Existing data sources for clinical epidemiology: The pharmo database network

The PHARMO Database Network provides a unique opportunity to gain insight in the complete patient journey and healthcare in the Netherlands. The PHARMO Database Network is a population-based network of electronic healthcare databases and combines anonymous data from different primary and secondary healthcare settings in the Netherlands. Healthcare settings include general practitioners, out-patient and in-patient pharmacies, hospitals and clinical laboratories. Furthermore, databases are linked with external registries suc

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

5-year adherence to adjuvant endocrine treatment in Dutch women with early stage breast cancer:a population-based database study (2006-2016)

BACKGROUND: Hormonal receptor (HR) positive breast tumors are common. Adjuvant hormonal therapy (AHT) with tamoxifen or Aromatase Inhibitors (AIs) is beneficial depending on the stage of the tumor. Despite the fact that AHT has been shown to improve survival and recurrence, Dutch adherence rates, which were mostly dependent on Tamoxifen prescriptions until 2006, plummeted from 80% after one year to 50% after five years. Nonadherence with AHT reduces its effectiveness. This research presents more recent adherence statistics (from 2006 to 2016), on a larger sample (7,996 vs 1,451), as well as factors that influence AHT adherence. In addition to tamoxifen data, AIs are now included. OBJECTIVE: As low use of adjuvant endocrine therapy is a potentially important and modifiable risk factor for poor outcome, it is important to monitor the rate as an indicator of women's burden of disease and the direction of adherence trends. METHODS: The Netherlands Cancer Registry (NCR) was used to find women with early-stage breast cancer who started AHT within a year of surgery and were linked to the PHARMO Database Network (n = 8,679). The Kaplan-Meier approach was used to measure AHT adherence five years after treatment was started, with a 60-day gap between refills as our primary outcome. Furthermore, the Medication Possession Rate (MPR) was determined using a cutoff of =80%. Analysis was performed on influential factors of adherence. RESULTS: The proportion of persistent women declined over time to reach 46.6% at the end of the fifth year and 53.3% of the women had a MPR =80% during the fifth year. Older and being diagnosed in 2006-2010 were associated with AHT adherence. CONCLUSION: Dutch 5-year AHT adherence appears to remain poor. Improving AHT adherence in HR+ breast cancer survivors is a critical medical need

Sex- and site-specific differences in colorectal cancer risk among people with type 2 diabetes

Purpose: The prevalence of colorectal cancer is higher among patients with type 2 diabetes mellitus (T2D) than among patients without diabetes. Furthermore, men are at higher risk for developing colorectal cancer than women in the general population and also subsite-specific risks differ per sex. The aim was to evaluate the impact of T2D on these associations. Methods: A population-based matched cohort study was performed using data from the PHARMO Database Network. Patients with T2D were selected and matched (1:4) to diabetes free controls. Cox proportional hazards models were used to estimate hazard ratios (HRs) for CRC and its subsites. HRs were determined per sex and adjusted for age and socioeconomic status. The ratio of distal versus proximal colon cancer was calculated for people with T2D and controls per sex and stratified by age. Results: Over 55,000 people with T2D were matched to > 215,000 diabetes free controls. Men and women with T2D were 1.3 times more likely to develop colorectal cancer compared to controls. Men with T2D were at higher risk to develop distal colon cancer (hazard ratio (95% confidence interval), 1.42 (1.08–1.88)), and women with T2D were at higher risk for developing proximal colon cancer (hazard ratio (95% confidence interval), 1.58 (1.13–2.19)). For rectal cancer, no statistically significant risk was observed for both men and women. Conclusions: Sex-specific screening strategies and prevention protocols should be considered for people with T2D. More tailored screening strategies may optimize the effectiveness of colorectal cancer screening in terms of reducing incidence and mortality

Real-world insights into risk of developing cardiovascular disease following GnRH agonists versus antagonists for prostate cancer: a methodological protocol to a study using five European databases

International audienc

Incidence of malignancies in patients with multiple sclerosis versus a healthy matched cohort: A population-based cohort study in the Netherlands using the PHARMO Database Network

