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PubMed1986

Confidence intervals for reporting results of clinical trials.

Tests of statistical significance are often used by investigators in reporting the results of clinical research. Although such tests are useful tools, the significance levels are not appropriate indices of the size or importance of differences in outcome between treatments. Lack of "statistical significance" can be misinterpreted in small studies as evidence that no important difference exists. Confidence intervals are important but underused supplements to tests of significance for reporting the results of clinical investigations. Their usefulness is discussed here, and formulas are presented for calculating confidence intervals with types of data commonly found in clinical trials.

Clinical Trials as Topic↗

PubMed1998

Mortality in rheumatoid arthritis: experience in four clinical series compared with the experience in the 1983 medical impairment study.

BACKGROUND: Survival curves and decimal Standardized Mortality Ratios (SMRs) were reported in 1994 for four clinical series of patients with Rheumatoid Arthritis (RA), with use of a common data processing system. It was felt to be desirable to compare the excess mortality observed in clinical patients with the excess mortality found in substandard policyholders with RA in the 1983 Medical Impairment Study. RESULTS: The weighted mean SMR was 2.25 for the male RA patients and 2.42 for the females. Although similar in magnitude to the percentage male and female Mortality Ratios (MRs) in the 1983 Medical Impairment Study, the derived Excess Death Rate (EDR) was higher for the clinical RA patients, despite the lower select mortality versus the population mortality, even after adjustment for difference in mean age between the clinical and insurance series. CONCLUSION: The higher EDR in four clinical series of RA patients probably reflects a higher proportion of more severe cases, who are declined for insurance or do not accept a highly rated offer.

Adult↗

PubMed1999

The Agincourt field site--evolution and current status.

OBJECTIVE: To describe the evolution and current status of the Agincourt field site, Bushbuckridge, in South Africa's rural north-east. SETTING: A defined subdistrict, with a population of some 60,000 people including Mozambican refugees, in a former 'homeland' area with substantial labour migration. APPROACH: Three phases are described: origins and establishment of the field site; a programme of health systems research underpinned by multi-round (prospective) demographic and health surveillance; and contributions to the University of the North's Dikgale field site. COMMENT: Knowledge of trends in population health (e.g. mortality) is important when shaping the skill base and organisational framework of a district health system. There are valuable opportunities for collaborative research with field sites elsewhere in sub-Saharan Africa, and within South Africa itself. This will be facilitated by a common data model. A country-wide network of field sites, with surveillance capability, would complement the occasional national census and demographic and health survey, and strengthen South Africa's embryonic health information system.

Community Health Services↗

PubMedDate not supplied

Experience with living related liver transplantation in 63 children.

