A European inventory of data elements for patient recruitment

INTRODUCTION

In the last few years much work has been conducted in creating systems that support clinical trials for example by utilizing electronic health record data. One of these endeavours is the Electronic Health Record for Clinical Research project (EHR4CR). An unanswered question that the project aims to answer is which data elements are most commonly required for patient recruitment.

METHODS

Free text eligibility criteria from 40 studies were analysed, simplified and elements were extracted. These elements where then added to an existing inventory of data elements for protocol feasibility.

RESULTS

We simplified and extracted data elements from 40 trials, which resulted in 1170 elements. From these we created an inventory of 150 unique data elements relevant for patient identification and recruitment with definitions and referenced codes to standard terminologies.

DISCUSSION

Our list was created with expertise from pharmaceutical companies. Comparisons with related work shows that identified concepts are similar. An evaluation of the availability of these elements in electronic health records is still ongoing. Hospitals that want to engage in re-use of electronic health record data for research purposes, for example by joining networks like EHR4CR, can now prioritize their effort based on this list.

A European inventory of common electronic health record data elements for clinical trial feasibility

Background

Clinical studies are a necessity for new medications and therapies. Many studies, however, struggle to meet their recruitment numbers in time or have problems in meeting them at all. With increasing numbers of electronic health records (EHRs) in hospitals, huge databanks emerge that could be utilized to support research. The Innovative Medicine Initiative (IMI) funded project ‘Electronic Health Records for Clinical Research’ (EHR4CR) created a standardized and homogenous inventory of data elements to support research by utilizing EHRs. Our aim was to develop a Data Inventory that contains elements required for site feasibility analysis.

Methods

The Data Inventory was created in an iterative, consensus driven approach, by a group of up to 30 people consisting of pharmaceutical experts and informatics specialists. An initial list was subsequently expanded by data elements of simplified eligibility criteria from clinical trial protocols. Each element was manually reviewed by pharmaceutical experts and standard definitions were identified and added. To verify their availability, data exports of the source systems at eleven university hospitals throughout Europe were conducted and evaluated.

Results

The Data Inventory consists of 75 data elements that, on the one hand are frequently used in clinical studies, and on the other hand are available in European EHR systems. Rankings of data elements were created from the results of the data exports. In addition a sub-list was created with 21 data elements that were separated from the Data Inventory because of their low usage in routine documentation.

Conclusion

The data elements in the Data Inventory were identified with the knowledge of domain experts from pharmaceutical companies. Currently, not all information that is frequently used in site feasibility is documented in routine patient care.

Safety of the combination of valsartan and benazepril in patients with chronic renal disease. European Group for the Investigation of Valsartan in Chronic Renal Disease

OBJECTIVE

Several experimental and clinical studies indicate that the renin system may play a pivotal role in progressing renal disease. The combination of an angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker could provide a higher degree of blockade of the renin-angiotensin system than either agent alone. Such enhanced suppression might be of benefit for patients exhibiting a progressive decline in renal function because of chronic renal disease.

METHODS

A pilot multinational, multicentre, randomized, active-controlled, parallel group open-label study has been conducted in a group of patients with progressive chronic renal failure (creatinine clearance 20-45 ml/min) either with or without proteinuria and hypertension. The primary aim of the study was to investigate the safety and tolerability of the combination of valsartan and benazepril. Patients were randomly assigned to one of three groups: group 1 received valsartan 160 mg once daily (n = 22); group 2 received valsartan 80 mg once daily plus benazepril 5 or 10 mg once daily (n = 42); group 3 received valsartan 160 mg once daily plus benazepril 5 or 10 mg once daily (n = 44). The study lasted for 5 weeks, and in groups 2 and 3 benazepril was added on top of valsartan after the first week of therapy with the angiotensin receptor blocker.

