosis of encephalopathy, cerebellar dysfunction, or peripheral neuropathy were included. Conditional logistic regression analyses were performed to estimate the risk of neurologic events associated with metronidazole use.

FINDINGS

Out of 476,066 first-time metronidazole prescriptions, the 100-day cumulative incidence of peripheral neuropathy was 0.016%, and 0.002% for cerebellar dysfunction or encephalopathy. In the case-time control study, we identified 17,667 persons with a first-time neurologic event and were included for the analysis. The estimated odds ratio for the combined neurologic events was 0.98 (95% CI, 0.59-1.64, P = 0.95) with no statistically significant association across different subgroups and time windows.

IMPLICATIONS

Our findings suggest that metronidazole-induced neurologic events may be rarer than previously described, and we did not find any consistent or statistically significant association between metronidazole exposure. Nonetheless, clinicians should remain vigilant to potential neurologic risks in patients receiving metronidazole, to ensure its safe and effective use.

Use of drugs with pharmacogenomics (PGx)-based dosing guidelines in a Danish cohort of persons with chronic kidney disease, both on dialysis and not on dialysis: Perspectives for prescribing optimization

AIM

The objective of this registry study is to assess the utilization of pharmacogenomic (PGx) drugs among patients with chronic kidney disease (CKD).

METHODS

This study was a retrospective study of patients affiliated with the Department of Nephrology, Aalborg University Hospital, Denmark in 2021. Patients diagnosed with CKD were divided into CKD without dialysis and CKD with dialysis. PGx prescription drugs were retrieved from the Patient Administration System. Actionable dosing guidelines (AG) for specific drug-gene pairs for CYP2D6, CYP2C9, CYP2C19 and SLCO1B1 were retrieved from the PharmGKB homepage.

RESULTS

Out of 1241 individuals, 25.5% were on dialysis. The median number of medications for each patient was 9 within the non-dialysis group and 16 within the dialysis group. Thirty-one distinct PGx drugs were prescribed. Altogether, 76.0% (943 individuals) were prescribed at least one PGx drug and the prevalence of prescriptions of PGx drugs was higher in the dialysis group compared to the non-dialysis group. The most frequently prescribed drugs with AG were metoprolol, pantoprazole, atorvastatin, simvastatin and warfarin.

CONCLUSION

This study demonstrated that a substantial proportion of patients with CKD are exposed to drugs or drug combinations for which there exists AG related to PGx of CYP2D6, CYP2C19, CYP2C9 and SLCO1B1.

Sedative drug prescription patterns in Danish adults from 2002 through 2021. A register-based cohort study

OBJECTIVE

Pharmacological treatment strategies for insomnia seem to vary, and there is lack of knowledge about how sedative drugs are used in a real-world setting. We investigated changes in sedative drug prescription patterns in Danish adults who initiated treatment between 2002 and 2016.

METHODS

All adults with a first-time purchase of a sedative drug registered in the Danish National Prescription Register from 2002 through 2016 were followed for five years between 2002 and 2021 for subsequent prescriptions of sedative drugs, death, or emigration. Sedative drugs were classified into anxiolytic benzodiazepines (N05BA), hypnotic benzodiazepines (N05CD), Z-drugs (N05CF), melatonin (N05CH01), promethazine (R06AD), and low-dose quetiapine (N05AH04). Analyses were stratified on time: 2002-2006, 2007-2011, and 2012-2016.

RESULTS

A total of 842,880 individuals purchased their first sedative drug between 2002 and 2016. Most of them (40.0%) initiated treatment between 2002 and 2006, whereas 29.2% initiated treatment in 2012-2016. In 2002-2006, anxiolytic benzodiazepines (46.4%), Z-drugs (42.8%), and hypnotic benzodiazepines (5.4%) were the most common first treatment. This pattern changed over time with a gradual increase in the use of melatonin, promethazine, and low-dose quetiapine, which in 2011-2016 accounted for 27% of all first treatments. During the five years from first prescription, around 27% shifted to a different sedative drug. This percentage increased slightly over time, but over time the first shift to another drug class was most often to a Z-drug or anxiolytic benzodiazepine. Few individuals (5.8%) had more than one shift and the third choice seemed randomly distributed across all other drug classes.

CONCLUSION

Sedative drug prescriptions are distributed on different drug classes, with Z-drugs and anxiolytic benzodiazepines as the most frequent first treatment, and second choice in case of shift.

Persistence and adherence with Latanoprost: A Danish register-based cohort study in older patients with glaucoma

PURPOSE

This study aims to assess the association between switching patterns and adherence/persistence in Danish patients over the age of 65, who started their first-ever glaucoma treatment with latanoprost eye drops.

METHODS

Patients were assigned to three different cohorts: (1) switchers, (2) non-switchers, and (3) preservative-free latanoprost (Monoprost®) users. Patients were followed for 1 year until the end of data coverage or censoring. Study covariates were used to compute the propensity score. In the adjusted analysis, the propensity score was added to the model as an independent variable. The Cox regression model was used to calculate the hazard ratio (HR) of discontinuation for the three cohorts (the non-switchers cohort was the reference level) in both adjusted and unadjusted analyses.

RESULTS

Non-switchers had a statistically significant lower adherence (proportion of days covered, PDC 92%) than switchers (PDC 96%; p < 0.001) and users of Monoprost® (PDC 99%; p < 0.001). Switchers had a 53% lower risk of treatment discontinuation compared to the reference group within 1 year after the first redemption of latanoprost in both unadjusted (HR 0.47; 95% Confidence interval, 95% CI: 0.41-0.53; p < 0.001) and adjusted (HR 0.47; 95% CI: 0.42-0.53; p < 0.001) analyses. In comparison to the non-switchers, Monoprost® users had a 78% lower risk for the above result in both unadjusted (HR 0.22; 95% CI: 0.17-0.28; p < 0.001) and adjusted (HR 0.22; 95% CI: 0.17-0.29; p < 0.001) analyses.

CONCLUSION

This study found increased adherence and persistence in latanoprost users among those who redeemed preservative-free latanoprost (Monoprost®) and among those who switched between different latanoprost formulations.

Older Adult-Onset of Inflammatory Bowel Diseases Is Associated With Higher Utilization of Analgesics: A Nationwide Cohort Study

INTRODUCTION

Patients with inflammatory bowel diseases (IBD) commonly require analgesic medications to treat pain, which may be associated with complications. We examined trends of analgesic use according to age at IBD onset.

METHODS

This nationwide cohort study included adults diagnosed with IBD between 1996 and 2021 in Denmark. Patients were stratified according to their age at IBD onset: 18-39 years (young adult), 40-59 years (adult), and older than 60 years (older adult). We examined the proportion of patients who received prescriptions for analgesic medications within 1 year after IBD diagnosis: strong opioids, tramadol, codeine, nonsteroidal anti-inflammatory drugs, and paracetamol. Multivariable logistic regression analysis was performed to examine the association between age at IBD onset and strong opioid prescriptions and the composite of strong opioid/tramadol/codeine prescriptions.

RESULTS

We identified 54,216 adults with IBD. Among them, 25,184 (46.5%) were young adults, 16,106 (29.7%) were adults, and 12,926 (23.8%) were older adults at IBD onset. Older adults most commonly received analgesic prescriptions of every class. Between 1996 and 2021, strong opioid, tramadol, and codeine prescriptions were stable, while paracetamol prescriptions increased and nonsteroidal anti-inflammatory drug prescriptions decreased. After multivariable logistic regression analysis, older adults had higher adjusted odds of receiving strong opioid prescriptions (adjusted odds ratio 1.95, 95% confidence interval 1.77-2.15) and the composite of strong opioid/tramadol/codeine prescriptions (adjusted odds ratio 1.93, 95% confidence interval 1.81-2.06) within 1 year after IBD diagnosis compared with adults.

DISCUSSION

In this nationwide cohort, older adults most commonly received analgesic prescriptions within 1 year after IBD diagnosis. Additional research is needed to examine the etiology and sequelae of increased analgesic prescribing to this demographic.

Proton pump inhibitors and dementia: A nationwide population-based study

INTRODUCTION

Proton pump inhibitors (PPIs) may increase dementia risk. However, it is currently unknown whether timing of exposure or age at dementia diagnosis influence the risk.

METHODS

We assessed associations between cumulative PPI use and dementia at different ages in a nationwide Danish cohort of 1,983,785 individuals aged 60 to 75 years between 2000 and 2018.

RESULTS

During follow-up, there were 99,384 all-cause dementia incidences. Incidence rate ratio (IRR) of dementia with PPI ever-use compared with never-use was 1.36 (95% CI, 1.29 to 1.43) for age 60 to 69 years at diagnosis, 1.12 (1.09 to 1.15) for 70 to 79 years, 1.06 (1.03 to 1.09) for 80 to 89 years, and 1.03 (0.91 to 1.17) for 90+ years. Longer treatment duration yielded increasing IRRs. For cases below 90 years, increased dementia rate was observed regardless of treatment initiation up to >15 years before diagnosis.

DISCUSSION

Regardless of timing of treatment initiation, PPI use was associated with increased dementia rate before age 90 years. Dementia rates increased with younger age at diagnosis.

HIGHLIGHTS

After following 1,983,785 individuals for a median of 10 years, 99,384 developed dementia PPIs were used by 21.2% of cases and 18.9% of controls PPI use was associated with increased dementia rate regardless of time of treatment onset Magnitude of associations increased with younger age at diagnosis PPI use was not associated with dementia occurring after age 90 years.