The incentive to develop intrafamilial living related liver transplantation (LRLT) originated from the shortage of cadaveric organ supply. We report our experience with LRLT in 63 children during 1993-1998 in the frame of a protocol approved by the Ethics Committee of our Institution. During this period, 152 potential intrafamilial (mostly parental) donors were evaluated; 44 (28.5%) were excluded because of surgical (n = 4), medical (n = 39) or psychosocial reason (n = 1). Out of 108 who matched all medical, surgical and psychological criteria of selection, 45 did not underwent living donation because their child received a cadaveric graft (n = 22; LRLT was their second option) or because one of the parents who had both been selected was chosen [by the surgical team because of more favourable anatomy (n = 8) or by mutual agreement between the two parents (n = 5)]. Sixty-three living donors (36 mothers, 24 fathers, one grand mother, one aunt and one uncle) underwent procurement of the left lobe (n = 52), the left lobe extended to part of segment IV (n = 8) or a left hepatectomy (n = 3) without mortality or any serious morbidity. Their median hospital stay was 7 days (range: 6-12); full physical rehabilitation and normalization of liver tests were usually obtained within three weeks. Their psychological follow-up did not disclose any longstanding serious sequellae. The median age of the recipients was 13 months (range 5-189); 30 were younger than one year at the time of transplant. Their median weight was 8.1 kg (range: 4.3 to 60); 36 had an actual weight under 10 kg. Fifty-two received an ABO identical and 11 received an ABO compatible transplant. The native liver diseases were similar to common data in children, with biliary atresia being the most frequent indication (74.6%). The median weight of the graft was 260 gr (range: 138-680) with a median ratio between the graft weight and the recipient body weight of 3.17% (range: 0.75-8.08). All grafts were implanted orthotopically with semi-microvascular reconstruction of the hepatic vein, portal vein and hepatic artery [end to end anastomosis in 58 (2 arteries were reconstructed in 7 patients) and interposition of an iliac arterial allograft from the infrarenal aorta in 5]. Base line immunosuppression consisted of a triple drug regimen including steroids, Azathioprine and either Cyclosporine-Sandimmun (n = 9), Cyclosporine Microemulsion formulation-Neoral (n = 13) or Tacrolimus-Prograft (n = 41). Biopsy-proved acute rejection was treated with intravenous bolus of steroids; steroid-resistant acute rejection was treated by a switch from Cyclosporine to Tacrolimus or addition of Mycophenolate-Mofetil (Cellcept) in Tacrolimus treated patients. Actuarial patient survival was 91.8% and 89.6% after LRLT at one and five years post-transplant, respectively, and 87.5% and 82.8% at one and five years, respectively, in 90 patients who received a cadaveric graft during the same interval. Actuarial graft survival was 91.8% and 84.1% after LRLT at one and five years, respectively, and 76.4% and 73.3% at one and five years, respectively, after cadaveric transplants. Vascular thrombosis was observed in 9.5% of the patients (arterial thrombosis: 1.6%; portal thrombosis: 7.9%) without graft loss. Biliary complications were observed in 26.9% (bile leak from cut surface in 3.1%, anastomotic stricture in 22.2% and intrahepatic stricture in 1.5%); two patients died from septic shock possibly related to uncompletely relieved anastomotic stricture; all other biliary complications were successfully treated either conservatively or surgically. The incidence of acute rejection was 90.9% in 22 patients with Cyclosporine-based immunosuppression; acute rejection was corticoresistant in 50%. It was 46.3% in 41 patients with Tacrolimus-based immunosuppression (64% with Prograft in capsules and 18.7% with Prograft in granules); no acute rejection was corticoresistant. (ABSTRACT TRUNCATED)

Adult↗

PubMed1999

Combining dictionary techniques with extensible markup language (XML)--requirements to a new approach towards flexible and standardized documentation.

In oncology various international and national standards exist for the documentation of different aspects of a disease. Since elements of these standards are repeated in different contexts, a common data dictionary could support consistent representation in any context. For the construction of such a dictionary existing documents have to be worked up in a complex procedure, that considers aspects of hierarchical decomposition of documents and of domain control as well as aspects of user presentation and models of the underlying model of patient data. In contrast to other thesauri, text chunks like definitions or explanations are very important and have to be preserved, since oncologic documentation often means coding and classification on an aggregate level and the safe use of coding systems is an important precondition for comparability of data. This paper discusses the potentials of the use of XML in combination with a dictionary for the promotion and development of standard conformable applications for tumor documentation.

Documentation↗

PubMed1999

HL7 document patient record architecture: an XML document architecture based on a shared information model.

The HL7 SGML/XML Special Interest Group is developing the HL7 Document Patient Record Architecture. This draft proposal strives to create a common data architecture for the interoperability of healthcare documents. Key components are that it is under the umbrella of HL7 standards, it is specified in Extensible Markup Language, the semantics are drawn from the HL7 Reference Information Model, and the document specifications form an architecture that, in aggregate, define the semantics and structural constraints necessary for the exchange of clinical documents. The proposal is a work in progress and has not yet been submitted to HL7's formal balloting process.

Humans↗

PubMed2000

General deming regression for estimating systematic bias and its confidence interval in method-comparison studies.