RESULTS

Serum creatinine increased in all three groups (mean change within a group: 11 micromol/l in group 1, P= 0.045; 9 micromol/l in group 2, P= 0.030; 15 micromol/l in group 3, P= 0.0006). Serum potassium also increased in all three groups of patients (mean change within a group: 0.28 mmol/l in group 1, P= 0.28; 0.48 mmol/l in group 2, P= 0.0008; 0.36 mmol/l in group 3, P= 0.02). After 5 weeks of treatment, the largest decrease in blood pressure was observed in group 3 (the mean change from baseline in seated diastolic blood pressure (SDBP) and seated systolic blood pressure (SSBP), respectively, were: -2.0 and -11.5 mmHg in group 1; -7.6 and -15.4 mmHg in group 2; -12.6 and -21.6 mmHg in group 3). In addition, both combination treatments resulted in the reduction of proteinuria. The total number of patients with adverse experiences were 10 (45.5%), 14 (33.3%) and 11 (25%) in groups 1,2 and 3, respectively. In six patients (5.6%) therapy was discontinued as a result of adverse experiences. Only one patient in each of the combined therapy groups withdrew from the study because of hyperkalaemia and no patients were forced to withdraw because of an increase in serum creatinine, acute renal failure or hospitalization.

CONCLUSIONS

These results indicate that short-term combination of an angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker is safe and well tolerated in patients with moderate chronic renal failure.

The effect of valsartan and captopril on lipid parameters in patients with type II diabetes mellitus and nephropathy

The study compared valsartan 80 mg or 160 mg o.d. with captopril 25 mg t.i.d. or placebo on plasma lipids in normotensive and treated hypertensive patients with type II diabetes and microalbuminuria. One hundred and twenty-two adult outpatients were randomised to receive either valsartan 80 mg or 160 mg, captopril 25 mg or placebo for 360 days. Changes from baseline to endpoint in plasma lipid parameters were measured. The primary criterion for tolerability was the incidence of adverse events. All treatment groups showed minor changes in lipid parameters. Triglyceride increased by 2.7% (valsartan 160 mg) to 9.1% (placebo). Total cholesterol decreased under valsartan 80 mg, while other groups showed increases of up to 0.031 mmol/l. Decreases in total cholesterol (p = 0.018), apolipoprotein B (p = 0.042) and apolipoprotein A1 (p = 0.025), were significant for the comparison of 80 mg valsartan and captopril. Valsartan 80 mg or 160 mg o.d. does not cause deleterious changes in the diabetic lipid profile and, unlike captopril, is not associated with dry cough.

Maspin plays an important role in mammary gland development

Maspin is a unique member of the serpin family, which functions as a class II tumor suppressor gene. Despite its known activity against tumor invasion and motility, little is known about maspin's functions in normal mammary gland development. In this paper, we show that maspin does not act as a tPA inhibitor in the mammary gland. However, targeted expression of maspin by the whey acidic protein gene promoter inhibits the development of lobular-alveolar structures during pregnancy and disrupts mammary gland differentiation. Apoptosis was increased in alveolar cells from transgenic mammary glands at midpregnancy. However, the rate of proliferation was increased in early lactating glands to compensate for the retarded development during pregnancy. These findings demonstrate that maspin plays an important role in mammary development and that its effect is stage dependent.

Valsartan and atenolol in patients with severe essential hypertension

The aim of this study was to evaluate the efficacy and tolerability of valsartan, a new angiotensin II receptor antagonist, versus atenolol in the treatment of severe primary hypertension. A total of 103 adult out-patients were randomised to receive either valsartan 160 mg or atenolol 100 mg once daily for 6 weeks. If necessary, additional blood pressure (BP) control could be provided as add-on therapy. Both valsartan and atenolol decreased mean sitting diastolic BP (DBP) and mean sitting systolic BP (SBP): least squares mean change from baseline in DBP; valsartan, -20.0 mm Hg; atenolol, -20.4 mm Hg: in SBP; valsartan, -30.0 mm Hg; atenolol, -25.5 mm Hg. There was no statistically significant difference between the treatment groups. Add-on hydrochlorothiazide (HCTZ) 25 mg was required by 97.2% of patients receiving atenolol and 83.6% of patients receiving valsartan; additional verapamil SR 240 mg was also required by 58.3% of patients receiving atenolol and 64.2% receiving valsartan. Valsartan was well tolerated, with a comparable incidence of treatment-related adverse experiences in both groups. In conclusion valsartan 160 mg is as well tolerated and effective as atenolol 100 mg in lowering BP in severely hypertensive patients.