This study estimated the incidence of malignancy in patients with multiple sclerosis (MS) versus a matched general population cohort in the Netherlands. Adults with a diagnosis of MS between 2006 and 2014 in the General Practitioner (GP) Database of the PHARMO Database Network with ≥ 1 year of patient history were matched to four non-MS individuals based on year of birth, sex, and GP practice. Patients were followed-up until the earliest malignancy diagnosis, death, or end of data collection. Age-adjusted incidence rates (IR) were measured overall and by cancer type. Standardized incidence ratios (SIR) were calculated as the ratio of stratification-specific IRs in the MS and non-MS cohorts. A total of 1,692 MS patients were matched to 6,768 non-MS patients. Age-adjusted IR of any malignancy, excluding non-melanoma skin cancer (n = 27), in the MS cohort was 48.3 (95%CI:30.1–66.5) per 10,000 PY. An increased incidence of any malignancy was observed in the MS cohort versus the non-MS cohort (SIR 1.8 [95%CI:1.1–2.5]). The most commonly observed malignancies in the MS cohort were breast cancer (n = 8; IR 20.4 [95%CI:6.3–34.5] per 10,000 PY) and melanoma (n = 6; IR 14.8 [95%CI:3.0–26.7] per 10,000 PY). The corresponding SIR observed between cohorts was 1.4 (95%CI:0.4–2.4) and 3.4 (95%CI:0.7–6.2), respectively. While the small increased incidence of malignancy in the MS cohort could be an artefact created by a different distribution of risk factors, an increased incidence of malignancy in MS patients in the Netherlands cannot be excluded

Risk of heart failure among colon and rectal cancer survivors: a population‐based case–control study

Abstract Aims This population‐based case–control study aims to investigate the occurrence of heart failure (HF) among colon and rectal cancer survivors compared with a cancer‐free control population taking into account pre‐existing cardiovascular risk factors and the influence of treatment. Methods and results Colon and rectal cancer survivors diagnosed between 2007 and 2014 were selected from a linked cohort of cancer and primary care data in the Netherlands and matched based on gender, birth year, general practitioner (GP) practice, and follow‐up period to cancer‐free controls. The occurrence of HF was identified based on GP recorded diagnoses after index date (diagnosis date for cases). A Cox proportional hazards model was used to estimate hazard ratios (HRs), adjusted for age, sex, hypertension, diabetes, and hypercholesterolaemia. A total of 5333 colon cancer cases and 2468 rectal cancer cases could be matched to a total of 31 204 cancer‐free controls. A statistically significant increased risk of HF was seen among all cases compared with cancer‐free controls (HR 1.33; 95% confidence interval: 1.12–1.59). This was also seen when analysing colon cancer and rectal cancer separately. Being diagnosed with stage IV cancer, having hypertension, or having hypercholesterolaemia statistically significantly increased the risk of HF among colon cancer. Hypertension was a statistically significant risk factor for developing HF among rectal cancer cases. Conclusions Colon and rectal cancer survivors are at increased risk for developing HF. More awareness should be created by treating physicians and GPs for this potential increased risk in order to further improve survival

Chemotherapy Exposure and outcomes of Chronic Lymphoid Leukemia Patients

This study describes chemotherapy exposure, healthcare utilization, overall survival (OS) and progression-free survival (PFS) among patients diagnosed with chronic lymphoid leukemia (CLL). Newly diagnosed CLL patients who received chemotherapy were selected from the Eindhoven Cancer Registry between 1998-2011, linked on a patient-level to the PHARMO Database Network including data on in- and out-patient drug dispensings, hospitalizations and clinical laboratory measurements. Chemotherapy was classified in regimens of use based on chemotherapy combinations. OS and PFS were determined after diagnosis and after chemotherapy. Healthcare utilization was assessed in the year before diagnosis and in the year after chemotherapy. In total, 125 CLL patients received chemotherapy: 52 patients (42%) started chemotherapy within 6 months and 73 patients (58%) started chemotherapy ≥6 months after diagnosis. Mean (±SD) age was 67(±10) years and 68% was male. About 50% had one treatment line and about 25% two lines of treatment. Chlorambucil was the most common type of first line chemotherapy. Prior diagnosis, 44% were hospitalized for any cause and 94% had at least one drug dispensing. After chemotherapy, this was 43% and 98%, respectively. One-year survival rate after diagnosis was 94%. Median PFS after first treatment line was 17 months for patients starting within 6 months and 27 months for patients starting ≥6 months after diagnosis. In conclusion, most CLL patients receiving chemotherapy were treated with chlorambucil. One-year after initial diagnosis, 94% were still alive. Median PFS after first line chemotherapy ranged from 17 to 27 months, depending on the timing of chemotherapy