Inconsistency in ferritin reference intervals across laboratories: a major concern for clinical decision making.

OBJECTIVES: Iron deficiency anemia is a significant global health concern, diagnosed by measuring hemoglobin concentrations in combination with plasma ferritin concentration. This study investigated the variability in ferritin reference intervals among laboratories in the Netherlands and examined how this affects the identification of iron-related disorders. METHODS: Ferritin reference intervals from 52 Dutch ISO15189-certified medical laboratories were collected. Ferritin, hemoglobin and mean corpuscular volume data of non-anemic apparently healthy primary care patients, measured by four laboratory platforms (Beckman, Abbott, Siemens, and Roche), were collected (n=397,548). Median ferritin levels were determined per platform, stratified by sex and age. The proportion of ferritin measurements outside of the reference interval was calculated using the reference intervals from the 52 laboratories (using a total of n=1,093,442 ferritin measurements). Lastly, ferritin data from 3,699 patients as captured in general practitioner (GP) data from the PHARMO Data Network were used to assess the variation of abnormal ferritin measurements per GP. RESULTS: Median plasma ferritin concentrations were approximately four times higher in men and twice as high in postmenopausal women compared to premenopausal women. Moreover, there are substantial differences in the median plasma ferritin concentration between the four platforms. However, even among laboratories using the same platform, ferritin reference intervals differ widely. This leads to significant differences in the percentages of measurements classified as abnormal, with the percentage of ferritin measurements below the reference limit in premenopausal women ranging from 11 to 53 %, in postmenopausal women from 3 to 37 %, and in men from 2 to 19 %. The percentage of ferritin measurements above the reference limit in premenopausal women ranged from 0.2 to 11 %, in postmenopausal women from 3 to 36 % and in men from 7 to 32 %. CONCLUSIONS: The lack of harmonization in ferritin measurement and the disagreement in plasma ferritin reference intervals significantly impact the interpretation of the iron status of patients and thereby the number of iron disorder diagnoses made. Standardization or harmonization of the ferritin assays and establishing uniform reference intervals and medical decision limits are essential to reduce the substantial variability in clinical interpretations of ferritin results.

Metadata for Data dIscoverability aNd Study rEplicability in obseRVAtional Studies (MINERVA): Development and Pilot of a Metadata List and Catalogue in Europe.

PURPOSE: Metadata for data dIscoverability aNd study rEplicability in obseRVAtional studies (MINERVA), a European Medicines Agency-funded project (EUPAS39322), defined a set of metadata to describe real-world data sources (RWDSs) and piloted metadata collection in a prototype catalogue to assist investigators from data source discoverability through study conduct. METHODS: A list of metadata was created from a review of existing metadata catalogues and recommendations, structured interviews, a stakeholder survey, and a technical workshop. The prototype was designed to comply with the FAIR principles (findable, accessible, interoperable, reusable), using MOLGENIS software. Metadata collection was piloted by 15 data access partners (DAPs) from across Europe. RESULTS: A total of 442 metadata variables were defined in six domains: institutions (organizations connected to a data source); data banks (data collections sustained by an organization); data sources (collections of linkable data banks covering a common underlying population); studies; networks (of institutions); and common data models (CDMs). A total of 26 institutions were recorded in the prototype. Each DAP populated the metadata of one data source and its selected data banks. The number of data banks varied by data source; the most common data banks were hospital administrative records and pharmacy dispensation records (10 data sources each). Quantitative metadata were successfully extracted from three data sources conforming to different CDMs and entered into the prototype. CONCLUSIONS: A metadata list was finalized, a prototype was successfully populated, and a good practice guide was developed. Setting up and maintaining a metadata catalogue on RWDSs will require substantial effort to support discoverability of data sources and reproducibility of studies in Europe.

Impact of implementing Dutch versus European guideline risk factor targets in older patients with ischaemic heart disease.

