Building transparency and reproducibility into the practice of pharmacoepidemiology and outcomes research.

Real-world evidence (RWE) studies are increasingly used to inform policy and clinical decisions. However, there remain concerns about the credibility and reproducibility of RWE studies. Observational researchers should highlight the level of transparency of their studies by providing a succinct statement addressing study transparency with the publication of every paper, poster, or presentation that reports on a RWE study. In this paper, we propose a framework for an explicit transparency statement that declares the level of transparency a given RWE study has achieved across five key domains: 1) protocol, 2) pre-registration, 3) data, 4) code sharing, and 5) reporting checklists.

Risk of fractures and use of bisphosphonates in adult patients with immune thrombocytopenia-A nationwide population-based study.

Corticosteroids remain the first-line treatment of immune thrombocytopenia (ITP), but increase the risk of osteoporosis and fractures. Bisphosphonates are used for the treatment of osteoporosis, but their usage among patients with ITP has not been systemically described. We investigated the risk of fractures and the use of bisphosphonates in adult patients with primary (pITP) and secondary ITP (sITP) compared with matched comparators in a nationwide registry-based cohort study. We identified 4030 patients with pITP (median age 60 years [IQR, 40-74]), 550 with sITP (median age 59 years [IQR, 43-74]) and 182 939 age-sex-matched general population comparators. All individuals were followed for incident fractures. Bisphosphonate use was estimated for calendar-years and in temporal relation to the ITP diagnosis. Adjusted cause-specific hazard ratio (csHR) for any fracture was 1.37 (95% confidence interval [CI] 1.23; 1.54) for pITP and 1.54 (1.17; 2.03) for sITP. The first-year csHR was 1.82 (1.39; 2.40) for pITP and 2.78 (1.58; 4.91) for sITP. Bisphosphonate use over calendar-years and in the early years following ITP diagnosis was higher among patients with ITP diagnosis compared with the general population. In conclusion, the risk of fractures and the use of bisphosphonates are higher in patients with ITP compared with the general population.

Mental health and use of psychotropic prescription drugs in adult patients with primary immune thrombocytopenia: a nationwide population-based cohort study.

Patients with primary immune thrombocytopenia (ITP) suffer from reduced survival and quality of life, but the underlying reasons for this are largely undescribed. Mental health and the use of psychotropic drugs in ITP is unknown. We investigated the risk of hospital registered mental health events including fatigue and the use of psychotropic drugs in adult patients with ITP compared with the general population, using nationwide registry-data. We identified 3,749 patients with ITP and 149,849 age-sex matched general population comparators in the Danish Health Registries in the period 1997-2016. The median age was 60 years (IQR 40-73) and 53% were women. We followed the individuals for incident mental health events and estimated the use of psychotropic drugs over calendar-years and in temporal relation to diagnosis of ITP. The first year cumulative incidence of any mental health event was 2.3% (95% confidence interval, 1.9-2.9) in patients and 0.7% (0.6-0.7) in comparators, yielding an adjusted cause-specific hazard ratio (csHR) of 3.57 (2.84-4.50). The corresponding estimates for depression were 1.2% (0.9-1.6) and 0.3% (0.3-0.4) respectively, with an adjusted csHR of 3.53 (2.56-4.85). We found similar findings for anxiety and fatigue, but risks generally diminished after 1-5 years. The use of opioids, antidepressants, and benzodiazepines increased in temporal relation to diagnosis of ITP. The risk of mental health events and the use of psychotropic drugs is higher in adult patients with ITP compared with the general population, and has a temporal relation to diagnosis of ITP emphasizing that mental health in ITP is a concern.

Use of prescribed analgesics before and after exercise therapy and patient education in patients with knee or hip osteoarthritis.