B-cell-specific coactivator OBF-1/OCA-B/Bob1 required for immune response and germinal centre formation

The B-lymphocyte-specific transcriptional factor called Oct binding factor (OBF)-1, OCA-B or Bob1 (refs 1-3) is thought to be involved in the transcription of immunoglobulin genes through recruitment to the highly conserved octamer site of immunoglobulin promoters, mediated by either Oct-1 or Oct-2. To define the in vivo role of OBF-1 we have used gene targeting in embryonic stem cells to generate mice lacking the coactivator OBF-1. Such OBF-1-/- mice are born normally, are fertile and seem healthy, and surprisingly, rearrangement and transcription of immunoglobulin genes are largely unaffected. However, mice deficient in OBF-1 have reduced numbers of mature B cells and a severe reduction in the number of recirculating B cells, but otherwise show normal B-cell differentiation. Serum IgA and particularly IgG levels are greatly reduced. If mutant mice are immunized with either a thymus-independent or a thymus-dependent antigen, their immune responses are dramatically weakened. Strikingly, germinal centres completely fail to develop after immunization with thymus-dependent antigen. Our results demonstrate that in vivo OBF-1 is not required for initial transcription of immunoglobulin genes or for B cell development, but instead is essential for the response of B cells to antigens, and is required for the formation of germinal centres.

Transgenic expression of embryonic MAP2 in adult mouse brain: implications for neuronal polarization

The major neuronal microtubule-associated protein MAP2 is selectively localized in dendrites, where its expression is under strong developmental regulation. To learn more about its potential effects on neuronal morphogenesis and its sorting within the neuronal cytoplasm, we have raised transgenic mice that express high levels of the embryonic form, MAP2c, in the adult brain. One transgenic line expressed higher levels of MAP2c than endogenous adult MAP2. This had no detectable effect on either the arrangement or morphology of neurons, suggesting that although MAP2c is necessary for neuronal morphogenesis it is not involved in its regulation. Like endogenous adult MAP2, transgenic MAP2c was present in dendrites but not axons, indicating that the signal responsible for its cytoplasmic sorting is contained within the 1.5 kb of its coding sequence. In situ hybridization with specific probes showed that transgenic MAP2c mRNA was limited to cell bodies. Thus, the dendritic localization of MAP2c protein cannot be the result of previous transport of its mRNA but must depend on a signal associated with the protein itself. Furthermore, because the amino acid sequence of MAP2c is present in all forms of MAP2, this signal is also contained within adult high-M(r) MAP2 protein. This raises the possibility that, rather than the conventional scheme of mRNA sorting preceding protein localization, the transport of adult MAP2 mRNA into dendrites could depend on it being part of a translation complex in which the targeting signal is on the nascent protein.

Overexpression of the neural growth-associated protein GAP-43 induces nerve sprouting in the adult nervous system of transgenic mice

Regulation of neurite outgrowth and structural plasticity may involve the expression of intrinsic determinants controlling growth competence. We have tested this concept by targeting constitutive expression of the growth-associated protein GAP-43 to the neurons of adult transgenic mice. Such mice showed striking spontaneous nerve sprouting at the neuromuscular junction and in the terminal field of hippocampal mossy fibers. In control mice, these nerve fibers did not express GAP-43, and did not sprout spontaneously. Lesion-induced nerve sprouting and terminal arborization during reinnervation were greatly potentiated in GAP-43-overexpressing mice. A mutant GAP-43 that cannot be phosphorylated by PKC had reduced sprout-promoting activity. The results establish GAP-43 as an intrinsic presynaptic determinant for neurite outgrowth and plasticity.