BACKGROUND: In patients with ischaemic heart disease (IHD) aged > 70 years, Dutch and European guidelines recommend different treatment targets: low-density lipoprotein cholesterol (LDL-c) < 2.6 versus < 1.4 mmol/l and systolic blood pressure (SBP) < 140 versus < 130 mm Hg, respectively. How this impacts cardiovascular event-free life expectancy has not been investigated. The study objective was to compare estimated lifelong treatment benefits of implementing Dutch and European LDL­c and SBP targets. METHODS: Data from patients aged 71-80 years hospitalised for IHD in 2017-2019 were extracted from the PHARMO Database Network, which links primary and secondary healthcare settings, with follow-up until 31 December 2020. Potential benefit according to treatment strategy (in gain in event-free years) was estimated using the SMART-REACH model. RESULTS: Of the 3003 eligible patients, 1186 (39%) had missing LDL­c and/or SBP measurements. Of the 1817 included patients (36% women, median age at event: 74 years (interquartile range (IQR): 72-77), 84% achieved the Dutch targets for both LDL­c and SBP; for European targets, this was 23% and 61%, respectively. If Dutch targets were met for LDL­c and SBP (n = 1281), the additional effect of reaching European targets was a median gain of 0.6 event-free life years (IQR: 0.3-1.0). The greatest effect could be reached in patients not reaching Dutch targets (n = 501), with a median gain of 0.6 (IQR: 0.2-1.2) and 1.7 (IQR: 1.2-2.5) event-free years with Dutch versus European targets. CONCLUSION: In patients aged > 70 years with IHD, implementation of European targets resulted in a greater gain of event-free years compared with Dutch targets, especially in patients with poorer risk factor control. The considerable number of patients with missing risk factor documentation suggested additional opportunities for risk reduction.

Risk of cardiovascular events after an exacerbation of chronic obstructive pulmonary disease: results from the EXACOS-CV cohort study using the PHARMO Data Network in the Netherlands.

BACKGROUND: People living with chronic obstructive pulmonary disease (COPD) have an increased risk of experiencing cardiovascular (CV) events, particularly after an exacerbation. Such CV burden is not yet known for incident COPD patients. We examined the risk of severe CV events in incident COPD patients in periods following either moderate and/or severe exacerbations. METHODS: Persons aged ≥ 40 years with an incident COPD diagnosis from the PHARMO Data Network were included. Exposed time periods included 1-7, 8-14, 15-30, 31-180 and 181-365 days following an exacerbation. Moderate exacerbations were defined as those managed in outpatient settings; severe exacerbations as those requiring hospitalisation. The outcome was a composite of time to first severe CV event (acute coronary syndrome, heart failure decompensation, cerebral ischaemia, or arrhythmia) or death. Hazard ratios (HR) were estimated for association between each exposed period and outcome. RESULTS: 8020 patients with newly diagnosed COPD were identified. 2234 patients (28%) had ≥ 1 exacerbation, 631 patients (8%) had a non-fatal CV event, and 461 patients (5%) died during a median follow-up of 36 months. The risk of experiencing the composite outcome was increased following a moderate/severe exacerbation as compared to time periods of stable disease [range of HR: from 15.3 (95% confidence interval 11.8-20.0) in days 1-7 to 1.3 (1.0-1.8) in days 181-365]. After a moderate exacerbation, the risk was increased over the first 180 days [HR 2.5 (1.3-4.8) in days 1-7 to 1.6 (1.3-2.1) in days 31-180]. After a severe exacerbation, the risk increased substantially and remained higher over the year following the exacerbation [HR 48.6 (36.9-64.0) in days 1-7 down to 1.6 (1.0-2.6) in days 181-365]. Increase in risk concerned all categories of severe CV events. CONCLUSIONS: Among incident COPD patients, we observed a substantial risk increase of severe CV events or all-cause death following either a moderate or severe exacerbation of COPD. Increase in risk was highest in the initial period following an exacerbation. These findings highlight the significant cardiopulmonary burden among people living with COPD even with a new diagnosis.

Women on diuretics have a higher risk of hospital admission because of hyponatremia than men.

PURPOSE: Recent studies suggest that women are more susceptible to diuretic-induced hyponatremia resulting in hospital admission than men. The aim of this study was to confirm whether these sex differences in hyponatremia-related hospital admissions in diuretic users remain after adjusting for several confounding variables such as age, dose, and concurrent medication. METHODS: In a case-control design nested in diuretic users, cases of hyponatremia associated hospital admissions between 2005 and 2017 were identified from the PHARMO Data Network. Cases were 1:10 matched to diuretic users as controls. Odds ratios (OR) with 95%CIs were calculated for women versus men and adjusted for potential confounders (age, number of diuretics, other hyponatremia-inducing drugs, chronic disease score) using unconditional logistic regression analysis. A subgroup analysis was performed for specific diuretic groups (thiazides, loop diuretics and aldosterone antagonists). RESULTS: Women had a statistically significantly higher risk of a hospital admission associated with hyponatremia than men while using diuretics (OR 1.86, 95%CI 1.64-2.11). Adjusting for the potential confounders resulted in an increased risk for women compared to men (ORadj 2.65, 95% CI 2.31-3.04). This higher risk in women was also seen in the three subgroup analyses after adjustment. CONCLUSION: Our findings show a higher risk of hyponatremia-related hospital admission in women than men while using diuretics. Further research is needed to understand the underlying mechanism of this sex difference to be able to provide sex-specific recommendations.