The aim of this study was to investigate utilisation patterns of prescribed analgesics before, during, and after an exercise therapy and patient education program among patients with knee or hip osteoarthritis. This cohort study is based on data from the nationwide Good Life with osteoarthritis in Denmark (GLA:D®) patient-register linked with national health registries including data on prescribed analgesics. GLA:D® consists of 8-12 weeks of exercise and patient education. We included 35,549 knee/hip osteoarthritis patients starting the intervention between January 2013 and November 2018. Utilisation patterns the year before, 3 months during, and the year after the intervention were investigated using total dispensed defined daily doses (DDDs) per month per 1000 population as outcome. During the year before the intervention, use of prescribed paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), and opioids increased with 85%, 79% and 22%, respectively. During the intervention, use of paracetamol decreased with 16% with a stable use the following year. Use of NSAIDs and opioids decreased with 38% and 8%, respectively, throughout the intervention and the year after. Sensitivity analyses indicated that the prescription of most analgesics changed over time. For paracetamol, NSAIDs, and opioids, 10% of analgesic users accounted for 45%, 50%, and 70%, respectively, of the total DDDs dispensed during the study period. In general, analgesic use increased the year before the intervention followed by a decrease during the intervention and the year after. A small proportion of analgesic users accounted for half or more of all paracetamol, NSAIDs, and opioids dispensed during the study period.

Antiplatelet drugs and breast cancer risk in a large nationwide Danish case-control study.

Low-dose aspirin has been hypothesized to prevent cancer risk by inhibiting platelet aggregation. However, the anti-cancer effect of low-dose aspirin has recently been questioned and its effect on breast cancer development remains unclear. The impact of other antiplatelet drugs on breast cancer risk has rarely been evaluated. Thus, this study aimed to investigate the associations between breast cancer risk and antiplatelet drug use in a nationwide nested case-control study. From the Danish healthcare registries, we identified as cases all women with invasive breast cancer diagnosis between 2001 and 2018 (n = 68 852). The date of diagnosis corresponded to the index date. We matched cases to 10 population controls on age and calendar time, using risk set sampling. Controls were assigned the same index date as their matched case. We used the prescription registry to identify exposure to low-dose aspirin, clopidogrel and dipyridamole. We defined ever use of antiplatelet drugs as at least two prescriptions filled up to 1 year before the index date. We applied conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals for breast cancer associated with the use of antiplatelet drugs, overall, by breast cancer subtype and by cumulative dose. Twelve percent of women had ever been exposed to low-dose aspirin, 2% to clopidogrel and 2% to dipyridamole. In multivariable models, breast cancer risk was not associated with ever use of low-dose aspirin (OR = 1.00 [0.97-1.03]), clopidogrel (OR = 0.93 [0.87-1.00]), and dipyridamole (OR = 1.02 [0.94-1.10]), compared with never use, and there was no evidence of a dose-response relation. However, we found an inverse association between dipyridamole use and breast cancer risk among women aged <55 years old, with suggestion of a dose-response relationship (OR per 1000 Defined Daily Doses = 0.72 [0.54-0.95]). Associations did not differ by breast cancer histological type, estrogen receptor status or clinical stage at diagnosis. Overall, the findings from this study do not support the use of antiplatelet drugs for breast cancer prevention.

Use of methotrexate and risk of skin cancer: a nationwide case-control study.

BACKGROUND: Methotrexate (MTX) use has been suspected of increasing the risk of skin cancer. The aim of this investigation was to examine the association between the use of MTX and the risk of basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC) and cutaneous malignant melanoma (CMM). METHODS: In a nationwide Danish case-control study, we identified incident, histologically verified cases of BCC (n = 131,447), cSCC (n = 18,661) or CMM (26,068) from 2004 to 2018. We matched 10 controls to each case on sex and birth year using risk-set sampling and computed crude and adjusted odds ratios (ORs) using conditional logistic regression for the use of MTX (≥2.5 g) compared with never-use. RESULTS: Use of MTX was associated with increased risk of BCC, cSCC and CMM with adjusted ORs of (95% confidence interval) 1.29 (1.20-1.38), 1.61 (1.37-1.89) and 1.35 (1.13-1.61), respectively. For BCC and cSCC, ORs increased with higher cumulative doses. When restricting the study population to patients with psoriasis, the ORs were 1.43 (1.23-1.67), 1.18 (0.80-1.74) and 1.15 (0.77-1.72), respectively. CONCLUSIONS: We observed an increased risk of BCC and cSCC associated with the use of MTX with evidence of a dose-response pattern; however, the association was not consistent when restricting the study population to patients with psoriasis.

