Proposal of an Architecture for Terminology Management in a Research Project

Clinical and medical knowledge evolve and this causes changes in concepts and terms that describe them. The objective of this work is to formally present an ontology-based standard architecture that will be used in the scenario of neurodegeneration research to maintain terminologies and their relations updated and coherent over the time. The proposed structure is composed by three elements that will allow the user to do a list of operations on the terminology resources explicitly contemplated by the Common Terminology Service Release 2 (CTS2).

Antibacterial and ATP Synthesis Modulating Compounds from Salvia tingitana

A surface extract of the aerial parts of Salvia tingitana afforded a nor-sesterterpenoid (1) and eight new sesterterpenoids (2-̵9), along with five known sesterterpenoids, five labdane and one abietane diterpenoid, one sesquiterpenoid, and four flavonoids. The structures of the new compounds were established by 1D and 2D NMR spectroscopy, HRESIMS, and VCD data and Mosher's esters analysis. The antimicrobial activity of compounds was evaluated against 30 human pathogens including 27 clinical strains and three isolates of marine origin for their possible implications on human health. The methyl ester of salvileucolide (10), salvileucolide-6,23-lactone (11), sclareol (15), and manool (17) were the most active against Gram-positive bacteria. The compounds were also tested for the inhibition of ATP production in purified mammalian rod outer segments. Terpenoids 10, 11, 15, and 17 inhibited ATP production, while only 17 inhibited also ATP hydrolysis. Molecular modeling studies confirmed the capacity of 17 to interact with mammalian ATP synthase. A significant reduction of ATP production in the presence of 17 was observed in Enterococcus faecalis and E. faecium isolates.

Real-Life Management of Diabetic Macular Edema with Dexamethasone Intravitreal Implant: A Retrospective Analysis of Long-Term Clinical Outcomes

PURPOSE

Inflammation plays a key role in the pathogenesis of diabetic macular edema (DME), and intravitreal corticosteroids are among the recommended therapies. The goal of this retrospective analysis was to describe outcomes with dexamethasone intravitreal implant (DEX implant) in real life.

METHODS

Medical digital records of DME patients treated with DEX implant and followed up for 3 years were analyzed. Treatment with DEX implant was started either as first-line therapy in pseudophakic patients and in patients with cardiovascular comorbidities or as second-line therapy in patients refractory to the inhibitor of the vascular endothelial growth factor (anti-VEGF) therapy. Analyzed outcomes included central macular thickness (CMT) and best-corrected visual acuity (BCVA). Mean number of implant injections per patient and mean duration of the interval between injections were also estimated.

RESULTS

Seventy-five patients (mean age 65.7 (±12.3) years; 53 phakic and 22 pseudophakic) with DME were included. Overall, 84 eyes were treated. Mean CMT improved from 380.1 (±100.3) µm at baseline to 306.8 (±77.0) µm at 36 months (p=0.0003). Mean BCVA improved for up to 6 months (p=0.08) and then started to decrease reaching values lower than baseline after 24 months. In pseudophakic patients, BCVA improvements were more pronounced and sustained up to 36 months (p=0.6). Over 36 months, each patient received on average 2.4 (±1.6) intravitreal injections of DEX implant. The time interval between consecutive injections was included between 180 and 240 days. No unexpected safety issues were reported.

CONCLUSIONS

With fewer than 3 injections per patient over a 3-year period, DEX implant was able to improve anatomic outcomes in DME patients. Only pseudophakic eyes showed also a long lasting functional benefit at 36 months.

Real-Life Data in the Treatment of Neovascular Age-Related Macular Degeneration: Results from the Imaculaweb Registry Evaluated in a Single Italian Medical Retina Center

<b><i>Introduction:</i></b> The aim of this study is to assess and compare the long-term clinical efficacy of anti-VEGF drugs using the Imaculaweb registry. <b><i>Methods:</i></b> In this observational study based on the Imaculaweb registry, outcome measures were the number of injections, the change in mean visual acuity (VA) and central macular thickness (CMT), and the time between diagnosis and the first injection. <b><i>Results:</i></b> In total, 126 eyes of 109 patients were included in the study. The mean VA was 49.4 ± 21.4, 54.1 ± 22.2, 51.6 ± 24.9, and 48.3 ± 25.7 letters at baseline and at the 1-, 2-, and 3-year follow-ups, respectively. Significant VA increases (<i>p</i> = 0.0002 for the first year and <i>p</i> = 0.045 for the second year) were documented at years 1 and 2 but not at year 3 (<i>p</i> = 0.8). The mean number of injections was 5.2, 2.6, and 2.3 at the 1-, 2-, and 3-year follow-ups, respectively. In the first year, 30% of the patients received at least 7 injections, while only 6.4% received &#x3c;3 injections. CMT decreased significantly during the overall follow-up period, and intra- and subretinal fluid decreased (<i>p</i> &#x3c; 0.0001). <b><i>Conclusion:</i></b> Imaculaweb turned out to be an effective tool to collect and share clinical data as well as to monitor patient outcome.