Potential preventive properties of GLP-1 receptor agonists against prostate cancer: a nationwide cohort study

AIMS/HYPOTHESIS

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been suggested to possess antineoplastic properties against prostate cancer. We examined the association between GLP-1RA use and prostate cancer risk in a real-world setting.

METHODS

We performed a nationwide register-based cohort study using an active-comparator, new-user design. We included all men in Denmark aged ≥50 years who commenced use of GLP-1RAs or basal insulin during 2007-2019. HRs and 95% CIs for incident prostate cancer were estimated using multivariable Cox regression in 'intention-to-treat' (ITT)- and 'per-protocol'-like analyses.

RESULTS

Among 14,206 initiators of GLP-1RAs and 21,756 initiators of basal insulin, we identified 697 patients with prostate cancer during a mean follow-up period of about 5 years from initiation of the study drugs. In comparison with basal insulin use, GLP-1RA use was associated with an adjusted HR of 0.91 (95% CI 0.73, 1.14) in the 'ITT' analysis and 0.80 (95% CI 0.64, 1.01) in the 'per-protocol' analysis. Stronger inverse associations were seen among older men (≥70 years) ('ITT' HR 0.56; 95% CI 0.38, 0.82; 'per-protocol' HR 0.47; 95% CI 0.30, 0.74), and in patients with CVD ('ITT' HR 0.75; 95% CI 0.53, 1.06; 'per-protocol' HR 0.60; 95% CI 0.39, 0.91).

CONCLUSIONS/INTERPRETATION

GLP-1RA use was inversely associated with prostate cancer risk compared with use of basal insulin in the 'per-protocol' analysis. Older men and patients with CVD exhibited stronger inverse associations in both the 'ITT' and 'per-protocol' analyses. Our results may indicate that GLP-1RA use could protect against prostate cancer.

Trends in use of attention deficit hyperactivity disorder medication among children and adolescents in Scandinavia in 2010-2020

The objective of the study was to compare the use of attention deficit hyperactivity disorder (ADHD) medication among children and adolescents in Scandinavia 2010-2020. Using aggregated prescription data for individuals aged 5-19 years, we calculated annual prevalence proportions of ADHD medication (users/1000 inhabitants) for each country, overall and stratified by age and sex. Overall, use of ADHD medication increased during 2010-2020 in all countries. The increase was pronounced in Sweden reaching 35 users/1000 inhabitants in 2020 (119% increase), whereas it reached 22/1000 in Denmark and Norway (equivalent to a 38% and 16% increase, respectively). Methylphenidate was the most frequently used drug and Sweden had the highest use reaching 25/1000 in 2020 compared to 16/1000 and 18/1000 in Denmark and Norway, respectively. Lisdexamfetamine use increased steadily and was also highest in Sweden (13/1000 in 2020). In 2020, atomoxetine use was higher in Sweden (4.6/1000) and Denmark (4.5/1000) compared to Norway (2.2/1000). From 2015, use of guanfacine increased in Sweden reaching 4.4/1000 in 2020 but remained low in Denmark (0.4/1000) and Norway (0.7/1000). Use of dexamphetamine was low (ranging from 0.47 to 0.75/1000 in 2020) in the three countries. ADHD medication use was highest in Sweden across all age groups. In all countries, the prevalence was higher in males compared to females. In conclusion, use of ADHD medication among children and adolescents in Scandinavia is increasing. The prevalence of use is higher in Sweden for all drug groups compared to Norway and Denmark.

Central nervous system tumours among users of vaginal oestradiol tablets: A nationwide population-based study

BACKGROUND AND PURPOSE

It is currently unknown whether vaginal oestradiol is associated with development of meningioma and glioma. The aim of this study was to examine associations between cumulative use and treatment intensity of vaginally administered oestradiol tablets and incidence of meningioma and glioma in a nationwide, population-based study.

METHODS

We conducted a nested case-control study within a nationwide cohort of Danish women followed from 2000 to 2018. The cohort consisted of 590,676 women aged 50-60 years at study start, without prior cancer diagnosis or use of systemic hormone therapy. Information on cumulative dose, duration, and intensity of vaginal oestradiol tablet use was assessed from filled prescriptions. Conditional logistic regression provided adjusted hazard ratios (HRs) for the association between vaginal oestradiol use and diagnosis of meningioma or glioma.

RESULTS

We identified 1108 women with meningioma and 835 with glioma. Of these, 19.8% and 14.0% used vaginal oestradiol tablets, respectively. The HRs in those with ever-use of vaginal oestradiol tablets was 1.14 (95% confidence interval [CI] 0.97-1.34) for meningioma and 0.90 (95% CI 0.73-1.11) for glioma. The corresponding HRs for new users exclusively were 1.18 (95% CI 0.99-1.40) for meningioma and 0.89 (95% CI 0.71-1.13) for glioma. Intensity of vaginal oestradiol tablet use according to duration and user status yielded slightly elevated HRs for meningioma without an apparent dose-response pattern, while the HRs for glioma were generally below unity. Among new users, the HR with high intensity of current or recent vaginal oestradiol tablet use for 2+ years was 1.66 (95% CI 1.09-2.55) for meningioma and 0.77 (95% CI 0.41-1.44) for glioma.

CONCLUSION

Use of vaginal oestradiol tablets was associated with a slightly increased incidence of meningioma but not of glioma. Owing to the observational nature of the study, residual bias cannot be ruled out.

Opioid prescriber responsibility: A Danish drug utilization study

AIMS

We describe the distribution of prescribers responsible for opioid initiation and maintenance (general practice, hospital prescribers and other prescribers) in Denmark.

METHODS

We leveraged data on opioid fills from a 20% sample of all Danes alive during 2000-2021.

RESULTS

Overall, general practitioners were responsible for most treatment initiation (74% during 2000-2021) and maintenance treatment (92%). However, while hospital prescribers initiated ≈20% of treatments during 2001-2012, this increased to 35% in 2021. Similarly, hospital prescriber's share of maintenance treatment increased from 5.9% during 2000-2012 to 13% in 2021. This change was particularly pronounced for morphine initiation (48% hospital prescribers in 2021 up from 38% during 2000-2010) and oxycodone initiation (78% up from 41%). Regarding choice of opioids, codeine use dropped markedly, in particular among hospital prescribers. Tramadol was consistently the most common first choice opioid in general practice (33% in 2021), whereas its use among hospital prescribers decreased (54% during 2000-2015 to 15% in 2021). Conversely, the proportion of treatment initiation by hospital prescribers composed of morphine and oxycodone increased to 38% and 42% in 2021, respectively.

CONCLUSIONS

General practice prescribes most opioids; however, hospital prescribers are increasingly responsible for opioid prescribing, in particular initiation of morphine and oxycodone.

Trends, Patterns and Associated User Characteristics of Antidepressant Prescriptions in Older Adults: A Nationwide Descriptive Cohort Study in Denmark

BACKGROUND AND OBJECTIVE

Antidepressant use in older adults (≥ 65 years) is understudied in large population-based samples, particularly in recent years and regarding user characteristics. We aimed to describe the trends, patterns, and associated user characteristics of all antidepressant prescriptions redeemed by older adults at community pharmacies in Denmark during 2015-2019.

METHODS

This register-based study used a cross-sectional design to characterize antidepressant prescription trends and patterns, and a cohort design to describe user characteristics associated with antidepressant prescription initiation. We used descriptive statistics to characterize trends and patterns, and Poisson regression for analyzing user characteristics.

RESULTS

During the years 2015-2019, 17.9% of 1.2 million older adults redeemed 4.84 million antidepressant prescriptions, where 48.5% were selective serotonin reuptake inhibitors, followed by noradrenergic and specific serotonergic antidepressants (26.2%), serotonin-norepinephrine reuptake inhibitors (12.7%), tricyclic antidepressants (11.2%), and others (1.4%). Amitriptyline and nortriptyline, considered potentially inappropriate medications, were among the 10 most frequently redeemed antidepressants. Only 60.5% of prescriptions had a treatment indication of depression. Prescription-proportion trends by drug classes and individual antidepressants remained consistent. A higher incidence rate ratio (IRR) and 95% confidence interval (CI) of initiating antidepressants was associated with female sex (IRR 1.20, 95% CI 1.07-1.34), older age (e.g., 81-85 years vs. 65-70 years: IRR 1.74, 95% CI 1.44-2.11), living in rural areas (North Denmark vs. Capital Region: IRR 1.31, 95% CI 1.09-1.58), and having somatic and psychiatric diagnoses (e.g., per one psychiatric diagnosis: IRR 1.10, 95% CI 1.05-1.15), while a lower ratio was associated with being non-Western (vs. Danish: IRR 0.50, 95% CI 0.28-0.89) and having hospital contacts for psychiatric treatment (per each contact: IRR 0.96, 95% CI 0.93-1.00).

CONCLUSION

SSRIs were the most commonly redeemed antidepressants, with consistent trends in Danish older adults. Besides clinical conditions, sociodemographics, e.g., sex, age, ethnicity, and place of residence, may influence antidepressant use.