An activated allele of the c-erbB-2 oncogene impairs kidney and lung function and causes early death of transgenic mice

The pathogenicity of the human c-erbB-2 oncogene was evaluated in transgenic mice. A DNA sequence comprising the promoter-enhancer region of the MMTV LTR and a constitutively activated allele of the human c-erbB-2 growth factor receptor gene was introduced into the germ line of mice. Expression of the transgene was observed in kidney, lung, mammary gland, salivary gland, Harderian gland, and in epithelial cells of the male reproductive tract. All transgenic mice expressing the c-erbB-2 receptor died within four months of birth. Histopathological analysis suggests that preneoplastic lesions in kidney and lung most likely caused organ failure and the early death of the transgenic mice. Focal dilatation and atypical proliferation of the tubular epithelial cells was found in the kidney. These hyperplastic lesions were found adjacent to normal tubules. Immunohistochemistry showed that normal renal structures were completely negative for c-erbB-2 protein expression. Atypical pseudopapillary proliferation of bronchial and bronchiolar epithelial cells narrowed the bronchial lumen in lung. Alveoli appeared normal. The expression of c-erbB-2 protein was strictly limited to the proliferating epithelial cells and not detected in normal tissue. The mammary glands of two parous mice were underdeveloped, lacking lobular-alveolar structures and were lactation deficient. Only a few ducts were interspersed in the fat pad. A virgin mouse developed a focal adenocarcinoma infiltrating the mammary fat pad. Expression of the c-erbB-2 protein was enhanced in the proliferating epithelial cells. Transgenic males were sterile. Epithelial hyperplasia and hypertrophy in the epididymis, vas deferens and seminal vesicles was found. The transgene is not uniformly expressed in the tissues where the MMTV LTR is transcriptionally active. The scattered transgene expression invariably coincides with epithelial hyperplasia.

Transgenes encoding mutant simian virus 40 large T antigens unmask phenotypic and functional constraints in thymic epithelial cells

Transgenes encoding simian virus 40 (SV40) T antigen (Tag) can cause hyperplastic or tumorigenic lesions of desired but also of unforeseen cellular origin. Unexpectedly the human growth hormone-releasing factor (GRF) gene promoter directs expression of SV40 Tag specifically in thymic epithelial (TE) cells. Expression starts in the neonate, in which GRF-Tag+ cells display strict numerical and spatial constraints. Tag supersedes mechanisms that constrain these features and GRF-Tag mice develop thymic hyperplasia. To characterize GRF-Tag+ TE cells and their putative normal counterparts we compared phenotypic and functional effects caused by transgenes encoding mutant large T antigens. This strategy is applicable to any situation in which T antigen is used to alter development. One large Tag mutant (K1 + 5080) does not cause thymic hyperplasia. GRF-Tag (K1 + 5080)+ TE cells display strict temporal and spatial constraints throughout life. TE cells expressing other mutant large T antigens that cause thymic hyperplasia do not obey these rules and reveal that phenotypically distinct GRF-Tag+ TE-cell stages exist in vivo. Analysis of conditional immortal GRF-Tag(tsA58)+ TE cells expressing a temperature-sensitive large Tag shows that large Tag blocks differentiation in these cells. Phenotype and functions in these cells are regulated by cellular differentiation and interleukin 4 (IL-4).

Thymic hyperplasia in transgenic mice caused by immortal epithelial cells expressing c-kit ligand