Statin use is associated with a reduced incidence of colorectal cancer expressing SMAD4.

BACKGROUND: Long-term use of statins is associated with a small reduced risk of colorectal cancer but their mechanism of action is not well understood. While they are generally believed to act on KRAS, we have previously proposed that they act via influencing the BMP pathway. The objective of this study was to look for associations between statin use and the risk of developing colorectal cancer of a particular molecular subtype. METHODS: By linking two registries unique to the Netherlands, 69,272 statin users and 94,753 controls were identified and, if they developed colorectal cancer, their specimens traced. Colorectal cancers were molecularly subtyped according to the expression of SMAD4 and the mutation status of KRAS and BRAF. RESULTS: Statin use was associated with a reduction in the risk of developing colorectal cancer regardless of molecular subtype (HR 0.77; 95% CI 0.66-0.89) and a larger reduction in the risk of developing SMAD4-positive colorectal cancer (OR 0.64; 95% CI 0.42-0.82). There was no relationship between statin use and the risk of developing colorectal cancer with a mutation in KRAS and/or BRAF. CONCLUSIONS: Statin use is associated with a reduced risk of developing colorectal cancer with intact SMAD4 expression.

Infliximab use in the Netherlands: Uptake and characteristics of originator and biosimilars over time.

AIMS: The objective of this retrospective cohort study was to provide an overview of the utilization of originator and biosimilar infliximab in the Netherlands. METHODS: All infliximab dispensings were selected from the PHARMO In-patient Pharmacy Database from 2002-2018. Descriptive analyses were performed in order to characterise initiators and to describe switching patterns over time. RESULTS: Overall, 3840 patients with 61 274 infliximab dispensings were identified. 2496 patients initiated an originator infliximab and 777 patients initiated a biosimilar infliximab. Overall, 57% of the patients was female and mean age was 43.2 years. Both originators and biosimilars were mostly prescribed by gastroenterologists, followed by internists and rheumatologists. After market authorisation of the first biosimilar, the proportion of new patients initiating the biosimilar increased from 39% in 2015 to 91% in 2018. Out of 704 patients eligible for switching 34% switched. Among switchers, the proportion of females was 60% and mean age at index was 45.1 years. Among nonswitchers, 55% were female and mean age was 39.8 years. The median time to switch was 1.7 years and switchers were most frequently initiated on infliximab by a rheumatologist (42%), while nonswitchers were most frequently initiated by a gastroenterologist (42%). CONCLUSION: The results of this large population-based cohort show an increase in biosimilar initiation in daily clinical practice. The number of switchers remains relatively low as nonmedical switch is not encouraged in the Netherlands.

Twenty-year trends in the use of anti-seizure medication among pregnant women in the Netherlands.

BACKGROUND: Anti-seizure medications (ASMs) are used to treat conditions such as epilepsy and bipolar disorder. Some of these drugs are associated with an increased risk of congenital malformations and adverse developmental outcomes. OBJECTIVES: To examine trends in use of ASMs among pregnant women in the Netherlands according to medication safety profile. METHODS: Using population-based data from the PHARMO Perinatal Research Network, we assessed trends in use of ASMs among pregnant women in the Netherlands between 1999 and 2019, stratified by medication safety profile. Individual treatment patterns were also assessed. RESULTS: In total, 671,709 pregnancies among 446,169 women were selected, of which 2405 (3.6 per 1000) were ASM-exposed. Over the study period, a significant increase was observed for use of known safest ASMs (0.7-18.0 per 10,000 pregnancies) as well as for those with uncertain risk (5.3-13.4 per 10,000 pregnancies). Use of ASMs with higher risk of congenital malformations decreased significantly (24.8-14.5 per 10,000 pregnancies), except for topiramate (0-6.7 per 10,000 pregnancies). Switches between ASM safety risk categories before and during pregnancy were uncommon; women rather discontinued treatment or switched within the same category. There was no clear change for the proportion using polytherapy during pregnancy (12% overall), however a non-significant trend toward inclusion of known safest ASMs was observed over time (1.9-3.6%). CONCLUSIONS: Over the last two decades, there has been an increase in use of known safest ASMs among pregnant women, together with a trend toward newer ASMs with uncertain risk. Only a small proportion of women switched to a safer alternative before or during pregnancy. Altogether, this highlights the need for an expansion of ASM risk knowledge and communication to healthcare providers and women of reproductive age to improve preconception counseling.