Healthcare Associated Infections: An Interoperable Infrastructure for Multidrug Resistant Organism Surveillance

Prevention and surveillance of healthcare associated infections caused by multidrug resistant organisms (MDROs) has been given increasing attention in recent years and is nowadays a major priority for health care systems. The creation of automated regional, national and international surveillance networks plays a key role in this respect. A surveillance system has been designed for the Abruzzo region in Italy, focusing on the monitoring of the MDROs prevalence in patients, on the appropriateness of antibiotic prescription in hospitalized patients and on foreseeable interactions with other networks at national and international level. The system has been designed according to the Service Oriented Architecture (SOA) principles, and Healthcare Service Specification (HSSP) standards and Clinical Document Architecture Release 2 (CDAR2) have been adopted. A description is given with special reference to implementation state, specific design and implementation choices and next foreseeable steps. The first release will be delivered at the Complex Operating Unit of Infectious Diseases of the Local Health Authority of Pescara (Italy).

Lipid profile changings after switching from rilpivirine/tenofovir disoproxil fumarate/emtricitabine to rilpivirine/tenofovir alafenamide/emtricitabine: Different effects in patients with or without baseline hypercholesterolemia

Tenofovir alafenamide (TAF) has similar efficacy compared to tenofovir disoproxil fumarate (TDF), but a less favorable effect on lipids. Aim of this retrospective multicentre study was to evaluate the impact on lipids of switching from rilpivirine (RPV)/ emtricitabine (FTC)/TDF to RPV/FTC/TAF in a cohort of HIV-1 infected patients. Total cholesterol (TC), high density lipoproteins (HDL) and low density lipoproteins (LDL) were compared at the moment of the switch and at the first following evaluation, by using paired t-test. Overall, 573 patients were considered, 99% with HIV-RNA <50 copies/ml, with mean age of 49.7 (±0.4) years and median 13.4 (6.9-22.5) years of HIV infection. In the study population with available data (431/573, 75%), mean TC changed from 173 ±1.7 to 188 ±1.8 mg/dl; mean HDL from 46 ±0.7 to 51± 0.7 mg/dl; mean LDL from 111 ±1.5 to 120 ±1.8 mg/dl (p<0.0001 for all). Neither LDL/HDL nor TC/HDL ratio changed significantly, with LDL/HDL from 2.6 ±0.5 to 2.5 ±0.5 (p = 0.12) and TC/HDL from 4.0 ±0.6 to 3.9 ±0.6 (p = 0.11). In patients with baseline diagnosis of hypercholesterolemia (TC>200 mg/dl, N = 87), there was no significant change in TC (224 ±2.2 to 228 ±3.4 mg/dl, p = 0.286) or LDL (150±2.5 to 151±3.2 mg/dl, p = 0.751), while HDL increased from 51 ±1.6 to 55 ±1.7 mg/dl (p<0.0001) and both LDL/HDL and TC/HDL ratio decreased significantly, from 3.2±0.1 to 3.0 ±0.1 (p = 0.025) and from 4.7±0.1 to 4.4 ±0.1 (p = 0.004). In this real life study, a slight increase in lipids was found after switching from RPV/FTC/TDF to RPV/FTC/TAF, but these results were not confirmed in people with hypercholesterolemia, in which lipids did not change and LDL/HDL and TC/HDL ratio decreased.

The Ligurian HIV Network: How Medical Informatics Standards Can Help Clinical Research

Integrating evidence from systematic research in daily clinical practice is one of the pillars of evidence-based medicine. Electronic data capture tools simplify data collection from different centers and supports the management of multicenter clinical trials. The Ligurian HIV Network (LHN) is one such tool, originating from a regional effort to integrate clinical trial capabilities for HIV and other chronic infectious diseases. In order to manually collect a complete report of all clinical tests on patients enrolled in a trial, a strenuous human effort and the allocation of great resources would be necessary. Moreover, the risk of error in a manual system is very high. The proposed system automatically extracts clinical data from the EHR of three hospitals of the LHN in a standardized way, and enhance their re-use in clinical trials. Through dedicated questionnaires, physicians reported a strongly positive feedback about the efficacy of the platform in supporting clinical research.