BACKGROUND: Various forms of least-squares regression analyses are used to estimate average systematic error (bias) and its confidence interval in method-comparison studies. When assumptions that underlie a particular regression method are inappropriate for the data, errors in estimated statistics result. In this report, I present an improved method for regression analysis that is free from the usual simplifying assumptions and is generally applicable to linearly related method-comparison data. METHODS: Theoretical equations based on the Deming approach, further developed by physicists and extended herein, were applied to method-comparison data analysis. Monte Carlo simulations were used to demonstrate the validity of the new procedure and to compare its performance to ordinary linear regression (OLR) and simple Deming regression (SDR) procedures. RESULTS: Simulation studies included three types of data commonly encountered in method-comparison studies: (a) constant within-method SDs for both methods, (b) constant within-method CVs for both methods, and (c) neither SDs nor CVs constant for both methods. For all cases examined, OLR produced unreliable confidence intervals of the estimated bias. However, OLR point estimates of systematic bias were reliable when the correlation coefficient was >0.975. SDR produced reliable estimates of systematic bias for all cases studied, but the confidence intervals of systematic bias were unreliable when SDs of methods varied as a function of analyte concentration. CONCLUSION: Only iteratively reweighted general Deming regression produced statistically unbiased estimates of systematic bias and reliable confidence intervals of bias for all cases.

Albumins↗

PubMedDate not supplied

Do HMOs make a difference? Introduction.

The study presented in this and the following five papers analyzes how health maintenance organizations (HMOs) affect privately insured individuals' access to health care, use of services, and assessments of care. Using a common data source and methodology, the study examines differences in a broad range of measures between HMOs and other types of insurance, controlling for health status and an extensive set of other individual characteristics and market location. HMO/non-HMO differences also are examined across population subgroups defined by health status, income, race, and age. Data come from the Community Tracking Study Household Survey, a recent, large national survey. Findings show that a person's type of health insurance coverage has little effect on the likelihood of unmet or delayed needs for medical care in the aggregate, but the types of access problems faced by HMO and non-HMO enrollees differ. HMO enrollees are less likely to face financial barriers to care, but more likely to face barriers related to the organization of care delivery. HMO enrollees use more ambulatory and preventive care, but results show no differences in hospital, surgery, and emergency room use. Compared with other types of insurance, physician visits under HMOs are more likely to be to primary care physicians than to specialists. Finally, across nearly all measures of patients' satisfaction, ratings of their last doctor's visit, and trust in their physicians, HMO enrollees' assessments of care are lower than those of people not in HMOs. Across all measures, the study finds few subgroup differences.

Age Factors↗

PubMedDate not supplied

Hepatitis C virus: a high risk factor for a second primary malignancy besides hepatocellular carcinoma. Fact or fiction?

PURPOSE: Second primary malignancies occur more and more often. But the hepatocellular carcinoma (HCC) linked to a second primary cancer is not frequent. MATERIALS AND METHODS: A retrospective study focused on a second primary cancer was performed in 37 patients with HCC, aged between 46 and 81 years, 27 males and 10 females. RESULTS: 5 out of them (13.5%), 3 males and 2 females, developed a second primary neoplasm before or after HCC. In 3 cases the second malignancy was a carcinoma of the kidney, of the breast, and the prostate. The fourth patient had a Hodgkin's lymphoma before HCC. The last and most unlucky case, besides HCC, had a basal cell carcinoma, a colorectal cancer, and a bladder carcinoma. The common data of these 5 patients were the presence of anti-HCV antibodies and the positivity of the HCV RNA polymerase reaction. One patient was also HBV positive. CONCLUSION: Considering that a large number of virus has been found linked to human cancers, our results brought us to hypothesize that HCV could have played an important role not only in the development of HCC but of the second primary malignancy too. This is likely favoured by constitutional or acquired biological and molecular alterations. Tumor suppressor genes alterations have been reported to be frequently linked to cancers of kidney and breast, of colorectal and skin, of prostate, and lymphoemopoietic tissue. Now just these organs are involved in our patients in addition to the liver. Our results, if confirmed, are of a relevant interest, considering that world-wide HCC is constantly increasing for the spreading of the virus risk-factors.

Aged↗

PubMed2001

The Cancer Informatics Infrastructure (CII): an architecture for translating clinical research into patient care.

Today, the clinical trial process remains slow and paper-based. The creation of a Cancer Informatics Infrastructure (CII) can provide the architectural base across the continuum of cancer research and cancer care. Recommendations of a Long Range Planning Committee identified near-term activities for the Office of Informatics at the National Cancer Institute (NCI). These include participating in national standards development; fostering oncology-related terminology and standards, e.g., Common Data Elements (CDEs); and leveraging mainstream informatics and Internet technologies, using the successful Internet model that focuses on facilitating stakeholder participation, sponsoring the CII rather than subsidizing it, and providing a test bed as well as an infrastructure. Diffusion tactics include extending the CII concept beyond its "early adopters" to the wider community through recommendations for the near-term and development of a major document defining next-phase activities.