Twenty-Three-Year Trends in the Use of Potentially Nephrotoxic Drugs in Denmark

Background

The occurrence of acute and chronic kidney diseases has been rising in the last decades. Although drug use is a common risk factor for impaired kidney function, changes in utilization of potential nephrotoxic drugs have received little attention.

Purpose

To describe temporal trends in the utilization of potentially nephrotoxic drugs in Denmark between 1999 and 2021.

Methods

Specific drugs known or suspected to be nephrotoxic were identified in the literature. Data on the sold defined daily doses (DDDs) of potentially nephrotoxic drugs between 1999 and 2021 were retrieved using the Danish Register of Medical Product Statistics. Trends in sales of DDDs per 1000 inhabitants per day were tabulated and illustrated graphically.

Results

From 1999 to 2021, the total sale of all selected drugs increased from 286 to 457 DDDs per 1000 inhabitants per day. The overall sale reached a preliminary peak in 2012 with 449 DDDs per 1000 inhabitants per day and remained relatively stable thereafter until reaching an all-time high in 2021 with 457 DDDs per 1000 inhabitants per day. Contributing with the majority in volume, sales of drugs inhibiting the renin-angiotensin-aldosterone system (RAAS) increased dramatically throughout the period. The same was observed for acetaminophen, methotrexate, tacrolimus, and iodinated contrast dye. In contrast, the sales of diuretics, acetylsalicylic acid, and ciclosporin decreased during the last decade of the study period.

Conclusion

From 1999-2021 considerable changes in sales of potentially nephrotoxic drugs were observed. In general, the sales increased, in volume predominated by RAAS inhibiting drugs. This increase in sales of potential nephrotoxins could contribute to an increasing occurrence of kidney diseases.

A cross-country utilization patterns comparison of high expenditure therapeutic groups between Portugal and six European countries: the two sides of the Portuguese coin

BACKGROUND

Understanding variability in prescribing patterns through comparative drug utilization studies can contribute to improve an efficient, effective and safe use of medicines.

OBJECTIVES

To perform a cross-country comparison of consumption patterns of ambulatory high expenditure therapeutic groups between Portugal and six European countries and simulate potential cost-saving scenarios through the adoption of the different prescribing patterns of studied countries.

METHODS

Cross-country comparison of 2019 drug consumption patterns between Portugal, Denmark, England, Finland, the Netherlands, Norway, and Spain. Analysis comprised antihypertensive drugs, glucose lowering drugs (GLD), insulins, lipid lowering drugs (LLD) and oral anticoagulants. Cost-saving analysis were performed using the Portugal average annual cost/daily defined dose and the potential reduction in expenditure simulating other European countries consumption pattern scenarios.

RESULTS

Portugal had the lowest consumption uptake of metformin and the highest consumption of GLD (30.1%) and LLD (8.5% vs <3%) fixed-dose combinations. Annual cost-savings scenarios showed that Portugal would have saved between 53 M€ and 305 M€ if it had the same prescribing patterns than Norway or the Netherlands, respectively.

CONCLUSIONS

Different utilization patterns across countries were found. Although Portugal has the lowest gross domestic product per capita among the countries studied, it had the highest uptake of newly and costly drugs.

Treatment indications and potential off-label use of antidepressants among older adults: A population-based descriptive study in Denmark

OBJECTIVES

Off-label prescriptions of antidepressants may be of special concern in older-adults. We aimed to study the potential off-label use of antidepressants among adults ≥65 years by describing the patterns, trends, and factors associated with missing and unspecified treatment indications.

METHODS

We used registry data to describe indications of all antidepressant prescriptions (N = 13.8 million) redeemed by older-adults in 2006-2019. We investigated factors associated with off-label use by considering prescriptions with missing and unspecified indications of the first antidepressant prescription using a multinomial logistic regression with the 'depression' indication as a reference category and reported odds ratios (ORs) with 95% confidence intervals (CI).

RESULTS

Overall, 18.1% of all antidepressant prescriptions had missing indications, and 9.9% had unspecified indications. The proportion of potential off-label use based on missing and unspecified prescriptions remained mostly consistent during 2006-2019. We identified similar associations in user characteristics whether considering missing or unspecified first prescription. ORs with 95% CI were raised in non-western ethnicity (vs. Danish, 1.12 (0.99-1.26) for missing indication and 1.28 (1.11-1.48) for unspecified indication) and female sex (vs. male, 1.05 (1.02-1.07) and 1.05 (1.02-1.07) respectively). ORs were reduced for shorter educational attainment (vs. long, 0.90 (0.87-0.94) and 0.92 (0.88-0.96)), older age (≥81 vs. 67-70 years, 0.66 (0.65-0.71) and 0.73 (0.70-0.76)) and hospital psychiatric diagnosis (per diagnosis 0.76 (0.73-0.78) and 0.88 (0.86-0.91)).

CONCLUSIONS

Nearly one-third of all antidepressant prescriptions redeemed by older-adults in Denmark had either missing or unspecified treatment indications. Whether these prescriptions were actual off-label use needs to be validated. Clinicians should pay special attention to patients' characteristics linking missing and unspecified indications and maintain adequate documentation while prescribing medication.

Association of Hormone Therapy With Depression During Menopause in a Cohort of Danish Women

IMPORTANCE

During menopause, the levels of estrogen and progesterone decrease and 60% to 70% of women experience menopausal symptoms, including mood disturbances. The latter might be prevented by hormone therapy (HT), yet some studies have suggested that use of HT might be associated with increased risk of depression.

OBJECTIVE

To examine whether use of HT during menopause was associated with a subsequent diagnosis of depression.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide register-based cohort and self-controlled case series study included all women in Denmark aged 45 years between January 1, 1995, through December 31, 2017 (n = 825 238), without prior oophorectomy, breast cancer, or cancer in reproductive organs. Follow-up was completed on December 31, 2018. The statistical analysis was performed from September 1, 2021, through May 31, 2022.

EXPOSURES

Redeemed prescriptions of different types of HT identified by the Anatomical Therapeutic Chemical classification system codes (G03C [estrogen] and G03F [estrogen combined with progestin]) in the Danish National Prescription Registry between 1995 and 2017. Type of administration was divided into systemic (oral or transdermal) and local (intravaginal or intrauterine).

MAIN OUTCOMES AND MEASURES

A hospital diagnosis of depression (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, codes F32-F33 and International Classification of Diseases, Eighth Revision, codes 296.09, 296.29, 298.0, and 300.49) between 1995 through 2018. Associations were examined in cohort and self-controlled case series analysis using Cox proportional hazards and fixed-effects Poisson regression models.

RESULTS

During follow-up from 45 years of age to a mean of 56.0 (range, 45.1-67.7) years, 189 821 women (23.0%) initiated systemically or locally administered HT and 13 069 (1.6%) were diagnosed with depression. Systemically administered HT was mainly initiated before 50 years of age and was associated with a higher risk of a subsequent depression diagnosis (hazard ratio [HR] for 48-50 years of age, 1.50 [95% CI, 1.24-1.81]). The risk was especially elevated the year after initiation of both treatment with estrogen alone (HR, 2.03 [95% CI, 1.21-3.41]) and estrogen combined with progestin (HR, 2.01 [95% CI,1.26-3.21]). Locally administered HT was initiated across all ages and was not associated with depression risk (HR, 1.15 [95% CI, 0.70-1.87]). It was, however, associated with a lower risk of depression when initiated after 54 years of age (HR for 54-60 years of age, 0.80 [95% CI, 0.70-0.91]). In self-controlled analysis, which efficiently accounts for time-invariant confounding, users of systemically administered HT had higher rates of depression in the years after initiation compared with the years before treatment (incidence rate ratio for 0-1 year after initiation, 1.66 [95% CI, 1.30-2.14]).

CONCLUSIONS AND RELEVANCE

These findings suggest that systemically administered HT before and during menopause is associated with higher risk of depression, especially in the years immediately after initiation, whereas locally administered HT is associated with lower risk of depression for women 54 years or older.

Factors associated with statin discontinuation near end of life in a Danish primary health care cohort

BACKGROUND

Long-term preventive treatment such as treatment with statins should be reassessed among patients approaching end of life. The aim of the study was to describe the rate of discontinuation of statin treatment and factors associated with discontinuation in the 6 months before death.

METHODS

This study is a retrospective cohort study using national registers and blood test results from primary health care patients. Patients in the Copenhagen municipality, Denmark who died between 1997 and 2018 and were statin users during the 10-year period before death were included. We calculated the proportion who remained statin users in the 6-month period before death. Factors associated with discontinuation were tested using logistic regression.

RESULTS

A total of 55,591 decedents were included. More patients continued treatment (64%, n = 35,693) than discontinued (36%, n = 19,898) the last 6 months of life. The 70 and 80 age groups had the lowest odds of discontinuing compared to the 90 (OR 1.59, 95% CI 0.93-2.72) and 100 (OR 3.11, 95% CI 2.79-3.47) age groups. Increasing comorbidity score (OR 0.89, 95% CI 0.87; 0.90 per 1-point increase) and use of statins for secondary prevention (OR 0.89, 95% CI 0.85; 0.93) reduced the likelihood of discontinuation as did a diagnosis of dementia, heart failure, or cancer.

CONCLUSION

A substantial portion of patients continued statin treatment near end of life. Efforts to promote rational statin use and discontinuation are required among patients with limited life expectancy, including establishing clear, practical recommendations about statin discontinuation, and initiatives to translate recommendations into clinical practice.