Medical Equipment Replacement Prioritisation: A Comparison Between Linear and Fuzzy System Models

In hospital management, health technology assessment techniques are being increasingly developed. This paper presents a comparison of the results obtained using two models for replacement priority value calculation applied to the Galliera hospital in Genoa (Italy). One the models was developed at the Galliera Hospital along the lines of the model by Fennigkoh and addresses four primary replacement issues: equipment service and support, equipment function, cost benefits and clinical efficacy, by a "yes-no" scheme. This model is compared with a model based on fuzzy logic. The comparison between the two models shows a conservative behaviour by the Galliera model, according to which 77.4% of the analysed instrumentation is maintained, whereas the classification by the fuzzy model allows for a better discrimination among the devices.

Vardenafil and Weaning from Inhaled Nitric Oxide: Effect on Pulmonary Hypertension in ARDS

We report a 66-year-old patient with refractory pulmonary hypertension secondary to ARDS who was being treated with inhaled nitric oxide. Enteral vardenafil (phosphodiesterase-5 inhibitor) was tried at two different doses (10 mg and 5 mg), in order to wean the patient from nitric oxide. The higher dose decreased pulmonary pressure but caused systemic hypotension and the drug was discontinued. Subsequently, a 5 mg dose of vardenafil decreased pulmonary pressure without hypotension. Pulmonary hypertension was controlled using vardenafil 10-15 mg divided in 2-3 daily doses. This therapy allowed nitric oxide withdrawal, weaning from mechanical ventilation and discharge from ICU.

Vardenafil acted in synergy with inhaled nitric oxide, permitted nitric oxide reduction and discontinuation and proved to be effective as a single, long-term treatment for pulmonary hypertension.

A Web-Based Tool for a Complete Evaluation of Fragility in Senior Hiv+ Patients

BACKGROUND

after the discovery of the antiretroviral therapy, life expectancy of HIV+ patient has become longer and this meant that he would start ageing. International literature demonstrated that the HIV+ patient is more fragile than any other person of the same age and that doesn't present the viral infection.

OBJECTIVE

design, development and test of a new web-based instrument to allow the self-administration of the new questionnaire SELFY MPI created during the European project Effichronic. Materials &amp; Methods: between June and September 2018, a group of senior 50 HIV+ patients, was involved. The questionnaire SELFY MPI enables to collect data about quality of life and cognitive functions.

RESULTS

the developed web-instrument collects pseudo-anonymous data into the Liguria HIV Network database. The subsequent statistical analysis highlighted a correlation between the two outcomes of SELFY MPI and the laboratory exam's parameter TCD4+ and viral load.

CONCLUSIONS

the great potentiality of this instrument is not only the support given to clinical research about the effects of HIV on chronical disease management but it can be also used as a follow-up instrument to evaluate different aspects of the geriatric patient life during the years.

A SOA Based Solution for MDRO Surveillance and Improved Antibiotic Prescription in the Abruzzo Region

Prevention and control of hospital and community acquired infections caused by multi drug resistant organisms (MDROs) are one major priority nowadays for health care systems worldwide. To improve actions and plans to tackle this problem, the creation of automated regional, national and international MDRO surveillance networks is a mandatory path for international health Institutions and Ministries. In this paper, the authors report on the surveillance system designed for the Abruzzo Region (Central Italy) to monitor the prevalence of MDROs in both infected and colonized patients, to verify appropriateness of antibiotic prescription in hospitalized patients and to interact with other national and sovra-national networks. Service Oriented Architecture (SOA) approach, different Healthcare Service Specification Project (HSSP) standards, local, national and international terminology and Clinical Document Architecture Release 2 (CDA R2) were adopted to design the overall architecture of this regional surveillance system. The Authors discuss the state of implementation of the project, itemizing specific design and implementation choices adopted so far and sketching next steps and reasons of some design and implementation choices, and indicate the next steps.