Survival in adult patients with chronic primary and secondary immune thrombocytopenia: A population-based study.

BACKGROUND: Few studies have investigated long-term survival in patients with primary immune thrombocytopenia (pITP). Further, changes in prognosis over the past decades and prognosis of secondary immune thrombocytopenia (sITP) are largely unstudied. Our objectives were to study comorbidity-adjusted prognostic changes and causes of death in chronic pITP and sITP patients. STUDY DESIGN/METHODS: Using nationwide Danish health registries 1980-2016, we identified 1762 patients with chronic pITP (median age 58 (IQR, 37-73) years) and 128 with chronic sITP (median age 59 (IQR, 40-73) years). Patients were age-sex-matched to 74,781 general population comparators. Comorbidity was assessed using Charlson Comorbidity Index (CCI). RESULTS: Overall median survival was reduced by 5.1 years (95% CI, 0.7-9.4) (p < .001) for pITP and 11.1 years (95% CI, 5.8-16.4) (p < .001) for sITP. 5-year survival increased from 69% (95% CI, 59-78) in 1980-89 to 80% (95% CI, 75-83) in 2010-16 for pITP, and decreased from 100% (95% CI, 89-98) to 64% (95% CI, 87-91) for sITP. However, numbers were small for sITP. 5-year survival for pITP with high CCI was 41% (95% CI, 32-49), and 85% (95% CI, 83-87) for low CCI. Bleeding, infection and hematological cancer were relatively frequent causes of death with adjusted subhazard ratios of 3.25 (95% CI, 2.33-4.52), 1.53 (95% CI, 1.08-2.16) and 2.16 (95% CI, 1.12-4.16) in pITP respectively, and 10.52 (95% CI, 1.43-77.36) for hematological cancer in sITP. CONCLUSIONS: Long-term survival is reduced in chronic ITP but seems to be improving. Comorbidity and sITP are associated with a poor prognosis.

Changes in the use of glucose-lowering drugs: A Danish nationwide study.

AIM: To investigate changes in the pattern of drugs used to treat type 2 diabetes in Denmark from 2005 to 2021. MATERIALS AND METHODS: A nationwide, population-based drug utilization study based on medical databases covering the Danish population was conducted. We assessed incident and prevalent use patterns among all 441 205 individuals initiating at least one non-insulin, glucose-lowering drug. RESULTS: The rate of new users of non-insulin, glucose-lowering drugs increased from 2005, peaked in 2011, decreased to stable levels during 2013 to 2019, then increased dramatically during 2020-2021. The prevalence of use increased from 2.1% (in 2005) to 5.0% (in 2021) of the entire adult population. In 2021, metformin comprised 39% of all glucose-lowering drug consumption, followed by insulin (17%), sodium-glucose co-transporter-2 inhibitors (SGLT-2is) (17%), glucagon-like peptide-1 receptor agonists (GLP-1RAs) (16%) and dipeptidyl peptidase-4 inhibitors (7.5%). Overall, 56% of users were on monotherapy, 28% used dual therapy, while 13% and 2.8% used three and four drug classes, respectively. Both the intensity and diversity of therapies increased substantially over time, with 15 different treatment regimens each covering more than 1% of users in 2021. General practitioners prescribed 88% of all glucose-lowering drugs. Marked shifts towards GLP-1RA initiation by general practitioners and SGLT-2i initiation by specialists were observed, and changing user profiles suggested increasing use for non-diabetes indications. CONCLUSIONS: The rate of new users of non-insulin, glucose-lowering drugs has increased in recent years and the prevalence of glucose-lowering drug use increases steadily. Glucose-lowering drugs are mainly prescribed by general practitioners, and the intensity, diversity and indications of glucose-lowering treatment are increasing.

Identifying diabetogenic drugs using real world health care databases: A Danish and Australian symmetry analysis.