Clinical Impact of Functional CYP2C19 and CYP2D6 Gene Variants on Treatment with Antidepressants in Young People with Depression: A Danish Cohort Study

Background: The clinical impact of the functional CYP2C19 and CYP2D6 gene variants on antidepressant treatment in people with depression is not well studied. Here, we evaluate the utility of pharmacogenetic (PGx) testing in psychiatry by investigating the association between the phenotype status of the cytochrome P450 (CYP) 2C19/2D6 enzymes and the one-year risks of clinical outcomes in patients with depression with incident new-use of (es)citalopram, sertraline, or fluoxetine. Methods: This study is a population-based cohort study of 17,297 individuals who were born between 1981 and 2005 with a depression diagnosis between 1996 and 2012. Using array-based single-nucleotide-polymorphism genotype data, the individuals were categorized according to their metabolizing status of CYP2C19/CYP2D6 as normal (NM, reference group), ultra-rapid- (UM), rapid- (RM), intermediate- (IM), or poor-metabolizer (PM). The outcomes were treatment switching or discontinuation, psychiatric emergency department contacts, and suicide attempt/self-harm. By using Poisson regression analyses, we have estimated the incidence rate ratios (IRR) with 95% confidence intervals (95% CI) that were adjusted for covariates and potential confounders, by age groups (<18 (children and adolescents), 19−25 (young adults), and 26+ years (adults)), comparing the outcomes in individuals with NM status (reference) versus the mutant metabolizer status. For statistically significant outcomes, we have calculated the number needed to treat (NNT) and the number needed to genotype (NNG) in order to prevent one outcome. Results: The children and adolescents who were using (es)citalopram with CYP2C19 PM status had increased risks of switching (IRR = 1.64 [95% CI: 1.10−2.43]) and suicide attempt/self-harm (IRR = 2.67 [95% CI; 1.57−4.52]). The young adults with CYP2C19 PM status who were using sertraline had an increased risk of switching (IRR = 2.06 [95% CI; 1.03−4.11]). The young adults with CYP2D6 PM status who were using fluoxetine had an increased risk of emergency department contacts (IRR = 3.28 [95% CI; 1.11−9.63]). No significant associations were detected in the adults. The NNG for preventing one suicide attempt/suicide in the children who were using (es)citalopram was 463, and the NNT was 11. Conclusion: The CYP2C19 and CYP2D6 PM phenotype statuses were associated with outcomes in children, adolescents, and young adults with depression with incident new-use of (es)citalopram, sertraline, or fluoxetine, therefore indicating the utility of PGx testing, particularly in younger people, for PGx-guided antidepressant treatment.

Short-term mortality following tramadol poisonings in Denmark

Tramadol is a commonly used opioid with a potential of addiction and abuse. Using Danish nationwide registers, we aimed to (1) characterise opioid poisonings; (2) assess the 30-day mortality following morphine, oxycodone, and mixed poisonings compared to tramadol poisonings; and (3) assess the development in tramadol poisonings during a 12-year period. Poisonings were identified from 2006 to 2017. A Cox proportional hazards regression model was used to estimate adjusted hazard ratios (aHRs) along with 95% confidence intervals (CIs) for 30-day mortality following morphine, oxycodone or mixed poisonings compared to tramadol poisonings. We identified 7718 opioid poisonings among 6365 patients. The patients with a tramadol poisoning were younger and had less comorbidities than the patients with a morphine, oxycodone or mixed poisoning. Within 30 days, a total of 205 patients died. The 30-day mortality risk was higher following morphine (aHR 3.2, 95% CI 2.0-5.1), oxycodone (aHR 2.1, 95% CI 1.2-3.6) and mixed poisonings (aHR 1.6, 95% CI 1.0-2.7) compared to tramadol poisonings. The annual number of tramadol poisonings increased from 233 in 2006 to 501 in 2013 and declined to 348 in 2017. In conclusion, despite a lower mortality risk compared to other opioid poisonings, physicians should consider the poisoning and abuse risks when prescribing tramadol.

Prescription opioids among older adults: ten years of data across five countries

BACKGROUND

Opioid use has increased globally in the recent decade. Although pain remains a significant problem among older adults, susceptibility to opioid-related harms highlights the importance of careful opioid therapy monitoring on individual and societal levels. We aimed to describe the trends of prescription opioid utilisation among residents aged ≥65 in all Nordic countries during 2009-2018.

METHODS

We conducted cross-sectional measurements of opioid utilisation in 2009-2018 from nationwide registers of dispensed drugs in Denmark, Finland, Iceland, Norway, and Sweden. The measures included annual opioid prevalence, defined daily doses (DDDs) per 1000 inhabitants per day (DIDs), and morphine milligram equivalents (MMEs) per user per day.

RESULTS

From 2009 to 2018, an average of 808,584 of adults aged ≥65 used opioids yearly in all five countries; an average annual prevalence of 17.0%. During this time period, the prevalence decreased in Denmark, Norway, and Sweden due to declining codeine and/or tramadol use. Iceland had the highest opioid prevalence in 2009 (30.2%), increasing to 31.7% in 2018. In the same period, DIDs decreased in all five countries, and ranged from 28.3 in Finland to 58.5 in Denmark in 2009, and from 23.0 in Finland to 54.6 in Iceland in 2018. MMEs/user/day ranged from 4.4 in Iceland to 19.6 in Denmark in 2009, and from 4.6 in Iceland to 18.8 in Denmark in 2018. In Finland, Norway, and Sweden, MMEs/user/day increased from 2009 to 2018, mainly due to increasing oxycodone utilisation.

CONCLUSIONS

The stable or decreasing opioid utilisation prevalence among a majority of older adults across the Nordic countries coincides with an increase in treatment intensity in 2009-2018. We found large cross-national differences despite similarities across the countries' cultures and healthcare systems. For the aged population, national efforts should be placed on improving pain management and monitoring future trends of especially oxycodone utilisation.

Who prescribes quetiapine in Denmark?

The second‐generation antipsychotic quetiapine is commonly used off‐label for its anxiolytic and hypnotic properties. However, quetiapine is associated with problematic side‐effects. We used Danish Medicinal Product Statistics and a 20% random sample of the Danish population's prescription fills (2001–2020) to describe the utilization of quetiapine and proportion of various prescriber types (general practitioner [GP], specialist in private practice, hospital physician and other prescribers) both in connection to first‐time and subsequent prescriptions. In 2020, 92% of all quetiapine was dispensed outside hospitals and the average daily dispensed quantity of quetiapine per user corresponded to 100 mg/user/d. A GP issued 53% of first‐time prescriptions and 75% of subsequent prescriptions for quetiapine in 2020. The proportion of quetiapine prescriptions issued by GPs varied by age group—from 14% among 0–17‐year‐olds to 93% among the ≥80‐year‐olds. Future initiatives on the rational use of quetiapine and related drugs, especially among adults, should target GPs.

Inhalation anaesthesia compared with total intravenous anaesthesia and postoperative complications in colorectal cancer surgery: an observational registry-based study†

BACKGROUND

Postoperative complications are common after colorectal surgery, and possibly related to the type of anaesthesia. We aimed to determine associations between the type of anaesthesia and complications after colorectal cancer surgery using Danish registries.

METHODS

Patients undergoing colorectal cancer surgery (2004-18) were identified in the Danish Colorectal Cancer Group Database. The cohort was enriched with the Danish Anaesthesia Database and Danish National Prescription Registry data linked by Danish Central Person Registration number. Patients were classified according to type of general anaesthesia: inhalation or TIVA. Confounders were adjusted by propensity score matching. The primary outcome was complications within 30 days postoperatively. Secondarily, we assessed specific medical and surgical complications.

RESULTS

We identified 22 179 individuals undergoing colorectal cancer surgery with accompanying anaesthesia data. Propensity score matching yielded 8722 individuals per group. After propensity score matching, postoperative complications were seen in 1933 (22.2%) patients undergoing inhalation anaesthesia and in 2199 (25.2%) undergoing TIVA (odds ratio [OR]=0.84; 95% confidence interval [CI], 0.79-0.91). Although no difference was observed for medical complications, 1369 (15.7%) undergoing inhalation anaesthesia had surgical complications compared with 1708 (19.6%) undergoing TIVA (OR=0.76; 95% CI, 0.71-0.83). Rates of wound dehiscence, anastomotic leak, ileus, wound abscess, intra-abdominal abscess, and sepsis were statistically significantly lower in the inhalation anaesthesia group.

CONCLUSION

In this propensity score-matched registry study, use of inhalation anaesthesia was associated with fewer postoperative complications after colorectal cancer surgery than use of TIVA. Inhalation anaesthesia was associated with fewer complications related to wound healing and surgical infections.

Intracranial Hemorrhage Following Anticoagulant Treatment in Denmark: Spontaneous Adverse Drug Reaction Reports Versus Real-World Data

INTRODUCTION

In Denmark, physicians are legally obliged to report serious adverse drug reactions (ADRs), such as intracranial hemorrhage (ICH) following anticoagulant (AC) treatment, to the Danish Medicines Agency. We were therefore puzzled to discover a high number of reports concerning ICHs following treatment with the direct oral anticoagulants (DOACs) dabigatran, rivaroxaban, and apixaban compared with warfarin. This was surprising, as all DOACs have been found to be associated with a lower risk of ICH compared with warfarin in phase III randomized controlled trials.