Information Technology System Including Patient Generated Health Data for Cancer Clinical Care and Research

This paper presents the extension of a service-oriented architecture framework for precision oncology to the management of patient generated health data from wearables. The solution follows the indication provided by the Health Level 7 (HL7) and Object Management Group (OMG) initiative Healthcare Service Specification Project (HSSP) and is compliant to Retrieve Locate and Update Service (RLUS) Release 1 standard adopting Clinical Document Architecture Release 2 (CDA R2) as semantic signifier. The system which has been developed supports the management of visits, the setting up of a clinical diary and a comprehensive view of the patients from the wearables data for improve clinical care and for research. The system structure is highly modular and the parameters relating to wearables data are only present in one module. Extension of the systems to other aspects, such as genomics and immune therapy, are planned following the same modular design criteria.

Cancer precision medicine today: Towards omic information in healthcare systems

INTRODUCTION:

This article focuses on the integration of omics data in electronic health records and on interoperability aspects relating to big data analysis for precision medicine.

METHODS:

Omics data integration methods for electronic health record and for systems interoperability are considered, with special reference to the high number of specific software tools used to manage different aspects of patient treatment. This is an important barrier against the use of this integrated approach in daily clinical routine.

RESULTS:

The correct use of all three levels of interoperability (technical, semantic, and process interoperability) plays a key role in order to achieve an easy access to a significant amount of data, all with correct contextualization, which is the only way to obtain a real value from data for precision medicine.

CONCLUSIONS:

The proposed architecture could improve the potentialities of data routinely collected in many health information systems to form a real patient center information environment.

Time to change the single-centre approach to management of patients with tuberculosis: a novel network platform with automatic data import and data sharing

Time to change the single-centre approach to TB http://ow.ly/lCeM30hBcbB.

CIGNOweb.it

We introduce CIGNOweb.it, a database of oncology resources for patients, the general public and healthcare professionals. It builds on the previous Italian cancer resource Azaleaweb and offers quality-evaluated content. It meets international bibliographic and technical standards such as the Open Archives Initiative (OAI) for web content interoperability and the Functional Requirements for Bibliographic Records (FRBR) for bibliographic description with respect to the different media, applications, and user needs. Database content is supplied in collaboration with non-profit associations, libraries and the network of Cancer Information Points that is currently being established all over Italy. Expert and customer evaluation and feedback are provided for in the system. The graphic layout has been painstakingly designed to be user-friendly for a non-expert public. CIGNOweb.it is multicentric and will in time offer health information outside the field of oncology. It is designed to become a multilingual tool to organize, optimize and access patient information produced in the languages of the “newer” European countries. It is hoped that CIGNOweb.it will support other European nations in enhancing the structure and organization of their own-language patient health information and will contribute towards making a common health information portal of the European Union a reality. Free full text available at www.tumorionline.it

Training and Mobility: A Priority for the Organisation of the European Cancer Institutes. How a National Mobility Initiative Could Enhance EU Cooperation in Cancer Research Contributing to the Development of an European Research Area: The Example of the Italian Comprehensive Cancer Centers’ Network “Alleanza Contro il Cancro”

It is widely recognized that productivity gains, sustained economic growth and employment are largely determined by technological progress, innovation and human capital. The 2000 Lisbon strategy to make Europe a competitive knowledge-based economy by 2010 and, more specifically, the Barcelona objectives agreed upon in 2002 to increase R&D investment in the EU to approach 3% of GDP, ensuring that there are sufficient human resources for research, are a preliminary step in this direction. If we want to reach this goal we have to succeed in retaining the best researchers, creating the right environment where they can perform their activities and develop their careers.

To this aim the Organization of European Cancer Institutes (OECI) has set up a working group on Education and Training with the mandate to encourage continuing education in cancer research and applications and to verify the feasibility to promote mobility programs inside the network and in association with industries.

Until now only few OECI training programs have been launched and a full mobility program has not been developed yet due to limited budget resources.

The Italian Network of Comprehensive Cancer Centers, Alleanza Contro il Cancro, has planned the launch of a mobility program awarding 70 annual fellowships over a period of 36 months. This program, which will be open to the world research community, could represent a first interaction through mobility among the members of the OECI network also involving industries. The program is a tangible approach to sustain the translational process needed for the development of an European Research Area in the field of cancer and its related biomedical disciplines, thus providing a practical answer to the 2005 renewed Lisbon Strategy.