A population-based linked cohort of cancer and primary care data: A new source to study the management of cancer in primary care.

OBJECTIVE: Insight into the management of cancer in the primary care setting is pivotal to improve early recognition and survival of cancer patients. Therefore, the Netherlands Cancer Registry (NCR) was linked to the General Practitioner (GP) Database of the PHARMO Database Network to make this research possible. METHODS: The NCR collects tumour data on all newly diagnosed cancer patients, whereas the GP Database comprises data from electronic patient records registered by GPs. Databases were linked using a probabilistic record linkage technology. RESULTS: Through record linkage of the NCR and the GP Database, we have established a large population-based cohort (NCR-PHARMO GP cohort) of 135,868 cancer patients. Data are available on demographics, tumour characteristics, primary health care use before and after cancer diagnosis including medication use, medical conditions, laboratory tests, and referrals. Data can be used for a number of different studies, for example, to study the diagnostic pathway in the primary care setting in order to identify possibilities for early recognition. CONCLUSION: The NCR-PHARMO GP cohort provides rich data on the primary care management of cancer facilitating large-scale observational cancer research in the primary care setting. The patient-level linkage allows for long-term follow-up of cancer patients, with ongoing annual updates.

Prognostic models for predicting the risk of foot ulcer or amputation in people with type 2 diabetes: a systematic review and external validation study.

AIMS/HYPOTHESIS: Approximately 25% of people with type 2 diabetes experience a foot ulcer and their risk of amputation is 10-20 times higher than that of people without type 2 diabetes. Prognostic models can aid in targeted monitoring but an overview of their performance is lacking. This study aimed to systematically review prognostic models for the risk of foot ulcer or amputation and quantify their predictive performance in an independent cohort. METHODS: A systematic review identified studies developing prognostic models for foot ulcer or amputation over minimal 1 year follow-up applicable to people with type 2 diabetes. After data extraction and risk of bias assessment (both in duplicate), selected models were externally validated in a prospective cohort with a 5 year follow-up in terms of discrimination (C statistics) and calibration (calibration plots). RESULTS: We identified 21 studies with 34 models predicting polyneuropathy, foot ulcer or amputation. Eleven models were validated in 7624 participants, of whom 485 developed an ulcer and 70 underwent amputation. The models for foot ulcer showed C statistics (95% CI) ranging from 0.54 (0.54, 0.54) to 0.81 (0.75, 0.86) and models for amputation showed C statistics (95% CI) ranging from 0.63 (0.55, 0.71) to 0.86 (0.78, 0.94). Most models underestimated the ulcer or amputation risk in the highest risk quintiles. Three models performed well to predict a combined endpoint of amputation and foot ulcer (C statistics >0.75). CONCLUSIONS/INTERPRETATION: Thirty-four prognostic models for the risk of foot ulcer or amputation were identified. Although the performance of the models varied considerably, three models performed well to predict foot ulcer or amputation and may be applicable to clinical practice.

Impact of EU regulatory label changes for diclofenac in people with cardiovascular disease in four countries: Interrupted time series regression analysis.