OBJECTIVES

The primary aim of the study was to estimate the level of underreporting of ICH as an ADR following treatment with warfarin, dabigatran, rivaroxaban, and apixaban.

METHODS

This observational study covered a 5-year period (2014-2018). Using nationwide registries held by the Danish Health Data Authority, the number of users, exposure time in person-years, and related ICH events for each of the study drugs were estimated. Data on ADR-ICH reports were extracted from the interactive ADR overviews held by the Danish Medicines Agency.

RESULTS

From 2014 to 2018, 97.0% of the identified warfarin-related ICH events were not reported as ADRs. For the DOACs, the level of underreporting ranged from 88.8 to 90.8%.

CONCLUSION

We found a heavy and differentiated level of underreporting of ICH as an ADR following treatment with the four study drugs.

Generating Real-World Evidence on the Quality Use, Benefits and Safety of Medicines in Australia: History, Challenges and a Roadmap for the Future

Australia spends more than $20 billion annually on medicines, delivering significant health benefits for the population. However, inappropriate prescribing and medicine use also result in harm to individuals and populations, and waste of precious health resources. Medication data linked with other routine collections enable evidence generation in pharmacoepidemiology; the science of quantifying the use, effectiveness and safety of medicines in real-world clinical practice. This review details the history of medicines policy and data access in Australia, the strengths of existing data sources, and the infrastructure and governance enabling and impeding evidence generation in the field. Currently, substantial gaps persist with respect to cohesive, contemporary linked data sources supporting quality use of medicines, effectiveness and safety research; exemplified by Australia's limited capacity to contribute to the global effort in real-world studies of vaccine and disease-modifying treatments for COVID-19. We propose a roadmap to bolster the discipline, and population health more broadly, underpinned by a distinct capability governing and streamlining access to linked data assets for accredited researchers. Robust real-world evidence generation requires current data roadblocks to be remedied as a matter of urgency to deliver efficient and equitable health care and improve the health and well-being of all Australians.

Ranitidine and Risk of Bladder and Kidney Cancer: A Population-Based Cohort Study

BACKGROUND

In 2019, ranitidine was withdrawn due to high levels of N-nitrosodimethylamine, a probable human carcinogen. The risk of bladder and kidney cancer in ranitidine users, however, remains unclear.

METHODS

In a Danish nationwide cohort study, we included adults (18 years or older) without previous cancer, who between 1996 and 2008 redeemed at least two prescriptions for ranitidine and, as two separate comparison cohorts, patients with at least two prescriptions for other H2-receptor antagonists (H2-blockers), or proton pump inhibitors (PPI). Follow-up for bladder or kidney cancer started at date of the second prescription and continued to date of cancer, death, emigration, or December 31, 2018, whichever occurred first. We used propensity scores for ranitidine use to compute stabilized inverse probability of treatment (sIPT) weights and used Cox regression to compute crude and weighted HRs.

RESULTS

We identified 31,393 initiators of ranitidine, 65,384 initiating other H2-blockers, and 509,849 initiating PPI. Compared with other H2-blockers, the crude HR for bladder cancer was 1.33 [95% confidence interval (CI): 1.15-1.55], but sIPT weighting attenuated this to 1.11 (95% CI: 0.95-1.29). Compared with PPI initiators, the weighted HR was 1.24 (95% CI: 1.04-1.48). For kidney cancer, the weighted HR was 0.89 (95% CI: 0.72-1.10) compared with users of H2-blockers and 0.87 (95% CI: 0.67-1.13) compared with users of PPI.

CONCLUSIONS

Our findings did not suggest a substantial increase in bladder or kidney cancer occurrence in ranitidine users.

IMPACT

These findings are reassuring for previous ranitidine users.

Desloratadine Exposure and Incidence of Seizure: A Nordic Post-authorization Safety Study Using a New-User Cohort Study Design, 2001-2015

Introduction

A small number of adverse events of seizure in patients using desloratadine (DL) have been reported. The European Medicines Agency requested a post-authorization safety study to investigate whether there is an association between DL exposure and seizure.

Objective

The aim was to study the association between DL exposure and incidence of first seizure.

Methods

A new-user cohort study of individuals redeeming a first-ever prescription of DL in Denmark, Finland, Norway, and Sweden in 2001–2015 was conducted. DL exposure was defined as days’ supply plus a 4-week grace period. DL unexposed periods were initiated 27 weeks after DL prescription redemption. Poisson regression was used to estimate the adjusted incidence rate and adjusted incidence rate ratio (aIRR) of incident seizure.

Results

A total of 1,807,347 first-ever DL users were included in the study, with 49.3% male and a mean age of 29.5 years at inclusion; 20.3% were children aged 0–5 years. The adjusted incidence rates of seizure were 21.7 and 31.6 per 100,000 person-years during DL unexposed and exposed periods, respectively. A 46% increased incidence rate of seizure was found during DL exposed periods (aIRR = 1.46, 95% confidence interval [CI] 1.34–1.59). The aIRR ranged from 1.85 (95% CI 1.65–2.08) in children aged 0–5 years to 1.01 in adults aged 20 years or more (95% CI 0.85–1.19).

Conclusion

This study found an increased incidence rate of seizure during DL exposed periods as compared to unexposed periods among individuals younger than 20 years. No difference in incidence rate of seizure was observed in adults between DL exposed and unexposed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01106-7.

Comparison of Multidrug Use in the General Population and among Persons with Diabetes in Denmark for Drugs Having Pharmacogenomics (PGx) Based Dosing Guidelines

Background: This study measures the use of drugs within the therapeutic areas of antithrombotic agents (B01), the cardiovascular system (C), analgesics (N02), psycholeptics (N05), and psychoanaleptics (N06) among the general population (GP) in comparison to persons with diabetes in Denmark. The study focuses on drugs having pharmacogenomics (PGx) based dosing guidelines for CYP2D6, CYP2C19, and SLCO1B1 to explore the potential of applying PGx-based decision-making into clinical practice taking drug–drug interactions (DDI) and drug–gene interactions (DGI) into account. Methods: This study is cross-sectional, using The Danish Register of Medicinal Product Statistics as the source to retrieve drug consumption data. Results: The prevalence of use in particular for antithrombotic agents (B01) and cardiovascular drugs (C) increases significantly by 4 to 6 times for diabetic users compared to the GP, whereas the increase for analgesics (N02), psycoleptics, and psychoanaleptics (N06) was somewhat less (2–3 times). The five most used PGx drugs, both in the GP and among persons with diabetes, were pantoprazole, simvastatin, atorvastatin, metoprolol, and tramadol. The prevalence of use for persons with diabetes compared to the GP (prevalence ratio) increased by an average factor of 2.9 for all PGx drugs measured. In addition, the prevalence of use of combinations of PGx drugs was 4.6 times higher for persons with diabetes compared to GP. In conclusion, the findings of this study clearly show that a large fraction of persons with diabetes are exposed to drugs or drug combinations for which there exist PGx-based dosing guidelines related to CYP2D6, CYP2C19, and SLCO1B1. This further supports the notion of accessing and accounting for not only DDI but also DGI and phenoconversion in clinical decision-making, with a particular focus on persons with diabetes.

Use of hypnotic drugs among children, adolescents, and young adults in Scandinavia

BACKGROUND

Hypnotic use in children and adolescents is controversial.

OBJECTIVE

To describe the use of hypnotic drugs (melatonin, z-drugs, and sedating antihistamines) among 5- to 24-year-old Scandinavians during 2012 to 2018.

METHODS

Aggregate-level data were obtained from public data sources in Sweden, Norway, and Denmark. We calculated annual prevalence (users/1000 inhabitants) stratified by age group, sex, and country. Quantity of use (Defined Daily Dose (DDD)/user/day) was estimated for Norway and Denmark.

RESULTS

Melatonin was the most commonly used hypnotic, and its use increased markedly from 2012 to 2018, particularly among females and 15- to 24-year-old individuals. Sweden had the highest increase in use (6.5 to 25/1000) compared with Norway (10-20/1000) and Denmark (5.7-12/1000). The annual prevalence of sedating antihistamine use was also highest in Sweden, reaching 13/1000 in 2018 in comparison to 7.5/1000 in Norway and 2.5/1000 in Denmark. Z-drug use decreased in all countries toward 2018, dropping to 3.5/1000 in Sweden, 4.4/1000 in Norway, and 1.7/1000 in Denmark. The quantity of hypnotic use in Norway and Denmark was 0.8-1.0 DDD/user/day for melatonin in 2018, as compared to 0.1-0.3 for z-drugs and antihistamines.

CONCLUSION

The use of melatonin and sedating antihistamines increased among young Scandinavians during 2012-2018, and the increase was twice as high in Sweden compared with Norway and Denmark. In addition, Sweden had the highest use of sedating antihistamines. The Scandinavian variation of hypnotic use could reflect differences in frequency of sleep problems between populations or variation of healthcare access or clinical practice between countries.

Vaginal estrogen and association with dementia: A nationwide population-based study

INTRODUCTION

Use of systemic hormone therapy has been positively associated with development of dementia. Little is known about the dose-dependent effect of vaginal estradiol on dementia risk.

METHODS

We assessed associations between cumulative dose of vaginal estradiol tablets and dementia in a case-control study nested in a nationwide Danish cohort of women aged 50 to 60 years at study initiation, who did not use systemic hormone therapy. Each case was age-matched to 10 female controls.