Tailoring Biomaterial Compatibility: In Vivo Tissue Response versus in Vitro Cell Behavior

Biocompatibility relies essentially on surface phenomena, represented by cell-cell, cell-material and material (polymer)-protein interactions. An in vivo and in vitro experimental investigation was carried out on the biomaterials of two different classes with a good potential for in situ utilisation. Non-resorbable (Polypyrrole, Polyaniline, Polyimide) and resorbable (PLLA-PDXO-PLLA) materials for tissue engineering were studied for their overall tissue tolerance and cellular interactions. These non-resorbable polymers conceived for biosensor applications and implantable drug-delivery systems are intrinsically conductive. The PLLA-PDXO-PLLA triblock copolymer showed interesting tensile properties for bone and cartilage tissue engineering due to the presence of 1,5-dioxepan-2-one. In vitro and in vivo parallel studies showed an interesting correspondence: a) the cells in contact with the resorbable material that appeared to be capable of migratory-regenerative aspects in vitro exhibited good compatibility in vivo; whereas b) the non-resorbable materials, which are designed to remain in situ in vivo, were seen to have the potential to represent an adverse factor (inflammation, fibrotic reactions) that correlated with some aspects of cell behaviour in vitro.

How to avoid and manage a pneumothorax

Pneumothorax is one of the most frequent complications during percutaneous central vascular cannulation. When choosing a site for central vascular access, the internal jugular vein is preferable to other vessels, for the lower frequency of related complications, including pneumothorax. This review intends to summarize the current state of the art on how to avoid and, if it occurs, to manage this rare but relevant complication. In order to prevent pneumothorax, as well as other relevant complications of central vein cannulation, it is advisable to use ultrasound guidance whenever possible. If pneumothorax occurs, it is important to recognize its signs and symptoms. To exclude the presence of asymptomatic pneumothorax, in the normal clinical routine a chest X-ray should be obtained within 4 hours from the procedure of central vein cannulation of subclavian and internal jugular veins. If promptly recognized, pneumothorax can be managed quickly and in a relatively easy way. Depending on its size and symptoms, and in particular when a tension pneumothorax is supected, treatment can vary from simple observation to a chest tube insertion or, in the latter case, to an emergency thoracentesis needle insertion in the pleural space.

Electronic Health Records: From the Management of Patients to the Research Use of Clinical Data

Paper based medical records are still widespread in Italian hospitals and the workflow to manage outpatients' visits is critical. Too many isolated software programs coexist in hospital wards and cause confusion and disorganization. A computerized medical record that unifies all the data contained in the various applications should be of fundamental importance in supporting physician's daily activities. Moreover, with the digital clinical record, data can be re-used for research purposes. The aim of this project is to create a web application for the management of outpatient visits to the Infectious Diseases Unit of the San Martino Hospital in Genoa. In order to orchestrate all the software programs acting in the visit workflow, a client application was developed to speed up the work of the medical staff at the time of the visits, ameliorating the quantity and quality of relevant information from a clinical point of view. A further extension allows standard data exchange between the developed application and the Ligurian HIV Network, which is the main regional research platform.

HAART Prescription Support Tool for Personalized Therapy

The importance of decision support systems is highly acknowledged as a key strategy to improve medical safety and quality of care. A strong interoperability between the hospital Electronic Health Record (EHR) and the Clinical Decision Support System (CDSS) is the key to reach a most reliable decision support, that could aid in better diagnosis, reduce medication errors and improve practitioner performances. Interoperability is granted by the use of standards for data representation and for system intercommunication. A CDSS to support HAART (Highly active antiretroviral therapy) prescription in HIV (Human Immunodeficiency Virus) naive patients was developed within the Ligurian HIV Network. GLIF3 (GuideLine Interchange Format) standard was used to represent clinical guidelines in machine interpretable format. HSSP (Healthcare Services Specification Project) DSS (Decision Support System) standard was used to develop the CDSS web service that evaluates patient's data according to the rules emerging from the GLIF representation of the guidelines. Patient's data are extracted from hospital EHR, formatted into standard vMR (virtual Medical Record) documents and sent to the DSS web service to be evaluated. The results are displayed by a client application in an intuitive way to guide physician's decisions.

CD8+CD28-CD127loCD39+ regulatory T-cell expansion: A new possible pathogenic mechanism for HIV infection?

BACKGROUND

HIV-associated immunodeficiency is related to loss of CD4⁺ T cells. This mechanism does not explain certain manifestations of HIV disease, such as immunodeficiency events in patients with greater than 500 CD4⁺ T cells/μL. CD8⁺CD28^-CD127^loCD39⁺ T cells are regulatory T (Treg) lymphocytes that are highly concentrated within the tumor microenvironment and never analyzed in the circulation of HIV-infected patients.