OBJECTIVE: Due to cardiovascular safety concerns, the European Medicines Agency (EMA) recommended new contraindications and changes to product information for diclofenac across Europe in 2013. This study aims to measure their impact among targeted populations. METHOD: Quarterly interrupted time series regression (ITS) analyses of diclofenac initiation among cohorts with contraindications (congestive cardiac failure [CHF], ischaemic heart disease [IHD], peripheral arterial disease [PAD], cerebrovascular disease [CVD]) and cautions (hypertension, hyperlipidaemia, diabetes) from Denmark, the Netherlands, England and Scotland. RESULTS: The regulatory action was associated with significant immediate absolute reductions in diclofenac initiation in all countries for IHD (Denmark -0.08%, 95%CI -0.13, -0.03; England -0.09%, 95%CI -0.13 to -0.06%; the Netherlands -1.84%, 95%CI -2.51 to -1.17%; Scotland -0.34%, 95%CI -0.38 to -0.30%), PAD and hyperlipidaemia, the Netherlands, England and Scotland for hypertension and diabetes, and England and Scotland for CHF and CVD. Post-intervention there was a significant negative trend in diclofenac initiation in the Netherlands for IHD (-0.12%, 95%CI -0.19 to -0.04), PAD (-0.13%, 95%CI -0.22 to -0.05), hypertension, hyperlipidaemia and diabetes, and in Scotland for CHF (-0.01%, 95%CI -0.02 to -0.007%), IHD (-0.017, 95%CI -0.02, -0.01%), PAD and hypertension. In England, diclofenac initiation rates fell less steeply. In Denmark changes were more strongly associated with the earlier EMA 2012 regulatory action. CONCLUSION: Although significant reductions in diclofenac initiation occurred, patients with contraindications continued to be prescribed diclofenac, the extent of which varied by country and target condition. Understanding reasons for such variation may help to guide the design or dissemination of future safety warnings.

Impact of EMA regulatory label changes on hydroxyzine initiation, discontinuation and switching to other medicines in Denmark, Scotland, England and the Netherlands: An interrupted time series regression analysis.

BACKGROUND: Hydroxyzine is indicated for the management of anxiety, skin and sleep disorders. In 2015, the European Medicines Agency (EMA) concluded that hydroxyzine was pro-arrhythmogenic and changes to the product information were implemented in Europe. This study aimed to evaluate their impact in Denmark, Scotland, England and the Netherlands. METHOD: Quarterly time series analyses measuring hydroxyzine initiation, discontinuation, and switching to other antihistamines, benzodiazepines and antidepressants in Denmark, England, Scotland and the Netherlands from 2009 to 2018. Data were analysed using interrupted time series regression. RESULTS: Hydroxyzine initiation in quarter one 2010 in Denmark, Scotland, England and the Netherlands per 100 000 was: 23.5, 91.5, 35.9 and 34.4 respectively. Regulatory action was associated with a significant: immediate fall in hydroxyzine initiation per 100 000 in England (-12.05, 95%CI -18.47 to -5.63) and Scotland (-19.01, 95%CI -26.99 to -11.02); change to a negative trend in hydroxyzine initiation per 100 000/quarter in England (-1.72, 95%CI -2.69 to -0.75) and Scotland (-2.38, 95%CI -3.32 to -1.44). Regulatory action was associated with a significant: immediate rise in hydroxyzine discontinuation per 100 000 in England (3850, 95%CI 440-7240). No consistent changes were observed in the Netherlands or Denmark. Regulatory action was associated with no switching to other antihistamines, benzodiazepines or antidepressants following hydroxyzine discontinuation in any country. CONCLUSION: The 2015 EMA regulatory action was associated with heterogeneous impact with reductions in hydroxyzine initiation varying by country. There was limited impact on discontinuation with no strong evidence suggesting unintended consequences of major switching to other antihistamines, benzodiazepines or antidepressants.

Use of intravenous iron and risk of anaphylaxis: A multinational observational post-authorisation safety study in Europe.

PURPOSE: This post-authorisation safety study estimated the risk of anaphylaxis in patients receiving intravenous (IV) iron in Europe, with interest in iron dextran and iron non-dextrans. Studies conducted in the United States have reported risk of anaphylaxis to IV iron ranging from 2.0 to 6.8 per 10 000 first treatments. METHODS: Cohort study of IV iron new users, captured mostly through pharmacy ambulatory dispensing, from populations covered by health and administrative data sources in five European countries from 1999 to 2017. Anaphylaxis events were identified through an algorithm that used parenteral penicillin as a positive control. RESULTS: A total of 304 210 patients with a first IV iron treatment (6367 iron dextran), among whom 13-16 anaphylaxis cases were identified and reported as a range to comply with data protection regulations. The pooled unadjusted incidence proportion (IP) ranged from 0.4 (95% confidence interval [CI], 0.2-0.9) to 0.5 (95% CI, 0.3-1.0) per 10 000 first treatments. No events were identified at first dextran treatments. There were 231 294 first penicillin treatments with 30 potential cases of anaphylaxis (IP = 1.2; 95% CI, 0.8-1.7 per 10 000 treatments). CONCLUSION: We found an IP of anaphylaxis from 0.4 to 0.5 per 10 000 first IV iron treatments. The study captured only a fraction of IV iron treatments administered in hospitals, where most first treatments are likely to happen. Due to this limitation, the study could not exclude a differential risk of anaphylaxis between iron dextran and iron non-dextrans. The IP of anaphylaxis in users of penicillin was consistent with incidences reported in the literature.