AIMS: Drug-induced diabetes is underreported in conventional drug safety monitoring and may contribute to the increasing incidence of type 2 diabetes. Therefore, we used routinely collected prescription data to screen all commonly used drugs for diabetogenic effects. METHODS: Leveraging the Danish nationwide health registries, we used a case-only symmetry analysis design to evaluate all possible associations between drug initiation and subsequent diabetes. The study was conducted among individuals aged ≥40 years with a first-ever prescription for any antidiabetic drug 1996-2018 (n = 348 996). Sequence ratios (SRs) and 95% confidence intervals (CIs) were obtained for all possible drug class-diabetes combinations. A lower bound of the 95% CI >1.00 was considered a signal. Signals generated in Denmark were replicated using the Services Australia, Pharmaceutical Benefits Scheme 10% data extract. RESULTS: Overall, 386 drug classes were investigated, of which 70 generated a signal. In total, 43 were classified as previously known based on the SIDER database or a literature review, for example, glucocorticoids (SR 1.67, 95% CI 1.62-1.72) and ß-blockers (SR 1.20, 95% CI 1.16-1.23). Of 27 new signals, three drug classes yielded a signal in both the Danish and Australian data source: digitalis glycosides (SR 2.15, 95% CI 2.04-2.27, and SR 1.76, 95% CI 1.50-2.08), macrolides (SR 1.20, 95% CI 1.16-1.24, and SR 1.11, 95% CI 1.06-1.16) and inhaled ß2-agonists combined with glucocorticoids (SR 1.35, 95% CI 1.28-1.42, and SR 1.14, 95% CI 1.06-1.22). CONCLUSION: We identified 70 drug-diabetes associations, of which 27 were classified as hitherto unknown. Further studies evaluating the hypotheses generated by this work are needed, particularly for the signal for digitalis glycosides.

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.

Dicloxacillin-warfarin drug-drug interaction-A register-based study and in vitro investigations in 3D spheroid primary human hepatocytes.

AIMS: Dicloxacillin is used to treat staphylococcal infections and we have previously shown that dicloxacillin is an inducer of cytochrome P450 enzymes (CYPs). Here, we employed a translational approach to investigate the effect of a treatment with dicloxacillin on warfarin efficacy in Danish registries. Furthermore, we assessed dicloxacillin as an inducer of CYPs in vitro. METHODS: We conducted a register-based study and analysed international normalized ratio (INR) levels in chronic warfarin users before and after short- and long-term use of dicloxacillin (n = 1023) and flucloxacillin (n = 123). Induction of CYPs were investigated in a novel liver model of 3D spheroid primary human hepatocytes at the level of mRNA, and protein and enzyme activity. RESULTS: Short- and long-term dicloxacillin treatments decreased INR levels by -0.65 (95% confidence interval [CI]: -0.57 to -0.74) and -0.76 (95% CI: -0.50 to -1.02), respectively. More than 90% of individuals experienced subtherapeutic INR levels (below 2) after long-term dicloxacillin treatment. Flucloxacillin decreased INR levels by -0.37 (95% CI: -0.14 to -0.60). In 3D spheroid primary human hepatocytes, the maximal induction of CYP3A4 mRNA, protein and enzyme activity by dicloxacillin were 4.9-, 2.9- and 2.4-fold, respectively. Dicloxacillin also induced CYP2C9 mRNA by 1.7-fold. CONCLUSION: Dicloxacillin induces CYPs and reduces the clinical efficacy of warfarin in patients. This effect is substantially exacerbated during long-term treatment with dicloxacillin. The in vitro results corroborated this drug-drug interaction and correlated to the clinical findings. Caution is warranted for warfarin patients that initiate dicloxacillin or flucloxacillin, especially for a long-term treatment of endocarditis.

Initiation of glucose-lowering drugs reduces the anticoagulant effect of warfarin-But not through altered drug metabolism in patients with type 2 diabetes.