Clinical Trials as Topic↗

PubMed2001

Modelling nitrogen transformations in surface flow wastewater treatment wetlands in Sweden.

The purpose of this study was to describe and compare the fate of nitrogen (N) in two Swedish wastewater treatment wetlands in the cities of Oxelösund and Hässleholm. Specifically, we wanted to see if a fairly simple model, developed with regard to common data availability, could satisfactorily describe the concentration dynamics at the outlet from the wetlands. A first-order area-based model, with two alternative expressions for temperature dependence, was set up to describe three major processes: ammonification, nitrification and denitrification. The N concentration dynamics at the outlet of the Oxelösund wetland was not satisfactorily described, R2(NH4+-N) = 0.33 and R2(NO3(-)-N) = 0.10, while the modelled concentrations corresponded quite well with measured concentrations in the Hässleholm wetland, R2(NH4+-N) = 0.83 and R2(NO3(-)-N) = 0.58. The NO3(-)-N concentrations, in both wetlands, could be slightly better described when introducing a temperature coefficient as an additional free parameter. The explained variances reported above were achieved when the model was calibrated individually for the two wetlands, when the resulting (optimised) reaction rate coefficients for each of the three processes were quite different between the two wetlands. To improve model performance, the rate equations may have to be changed to include factors in addition to concentration and temperature, such as dissolved oxygen and hydraulic efficiency. It may also be important to include other processes, such as plant uptake/decay and ammonia volatilisation.

Ammonia↗

PubMed2001

Cross-tool communication: from protocol authoring to eligibility determination.

To be effective, informatics tools for clinical trial protocols must inter-operate and share knowledge. We demonstrate a simple XML-based communication of eligibility criteria information between two independently-developed informatics tools. Using a shared DTD model of criteria, an authoring tool (developed within the Protégé environment) can send a list of eligibility criteria to a commercial system for automatic eligibility determination (the "iKnowChart" system by iKnowMed). The criteria model, developed as a Protégé ontology, includes both the terminology and the logic needed to compute eligibility for a given patient. As a demonstration of cross-tool communication, we have encoded criteria from an active clinical trial protocol (E1199), and shown how use of the authoring tool can effectively update the eligibility knowledge and the behavior of the commercial iKnowChart system. As part of the cross-tool knowledge sharing, we use Common Data Elements, an oncology terminology developed by the National Cancer Institute.

Clinical Protocols↗

PubMed2002

Survey methodology for the uninitiated.

Mailed, self-administered questionnaires are a common data collection method used in family practice research. However, little guidance exists in the medical literature about survey methodology specifically designed for family practitioners. As a result, primary care physicians sometimes struggle with questionnaire design and interpretation. Our goal was to synthesize general survey methodology guidelines (from other disciplines as well as our own) in a manner that would be meaningful to novice family practice researchers.

Data Collection↗

PubMed2003

Evidence on the use of paracetamol in febrile children.

Antipyretics, including acetaminophen (paracetamol), are prescribed commonly in children with pyrexia, despite minimal evidence of a clinical benefit. A literature review was performed by searching Medline and the Cochrane databases for research papers on the efficacy of paracetamol in febrile illnesses in children and adverse outcomes related to the use of paracetamol. No studies showed any clear benefit for the use of paracetamol in therapeutic doses in febrile children with viral or bacterial infections or with malaria. Some studies suggested that fever may have a beneficial role in infection, although no definitive prospective studies in children have been done to prove this. The use of paracetamol in therapeutic doses generally is safe, although hepatotoxicity has occurred with recommended dosages in children. In developing countries where malnutrition is common, data on the safety of paracetamol are lacking. The cost of paracetamol for poor families is substantial. No evidence shows that it is beneficial to treat febrile children with paracetamol. Treatment should be given only to children who are in obvious discomfort and those with conditions known to be painful. The role of paracetamol in children with severe malaria or sepsis and in malnourished, febrile children needs to be clarified.

Acetaminophen↗

PubMed2001

Qualitative Inquiry in Athletic Training: Principles, Possibilities, and Promises.