A steep increase in healthcare seeking behaviour in the last months before colorectal cancer diagnosis.

BACKGROUND: Timely recognition of colorectal cancer related symptoms is essential to reduce time to diagnosis. This study aims to investigate the primary healthcare use preceding a colorectal cancer diagnosis. METHODS: From a cohort of linked cancer and primary care data, patients diagnosed with primary colorectal cancer in the period 2007-2014 were selected and matched to cancer-free controls on gender, birth year, GP practice and follow-up period. Primary healthcare use among colorectal cancer cases before diagnosis was compared with matched cancer-free controls. Mean monthly number of GP consultations and newly prescribed medication was assessed in the year before index date (diagnosis date for cases). Results were stratified by colorectal cancer site: proximal colon cancer, distal colon cancer and rectal cancer. RESULTS: A total of 6,087 colorectal cancer cases could be matched to four cancer-free controls (N = 24,348). While mean monthly number of GP consultation were stable through the year among cancer-free controls, a statistical significant increase was seen among colorectal cancer cases in the last 4-8 months before diagnosis. Proximal colon cancer cases showed the longest time interval of increased mean monthly number of GP consultations. This increase was largely driven by a consultation for malignant neoplasm colon/rectum. The number patients receiving a newly prescribed medication was stable around 120 per 1,000 persons per month until 8 months before index date for proximal colon cancer cases, 4 months before index date for distal colon cancer cases and 3 months for rectal cancer cases. This increase was mainly driven by the prescription of laxatives drugs. CONCLUSION: An increase in the healthcare seeking behaviour of colorectal cancer patients prior to diagnosis was seen. The longest period of increased GP consultations and newly prescribed medication was seen among patients diagnosed with proximal colon cancer. This can be explained by the difficultly to diagnose proximal colon cancer given the more subtle signs compared to distal colon cancer and rectal cancer. Therefore, faster diagnosis for this specific tumour subtype may only be possible when clear clinical signs and symptoms are present.

Prediction models for development of retinopathy in people with type 2 diabetes: systematic review and external validation in a Dutch primary care setting.

AIMS/HYPOTHESIS: The aims of this study were to identify all published prognostic models predicting retinopathy risk applicable to people with type 2 diabetes, to assess their quality and accuracy, and to validate their predictive accuracy in a head-to-head comparison using an independent type 2 diabetes cohort. METHODS: A systematic search was performed in PubMed and Embase in December 2019. Studies that met the following criteria were included: (1) the model was applicable in type 2 diabetes; (2) the outcome was retinopathy; and (3) follow-up was more than 1 year. Screening, data extraction (using the checklist for critical appraisal and data extraction for systemic reviews of prediction modelling studies [CHARMS]) and risk of bias assessment (by prediction model risk of bias assessment tool [PROBAST]) were performed independently by two reviewers. Selected models were externally validated in the large Hoorn Diabetes Care System (DCS) cohort in the Netherlands. Retinopathy risk was calculated using baseline data and compared with retinopathy incidence over 5 years. Calibration after intercept adjustment and discrimination (Harrell's C statistic) were assessed. RESULTS: Twelve studies were included in the systematic review, reporting on 16 models. Outcomes ranged from referable retinopathy to blindness. Discrimination was reported in seven studies with C statistics ranging from 0.55 (95% CI 0.54, 0.56) to 0.84 (95% CI 0.78, 0.88). Five studies reported on calibration. Eight models could be compared head-to-head in the DCS cohort (N = 10,715). Most of the models underestimated retinopathy risk. Validating the models against different severities of retinopathy, C statistics ranged from 0.51 (95% CI 0.49, 0.53) to 0.89 (95% CI 0.88, 0.91). CONCLUSIONS/INTERPRETATION: Several prognostic models can accurately predict retinopathy risk in a population-based type 2 diabetes cohort. Most of the models include easy-to-measure predictors enhancing their applicability. Tailoring retinopathy screening frequency based on accurate risk predictions may increase the efficiency and cost-effectiveness of diabetic retinopathy care. REGISTRATION: PROSPERO registration ID CRD42018089122.