AIMS: Drug metabolism might be altered in patients with type 2 diabetes. We aimed to evaluate if initiation of glucose-lowering drugs impacts warfarin efficacy and drug metabolism. METHODS: First, we conducted a register-based self-controlled cohort study on Danish and Scottish warfarin users. Warfarin efficacy (international normalized ratio [INR]) was compared before and after initiation of glucose-lowering drugs. Second, we conducted a clinical pharmacokinetic trial comprising treatment-naïve type 2 diabetes patients. Patients ingested probe drugs for drug-metabolizing enzymes (the Basel Cocktail) before initiating glucose-lowering treatment, and after 3 and 12 weeks of treatment. Drug metabolism, glycaemic control, and inflammation were assessed on each visit. RESULTS: In the Danish and Scottish cohorts (n = 982 and n = 44, respectively), initiating glucose-lowering drugs reduced warfarin efficacy. INR decreased from 2.47 to 2.21 in the Danish cohort (mean difference -0.26; 95% CI -0.35; -0.17) and from 2.33 to 2.13 in the Scottish cohort (-0.21; 95% CI -0.52; 0.11) after initiation of glucose-lowering treatment. This impact on INR was more pronounced among individuals with stronger effects of glucose-lowering treatment. In the clinical pharmacokinetic trial (n = 10), initiating metformin did not affect drug metabolism after 3 weeks (geometric mean ratio of CYP3A metabolic ratio: 1.12 [95% CI: 0.95; 1.32]) or 12 weeks of metformin treatment. Glycaemic control improved during treatment, while inflammation remained low and unchanged during treatment. CONCLUSIONS: In conclusion, initiation of glucose-lowering drugs among chronic warfarin users seems associated with a reduction in INR, particularly among individuals with a large decrease in HbA1c . This effect seems unrelated to CYP enzyme activity and warfarin drug metabolism.

High-dimensional propensity scores for empirical covariate selection in secondary database studies: Planning, implementation, and reporting.

Real-world evidence used for regulatory, payer, and clinical decision-making requires principled epidemiology in design and analysis, applying methods to minimize confounding given the lack of randomization. One technique to deal with potential confounding is propensity score (PS) analysis, which allows for the adjustment for measured preexposure covariates. Since its first publication in 2009, the high-dimensional propensity score (hdPS) method has emerged as an approach that extends traditional PS covariate selection to include large numbers of covariates that may reduce confounding bias in the analysis of healthcare databases. hdPS is an automated, data-driven analytic approach for covariate selection that empirically identifies preexposure variables and proxies to include in the PS model. This article provides an overview of the hdPS approach and recommendations on the planning, implementation, and reporting of hdPS used for causal treatment-effect estimations in longitudinal healthcare databases. We supply a checklist with key considerations as a supportive decision tool to aid investigators in the implementation and transparent reporting of hdPS techniques, and to aid decision-makers unfamiliar with hdPS in the understanding and interpretation of studies employing this approach. This article is endorsed by the International Society for Pharmacoepidemiology.

HARmonized Protocol Template to Enhance Reproducibility of hypothesis evaluating real-world evidence studies on treatment effects: A good practices report of a joint ISPE/ISPOR task force.

PROBLEM: Ambiguity in communication of key study parameters limits the utility of real-world evidence (RWE) studies in healthcare decision-making. Clear communication about data provenance, design, analysis, and implementation is needed. This would facilitate reproducibility, replication in independent data, and assessment of potential sources of bias. WHAT WE DID: The International Society for Pharmacoepidemiology (ISPE) and ISPOR-The Professional Society for Health Economics and Outcomes Research (ISPOR) convened a joint task force, including representation from key international stakeholders, to create a harmonized protocol template for RWE studies that evaluate a treatment effect and are intended to inform decision-making. The template builds on existing efforts to improve transparency and incorporates recent insights regarding the level of detail needed to enable RWE study reproducibility. The overarching principle was to reach for sufficient clarity regarding data, design, analysis, and implementation to achieve 3 main goals. One, to help investigators thoroughly consider, then document their choices and rationale for key study parameters that define the causal question (e.g., target estimand), two, to facilitate decision-making by enabling reviewers to readily assess potential for biases related to these choices, and three, to facilitate reproducibility. STRATEGIES TO DISSEMINATE AND FACILITATE USE: Recognizing that the impact of this harmonized template relies on uptake, we have outlined a plan to introduce and pilot the template with key international stakeholders over the next 2 years. CONCLUSION: The HARmonized Protocol Template to Enhance Reproducibility (HARPER) helps to create a shared understanding of intended scientific decisions through a common text, tabular and visual structure. The template provides a set of core recommendations for clear and reproducible RWE study protocols and is intended to be used as a backbone throughout the research process from developing a valid study protocol, to registration, through implementation and reporting on those implementation decisions.