OBJECTIVES

We sought to analyze the frequency of CD8⁺CD28^-CD127^loCD39⁺ Treg cells in the circulation of HIV-infected patients.

METHODS

The frequency of circulating CD8⁺CD28^-CD127^loCD39⁺ Treg cells was analyzed and correlated with viral load and CD4⁺ T-cell counts/percentages in 93 HIV-1-infected patients subdivided as follows: naive (n = 63), elite controllers (n = 19), long-term nonprogressors (n = 7), and HIV-infected patients affected by tumor (n = 4). The same analyses were performed in HIV-negative patients with cancer (n = 53), hepatitis C virus-infected patients (n = 17), and healthy donors (n = 173).

RESULTS

HIV-infected patients had increased circulating levels of functional CD8⁺CD28^-CD127^loCD39⁺ Treg cells. These cells showed antigen specificity against HIV proteins. Their frequency after antiretroviral therapy (ART) correlated with HIV viremia, CD4⁺ T-cell counts, and immune activation markers, suggesting their pathogenic involvement in AIDS- or non-AIDS-related complications. Their increase after initiation of ART heralded a lack of virologic or clinical response, and hence their monitoring is clinically relevant.

CONCLUSION

HIV infection induces remarkable expansion of CD8⁺CD28^-CD127^loCD39⁺ Treg cells, the frequency of which correlates with both clinical disease and signs of chronic immune cell activation. Monitoring their frequency in the circulation is a new marker of response to ART when effects on viremia and clinical response are not met.

A SOA-Based Platform to Support Clinical Data Sharing

The eSource Data Interchange Group, part of the Clinical Data Interchange Standards Consortium, proposed five scenarios to guide stakeholders in the development of solutions for the capture of eSource data. The fifth scenario was subdivided into four tiers to adapt the functionality of electronic health records to support clinical research. In order to develop a system belonging to the "Interoperable" Tier, the authors decided to adopt the service-oriented architecture paradigm to support technical interoperability, Health Level Seven Version 3 messages combined with LOINC (Logical Observation Identifiers Names and Codes) vocabulary to ensure semantic interoperability, and Healthcare Services Specification Project standards to provide process interoperability. The developed architecture enhances the integration between patient-care practice and medical research, allowing clinical data sharing between two hospital information systems and four clinical data management systems/clinical registries. The core is formed by a set of standardized cloud services connected through standardized interfaces, involving client applications. The system was approved by a medical staff, since it reduces the workload for the management of clinical trials. Although this architecture can realize the "Interoperable" Tier, the current solution actually covers the "Connected" Tier, due to local hospital policy restrictions.

Is it still worthwhile to perform quarterly cd4+ t lymphocyte cell counts on hiv-1 infected stable patients?

BACKGROUND

In the last 20 years routine T CD4+ lymphocyte (CD4+) cell count has proved to be a key factor to determine the stage of HIV infection and start or discontinue of prophylaxis for opportunistic infections. However, several studies recently showed that in stable patients on cART a quarterly CD4+ cell count monitoring results in limited (or null) clinical relevance. The research is intended to investigate whether performing quarterly CD4+ cell counts in stable HIV-1 patients is still recommendable and to provide a forecast of the cost saving that could be achieved by reducing CD4+ monitoring in such a category of patients.

METHODS

The study is based on data referring to all HIV-infected patients > 18 years of age being treated at two large infectious diseases units located in the metropolitan area of Genoa, Italy. The probability of CD4+ cell counts dropping below a threshold value set at 350 cells/mm³ is assessed using confidence intervals and Kaplan-Meier survival estimates, whereas multivariate Cox analysis and logistic regression are implemented in order to identify factors associated with CD4+ cell count falls below 350 cells/mm³.

RESULTS

Statistical analysis reveals that among stable patients the probability of maintaining CD4+ >350 cell/mm³ is more than 98%. Econometric models indicate that HCV co-infection and HIV-RNA values >50 copies/mL in previous examinations are associated with CD4+ falls below 350 cells/mm³. Moreover, results suggest that the cost saving that could be obtained by reducing CD4+ examinations ranges from 33 to 67%.

CONCLUSIONS

Empirical findings shows that patients defined as stable at enrollment are highly unlikely to experience a CD4+ value <350 cell/mm³ in the space/arc of a year. The research supports a recommendation for annual CD4+ monitoring in stable HIV-1 patients.