OBJECTIVE: To discuss the principles of qualitative research and provide insights into how such methods can benefit the profession of athletic training. BACKGROUND: The growth of a profession is influenced by the type of research performed by its members. Although qualitative research methods can serve to answer many clinical and professional questions that help athletic trainers navigate their socioprofessional contexts, an informal review of the Journal of Athletic Training reveals a paucity of such methods. DESCRIPTION: We provide an overview of the characteristics of qualitative research and common data collection and analysis techniques. Practical examples related to athletic training are also offered. APPLICATIONS: Athletic trainers interact with other professionals, patients, athletes, and administrators and function in a larger society. Consequently, they are likely to face critical influences and phenomena that affect the meaning they give to their experiences. Qualitative research facilitates a depth of understanding related to our contexts that traditional research may not provide. Furthermore, qualitative research complements traditional ways of thinking about research itself and promotes a greater understanding related to specific phenomena. As the profession of athletic training continues to grow, qualitative research methods will assume a more prominent role. Thus, it will be necessary for consumers of athletic training research to understand the functional aspects of the qualitative paradigm.

Journal Article↗

PubMed1992

[Narcolepsy and alopecia areata: a new association?].

We here present three cases with Alopecia Areata and Narcolepsy, an association we believe to be hitherto undescribed. Narcolepsy is a low-frequency (0.5%) disorder. It is now accepted that the majority of patients with narcolepsy are DR2 positive. Alopecia Areata is a disease whose incidence in Caucasian population is between 0.05% and 1%. In both diseases there is a set of common data and the origins of the two diseases have been related to an autoimmunity mechanism. In both, a higher than normal incidence of diabetes has been recorded, together with a predominant HLA type pattern. We believe that this association is not casual although epidemiological studies are needed to test our working hypothesis.

Adolescent↗

PubMed2004

[Lifetime social, psychological and physical background of suicides --research on the number of suicides during a year in Fukushima prefecture].

We performed a questionnaire survey of the bereaved families of decedents in 523 cases of suicide which occurred during the year beginning July 17, 1997, in Fukushima prefecture in Japan. The questionnaire consisted of 33 items which indicated decedents' behavior changes and stress factors before death. Of the 523 cases, 420 questionnaires were completed by the surviving family members. The risk factors for suicide which are conventionally accepted were found with high frequency in the data. Common stress factors were occupational and financial problems in males and difficulties with human relationships and family problems in females. The sexes were clearly differentiated in this respect. Common changes preceding suicide were expressed as "becoming depressed" or "social isolation". These statements were common and tended to be associated with depression. Hanging was the most frequent method of committing suicide in both sexes and at all ages. Thirty one percent of the victims were diagnosed and treated for mental diseases, and 39% for physical diseases. Many of the 39% who had physical diseases also showed depressive behaviors. The screening and treatment of depression is a matter of highest priority in the strategy of suicide prevention. It is therefore important that general practitioners, occupational physicians and public health nurses improve their skills in managing depressive disorder as a common condition. Psychiatrists should undertake their role of education in the diagnosis and treatment of depressive disorders more seriously.

Adolescent↗

PubMed1992

Criteria for audit of annual reports on the public health: do they exist?

Production of an annual report is a statutory duty of the Director of Public Health; its production uses significant resources. Audit of reports may help in the effective use of these resources. For audit to be performed criteria need to be agreed upon which to set standards. The present study investigated whether Directors of Public Health agree on suitable criteria for the audit of annual health reports. Districts within North East Thames Regional Health Authority were paired; Directors of Public Health, who had produced the most recent report, interviewed each other using a semi-structured questionnaire. Reports were examined for the presence of the 'key indicators' from the common data set. The results show that there was little agreement on what were suitable criteria to evaluate reports. The criteria in the Toolbox produced by the Faculty of Public Health Medicine were thought to be unsuitable because of the diversity of Districts. Effective audit requires agreed criteria and standards but these were not identified. The Faculty criteria were not considered suitable. Directors of Public Health may develop criteria that they consider suitable for audit of their annual report in discussion, focusing upon their objectives in producing an annual report. This should be the first step in the audit process and an integral part of producing an annual report.

Annual Reports as Topic↗