RESULTS

A total of 4574 dementia cases were matched to 45,740 controls. Cumulative use of vaginal estradiol tablets was not associated with all-cause dementia; adjusted hazard ratio 1.02 (95% confidence interval [CI] 0.89-1.18) for low dose (< 750 mcg), 1.07 (0.94-1.21) for medium dose (750-2000 mcg), and 0.93 (0.84-1.03) for high dose (> 2000 mcg). Similarly, Alzheimer's disease (AD) only was not associated with vaginal estradiol.

DISCUSSION

Exposure to vaginal estradiol tablets was not associated with all-cause dementia or AD only.

Nordic Health Registry-Based Research: A Review of Health Care Systems and Key Registries

The Nordic countries are Denmark, Finland, Iceland, Norway, and Sweden and comprise a total population of approximately 27 million. The countries provide unique opportunities for joint health registry-based research in large populations with long and complete follow-up, facilitated by shared features, such as the tax-funded and public health care systems, the similar population-based registries, and the personal identity number as unique identifier of all citizens. In this review, we provide an introduction to the health care systems, key registries, and how to navigate the practical and ethical aspects of setting up such studies. For each country, we provide an overview of population statistics and health care expenditures, and describe the operational and administrative organization of the health care system. The Nordic registries provide population-based, routine, and prospective data on individuals lives and health with virtually complete follow-up and exact censoring information. We briefly describe the total population registries, birth registries, patient registries, cancer registries, prescription registries, and causes of death registries with a focus on period of coverage, selected key variables, and potential limitations. Lastly, we discuss some practical and legal perspectives. The potential of joint research is not fully exploited, mainly due to legal and practical difficulties in, for example, cross-border sharing of data. Future tasks include clear and transparent legal pathways and a framework by which practical aspects are facilitated.

The Validity of Danish Prescription Data to Measure Use of Aspirin and Other Non-Steroidal Anti-Inflammatory Drugs and Quantification of Bias Due to Non-Prescription Drug Use

Purpose

To evaluate the potential of Danish prescription registries to capture aspirin and non-aspirin non-steroidal anti-inflammatory drug (NSAID) use and to quantitatively evaluate the magnitude of bias from misclassification of true NSAID and aspirin use as apparent non-use in drug outcome studies.

Patients and Methods

In a population-based cohort study, we retrieved sales statistics for NSAIDs and aspirins based on nationwide data from the Danish Health Data Authority and the Danish National Prescription Registry. We estimated prevalence of recorded and non-recorded NSAID use in the prescription registry and resulting proportions of true NSAID and aspirin use misclassified as apparent non-use from 1999 to 2019 at population and patient levels.

Results

The prevalence of true use misclassified as non-use (mainly due to over-the-counter use) peaked at 4.7% in 2012 for NSAIDs overall, 5.5% in 2012 for ibuprofen, and at 5.9% in 2002 for high-dose aspirin. Misclassification of other individual NSAIDs was near null. Misclassification of true low-dose aspirin use as non-use declined during the study period but remained around 1% since 2005. In subgroups of cardiac patients, the highest prevalence of true NSAID use misclassified as non-use was 5.0% in 2002 and 4.3% in 2017. Quantitative bias analyses showed how such misclassification of true NSAID and aspirin use as non-use remained minimal both at population and patient levels. In hypothetical examples simulating real study populations with differing exposure prevalence and prevalence of true NSAID and aspirin use misclassified as apparent non-use, the approximate percentage change due to misclassification of use as non-use did not exceed 5% and in most scenarios stayed around 1%.

Conclusion

The Danish prescription registries are valid data sources for assessing the effects of aspirin and NSAID use. The influence of non-recorded NSAID and aspirin use on estimates of association is virtually negligible.

Low-dose aspirin for primary and secondary prevention of cardiovascular events in Denmark 1998-2018

Randomised controlled trials have shown a neutral or even unfavourable risk–benefit balance of aspirin for primary prevention of cardiovascular events. Using Danish nationwide registries, we investigated aspirin use and associated risks during the past two decades (1998–2018). We linked individual patient data on repeated aspirin redemptions with registered hospital ICD-10 diagnoses of atherosclerotic cardiovascular disease and bleedings. The prevalence of aspirin use among 1.1 million Danish adults fluctuated over the 20-year study period peaking in 2008 with 8.5% (5.4% primary prevention) and dropping to 5.1% (3.1% primary prevention) in 2018. Aspirin use showed strong age dependency, and 21% of individuals > 80 years were treated with aspirin for primary prevention in 2018. Medication adding to bleeding risk was used concurrently by 21% of all aspirin users in 2018. The incidence of major bleedings were similar with primary and secondary prevention aspirin use and highest in elderly (2 per 100 patient years among individuals > 80 years in 2018). In conclusion, low-dose aspirin use for primary prevention of cardiovascular events remains prevalent. The widespread use of aspirin, especially among older adults, and substantial concomitant use of medications adding to bleeding risk warrant increased focus on discontinuation of inappropriate aspirin use.

Antihistamines and Ovarian Cancer Survival: Nationwide Cohort Study and in Vitro Cell Viability Assay

Antihistamines with cationic amphiphilic drug (CAD) characteristics induce cancer-specific cell death in experimental studies. Epidemiologic evidence is, however, limited. In a Danish nationwide cohort of ovarian cancer patients diagnosed during 2000-2015 (n = 5075), we evaluated the association between filled antihistamine prescriptions and cancer mortality. We used Cox regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for ovarian cancer mortality. In an in vitro cell viability assay, we evaluated cell death in three ovarian cancer cell lines after treatment with clinically relevant doses of eight antihistamines. In our cohort study, CAD antihistamine use (≥1 prescription; n = 133) was associated with a hazard ratio of 0.63 (95% CI = 0.40 to 0.99) compared to use of non-CAD antihistamines (n = 304), and we found a tendency toward a dose-response association. In our cell viability assay, we found consistent and dose-dependent cytotoxicity for all CAD but not non-CAD antihistamines. In this nationwide cohort study, use of antihistamines with CAD characteristics is associated with a prognostic benefit in ovarian cancer patients.

Use of non-insulin antidiabetic drugs in children and young adults - A Scandinavian drug utilization study from 2010-2019

Knowledge on utilization patterns of non-insulin antidiabetic drugs in childhood and youth is limited. Therefore, we conducted a population-based drug utilization study using publicly available aggregate data on use of non-insulin antidiabetics from 2010 to 2019 in Scandinavia (Denmark, Norway and Sweden) in individuals aged up to 24 years. For each non-insulin antidiabetic drug, we calculated the annual prevalence proportion of users, overall and for specific age groups. From 2010 to 2019, the prevalence of non-insulin antidiabetic users in Scandinavia increased 37% from 0.43 to 0.59/1000 individuals. The prevalence proportions were highest among female adolescents and young adults, but the largest relative increase in use was seen among 10-14-year-olds (78%). Metformin was by far the most widely used non-insulin antidiabetic drug with a prevalence proportion of 0.51/1000 in 2019, followed by glucagon-like peptide-1 (GLP-1) analogues, which, however, showed an eight-fold relative increase during the study period.

Use of Clopidogrel and Proton Pump Inhibitors Alone or in Combinations in Persons with Diabetes in Denmark; Potential for CYP2C19 Genotype-Guided Drug Therapy

Background: Clopidogrel and proton pump inhibitors (PPIs) are among the most used drugs in Denmark for which there exists pharmacogenomics (PGx)-based dosing guidelines and FDA annotations. In this study, we further scrutinized the use of clopidogrel and PPIs when prescriptions were redeemed from Danish Pharmacies alone or in combination in the Danish population and among persons with diabetes in Denmark. The focus deals with the potential of applying PGx-guided antiplatelet therapy taking both drug–drug interactions (DDI) and drug–gene interactions (DGI) into account. Methods: The Danish Register of Medicinal Product Statistics was the source to retrieve consumption data. Results: The consumption of PPIs and clopidogrel in terms of prevalence (users/1000 inhabitants) increased over a five-year period by 6.3% to 103.1 (PPIs) and by 41.7% to 22.1 (clopidogrel), respectively. The prevalence of the use of clopidogrel and PPIs in persons with diabetes are 3.8 and 2.1–2.8 times higher compared to the general population. When redeemed in combination, the prevalence increased to 4.7. The most used combination was clopidogrel and pantoprazole. Conclusions: The use of clopidogrel and PPIs either alone or in combination is quite widespread, in particular among the elderly and persons with diabetes. This further supports the emerging need of accessing and accounting for not only DDI but also for applying PGx-guided drug therapy in clinical decision making for antiplatelet therapy with clopidogrel having a particular focus on persons with diabetes and the elderly.

Bottleneck analysis: Simple prediction of the precision of a planned case-control or cohort study based on healthcare registers

PURPOSE

In pharmacoepidemiological studies, the precision of effect estimates usually depends on the lowest number in the underlying two by two table. We denote this the "bottleneck count" (BNC). We describe how to translate the BNC into an achievable precision and provide empirical examples.

METHODS

First, we derive a theoretical prediction of the precision in a study where only the BNC determines precision. As an illustration, we calculated the expected precision of a null-effect study on retinoids and peptic ulcer bleeding, expressed as the upper/lower confidence limit ratio (ULCLR). Finally, we reviewed 126 effect estimates from the literature, analyzing the relationship between the predicted and achieved precision.