Dutch trends in the use of potentially harmful medication during pregnancy.

AIMS: Recent population-based data on drug utilization around pregnancy are lacking. This study aims to examine the prevalence of drug exposure in the Netherlands during the preconception, pregnancy and postpartum periods, with special emphasis on trends of potentially harmful medication over the years. METHODS: A population-based study was conducted using records from the PHARMO Perinatal Research Network. From 1999 to 2017, the proportion of pregnancies during which women used any medication or potentially harmful medication was assessed, overall and stratified by timing of exposure relative to pregnancy and by the year of delivery. RESULTS: Overall, 357 226 (73%) and 166 484 (34%) of 487 122 selected pregnancies were exposed to any and potentially harmful medication, respectively. Among these 487 122 pregnancies, preconception prevalence for use of potentially harmful medication was 43%, 24% during the first trimester, 19% during the second, 16% during the third, and 45% postpartum. A declining trend was observed for exposure to any medication, from 84% in 1999 to 68% in 2017. No clear changes were observed over time for the proportion of pregnancies exposed to potentially harmful medication. CONCLUSIONS: Our study shows that the use of potentially harmful medication was high over the last two decades. Although there was a declining trend over the years in overall medication use, during a steady one-third of pregnancies, women used potentially harmful medication. Our findings highlight the need for an increased sense of urgency among both healthcare providers and women of reproductive age regarding potential risks associated with pharmacological treatment during pregnancy.

Prevalence and incidence rate of hospital admissions related to medication between 2008 and 2013 in The Netherlands.

PURPOSE: In 2009 a Dutch guideline was published containing recommendations to reduce Hospital Admissions Related to Medications (HARMs). This study aims to examine time-trends of HARMs and their potential preventability between 2008 and 2013 in The Netherlands. METHODS: A retrospective prevalence study was conducted using the Dutch PHARMO Database Network. A semi-automated pre-selection was used to make a crude identification of possible HARMs of which four samples were selected. These were independently assessed with respect to causality and potential preventability by a physician and pharmacist. The results were stratified by age into 18-64 years and 65 years and older. For these groups the net prevalences and incidence rates of HARMs and potentially preventable HARMs were calculated for the years 2008, 2009, 2011 and 2013. RESULTS: Four samples of 467 (2008), 447 (2009), 446 (2011) and 408 (2013) admissions were assessed. The net prevalence of HARMs in the 18-64 years group was approximately four times smaller compared to the older group with a mean prevalence of 2.7% (95% confidence interval [CI]:2.4%-3.0%) and 10.2% (95%CI: 9.7%-10.7%) respectively. The potential preventability was 25.1% (18.4%-31.8%) and 48.3% (95%CI: 44.8%-51.8%), respectively. The prevalence of HARMs in both groups did not change significantly between 2008 and 2013 with 2.4% (95%CI: 1.9%-3.0%) and 10.0% (95%CI: 9.0%-11.0%) in 2008 and 3.1% (2.7%-3.5%) and 10.4% (95%CI: 9.4%-11.4%) in 2013, respectively. CONCLUSION: Despite efforts to reduce HARMs, the prevalence did not decrease over time. Additional measures are therefore necessary, especially in the elderly population.

Impact of EMA regulatory label changes on systemic diclofenac initiation, discontinuation, and switching to other pain medicines in Scotland, England, Denmark, and The Netherlands.