Melatonin use among children, adolescents, and young adults: a Danish nationwide drug utilization study.

We aimed to provide a detailed description of the use of melatonin in Danish children, adolescents, and young adults during 2012-2019. We identified melatonin users 0-24 years of age (n = 43,652; median age 16 years) via the Danish nationwide health registers. Melatonin is a prescription drug in Denmark. The incidence of melatonin use increased from 2.4 to 3.9/1000 person-years during 2012 to 2019. Among 6,557 incident users in 2019, 53% filled only a single prescription within the first 6 months. Long-term use was most common among the younger age groups, with 17% of 5-9-year-olds and 14% of 10-13-year-olds being in continued treatment (no treatment breaks) 12 months after their first melatonin prescription. Disregarding treatment breaks, 3 in 10 were using melatonin 12 months after their first melatonin prescription and this proportion was also highest among 5-9-year-olds (63%) and 10-13-year-olds (51%). Psychopathology was common among melatonin users with 75% registered with either a psychiatric disorder diagnosis (54%), a filled prescription for another psychotropic (58%), or a contact to a private practice psychiatrist (15%) within ± 12 months of treatment initiation. General practitioners authorized melatonin prescriptions to almost half of all new users (48%), while psychiatric specialists authorized 37% of first prescriptions. In conclusion, the incidence of melatonin use increased in Denmark from 2012 to 2019. A substantial proportion of users had concurrent psychopathology most likely explaining their use of melatonin. Long-term melatonin use was more common among the youngest age groups, which should be a focus of interest due to limited safety data.

Oral anticoagulants in patients with atrial fibrillation at low stroke risk: a multicentre observational study.

AIMS: There is currently no consensus on whether atrial fibrillation (AF) patients at low risk for stroke (one non-sex-related CHA2DS2-VASc point) should be treated with an oral anticoagulant. METHODS AND RESULTS: We conducted a multi-country cohort study in Sweden, Denmark, Norway, and Scotland. In total, 59 076 patients diagnosed with AF at low stroke risk were included. We assessed the rates of stroke or major bleeding during treatment with a non-vitamin K antagonist oral anticoagulant (NOAC), a vitamin K antagonist (VKA), or no treatment, using inverse probability of treatment weighted (IPTW) Cox regression. In untreated patients, the rate for ischaemic stroke was 0.70 per 100 person-years and the rate for a bleed was also 0.70 per 100 person-years. Comparing NOAC with no treatment, the stroke rate was lower [hazard ratio (HR) 0.72; 95% confidence interval (CI) 0.56-0.94], and the rate for intracranial haemorrhage (ICH) was not increased (HR 0.84; 95% CI 0.54-1.30). Comparing VKA with no treatment, the rate for stroke tended to be lower (HR 0.81; 95% CI 0.59-1.09), and the rate for ICH tended to be higher during VKA treatment (HR 1.37; 95% CI 0.88-2.14). Comparing NOAC with VKA treatment, the rate for stroke was similar (HR 0.92; 95% CI 0.70-1.22), but the rate for ICH was lower during NOAC treatment (HR 0.63; 95% CI 0.42-0.94). CONCLUSION: These observational data suggest that NOAC treatment may be associated with a positive net clinical benefit compared with no treatment or VKA treatment in patients at low stroke risk, a question that can be tested through a randomized controlled trial.

Low-dose oral corticosteroids in asthma associates with increased morbidity and mortality.