RESULTS

The log-log transformed ULCLR was shown to be a simple linear function of log(BNC). The expected annual number of retinoid-users experiencing a peptic ulcer bleeding was 9.8, yielding an estimated ULCLR for a 1-year study of 3.84. The literature review showed an inverse linear relationship between the logarithmic BNC and the log-log transformed ULCLR, which was largely independent of study design, effect measure and category of BNC. Achieved precision deviated little from predictions but was usually lower than predicted, particularly with low BNC.

CONCLUSION

The precision of a study can be predicted simply and with good accuracy from the BNC, which is useful for determining whether a study is worth pursuing or not.

Atorvastatin impairs liver mitochondrial function in obese Göttingen Minipigs but heart and skeletal muscle are not affected

Statins lower the risk of cardiovascular events but have been associated with mitochondrial functional changes in a tissue-dependent manner. We investigated tissue-specific modifications of mitochondrial function in liver, heart and skeletal muscle mediated by chronic statin therapy in a Göttingen Minipig model. We hypothesized that statins enhance the mitochondrial function in heart but impair skeletal muscle and liver mitochondria. Mitochondrial respiratory capacities, citrate synthase activity, coenzyme Q10 concentrations and protein carbonyl content (PCC) were analyzed in samples of liver, heart and skeletal muscle from three groups of Göttingen Minipigs: a lean control group (CON, n = 6), an obese group (HFD, n = 7) and an obese group treated with atorvastatin for 28 weeks (HFD + ATO, n = 7). Atorvastatin concentrations were analyzed in each of the three tissues and in plasma from the Göttingen Minipigs. In treated minipigs, atorvastatin was detected in the liver and in plasma. A significant reduction in complex I + II-supported mitochondrial respiratory capacity was seen in liver of HFD + ATO compared to HFD (P = 0.022). Opposite directed but insignificant modifications of mitochondrial respiratory capacity were seen in heart versus skeletal muscle in HFD + ATO compared to the HFD group. In heart muscle, the HFD + ATO had significantly higher PCC compared to the HFD group (P = 0.0323). In the HFD group relative to CON, liver mitochondrial respiration decreased whereas in skeletal muscle, respiration increased but these changes were insignificant when normalizing for mitochondrial content. Oral atorvastatin treatment in Göttingen Minipigs is associated with a reduced mitochondrial respiratory capacity in the liver that may be linked to increased content of atorvastatin in this organ.

Outcomes in patients with lung cancer treated with crizotinib and erlotinib in routine clinical practice: A post-authorization safety cohort study conducted in Europe and in the United States

PURPOSE

We examined safety outcomes of interest (SOI) and overall survival (OS) among lung cancer patients initiating crizotinib and erlotinib in routine clinical practice.

METHODS

This descriptive cohort study used routinely collected health data in Denmark, Finland, Sweden, the Netherlands, and the United States (US) during 2011-2017, following crizotinib commercial availability in each country. Among crizotinib or erlotinib initiators, we reported baseline characteristics and incidence rates and cumulative incidences of the SOI - hepatotoxicity, pneumonitis/interstitial lung disease, QT interval prolongation-related events, bradycardia, vision disorders, renal cysts, edema, leukopenia, neuropathy, photosensitivity, malignant melanoma, gastrointestinal perforation, cardiac failure and OS. Results from the European Union (EU) countries were combined using meta-analysis; results from the US were reported separately.

RESULTS

There were 456 patients in the crizotinib cohort and 2957 patients in the erlotinib cohort. Rates of the SOI per 1000 person-years in the crizotinib cohort ranged from 0 to 65 in the EU and from 0 to 374 in the US. Rates of the SOI per 1000 person-years in the erlotinib cohort ranged from 0 to 91 in the EU and from 3 to 394 in the US. In the crizotinib cohort, 2-year OS was ~50% in both EU and US. In the erlotinib cohort, 2-year OS was 21% in the EU and 35% in the US.

CONCLUSIONS

This study describes clinical outcomes among lung cancer patients initiating crizotinib or erlotinib in routine clinical practice. Differences between SOI rates in EU and US may be partially attributable to differences in the underlying databases.

Inhalation or total intravenous anaesthesia and recurrence after colorectal cancer surgery: a propensity score matched Danish registry-based study

BACKGROUND

During colorectal cancer surgery, the immune-modulating effects of inhalation anaesthesia may create a favourable environment for metastasis formation, leading to increased risk of recurrence. Our aim was to assess the association between inhalation vs intravenous anaesthesia and cancer recurrence in patients undergoing colorectal cancer surgery.

METHODS

Patients undergoing colorectal cancer surgery in 2004-18 were identified in the Danish Colorectal Cancer Group Database and Danish Anaesthesia Database. After exclusion of patients with residual tumour registered in postoperative pathology reports, local endoscopic resections, and stent insertions, we classified patients according to exposure to inhalation anaesthesia. The primary outcome was recurrence (time to recurrence), whereas secondary outcomes were all-cause mortality (time to death) and disease-free survival (time to either recurrence or death). Events of recurrence and death were identified using The Danish Civil Registration System, Danish National Pathology Registry, and Danish National Patient Registry. The sub-distribution hazards approach was used to estimate hazard ratios (HRs) for recurrence, and Cox regression was used for all-cause mortality and disease-free survival.

RESULTS

We identified 5238 patients exposed to inhalation anaesthesia and 6322 to intravenous anaesthesia. Propensity score matching yielded 4347 individuals in each group with balanced baseline covariates. We found a weak association between recurrence and exposure to inhalation anaesthesia (HR=1.12; 95% confidence interval [CI], 1.02-1.23). The HR estimates for all-cause mortality and disease-free survival were 1.00 (95% CI, 0.93-1.07) and 1.04 (95% CI, 0.98-1.11) respectively.

CONCLUSION

Exposure to inhalation anaesthesia was associated with increased risk of recurrence after colorectal cancer surgery.

Using the Case-Crossover Design to Assess Short-Term Risks of Bleeding and Arterial Thromboembolism After Switching Between Oral Anticoagulants in a Population-Based Cohort of Patients With Atrial Fibrillation

Using nationwide Danish registries, we conducted a population-based case-crossover study evaluating the association between switching from a vitamin K antagonist (VKA) to a direct oral anticoagulant (DOAC), and vice versa, and 30-day risks of bleeding and arterial thromboembolism in patients with atrial fibrillation (AF). The case-crossover population was identified among oral anticoagulant users during 2011-2018 (n = 123,217) as patients with AF with 1) a case-defining outcome and 2) an anticoagulant switch during the 180 days preceding the outcome. Odds ratios were estimated using conditional logistic regression by comparing the occurrence of switching during the 30-day window immediately preceding the outcome to that in reference windows in the same individual 60-180 days before the outcome. The case-crossover populations for switching from VKA to DOAC and DOAC to VKA comprised 1,382 and 287 case patients, respectively. Switching from VKA to DOAC, but not from DOAC to VKA, was associated with an increased short-term risk of bleeding (odds ratio = 1.42; 95% confidence intervals: 1.13, 1.79, and 1.06; and 0.64, 1.75, respectively) and ischemic stroke (odds ratio = 1.74; 95% confidence intervals: 1.21, 2.51, and 0.92; and 0.46, 1.83, respectively). Our findings suggest that switching from VKA to DOAC is an intermittent risk factor of bleeding and ischemic stroke in patients with AF.

Modelling the fate of micropollutants in integrated urban wastewater systems: Extending the applicability to pharmaceuticals

Pharmaceutical active compounds (PhACs) are a category of micropollutants frequently detected across integrated urban wastewater systems. Existing modelling tools supporting the evaluation of micropollutant fate in such complex systems, such as the IUWS_MP model library (which acronym IUWS stands for Integrated Urban Wastewater System), do not consider fate processes and fractions that are typical for PhACs. This limitation was overcome by extending the existing IUWS_MP model library with new fractions (conjugated metabolites, sequestrated fraction) and processes (consumption-excretion, deconjugation). The performance of the extended library was evaluated for five PhACs (carbamazepine, ibuprofen, diclofenac, paracetamol, furosemide) in two different integrated urban wastewater systems where measurements were available. Despite data uncertainty and the simplicity of the modelling approach, chosen to minimize data requirements, model prediction uncertainty overlapped with the measurements ranges across both systems, stressing the robustness of the proposed modelling approach. Possible applications of the extended IUWS_MP model library are presented, illustrating how this tool can support urban water managers in reducing environmental impacts from PhACs discharges.

Adverse outcomes and mortality in users of non-steroidal anti-inflammatory drugs who tested positive for SARS-CoV-2: A Danish nationwide cohort study

BACKGROUND

Concerns over the safety of non-steroidal anti-inflammatory drug (NSAID) use during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been raised. We studied whether use of NSAIDs was associated with adverse outcomes and mortality during SARS-CoV-2 infection.