PURPOSE: In June 2013 a European Medicines Agency referral procedure concluded that diclofenac was associated with an elevated risk of acute cardiovascular events and contraindications, warnings, and changes to the product information were implemented across the European Union. This study measured the impact of the regulatory action on the prescribing of systemic diclofenac in Denmark, The Netherlands, England, and Scotland. METHODS: Quarterly time series analyses measuring diclofenac prescription initiation, discontinuation and switching to other systemic nonsteroidal anti-inflammatory (NSAIDs), topical NSAIDs, paracetamol, opioids, and other chronic pain medication in those who discontinued diclofenac. Absolute effects were estimated using interrupted time series regression. RESULTS: Overall, diclofenac prescription initiations fell during the observation periods of all countries. Compared with Denmark where there appeared to be a more limited effect, the regulatory action was associated with significant immediate reductions in diclofenac initiation in The Netherlands (-0.42%, 95% CI, -0.66% to -0.18%), England (-0.09%, 95% CI, -0.11% to -0.08%), and Scotland (-0.67%, 95% CI, -0.79% to -0.55%); and falling trends in diclofenac initiation in the Netherlands (-0.03%, 95% CI, -0.06% to -0.01% per quarter) and Scotland (-0.04%, 95% CI, -0.05% to -0.02% per quarter). There was no significant impact on diclofenac discontinuation in any country. The regulatory action was associated with modest differences in switching to other pain medicines following diclofenac discontinuation. CONCLUSIONS: The regulatory action was associated with significant reductions in overall diclofenac initiation which varied by country and type of exposure. There was no impact on discontinuation and variable impact on switching.

Compliance with the guidelines for laboratory monitoring of patients treated with lithium: A retrospective follow-up study among ambulatory patients in the Netherlands.

OBJECTIVES: Laboratory monitoring of patients using lithium is important to prevent harm and to increase effectiveness. The aim of this study is to determine compliance with the guidelines for laboratory monitoring of patients treated with lithium overall and within subgroups. METHODS: Patients having at least one lithium dispensing for 6 months or longer between January 2010 and December 2015 were identified retrospectively using data from the Dutch PHARMO Database Network. Laboratory monitoring was defined as being compliant with the Dutch Multidisciplinary Clinical Guideline Bipolar Disorders when lithium serum levels, creatinine and thyroid-stimulating hormone (TSH) had been measured at least every 6 months during lithium use. RESULTS: Data were analyzed from 1583 patients with a median duration of 7- to 6-months period of lithium use. Results indicated that patients had been monitored over 6-month period for lithium serum levels 65% of the time, for creatinine 73% of the time and for TSH 54% of the time. Just over one seventh (16%) of patients had been monitored in compliance with the guidelines for all three parameters during total follow-up. Especially males, patients aged below 65 years, patients receiving prescriptions solely from general practitioners, prevalent users of lithium, patients without interacting co-medication, and patients without other days with laboratory measurements had been monitored less frequently in compliance with the guidelines. CONCLUSIONS: A considerable proportion of patients had not been monitored in accordance with the guidelines. Further research is needed to understand the reasons for noncompliance and to implement strategies with the ultimate goal of optimizing safety and effectiveness for patients treated with lithium.

How representative of a general type 2 diabetes population are patients included in cardiovascular outcome trials with SGLT2 inhibitors? A large European observational study.

AIMS: Enrollment criteria vary substantially among cardiovascular outcome trials (CVOTs) of sodium-glucose cotransporter-2 inhibitors (SGLT-2is), which impacts the relationship between a trial population and the general type 2 diabetes (T2D) population. The aim of this study was to evaluate the representativeness of four SGLT-2i CVOTs of a general T2D population. METHODS: T2D patients from Germany, The Netherlands, Norway and Sweden were included in the study. Given the available data per country, key inclusion and exclusion criteria were defined by diagnoses, procedures and drug treatments to facilitate comparability among countries. Representativeness was determined by dividing the number of patients fulfilling the key enrolment criteria of each CVOT (CANVAS, DECLARE-TIMI 58, EMPA-REG OUTCOME, VERTIS-CV) by the total T2D population. RESULTS: In 2015, a total T2D population of 803 836 patients was identified in Germany (n = 239 485), in The Netherlands (n = 36 213), in Norway (n = 149 782) and in Sweden (n = 378 356). These populations showed a 25% to 44% cardiovascular (CV) disease baseline prevalence and high CV-preventive drug use (>80%). The general T2D population had less prevalent CV disease and patients were slightly older than those included in the CVOTs. The DECLARE-TIMI 58 trial had the highest representativeness, 59% compared to the general T2D population, and this representativeness was almost 2-, 3- and 4-fold higher compared to the CANVAS (34%), EMPA-REG OUTCOME (21%) and VERTIS-CV (17%) trials, respectively. CONCLUSIONS: In large T2D populations within Europe, consistent patterns of representativeness of CVOTs were found when applying the main enrolment criteria. The DECLARE-TMI 58 trial had the highest representativeness, indicating that it included and examined patients who are most representative of the general T2D patients in the studied countries.