To dissect mechanisms that co-ordinate specific events in thymopoiesis we have characterized alterations in thymic structure and function caused by expression of a transgene. This gene encodes SV40Tag and is specifically expressed in a subset of thymic epithelial (TE) cells around birth. As a result the number of immortal TE cells increases, thymic mass increases (up to 3 g), and thymopoiesis is expanded. The latter is reflected by a approximately 100-fold increase of the major thymocyte subsets and increased peripheral T cell counts. Grossly hyperplastic thymi retain many but not all morphological features of a normal thymus. Also in grafts, SV40Tag+ TE cells steer expansion (up to 8 g) and organize a tissue with mainly cortex-like features that includes mainly SV40Tag+ TE cells, thymocytes, and macrophages. To investigate expression of specialized gene functions in the immortal TE cells, a cell line was derived. The Epi-A1 cell line expresses the genes for major histocompatibility complex class I and II, Thy-1, interleukin (IL)-6, IL-7, macrophage-colony-stimulating factor, and transforming growth factor-beta 3. Most importantly, Epi-A1 cells also express the IL-4 receptor and the c-kit ligand (KL), a factor that, in concert with commitment factors, channels progenitors into hemopoietic lineages. The expression of low constitutive levels of KL mRNA does not require IL-4, but KL mRNA levels are increased dramatically in response to IL-4. Since constitutive expression of KL mRNA in vivo is restricted to a small subset of TE cells in the thymus, our findings reveal a novel specific interaction between thymocytes and a specialized subset of TE cells.

A lymphoproliferative abnormality associated with inappropriate expression of the Thy-1 antigen in transgenic mice

The Thy-1 antigen is a cell-surface glycoprotein of unknown function expressed on mouse T lymphocytes, neurons, and hematopoietic stem cells. To alter the normal pattern of Thy-1 expression during hematopoietic differentiation, we created transgenic mice using a hybrid Thy-1 gene containing a transcriptional enhancer of the mouse immunoglobulin heavy chain gene (E mu). Strains of mice bearing the Thy-1.2/E mu gene express the Thy-1.2 antigen on mature B lymphocytes and their progenitors, and develop a heritable lymphoid hyperplasia characterized by massive expression of the Thy-1.2 antigen in the bone marrow and lymph nodes. The phenotype associated with inappropriate developmental regulation of the Thy-1 gene suggests that the Thy-1 antigen may play a role in inducing activation or differentiation events on early lymphocyte progenitor cells.

Proto-oncogene expression in regenerating liver is simulated in cultures of primary adult rat hepatocytes

Proto-oncogene fos mRNA levels are rapidly and transiently elevated 12-fold in regenerating liver 10-60 min following partial hepatectomy. This response, and the induction of fos protein synthesis, has been simulated qualitatively and quantitatively in long term primary cultures of quiescent adult rat hepatocytes where proliferative transitions can be initiated directly in serum-free medium by known hepatocyte mitogens like epidermal growth factor. Expression of a second proto-oncogene, c-rasH, in proliferatively activated hepatocyte cultures between 6 and 24 h also simulates the delayed hepatic response that occurs in vivo following partial hepatectomy. These results suggest that sequential proto-oncogene expression during liver regeneration is caused directly by hepatocellular interactions with specific mitogens. In addition, a role for monovalent cations in the regulation of hepatocyte gene expression is implicated from findings that Na+ deprivation inhibits induction of fos expression in cultured hepatocytes by epidermal growth factor under chemically defined conditions.

Developmental fate of a human insulin gene in a transgenic mouse

A plasmid containing a genomic human insulin clone was microinjected into a pronucleus of the fertilised mouse egg. Eggs were subsequently transferred into oviducts of pseudopregnant Swiss/Alb females. Embryos developed to term and the DNA was extracted from different organs. Southern blotting analyses revealed 1 transgenic female out of 96 animals born after microinjection of C57BL/6 mouse eggs. A tandem integration was found at one locus within the mouse genome and molecular rearrangement was found within this locus. The structure of the entire locus was identical in DNA from all tissues. Both the human insulin gene sequences and the pBR322 sequences were found to be extensively methylated, although some sites were hypomethylated in the pancreas and liver. The transgenic female produced ten offspring, none of which retained the insulin gene sequences. Seven offspring retained some pBR322 sequences which were stably transmitted to the F2 and F3 generations. Homozygous F3 delta pBR/delta pBR animals were obtained, which showed neither visible defects nor sterility. The loss of the tandem locus in the F1 generation did not seem to be due to mosaicism, but involved excision due to recombination. Sequences close to the ends of the tandem locus were involved in this event. A mechanism implying excision during germ cell formation is discussed.