METHODS AND FINDINGS

We conducted a population-based cohort study using Danish administrative and health registries. We included individuals who tested positive for SARS-CoV-2 during the period 27 February 2020 to 29 April 2020. NSAID users (defined as individuals having filled a prescription for NSAIDs up to 30 days before the SARS-CoV-2 test) were matched to up to 4 non-users on calendar week of the test date and propensity scores based on age, sex, relevant comorbidities, and use of selected prescription drugs. The main outcome was 30-day mortality, and NSAID users were compared to non-users using risk ratios (RRs) and risk differences (RDs). Secondary outcomes included hospitalization, intensive care unit (ICU) admission, mechanical ventilation, and acute renal replacement therapy. A total of 9,236 SARS-CoV-2 PCR-positive individuals were eligible for inclusion. The median age in the study cohort was 50 years, and 58% were female. Of these, 248 (2.7%) had filled a prescription for NSAIDs, and 535 (5.8%) died within 30 days. In the matched analyses, treatment with NSAIDs was not associated with 30-day mortality (RR 1.02, 95% CI 0.57 to 1.82, p = 0.95; RD 0.1%, 95% CI -3.5% to 3.7%, p = 0.95), risk of hospitalization (RR 1.16, 95% CI 0.87 to 1.53, p = 0.31; RD 3.3%, 95% CI -3.4% to 10%, p = 0.33), ICU admission (RR 1.04, 95% CI 0.54 to 2.02, p = 0.90; RD 0.2%, 95% CI -3.0% to 3.4%, p = 0.90), mechanical ventilation (RR 1.14, 95% CI 0.56 to 2.30, p = 0.72; RD 0.5%, 95% CI -2.5% to 3.6%, p = 0.73), or renal replacement therapy (RR 0.86, 95% CI 0.24 to 3.09, p = 0.81; RD -0.2%, 95% CI -2.0% to 1.6%, p = 0.81). The main limitations of the study are possible exposure misclassification, as not all individuals who fill an NSAID prescription use the drug continuously, and possible residual confounding by indication, as NSAIDs may generally be prescribed to healthier individuals due to their side effects, but on the other hand may also be prescribed for early symptoms of severe COVID-19.

CONCLUSIONS

Use of NSAIDs was not associated with 30-day mortality, hospitalization, ICU admission, mechanical ventilation, or renal replacement therapy in Danish individuals who tested positive for SARS-CoV-2.

TRIAL REGISTRATION

The European Union electronic Register of Post-Authorisation Studies EUPAS34734.

How patients in Denmark acquire their medicines: overview, data sources and implications for pharmacoepidemiology

The means by which patients acquire their medications differ between countries, and a knowledge of this is essential when conducting and interpreting pharmacoepidemiological studies. The aim of this paper is to provide an overview of how patients obtain medicines in Denmark, to relate these to nationwide registries available for research and to discuss the implications for research. Health services are predominantly tax-funded in Denmark, with dentistry and some medicine bought at community pharmacies being exceptions, involving partial reimbursement of charges. The paper gives an overview of prescription medicines acquired from community pharmacies (including magistral preparations), over-the-counter medicines, vaccinations and in-hospital medicine including so-called "free medicine" (in Danish: "vederlagsfri medicin"). "Free medicine" is medicines for a defined list of diseases and indications that is provided free of charge to patients in outpatient clinics. The paper also describes the content of the various Danish data sources about medicine use, summarizes their strengths and limitations, and exemplifies the ways of evaluating their completeness. An example is provided of the regional variation in the means by which medicines are acquired.

Lipid-lowering therapy and low-density lipoprotein cholesterol goal attainment after acute coronary syndrome: a Danish population-based cohort study

Background

Patients with acute coronary syndrome (ACS) are at high risk of recurrent cardiovascular (CV) event. The European guidelines recommend low-density lipoprotein cholesterol (LDL-C) levels < 1.8 mmol/L and early initiation of intensive lipid-lowering therapy (LLT) to reduce CV risk.

In order to reduce the risk of further cardiac events, the study aimed to evaluate LDL-C goal attainment and LLT intensity in an incident ACS population.

Methods

A cohort study of patients with residency at Funen in Denmark at a first-ever ACS event registered within the period 2010–2015. Information on LLT use and LDL-C levels was extracted from national population registers and a Laboratory database at Odense University Hospital. Treatments and lipid patterns were evaluated during index hospitalization, at 6-month and 12-month follow-up.

Results

Among 3040 patients with an LDL-C measurement during index hospitalization, 40.7 and 39.0% attained the recommended LDL-C target value (< 1.8 mmol/L) within 6- and 12-month follow-up, respectively. During 6- and 12-month follow-up, a total of 89.2% (20.2%) and 88.4% (29.7%) used LLT (intensive LLT). Of the intensive LLT users, 43.4 and 47.7% reached the LDL-C target value at 6- and 12-month follow-up. The frequency of lipid monitoring was low: 69.5, 77.7 and 53.6% in patients with a first-ever ACS during index hospitalization, 6- and 12-month follow-up, respectively.

Conclusion

Using national health registers and laboratory data, a considerably gap was observed between treatment guidelines and clinical practice in the management of dyslipidemia leaving very high-risk patients without adequate lipid management strategy. Therefore, improved lipid management strategies aimed at reaching treatment targets are warranted.

Primary Care Prescription Drug Use and Related Actionable Drug-Gene Interactions in the Danish Population

Pharmacogenetics (PGx) aims to improve drug therapy using the individual patients' genetic make-up. Little is known about the potential impact of PGx on the population level, possibly hindering implementation of PGx in clinical care. Therefore, we investigated how many patients use actionable PGx drugs, have actionable genotypes or phenotypes and which patients could benefit the most of PGx testing. We included PGx recommendations from two international PGx consortia (Clinical Pharmacogenetics Implementation Consortium (CPIC) and Dutch Pharmacogenetics Working Group (DPWG)). Using data from publically accessible sales information drawn from the Danish Register of Medicinal Product Statistics (MEDSTAT), we identified the number of users of actionable prescription PGx drugs among the total Danish population in 2017. We estimated actionable genotypes or phenotypes based on reported frequencies from literature. We identified 49 drug-gene interactions related to 41 unique prescription drugs. The estimated median frequency of actionable genotypes or phenotypes among prescription drug users was 25% (interquartile range 7-26%). Six of 41 drugs were used more than twice as much in women. Actionable PGx drugs were most frequently used by 45-79 year old patients (62%), followed by 25-44 year old patients (18%). Almost half of the actionable PGx drugs (19/41) were psychotropics (i.e., antidepressants, antipsychotics, or psychostimulants). PGx testing can have a substantial impact on the population, as one in four prescription drug users has an actionable genotype or phenotype and could thus benefit from PGx testing. We advocate for prospective panel-based PGx testing at the time of the first PGx drug prescription ("as needed"), with PGx results ready prior to start of the first, and all future, therapies.

Association of Nonsteroidal Anti-inflammatory Drug Use and Adverse Outcomes Among Patients Hospitalized With Influenza

IMPORTANCE

During the ongoing coronavirus disease 2019 pandemic, case reports have suggested that the use of nonsteroidal anti-inflammatory drugs (NSAIDs) may lead to adverse outcomes.

OBJECTIVE

To study the association of NSAID use with adverse outcomes in patients hospitalized with influenza or influenza pneumonia.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used propensity score matching among 7747 individuals aged 40 years or older who were hospitalized with influenza, confirmed by polymerase chain reaction or antigen testing, between 2010 and 2018. Data were collected using Danish nationwide registers. All analyses reported were performed on May 29, 2020.

EXPOSURES

Prescription fill of an NSAID within 60 days before admission.

MAIN OUTCOMES AND MEASURES

Risk ratio (RR) and risk difference (RD) with 95% CIs for intensive care unit admission and death within 30 days of admission.

RESULTS

A total of 7747 patients (median [interquartile range] age, 71 [59-80] years, 3980 [51.4%] men) with confirmed influenza were identified. Of these, 520 (6.7%) were exposed to NSAIDs. In the unmatched cohorts, 104 of 520 patients (20.0%) who used NSAIDs and 958 of 7227 patients (13.3%) who did not use NSAIDs were admitted to the intensive care unit. For death within 30 days of admission, we observed 37 events (7.1%) among those who used NSAIDs compared with 563 events (7.8%) among those who did not. Current NSAID use was associated with intensive care unit admission (RR, 1.51; 95% CI, 1.26 to 1.81; RD, 6.7%; 95% CI, 3.2% to 10.3%), while NSAID use was not associated with death (RR, 0.91; 95% CI, 0.66 to 1.26; RD, -0.7%; 95% CI, -3.0% to 1.6%). In the matched cohorts, risks were unchanged for patients who used NSAIDs, while 83 ICU admissions (16.0%) and 36 deaths (6.9%) were observed among matched individuals who did not use NSAIDs. Matched (ie, adjusted) analyses yielded attenuated risk estimates for intensive care unit admission (RR, 1.25; 95% CI, 0.95 to 1.63; RD, 4.0%; 95% CI, -0.6% to 8.7%) and death (RR, 1.03; 95% CI, 0.66 to 1.60; RD, 0.2%; 95% CI, -2.9% to 3.3%). Associations were more pronounced among patients who used NSAIDs for a longer period (eg, for intensive care unit admission: RR, 1.90; 95% CI, 1.19 to 3.06; RD, 13.4%; 95% CI, 4.0% to 22.8%).

CONCLUSIONS AND RELEVANCE

In this cohort study of adult patients hospitalized with influenza, the use of NSAIDs was not associated with 30-day intensive care unit admission or death in adjusted analyses. There was an association between long-term use of NSAIDs and intensive care unit admission.