BACKGROUND: Long-term oral corticosteroid (OCS) treatment for severe asthma is known to cause significant adverse effects, but knowledge on effects of lower exposures in general asthma populations is limited. We aimed to explore this in a nationwide Danish asthma population. METHODS: Users of asthma medication aged 18-45 years were identified in the Danish nationwide registers during 1999-2018 and followed prospectively in an open-cohort design. Incident OCS users were matched 1:4 to nonusers by propensity scores with replacement. Associations between OCS use and incident comorbidities were examined by Cox regression. Mortality rates, causes of death and rates of unscheduled hospital visits were assessed. RESULTS: OCS users (n=30 352) had, compared with nonusers (n=121 408), an increased risk of all outcomes with evident dose-response relationships starting at cumulative doses of ≤500 mg (prednisolone-equivalent). Hazard ratios ranged from 1.24 (95% CI 1.18-1.30) for fractures to 8.53 (95% CI 3.97-18.33) for adrenal insufficiency. Depression/anxiety had the highest incidence rate difference at 4.3 (95% CI 3.6-5.0) per 1000 person-years. Asthma-specific mortality rates were generally low at 0.15 (95% CI 0.11-0.20) and 0.04 (95% CI 0.02-0.06) per 1000 person-years for OCS users and nonusers, respectively. Mortality rates and unscheduled hospital visits increased with increasing OCS exposure. CONCLUSION: The study findings should be interpreted with their observational nature in mind. However, we found that even at low cumulative exposure, OCS use in asthma management was associated with increased risk of comorbidities, mortality and unscheduled hospital visits. Effective strategies for optimising asthma control and reducing OCS use are pivotal in asthma management.

The effect of immunosuppressants on the prognosis of SARS-CoV-2 infection.

BACKGROUND: Immunosuppression may worsen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We conducted a nationwide cohort study of the effect of exposure to immunosuppressants on the prognosis of SARS-CoV-2 infection in Denmark. METHODS: We identified all SARS-CoV-2 test-positive patients from February 2020 to October 2020 and linked healthcare data from nationwide registers, including prescriptions for the exposure (immunosuppressant drugs). We estimated relative risks of hospital admission, intensive care unit (ICU) admission and death (each studied independently up to 30 days from testing) with a log-linear binomial regression adjusted for confounders using a propensity score-based matching weights model. RESULTS: A composite immunosuppressant exposure was associated with a significantly increased risk of death (adjusted relative risk 1.56 (95% CI 1.10-2.22)). The increased risk of death was mainly driven by exposure to systemic glucocorticoids (adjusted relative risk 2.38 (95% CI 1.72-3.30)), which were also associated with an increased risk of hospital admission (adjusted relative risk 1.34 (95% CI 1.10-1.62)), but not of ICU admission (adjusted relative risk 1.76 (95% CI 0.93-3.35)); these risks were greater for high cumulative doses of glucocorticoids than for moderate doses. Exposure to selective immunosuppressants, tumour necrosis factor inhibitors or interleukin inhibitors was not associated with an increased risk of hospitalisation, ICU admission or death, nor was exposure to calcineurin inhibitors, other immunosuppressants, hydroxychloroquine or chloroquine. CONCLUSIONS: Exposure to glucocorticoids was associated with increased risks of hospital admission and death. Further investigation is needed to determine the optimal management of coronavirus disease 2019 (COVID-19) in patients with pre-morbid glucocorticoid usage, specifically whether these patients require altered doses of glucocorticoids.

Prescription rates for commonly used drugs before and after a prostate cancer diagnosis.

PURPOSE: To investigate differences in prescription rates of commonly used drugs among prostate cancer patients and cancer-free comparisons and between patients diagnosed with localized and non-localized disease. METHODS: We conducted a register-based study including all men aged 50-85 years diagnosed with prostate cancer in Denmark from 1998 to 2015 and an age-matched cancer-free comparison cohort. We calculated the number of new and total prescriptions from three years before to three years after the date of diagnosis of the case for selected drug classes divided by the number of person-months and stratified by stage at diagnosis. RESULTS: We included 54,286 prostate cancer patients and 249,645 matched comparisons. 30,712 patients were diagnosed with localized disease and 12,884 with non-localized disease. The rates of new prescriptions increased considerably among patients within the year before the diagnosis. Hereafter the rates varied between drug classes. For most drug classes, total prescription rates for patients and comparisons increased similarly in the study period. Total prescription rates varied between men with localized and non-localized disease for all drug classes apart from statins. CONCLUSION: Our findings indicate that a large proportion of prostate cancer cases are likely diagnosed during medical work-up for other reasons than prostate cancer. Increased rates occur within the last year before diagnosis and future studies on the interaction between drug use and prostate cancer should at least include a one year pre-diagnostic lag-time. Post-diagnostic prescription rates demonstrated an increased use of drugs most likely associated with the consequences of the disease.

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.